Regards, Raul: Concerning the 420, my initial thoughts were similar to yours. On a back-up Denon DP-60L TT, resonances were so aggresive it was difficult to listen to the cart for any extended time. Cymbols were "hisssy" and the mids somewhat muffled. After six hours, realigned it from Baerwald to Stevenson overhang, much better but still very "hot" and the Denon is a lively deck so the 420 was moved to an EPA-250 arm and a Sumiko 12gm headshell. With some carts the arm is over-damped and uninspiring but the 420 was improved. Anyway, after 20 hrs. or so, my example of the 420 has settled nicely in, performance is approaching that of the LPM 320 which is indeed a very nice cart. Both loaded at 160k Ohm (total), 50pF. More seemed detrimental so it would help in understanding your findings if you would be so good as to mention the arm and loading used. The 420, like a chameleon, is extremely responsive to it's environment.
Thank you for the time taken to listen and report, I'm looking forward to your review of the M 320STR, and also the occasion when you choose to finally reveal your LOMC reference cart.
Peace, |
Regards, Raul: Again, thanks for taking the time to express yourself. I've a (LPM) 310, 312, 315, 320, 412, 415 and the 420. Each has it's own signature sound, each does what it does well, none are an immaculate performer and each has also required an extended break-in period.
It does seem there is a shift in voicing goals with the later production models. There were comments made in earlier posts concerning the influence of early "perfect sound forever" (ahem) digital recordings/playback gear influencing listeners' expectations. Although there may be some of this effect concerning the 415/420, much of this "splashy" character is diminished with extended use, bass overshoot tightens up too. Please don't perceive this as argument but it would be regretable if one were to dismiss the 420 as a poor performer before allowing it to run for a time sufficient for the somewhat aged suspension to relax and the cart to reach it's potential. Whether one then likes it or not is a different matter. IMHO an interesting cart and capable enough each listener should hear it in his own rig and make up his own mind.
In re-reading recent posts, I need to make a correction. With the 420 (in my old rig) hf/upper mid glare is reduced at 50k/100pF (shunted), not 50pF/160k total as erroneously posted late last night. It was a long day.
Now, about that mysterious LOMC---
Peace, |
Regards, Raul: It's understood what you're saying; "hope that the 420 could improve to the LPM320IIISTR quality performance level but unfortunatelly it stayed a little short". If I had to choose to keep only one of the Acutex here, it would be the LPM 320, for which I fortunately have two styli. This did not prevent me from ordering a second 420 and I'm pleased to have them, IMHO a good cart. Your opinion is not without influence, it would be unfortunate if someone else was discouraged from allowing the 420 an adequate audition to the point of running it in to it's full potential because of your comments being misinterpreted.
The M320 offered here was tempting but I kept recalling the $80 or so price these went for just several years ago, another case of "if I had known then what I know now"! Holding out for a more reasonable price, if I listened to a different cart every day it would be an embarassing number of days before returning to the first. Retired and on a budget, even if it is a comfortable one, dang it, it's still a budget. The M320STR, Empire 4000D 111 and CA Virt. are, however, definitely on the wish list.
You're avoiding mention of your "reference" LOMC, I'm starting to believe you just made that up ;).
Peace, |
Regards, Nandric: Thanks for the research. After ?eighty? years, still being done by hand. In the future, when I lower the tonearm I'll think of the gal who made the stylus not as a technician but instead as a muse. And pretty, too.
Peace, |
Raul: WOW, that comment is a month old, did you really go throught all those posts just to find that?
More midrange presence than the 320. As you also mentioned, it stops short of the LPM 320's neutrality. Lots of information in the mids and hf's, needs run-in time to establish clarity. Bass starts tightening up after four hours, six hours to start finalizing it's voice. Moved to another headshell/arm and realigned, did it a lot of good. Cart has good detail, needs a lot of attention to alignment and VTA to find it. Not the finest cart ever but IMHO it is a good one. If you're looking for a model of analytical detail, dynamic shading or hall ambience, look elsewhere. Said it all before, I'm not sure I understand your point but I am aware there have been times in the past when you've made similar posts for your own reasons.
Raul, there are those who are pleased to enjoy audio and are pleased for others to do the same without obsessing compulsively about THE BEST, even though many of them know the difference. Sometimes it's rewarding to just enjoy letting it play instead of needing to "catch the cat" and dissect it.
"If you compare yourself with others, you may become vain or bitter; for always there will be greater and lesser persons than yourself". Desiderata, Max Ehrmann.
Peace. |
Regards, Ct0517: Hi, Chris. How much better is the 320? Raul was being diplomatic when he said, IIRC, "A hair", but this depends on what you're listening for and that's a whole discussion in itself. The 320 offers excellent clarity in the hfs, mids not quite so forward and bass transitions are nicely punctuated but delivers less of recorded resonances. Harmonics are not as effectively displayed and transitions don't have quite the same snap. Depending on perspective, when both carts are working at optimal the 320 is either more refined or less aggressive. Raul would, I suspect, describe it differently and he has been very gracious.
Not much has been said about the 312/412, these will require the same careful set-up as their "big brothers", those who thought to order the 412 are in for a pleasant surprise, they both compare (IMHO) favorably.
The 315 is best described in Raul's review and his recent comments. For me, the most interesting of the Acutex carts and is the one in the series that I can listen to for extended periods without listener's fatigue. The bass is something special. I was disappointed with the 415 but was eager to move on to the next in line so there is a real possibility it was not spun long enough and needs to be revisited. Hopefully someone who recieved a 415 will find good things to say and I'll be inspired to work harder on it.
In tweaking the latest Acutex I too spent two days aligning it. The day I started and the one on which I finally nailed it. The other day in-between, that we can ignore?
Peace, |
Regards, Griffithds, Travbrow: In the kit here there's a Denneson "Geometric Soundtractor", Baerwald geometry. The Denneson is handy for getting the cart aligned within "ballpark" standards and this is a good starting point, the remainder done by ear. Cart gently clockwise for IGD, counterclockwise for OGD. Distorion at both extremes, cart towards the pivot (decreases offset angle) & the reverse. This has worked well for me. When finally finished with the Acutex, it was just short of 14mm overhang. Conrad Hoffman's template generator for Lofgren A alignment (almost Baerwald) calculates IEC overhang for the EPA-250 at 15.487mm and for Stevenson geometry, 13.786mm overhang. Technics compromises at 15mm overhang, square to the headshell. The cart seemed best (IMHO) on the EPA-250 at just short of 14mm, this alignment/overhang is closer to Stevenson than Baerwald. Hope the above makes sense, somewhat smashed following a recent (minor) oral surgery and the keyboard is looking like a very complicated peice of machinery. Peace, |
Regards, Travbrow: The numbers you've run are for P/S of 235mm, try plugging in P/S of 250mm, I believe this is correct for your EPA-100.
Lofgren writes (pg. 9 of his ca. 1938 report), "the largest distortion risk occurs when the overhang is not set correctly for the linear offset (cutting stylus). On the other hand, the angular offset is not so critical". Angular offset becomes more important with the introduction of the elliptical stylus/stereo Lp.
Relative to your earlier comments, Lofgren also identifies alignment as influenceing the relation of summation and difference tones, suggesting RMS values depend on the frequency ratio and that alignment variances can result in either of these ratios becoming multiple times larger than the other. This particular section of math is fairly demanding and I'll not offer to offer proof but it could be fun to speculate that there is a difference to be heard with various stylus profiles and the effect on harmonics from alternate alignment sets. (That's s p e c u l a t e, I believe I spelled it correctly).
I've "no dog in this fight", but have had similar thoughts in the past. Keep in mind his observation that the most accurate alignment results in the least record wear.
Peace, |
Regards, Griffidths: Hi, Don. Looking forward to your comments following the Axelization of the failed suspension ("turtle") stylus, I hope the beryllium cantilever and excellent Signet lc stylus are salvageable. By your other comments, I take it you're pleased with the midrange performance of the cart?
Peace, |
Regards, all, and seasons greetings: Nandric, fortunately (beware, a lot of opinion follows) the 412 has more in common with the 320 than does the 415, which in spite of extensive effort I cannot bring myself to enjoy. The somewhat overlooked 312 (catching up on previous posts, I notice Stltrains has made some understandably positive comments) is a STR stylus bonded to titanium and the cantilever is of nicely tapered titanium. Be glad the mislabeled carts weren't 415's. I found a NOS example several months ago and if it is typical of the 415 then I'm in perfect agreement with Raul's impression, a lack of dynamic swing, glassy hfs and brassy mids. Perhaps a good choice to brighten up a mid-fi or darker sounding rig? The quality of performance of my 415 reminds me of public announcement gear, a pretty good one but still P.A. The 312 is, out of the box, a near parallel to the 320, good tonality and a presentation with a sense of immediacy not often found. Again I'm concurring with Raul, the LPM 3xx carts are, to my ears, a better listening experience than the later 4xx series. You might consider either keeping the 412 carts or exchanging them for the still available LPM 312 rather than obtaining the 415 alternative. IMHO, the 310e (elliptical) is unremarkable.
Griffithds: Spent some significant time with the Signet TK7SU/hand selected Akai RS180 cantilever assembly transplanted into the OEM Signet grip, a "synergistic" combination that beats up the Acutex 415 pretty handily. A 9.5gm Ortofon Japanese oakwood headshell cleans up the somewhat rounded and resonant bass of the Signet, hf's retain the silk-smooth Shibata character. Not up to the performance of the crisper TK7lca but I'm always pleased to listen to the 7SU. My old computer expired and all previous research was lost but IIRC, the RS150 stylus is a bonded stylus. I've no experience of it but it may, however, be another "sleeper", possibly comparable to the ATN15XE, a stylus which is now nearly, in NOS condition, extinct.
Acman3: The OEM TK7lca stylus is superb. A subtle step up in clarity and resolution from the ATN155lc, but definitely an upgrade. Have been looking for a spare stylus, if you find a shoebox full of them let Henry and me know!
Those with a low eff. mass TA and the inclination to experiment might sample the AT7V with an AT140lc stylus hitched to it, higher compliance (nom. 1.1 gm. VTF) than the 7V elliptical stylus and as typical (IMHO) of a LC stylus on a comparable cantilever, not as bright as the elliptical.
Peace, |
Regards, Griffithds, Nandric:
Griff: Thanks for your comiseration re. the computer, best described as a catastrophic failure. In the process now of transitioning from Microsoft to Apple processes on a new unit, all previous saved data is lost. Speaking of apples, the TK5ea is 5.5mv output, the TK7SU is 2.7. In broad terms, the 5ea with any of the styli you mention will offer more detail and faster leading edge transients than the 7SU, which will have a more "organic" presentation. Both Signets "fell from the same tree" but sonically the comparison is apples/oranges. For the TK5ea, the beyrillium cantilever on the ATN155lc for faster rise time without emphasizing the AT "house sound", or a tendency towards, in some systems, an impression of shrillness. The TK5ea will approach the quality of the TK7lca, but the hand wound coils and PCOCC windings of the individually bench assembled and tested TK7lca generator are evident in immediate comparison, the components of the TK7/9/10 and their brother AT15/20/22-25 carts were not simply pulled out of a parts bin.
Nikola: Just now took a look at the lenco heaven "Acu-tex-bar" thread Dyna-5x linked to earlier, a poster to that thread has some cogent comments about the 415. So many impressions of cartridge performance relate to system differences it would be imprudent to say the 415 is a poor performer but personally, I'd not exchange any of the 312's (or a 412) for the 415. If you visit the thread there are some very good photos of the stylus assemblies. The 412/415 have a straight pipe cantilever, the 420 a longer tapered cantilever, all of undetermined material, best guess would be a Ti/Al alloy. The LPM 3xxSTR cantilevers are the longer tapered titanium cantilevers. Longer cantilevers are often described as being slower in leading edge transients and thereby "softening" detail, of which the 415 seems to me to have an excess and consequently distracts from the homogeneity of the composition. "Overly analytic" carts do not appeal to me, the result is listener fatigue. Raul (in his usual subtle style) described the 415 as "unlistenable". The diamond of the 3xx carts are uncolored gems, the 412 and 415 are dark. This is not necessarily bad but the clear diamonds are generally held to be superior.
It's regrettable the carts were mislabeled, in the overall view of cartridges the LPM 420 will probably be held as fairly high in the ranks. Best of luck in resolving this to your satisfaction.
Peace, |
Regards, Raul: The comment you refer to was specifically related to the difference in cantilever influence on the carts Griffithds had asked about, cantilever materials for the styli mentioned were I believe either beryllium or boron. Most would say a beyrillium cantilever will be, not always but usually, less resonant than an aluminum cantilever. The bass seems in particular to be much less rounded and due to what I suspect is cantilever rigidity and the greater tendency for aluminum to flex and the resultant increase of rise time, the hf's more precise with a be. cantilever. There are too many variables to state this will be always so, mass and compliance needs to also be considered. This was not intended to be a comment on the carts themselves (the TK7SU/E motor itself is first class construction), inductance/output impedance is (I really miss my lost data) greater for the 5ea than the 7SU, a significant factor and one that IMHO, results in a degree of "blare" in the higher output carts. This is not the same consideration as detail retrieval.
To answer your question directly, SPL was not a consideration. The comment was derived from long term familiarity with both carts. If you are saying the TK7SU is not lacking in detail, I'll happily agree but the point is with the TK5ea, this is improved with a be. cantilever as compared to one of aluminum. This brings a question of good nature in return, do you not consider excessive resonance (from whatever influence) a fault in detail portrayal? In this consideration, the 5ea with a be. cantilever is superior to the 7SU/aluminum cantilever. Voicing, sound staging and layering is a different matter and in this I find the 7SU more pleasing than the sometimes "crowded" impression I have of the 5ea. As these may be overlapping distinctions, I hope this makes sense.
Most recently listening to J. J. Cale "Troubadour", Clapton "461 Ocean Boulevard" and Johnny Adams "Walking A Tightrope", transducer is a Signet AM20me (miniature elliptical) on a modest(!) second system Pio. PL-70L 11 turntable/carbon fiber arm, Tannoy DC-3000 dual concentric speakers and a 1976 vintage but just last week bench tested and serviced Pio. SX-1050 (gasp) receiver doing the grunt work, two Sony (another gasp) HT active subs chuffing along on the bottom end. At (possibly) the higher end of mid-fi, the gear fits the attitude of the music well enough to leave me just listening to the music instead of the gear, smiling. Am I the only blues enthusiast among this flock of jazz aficionados? Blues groups have saxophonist too!
Thanks for the welcome back, the thread is a "community center" for a number of sophisticated and generous natured audiophiles and I regret not following the progress of the potential for cartridge improvement being discussed by the very knowledgable participants, essentially cartridge design and not a matter for dilettantes. Still curious about your mysterious MC reference cart?
Peace, |
Regards, Halcro: Hi, Henry. I'm also struggling with a loss of memory that doesn't have anything to do with computers so let's see how well this goes!
The TK3ea and 5ea (IIRC) had the same raw specs. The TK1e output increased from 5.0mv to 5.5mv, output impedance was 760? Ohm, the 1ea also had a plastic mount and was subject to microphonic disturbance. Best recollection is that the better measuring carts were designated as "5's", those that measured less well were "3's". The TK7ea/lca measured 580 Ohm and had hand wound coils, AT allowed 20 minutes for the winding of each's coils. The 7's were a tightly controlled and limited production cart, these are well worth seeking out.
The AM (analog master) carts followed the same schedule, the AM10 was higher output, the AM20 through AM50 shared engines, the difference being the quality of the stylus/cantilever. The MR (maximum resolution) line is similarly ranked, starting with the higher ouput 5.0 Basic entry cart with .4 x .7 bonded ellipt., then 5.0e, me, lc and TOTL, the ML, a micro line on Be. cantilever. All styli from what is sometimes referred to as the AT100 body are exchangeable between these carts except for the MR's, which in order to fit the other models will need some plastic surgery.
All of that out of the way, and even if Nikola scolds me for "generalizations" , there is an observable pattern and it might be safe to presume that as with the AT120 through 150 carts, or AT12 through 20, quality improves in both styli and specs as the numbers increase, perhaps the same for the mystifying Acutex engines. It would be risky to argue there is no difference without hard facts on hand.
As you know, the Yamamoto ebony headshell, the one you insisted I have, is very complimentary to the TK7LCa. I'm left wondering how it compares to the TOTL MR 5.0 you've so fleetingly praised?
Peace, |
Regards, Pryso, Griffithds: What? No mention of forty minutes of percussion?
My handy measure is if it sounds good from the next room, it's ok. If it sounds BETTER from the next room, you might want to work on your rig a little...
Peace, |
Regards, Griffithds: Don, the TK5ea is a good cart, it's pretty high in the AT/Signet lineup, the 155lc stylus will demonstrate it's potential. Don't be surprised if you find the performance of the 5ea/155lc combination gives you cause to reconsider the TK7SU/155lc transplant, listener's objectives vary. If you should later find a TK7ea or lca and already have the 155lc stylus, then you're good to go. If you want to experiment, then you're my kind of guy but before you begin ask yourself if you're really ready to risk destruction of a desirable, rare and relatively expensive stylus. This precaution is due to a value conscious nature derived from Scots ancestry, my fore bearers thought the stock market was something with a fence around it and 2:00 AM stock acquisitions were ;-) free.
Should you decide to remove the cantilever from the grip, be sure to remove all possible sealant from the well into which the compliance screw is threaded and especially the slot in the head of the screw. Use a precision screwdriver to back off the screw slightly, it doesn't need to be removed and I'd suggest that as the screw is either brass or soft non-magnetic alloy you reverse the screw repeatedly, don't try to do it all with one twist and two or so turns will do. Use a pin or other small rod to push the cantilever out from the back of the plug if it doesn't simply fall out. It's a very finicky procedure and somewhat stressful, you might practice with the old 7SU grip/cantilever stub first. It helps in establishing azimuth to view the installed assembly from the back, using a sight line relative to a flat portion of the grip and the top of the V-magnets as a reference. The compliance is determined by both the plasticity of the donut at the rear of the cantilever and the pressure with which it's seated against the plug so some longitudinal force will be required to induce pressure at this juncture before tightening the screw. Walk yourself, mentally, through the procedure several times and don't expect to get azimuth and compliance right the first time. When returning the grip to the cart, observe and make certain the magnets fit into the opening instead of contacting the cart shroud, mount the cart and then check it for VTF. You may have to do this repeatedly, if you hear extreme distortion, the v-magnets are contacting the coil poles so don't panic, you'll want to adjust the seating pressure. Those with three hands will find it much easier.
If you have an AT20 stylus it's a drop-in fit for the 7SU, you can audition the 7SU with a beryllium cantilever and the Super Shibata stylus, this will not prevent the return of the 20ss stylus to it's intended cartridge. I've not tried this as I'm pretty happy with the RS180 cantilever transplant, Raul did try the 20SS and thought there was some improvement.
Fleib might offer a few other insights. It isn't all that complicated but does require watchmaker-like precision, forethought and patience. I've been fortunate enough to be successful in the several transplants I've done, call it the luck of the draw.
Peace, |
Regards, Griffithds: Curiosity piqued and because I'd not done it before, the ATN20SS on the TK7SU is an exact fit, required a little racking of the cart for crude alignment as the 20's cantilever is approx. 1mm shorter than the tapered RS180 cantilever and distortion was very evident. Hmmm. Sounds much like the AT20SS cart. It should, other than structural differences, the engine is the same. Next was a trial of the ATN20SS on an AT15S. In a rushed comparison, very much the equivalent. On a roll now, a Signet TK5ea with a stylus transplant from a Signet .3 x .7 nude on micro mass tapered alloy from a NOS AM20me stylus, a stylus I really like, it's performance is not far off from the ATN155lc stylus on the 5ea.
The AT15S with an ATN15XE is not appreciably different from the RS180 stylus, then a return to the TK7lca/ATN155lc, oh, yes!
The 7SU and AT20SS are on Orto. LS-6000 Japanese oakwood headshells, the AT15S on Yamamoto HS-3, boxwood. The TK5ea on the OEM EPA-250 HS, the TK7lca on a Yama. HS-1As Ebony shell. Other than for the TK7SU/ATN20SS, alignment was not altered.
Don, I hope this makes sense. A minimum of attention was paid to alignment, VTA was eyeball arm-level, VTF a universal 1.1gm except for the ATN20SS which was run at 1.4gm in each application. "Santana" and "Abraxas", "Aja" on the deck.
A quick assessment, full of faulty procedure and done in two hours instead of over several weeks. As each configuration was given about ten minutes, exception or varying opinion will not be contested. If you want to enjoy the 7SU as a 7SU, transplant the RS180 stylus to the OEM grip. With the 20SS stylus, you essentially have a zippo lighter sized AT20SS, might as well use it on a 15XE, 15Sa, 20Sla or 20SS cart, they're a whole lot prettier. The ATN15XE works in any of the above mentioned carts that accept the round plug and needs no modification, even on the TK7SU. The RS180 stylus transforms each into an upscale AT14/TK7SU, but as you know the grip needs to be clipped at the rear. The TK5ea is a good cart with the OEM stylus (the transplanted SAM-20me is a near match) but is bettered with the ATN155lc.
I hesitate to recommend but instead suggest you work with the TK5ea/155lc for a while and although the AT155lc cart has good references, the recent shuffling of carts/styli reminds me of why the TK7lca gets so much arm time here. Had a lot of fun doing something I should have done long ago, was pleased with the XE stylus beyond expectation.
Peace, |
Regards, Rangefinder: Nice deck. Both are interesting carts, 312 stylus is clear diamond, tapered titanium cantilever. 412 slightly more forward, no lack of immediacy. Won't recommend one over the other, you'd really need to hear both to decide but the consensus seems to be the 312 is a bargain, you can hardly go wrong at it's price. Hopefully someone else will offer an opinion, more input might help you decide. Good luck.
Peace, |
Regards, Fleib: Dlaloum (Hi, David) has answered one question. I checked the cantilever angle with a Sterrett adjustable protractor and for the 15XE, 20SS and TK7SU it's 22* unsprung. In lieu of hard data 20* at VTF seems realistic. Apprehensive about tool steel in contact with any of these styli, a micrometer was set to butt at the plug and from there to the full length of the 7SU/RS180 assembly. The 20SS is slightly shorter, the 15XE longer, difference is approx. 0.5 - 0.6mm total between the three samples. Other than alignment concerns, the three are physically interchangable but how this small discrepency affects the relation of magnets to pole pieces will have to be determined by someone with steadier hands, better vision and a supply of sacrificial styli. All pertinent cartridge surfaces are also parallel. It would seem unlikely there's any change in SRA, I'm willing to write off any differences as being within manufacturer's specs.
Please don't take any comparisons in a previous post seriously, was largely a "voyage of exploration" (dang autocorrect would have it "voyage of expiration", not quite there, yet. LOL). I need to listen with more intent for specific differences. YMMV.
Rangefinder: Artillerist, photographer, golfer? All three? Not personally enamored with the 415, sharp transients and it gains no bragging rights for dynamic swing. Does soundstage & layering well though, bass is pretty punchy. I understand you need to maximize your investment, ***the 312 is a bargain***. You might also take a detour to the AudioKarma Turntable Forum where the very reasonably priced AT95 is much praised, Stereophile Mag. gives it high marks too. With readily available replacement styli at various performance levels it's worth considering. Relative to stylus wear, the availability of the currently fashionable Acutex LPM 312STR 111 is finite, the current production AT95 will be around, apparently, for quite a while. Suggest you refine your objectives and decide if you want to experience a cartridge with current cache' and a very limited window of availability or invest in one that will get you well on down the road.
Peace, |
Regards, Rnadell: A safe means of checking azimuth is to drop, umm, lower the stylus on the shiny side of a CD, check for a hour-glass or figure eight image of the stylus and its reflection with a 10x (or so) jewelers loupe. This works surprisingly well. Attention to antiskate can also move the center image around as well as affect channel balance.
Griffithds: Don, glad to hear you find the TK5ea/155lc worth listening to. Henry has just about persuaded me the TK7lca is another pretty good cart ;-).
Fleib: The above Signets share the long running AT "100" configured body with the AT120 through 150/155, and the AT7v. The Signet MR series will also accept these styli, the MR grips are deeper and need trimming to fit the others. Output impedance does vary from 580 Ohm for the TK7ea up to 3200 for the AT140/440 so cantilever damping is a factor when making any exchange. I suspect you already know this. BTW, an AT brochure from the late '70s showing specs for the TK7e/SU at 370mH/500 Ohm. Thanks for the scan, Henry. Is it possible that with the Signets and the AT20, this may have been altered for later production carts, as Dlaloum reported last week?
Peace, |
Regards, Dlaloum: David, on the Rockwell scale beryllium is also harder than boron, but like sapphire it weighs more than an equivalent mass of boron. Boron is harder than titanium, aluminum is the lightest (equivalent mass) of the materials frequently seen in cantilever construction but is the least rigid. Carbon/graphite fibre cantilevers are known to me only from entry level AT styli, there would seem to be potential for the material but I suspect there's a reason for it not being utilized in TOTL products (that I'm aware of). Makes a good fly rod although bamboo is preferred by the purist, the other mentioned materials are not commonly utilized in this application.
It would be surprising if anyone were to deny that neither stylus profile or materials used in cantilever construction contributed their signature, or that some combinations were not more favorable than others. The Grace F-9L is the most "musical" cart here, the also alu. cantilevered F-9E ain't too shabby either. There are those, our own Raul is one, who are firm in their conviction that the F-9R is their superior and although I've never compared the three I'd not toss the F-9R because it had the "inferior" ruby cantilever. Function precedes form and like a cake without egg, if influences aren't well considered neither cake or cart will stand on it's own. The comment about any potential for damaging a cart from an unfortunate incident with a sapphire cantilever is certainly to be taken into consideration but as a simple end-user, it's primarily "all about the sound". Variety is the spice of commerce and it's probable that if a designer WANTED to make a sapphire cantilever work, it would be done. Posted from the perspective of the existentialist where the concern is not so much how as how well, it has it's conveniences.
Peace, |
Raul, by your fervor There's reason to be impressed. Let's not forget subsonic bass, It's foundation for the rest. But it's not heard said Dlaloum more Watching as silent bass danced the chair, And backed the nails out from the floor. But we do know David is a sly one. Aye, We've been baited by the best.
Peace, |
EPC-102SP offered on Agon, someone please buy it. |
Regards, Nikola: There are some carts that are excessively analytical, IMHO the AT440MLa is one, loss of cohesion results. For me, anyway. Excessive detail results in distraction and basic pleasure found in the flow of the performance as a united composition is diminished. I've also a Tech. EPC-U25, which from the specs (low inductance, output impedance) should be a winner but with a conical stylus and the reduction of "distortion" (if that's really what's going on) it's just plain dumbed-down DULL.
There's a balance to be found somewhere between, similar to the character of a well conceived TT, whatever one thinks that may be. Personal experience indicates there's an interaction between constituent components, I find a well composed blend of a good quality cantilever and Shibata or Line Contact stylus on a cart with lower inductance (100pF suggested cap) suits me quite well, there are others who would agree. The same has been said of carts with conical styli, there're good reasons for Denon having sold a million.
Belt drive/DD or idler, conical/elliptical or ML, the discussions are always interesting, sometimes fun and it's inevitable that someone will learn something. Thanks for introducing the topic.
Peace, |
Regards, Dlaloum: Re. the 440MLa: Loading plugs have been considered. The 440s' stylus is good on any of the lower output impedance Signet/AT carts. To your interest (and any others), the influence of UHF on the perceptions would seem to have commonality with research done with supertweeters. There's a plain language but well supported article from Townsend audio identifying the conventional wisdom of musical instruments not exceeding the 20-20k range is based on studies going back to work done by Bell Tel. researchers going as far back as the '30s. More accurate equipment and recent research results in the quote:“At least one member of each instrument family (strings, woodwinds, brass and percussion) produces energy to 40kHz or above, and the spectra of some instruments reach this work’s measurement limit of 102.4kHz. Harmonics of muted trumpet reach to 80kHz; violin and oboe, to above 40kHz; and a cymbal crash was still strong at 100kHz.” read more here: http://www.townshendaudio.com/the-way-and-the-how-of-supertweeters. Another: http://jn.physiology.org/content/83/6/3548.full.pdf , "(Danielsson and Landstrom 1985) suggested that "the biological sensitivity of human beings may not be parallel with the 'conscious' audibility of air vibration. Second, the natural environment, such as tropical rain forests, usually contains sounds that are extremely rich in HFCs over 100 kHz. From an anthropogenetic point of view, the sensory system of human beings exposed to a natural environment would stand a good chance of developing some physiological sensitivity to HFCs. It is premature to conclude that consciously inaudible high-frequency sounds have no effect on the physiological state of listeners." This one proceeds to get very scientific although it must be said neither is a barnburner to read. Facinating stuff nonetheless. Peace, |
Regars, Dlaloum: You posed: "none of these research articles have identified is what the mechanism whereby we sense the HF". Easy answer, so easy you'll rap yourself on the head. When you do you'll sense the sound predominately through the bone structure of, in my case, a very thick skull. It's somatic sound, also realized when one clicks teeth together. It might be inaudible to another but definitely registered by the person gnashing his teeth, the one with a most distracted expression. The skin will also act in a "tympanic" manner, and of course fluids also transmit vibration. If this is Voodoo, ah'm a goin'a look further into it.
Thanks for asking the question of what's recorded on the Lp. That and how it relates to stylus profile are two items of curiosity for me. I'll homestead the position for now that if it's on the record then I want to hear it. Leave your brickwalls out of my music, please.
Who was it who said "If less is more, imagine how much more would be"?
Peace, |
Regards, Fleib: Wow, burr under the old saddle? Feel better now?
I have a personal negative response to the 440MLa, which is similar to most carts with more than 2600 Ohm output impedance: Bright mids and hfs bordering on glassy. The ML stylus/resonant Alu. cantilever doesn't do much to alleviate this. Yes, reco. load 47k/100pF, tried on EPA-250 (12gm eff. mass), EPA-500 (7gm eff. mass) and Black Widow (first model, 3gm eff. mass). I just don't care for the cart, OEM. I'm not alone in this. As is, it is what it is.
Want to buy one cheap? That way, you CAN have less for less.
Apples to apples, please.
Peace, |
Regards, Anyone? Easy to understand: http://www.rense.com/products/AboutFreque-08.pdf"The “1’st” Harmonic is the actual fundamental frequency itself. The “2’nd” Harmonic is a frequency that is twice as large as the fundamental frequency. The “3’rd” Harmonic is a frequency that is 3 times as large as the fundamental frequency, and so on. Example: For a Frequency of 100 Hz, the 2’nd Harmonic is 200 Hz; the 3’rd Harmonic is 300 Hz." Nikolas' reference to conical styli, David's teasing comments and several posts by experienced broadcast/recording engineers on other boards -SEEM- to assert that the core of a musical performance is presented in the audible range from 30 - 15k Hz. A quick search of the VE database in the category "stylus, conical" shows a nom. 18% with hf capabilities above 20k, several up to 50k. Groove modulation and contact area or "patch", hold that thought. To my simple layman's mind, resonance and to some extent harmonic apparency is determined by rise time, by overshoot, by ringing and by damping wether it be it overdamped, underdamped or critically so. These considerations extend beyond electrical parameters into the physical characteristics of a specific cartridge and all it's permutations of tip mass, cantilever build, rigidity, cantilever resonance/damping, I also assume the suitability of the tonearm for the particular cu of that cartridge has an influence. Not hesitating to demonstrate my ignorance but still hoping to avoid the "slings and arrows" of my outrageous forum behavior ;-), they're several areas in which I'm puzzled: (1) In order for a statement to be true, the reverse must bear scrutiny. In the condition of either absence on the recording, or the ability of the stylus to operate in a fundamental frequency of, let's say 25k, would the harmonics effectively "reconstruct" the absent fundamental? Psychoacoustics or measurable? Current thoughts are yes-no-maybe, but IMHO these fundamentals and associated harmonics are integral to the original performance, wouldn't it be best if this information was actually recorded to the lp and the transducer in question was capable of retrieving said information? (2) Lost all my references when the old notebook crashed and burned so consider this as garbage data. IIRC, a "typical" conical stylus has a round contact patch of 18um. A "typical" elliptical a major 30 (something)um. Shibata, line contact, or the Orto. Replicant from 45 to 100um, the minor radius is much finer but the major radius is in extended vertical contact with the sidewall modulations. Relating to FR, the minor radius is, I believe, the main concern. The higher the frequency, the finer the modulation, in order to trace these frequencies above 20k an elliptical tip of .4mil minor radius is effective. Shibata/LC/ML/Parawhatever are further reduced in this plane, 2um or less. The extended major (vertical, 45-100um)) radius serves to spread the actual pressures involved so that the effect is a finer vertical involvement of stylus-to-groove is enabled while at the same time relieving the concerns for record wear due to elevated psi conditions. Frequency response is improved while record wear is less evident. In consideration of the existence of extended uhfc (and subsonics) and assuming one finds their harmonic influence desirable in playback, a conical stylus may not be the best choice. Or, perhaps as hinted at in the entirely speculative Para. (1), these "desirable" harmonics/resonances come pre-packaged on the LP and cartridges equipped with conical styli and considered desirable are designed by people who are really quite clever (I think they are, anyway). Fire at will. Peace, |
Regards, Fleib, Griffithds. Don, congratulations on the Astatic.
Fleib/Don: As an inveterate stylus-cart swapper and well aware of the influences of loading as well as the effect of cantilever damping, a personal preference for carts with an output impedance of less than 780 Ohm has developed. This is reflected in capacitance, carts that open to 300-400pF frequently exhibit a bright mid and sometimes overly crisp hfs.
Gear is a thing to be kept in mind, antique amplification is SS, current mirror loaded with a three stage Darlington SEPP circuit, DC power with zero NFB. Speakers are four Paradigm Signature S4 stand-mounters, the surprisingly smooth beryllium tweeters run to 45k. An active DSP 12" sensibly integrated sub sits just to the inside of each. Altogether a neutrally voiced rig with good attack and sustain, endless overhead but don't feed it anything with sharp edges.
And headshells. One of those who post here (ahem) had at last count 28 cartridges mounted on headshells ranging in weight from nom. 6 to 12gm, materials are magnesium, alu., carbon graphite, composite and three species of wood. The headshell selection is tested and leads selected to best compliment the cartridge requirements. This guy would be pretty adamant that doing so is not a demonstration of incompetence but a personal choice made with full recognition of the performance variables as compared to an arm with fixed headshell (of which "he" has several).
I'm really more interested in wether anyone thinks that through resonant interaction, at least the impression of unrecorded uhfs can be Lazarus-like raised from the dead. Not likely but still an entertaining proposal to toss around.
Peace, |
Regards, Nandric: LOL, glad to see the "Balkan" humor intact. 30% Fiat accompli?
How to double the value of your Yugo---
Fill it with gas. (GRIN)
Peace, |
Regards, Nandric: Nikola, you've introduced a marvelous topic. Relax, it's no longer P. C. to shoot the messenger. Referring back to our brothers at Lenco Heaven and the comments from the very competent Reto:
"Shiga had established, that by a given design (ie. precisely defined moving mass of the generator system and a spherical stylus in conjunction with the elasticity of vinyl at room temperature) the playback distortion could be compensated for by the plastic deformation of the vinyl and the temporary change of the groove geometry.
"Some clever trickery there, it appears, specifically requiring a spherical stylus--- John Walton, a cartridge development engineer at Decca picked up Shigas study in 1966 and confirmed:
"...So it turned out, that equipping even the best cartridges with elliptical styli effected no reduction in distortion whatsoever, rather, an increase..."
Other comments relate to the increased phasing inevitable with the more radical profiles such as the Orto. Replicant which is famous for frustrating those who are impatient in alignment concerns.
Categorically, the finer the minor radius of the stylus, HFs are better reproduced but at the cost of phase related distortion. Sufficient documentation exists showing there is an "anthropogenetic" subliminal response to UHFCs. Harmonics go both up and down the scale, these fundamentals and harmonics exist in live music. If then the presence of UHFs is considered a positive event and considering the relation of stylus minor radius to groove sidewall modulation, in order for a conical stylus to perform at these frequencies it needs to be fine indeed. In anthropomorphic terms, your vinyl might resent that.
Meanwhile, if Nikola (or anyone) should chose to drive a conical stylus rather than an exotic, as always the trade-offs exist and it remains their choice. Like selecting a Bentley Mulsanne for it's mid RPM torque and luxurious ride, or another who chooses a Mitsu. Evo for it's sharp responses and tracking ability in the twists, there's cause for neither shame or criticism. Cars & carts, there's a model for every need. The crux of the matter is the ability to distinguish between "better" and "worse". Any of you autophiles want to confess to desiring a Yugo?
Q.: Why does a Yugo have a heated rear glass? A.: To keep your hands warm while you push it :-).
Peace, |
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Regards, Pauze: Agree with Fleib. There's a hint of what he's suggesting in your comments about resonance increasing with the lighter arm. If you have a headshell weight, you might try it. My 315 didn't settle down until, out of frustration, I isolated it from the headshell with a surfaced dime. Running it at 1.35-1.4gm VTF, a 9.5gm Acos headshell on an EPA-250, loading at 300pF seems about right.
Peace, |
Regards, Raul: You wrote: "I know that especially vintage cartridges maybe cartridge suspension is not the same, my experiences about were different from yours and from Timeltel ones.--- "Please don't be so sticky on that resonance frequency ( tonearm/cartridge. ) and more on whole cartridge set up".
Relative to the Acutex 315, I believe we arrived at just about the same destination, a mid mass arm with nom. 12gm at the headshell, but by different routes. Nonetheless, there are practical applications for the introduction of a number of materials, not just as additional weight at the headshell but also for effecting critical mechanical damping of the cartridge.
There are many comments on cart/headshell/arm match ups but it's audiophile mysticism to suggest that, in some instances, a positive effect can be effected in either resonance reduction or the influence on voice when introducing an isolating device. Meanwhile the same practitioners who suggest shims or espouse various materials used in the fabrication of their headshells don't bat an eye when viewing cartridge isolation as gimmickry.
As doing so has a discernible effect I don't hesitate to try this when "tuning" a cart to the headshell/arm so I'm curious about how many have explored the cartridge isolation option and what their impressions are. Please don't misunderstand, this is not suggested as a universal improvement, but when faced with a cartridge one feels is not performing to its potential, experimenting with cartridge isolation is not a thing to be casually dismissed.
BTW, Lew, congratulations on the Beveridge 2SWs.
Peace, |
Regards, Stltrains: Whoa there, partner. I listen to rock 90% of the time. Van Morrison, Michelle Shocked, Santana, "Slow Hand" Clapton, J. J. Cale, and Joni Mitchell are particular favorites.The rest is jazz, blues and anything Bach, Pachelbel, Corelli, Vivaldi, Telemann, Mark Knofler or Mozart wrote. Don't dismiss Diana Washington, Count Basie or Shirley Horn either.
Wagner? A wag once said "He has his moments. Hours too".
Can I suggest two chill pills and call in the morning?
PEACE! |
Regards, Raul: A quick post & then it's Super Bowl time.
Time indeed, the AKG is at my elbow now. I've a loose ADC 6.5gm headshell with unknown leads and it's been too long since the AKG has had any exercise. What HS are you using? It seems you're getting outstanding results.
Peace, |
Regards, Nikola: Get a hacksaw and MAKE your styli, whatever the heck they are, look like the one in the link Raul offered. If you would oblige us by simply doing so (open the provided link) instead of performing linguistic alchemy in the effort to make the X8S stylus in my possession no longer an appropriate fit for the AKG P8E cart, also in my keeping, suddenly something that they are not now we will loose much in amusement but gain hugely in tranquility.
I assure you, the one pictured in the offering is exactly, box, brochure and all, like the one in my possession and it fits perfectly to the AKG P8E cartridge, the one that says "P8E" in raised characters on the cartridge body, also in my possession.
Your pet semanticist Froggy and all his arguments will not alter this fact. ;).
Peace (& out of this endless loop), |
Regards, Nandric: 'The despute was about the X8E and the question if THIS stylus can be used for P8ES. I am still very obstinate in this regard. Why is it so difficult to believe that I own this stylus and know that it does not fit P8ES?" No need to read this carefully. You have answered your own question. After the statements of several experienced others, manufacturers' specs, established dealers' recommendations and numerous images of the correct replacement your concern is not resolved. Here's another: http://www.stereoneedles.com/AKG.htmlPlease note that the vendor (no relation) states that the X6E is in stock and a recommended substitute for the P7E, P8E and A8ES. Another: http://translate.google.com/translate?hl=en&sl=de&u=http://nadelshop.com/&ei=kjsxT43sH82ltwfjx6DgBg&sa=X&oi=translate&ct=result&resnum=6&ved=0CFUQ7gEwBQ&prev=/search%3Fq%3Dplattenspielernadel.com%26hl%3Den%26client%3Dsafari%26pwst%3D1%26rls%3Den%26prmd%3DimvnsMore photos: http://www.adelcom.net/AKGStylus1.htm1: AKG produced a cartridge identified as the P8E. 2: Styli labeled X6R, X6E, X7E, X8E and X8S are interchangeable. 3. Styli intended for other models do not fit the P6/7/8 series. 4: Your styli doesn't fit. Nikola, there is no "despute", just an honest attempt to answer your question but it seems you remain adamant that the manufacturer, vendors and those who have the actual item are mistaken. Someone used the term "obstinate", it was not I. Peace, |
Regards, Nandric: Raul has clarified the issue in a few words. The "new" P8E body/stylus grip is a tapered hexagon, the "old" P8E/ES is square and has a clear body.
Do I remember correctly, there were rumors of magnets failing and reports of one or both channels dropping out?
Nikola, thanks for bringing this to our attention, and thanks, Raul, for encouraging me to revisit the AKG. I'm delighted with the (early) P8E/X8S upgrade stylus & anticipating your comments will be positive. If you've been listening to the P8E for over a week and, how did you put it, "listening for what it does wrong", you may be a bit longer with the P8E(X8S).
Abbot & Costello, wasn't Lew the serious one?
Peace, |
Hi, Lew: Confucius is the usual cited source for the observation that: "Opportunity is not so rare as the ability to recognize it". There's another old piece of advice, "caveat emptor".
When searching for an elusive pickup, like the chicken or the egg, I don't care which comes first, the stylus or cartridge. When Raul gave what I took to be an unreserved recommendation for the Acutex M 320STR (square nose), I undertook a search for either stylus or body and found a listing for a NOS stylus. Looking at the photo, there was no OEM label on the item so I did a little more research and found a reference from an enthusiast who had patronized the vendor (guess which one) but under magnification found his stylus was a common conical, not the very good STR profile. The vendor would not respond and the poor fellow ended up out $190.00 for a generic replacement.
I know you are methodic and extremely patient in your selection of cartridges but if you have the occasion to compare the AKGs, and care to do so, it would be appreciated.
Have you fired up your Beveridge 2SWs?
Peace, |
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"Poem" by Henry Gibson.
Tom Cruise can allude to scientology John Travolta to L. Ron Hubbard's eternity The perfectionist though for AKG Requires a most precise lexicography
So is then cartridge design Evidence of science or art Ask but none can assign which plays the greater part.
Peace ;), |
Regards, Nandric: What you write makes good sense. I was thinking the same earlier as I took a Pickering XV-15 out of the grits box. (Grin) It had been in there a while, like a boring beetle dug deep in a pine log. The first thing was to remove the plastic gripper from the cart, I didn't want the thing at the end all bollixed up. Next was to push those little wires onto the thingamajigs at the back of the cart, then to screw it to the arm all the while trying to keep it as straight as a Georgia Baptist preacher.
The gripper was pushed back into the cart and I made sure to remove the flapdoodle that covered the pointy doohicky before playing a record. It sounded crackly towards the end so I knew it was all catawampus, just gave it a little twist & it was as sweet as Sunday tea.
I appreciate your confidence but hopefully someone more technically accomplished will step forward to unify terminology? Hoping to find a useable reference, I did (seriously) Google around a little, even the manufacturers use a bewildering variety of terms in description of the same item. Those who use english as an alternate language are (on this forum) at a severe disadvantage so ignore the colloquialisms above. You have a natural eloquence as well as many friends here, all you need to do is ask.
Stylus holder or plastic mount is easily understood, the brass tube carrying the cantilever/suspension might be called the insert or simply "tube". Tubes, rods or pins are inserted into holes, squared extensions fit into slots. Not sure about "lips", ridges perhaps? Extensions wrapping around the side are "ears", wrapping upwards from underneath, "wings". "Plugs" fit "sockets" (a la AT stylus assemblies), and the entire construct can be referred to as the aforementioned stylus assembly. Others may supply different terms, it's alright if they do.
(Don, glad to hear it.)
Peace, |
Regards, Dlaloum: From my post 2//06/12: "The X8E/X8ES styli are .2 x .7 nude ellipts., FR is either 10-23k or 10-28k. Tracking at a nom. 1.0gm, output is either 4.0 or 3.75mV. Following Lews' train of thought, the difference between the 8E & ES may very well be in the stylus assembly. The X8S is shorter, does not extend into the body as much, and thanks to Raul we know the cantilever wall is thinner." Sorry Nikola, "that's my story and I'm sticking to it". It's of interest that in his review of components for Hi Fi Mag. in 1976, Martin Colloms placed the P7E, P8E and P8ES on his "approved" list, the Shure V15-111 and Stanton 681EEE were not recommended. In the same issue containing this report, http://www.bostonaudiosociety.org/pdf/bass/BASS-06-01-7710b.pdf there were positive comments concerning the P6R and a host of interesting comments concerning cartridge loading. Sure was a lot of attention being paid, at that time (and this), by dedicated audiophiles to this "piss ant" :^0 cart! David, the P6R, 6E & 7E can be found on Ebay, NOS & relatively inexpensive. It might be taken into account that AKG, as did Empire, cautioned that although a cart might be upgraded by utilizing a better stylus, the performance of the cart would not be the same as the same stylus in the more upscale cart. This might lead one to presume that a certain amount of testing was done, the better motors were scheduled for the higher end carts and that it is likely that the lower end units were equipped with a longer cantilever (longer at both ends relative to the pivot), thereby increasing output at the expense of response. The more refined stylus would, of course, also contribute. This part I'm not "sticking to" but might do until something better comes along. Danny, I missed the MF 200 recently sold, there is a NOS MF 300 (Moving Flux) on ebay now. Mike, I've not heard it but from all accounts the P-100le is one of the "high water marks" of carts. Meanwhile, enjoy the P8ES. Peace, |
Hi, Mechans: A feature I miss. whitmat@gmail.com.
Peace, |
A little indulgence please?
Fig. 1: /) start of play. (Platter rotation top to bottom.)
Fig. 2: \) end of play.
Fig. 3: -) equilibrium in vectors, ^/v.
Fig. 4: *- ) *= effective position of pivot due to overhang/offset.
Fig. 5: ( + ) magnet in ideal relation to poles.
It takes me (sometimes) two weeks of fiddling before I'm happy with setup. Go ahead, laugh. Regarding AS, visualize fig. 1 to represent the starting position of the tonearm relative to the arc it traverses as play begins. It shouldn't require an epiphany to perceive a tendency for the tonearm [ / ] to travel inwards. Fig. 2 would be the position of the tonearm at the run-out groves, but relative to AS, here there's "a hitch in it's get-along". Fig. 3, the ideal, should be self explanatory, the complication is in that where this "equilibrium" is achieved is influenced by the stylus' overhang, Fig. 4 (use your ability to visualize the relationship with this one). By fixing the tonearm "beam" at its pivot, centripetal force will tend to draw the point at which contact occurs towards the center. If there is no overhang then the stylus will traverse an arc and "equilibrium" or the position at which contributing forces cancel each other out will be achieved at the spindle. Stylus overhang throws a monkey wrench into this picture, moving this point of "equilibrium" away from the spindle. To a degree, the greater the overhang the more this is so, then with further extension of overhang back again towards the spindle. Friction (wether VTF/stylus drag/bearing friction/TA damping striction) is a key determinant of necessary AS force.
If one looks at fig. 5 and analogizes "( + )" as the correct relation of a magnet to its coil in a magnetic current generating system, here is another point at which all forces should be balanced. It's a wonderful concept but as usual with vinyl everything's a moving target. Record warp, off center pressings, bearing friction, tangental error, etc. VTA, VTF, AS, azimuth, they're all contingent and with a pivoted arm to change one is to change them all. Why bother? Because when optimized it's much more gloriouser!
If there is a discernible difference heard when correct VTF positions the magnet in it's most effective relation to poles for intended output, the same, unless I'm mistaken, holds true for AS and channel balance. Shouldn't it? Problem is, it's a moving target due to the necessary evil of overhang/nom. 22* offset required to minimize tracing error (ref. Fig. 4), this has the effect of reversing friction derived skating forces at some point before the stylus reaches the end of the record, one can indulge in some simple drafting to illustrate the point to ones' own satisfaction. In very general terms, accompanying instruments are blended L & R, this gives the impression of placement. Fiddling with phasing, soundstage. Solo instruments, vocalists, percussion or whatever are usually mixed with equal levels from both channels and when AS is correct there is a believable representation of a strong center image, consequently soundstage & layering are also improved. Physically, this also represents equal involvement of the stylus to both L & R groove walls, stylus and vinyl wear are also minimized. Obviously I'm a believer in the importance of AS. Correct AS. Determined by ear AS.
Be it opinion or fact, if you can bring yourself to believe that most of the above is true then twisted wires would seem to be the least satisfactory solution, having the weakest influence where the skating force is greatest and increasing torsion when it needs to be relaxing. Weights on a string? Would seem to be better as their effect does diminish as the tonearm nears the end of its arc but somehow, I keep thinking about vibrating guitar strings. Coil springs, these make sense. Frictionless and provide diminishing influence as they loose tension towards the end of travel. Do they resonate? And what about that reverse torque near the end of play? Two springs tensioned in opposition? One perfectly tensioned spring? Levered weights?
BTW: Those who question "reverse" skating, protect or remove your stylus and lower the arm on a bare rotating mat. You may be surprised where, with the AS at zero, it stops traveling. A tri-magnet graduated attraction/repulsion system with stasis at the center of travel would be an elegant solution to this worrisome phenomena, does anyone make such a tonearm?
Peace, |
Regards, Nandric: "all of those 'non-believers and sinners' are native English speakers". If A = B + C, then B + C = A. Are then you saying all who speak english as their native language are "non-believers and sinners"?
Perhaps there are one or two (those other guys) who avoided becoming reprobates?. ;-)
Peace, |
Regards, Lewm: I've read the same (about offset being the cause of skating) but I'm not entirely convinced.
This is why: Offset is the angle at which the long axis of the cantilever intersects that of the tonearm. In the case of a curved arm, the divergent angle at which it would intersect a straight line drawn from the stylus to the pivot. I mean, really, a tonearm could be as crooked as the twisted coat hanger wire that held the muffler up (radiator too) in my old 1960 Austin Healey 106 but offset angle is still reckoned relative to a point A to point B description.
If you stop to think about it, skating force for a given effective length and under similar conditions will be equal, or nearly so, regardless of offset angle. This angle will vary with tonearm length and is calculated so that the tensional forces presented to a cartridges' suspension are maintained in line with its axis and, more importantly, to orient the stylus at right angles to the groove. Overhang and arm pivot-to-stylus determines offset angle, a longer arm will require less offset as compared to a shorter arm if overhang is the same. In other words, on the same arm the required offset angle would be about two pin-head angels (PHAs) greater for 17mm overhang than at 15mm.
Offset then is determined by eff. length and overhang, these are alignment concerns and a matter of geometry. The extent of skating force is related to overhang and Newton's laws of motion apply. This is a situation where Archimedes meets Sir Isaac, I hope I haven't mixed the two of them up.
I never (well, hardly ever) object to being corrected so if I've got this wrong somebody say it's not so.
Peace, |
Regards, Lew(m): And every other interested person: http://www.vinylengine.com/library/sony/pua-237.shtml. Two items related to the discussion, go to this link and click on "owners manual", the geometry of the tonearm is pictured on the last two pages and also gives two offset angles, one for the 12" and one for the 16" Sony arm. Hopefully it can be seen that the importance of offset is a matter of alignment and not the "offset" appearance of the headshell. That a headshell appears to be out of congurence with the center-line of the arm and is largely the cause of skating needs to be dismissed. Picture is worth a 1,000 words. Then bring up the "bias compensator" page. Those searching for mathematic proof will be delighted. Thanks to a certain sly Balkan for offering the suggestion that the Sony PUA-237 would be a good place to look, apparently our friend is about thirty years ahead of the rest of us. And Lew, did the author of the "paddle" allusion consider the outcome if a conical paddle were to be used? (Sorry, I couldn't help asking) ;-). Peace, |
Regards, All: Sorry for the dbl. post, fired the Mac up, has a mind of it's own. Now I know to clear the page before shutting down.
Jcarr, your visits are always attended to, your description is elegant in its simplicity and illuminates the phenomena from the builders perspective. The interaction of opposing forces is best described in terminology appropriate to the medium.
The willful Apple (not Sir Isaac's) and it's behavior does give me the opportunity to say thanks.
Peace, |
Regards, Lewm: "(T)he prime determinant of skating force is stylus friction in the groove. Without Ff, as we used to abbreviate friction in college, you cannot generate the skating force Fs."
Isaac Newton in his "Principia" states: "A centripetal force is that by which bodies are drawn or impelled, or any way tend, towards a point as to a center."
Gravity acts as the centripetal force holding a satellite in orbit, the opposing influence is centrifugal force. Although it may encounter a stray particle or two, entropy rather than friction is the greater concern. Please note that this is not intended to contradict what you wrote, neither should the introduction of the effects of friction invalidate the above observation. There is no paradox here, just a matter of which aspect one wishes to focus one's attention on, the observable phenomena or splitting hairs over the factors that modify it.
Our irrefutable resource person, Jcarr, refers to these forces as vectors, terminology that is significantly more contemporary than that of the eminent Mr. Newton. I don't perceive any argument here, just an opportunity to look at how the phenomena effects our passion for the medium. And maybe split a few hairs while we're at it.
Porches of any vintage are great machines. I've looked twice at a Cayman "R" (inspired by the German R Gruppe Porsche junkies) with longing. I hope that the dealer sells it soon.
Peace, |