Lew, re:
"I am surprised that one good oil would be noticeably superior to another good oil in a tt turning at most 45rpm", studying fluid mechanics would indicate that the toughest lubrication applications are slow speed as opposed to high speed where lubrication "wedge" can be easily generated by the fast moving parts.
That is why slow turning gears use high viscosity lubricants with extreme pressure additives to reduce wear and minute "welding" of the gear parts.
This is basic lubrication.
Viscosity is part of the equation. Another part is film strength and anti friction agents to support moving parts at high pressure.
The lubrication of a tiny ball bearing moving against a disc at slow speed is actually a tough application. It's like stilettos: The pressure of the bearing is fairly high (P=F/A) where A (area) is very small and F (force) is not insignificant and the slow 33 or 45 RPM is not sufficient to easily build a fluid film between the ball bearing tip and the disc.
A good lubricant can help since reducing friction in this point will benefit in less noise which transfers from the spindle to the platter.
Just my thoughts and personal experience.
Stop times are dictated by viscous shear (internal friction of the fluid layers) and asperity contact at the tip of the bearing. The higher the lubricant's film strength the less the asperity contact would be a factor and stop times will be dictated by viscous shear. That is why adding weight didn't really change our results with RP. |
|
Doron,
+1
I have read your post a couple of times. Made me think!
Thanks. |
Halcro,
When your Acromat arrives, you will notice that it has square edges. Looking at the inside of the base of the raised edge on the platter, you will see that there is a slight radius. Because the Acromat's diameter is a tight fit when placed in the lip of the Victor's platter,this radius to square corner bothered me so I did slightly chamfer (bevel), the underside edge of the Acromat so that I wasn't worried about interference (the square corner riding a radius). I might have been overreacting to a possible non-existent problem but had I not done something, I would have thought about this for ever. Anyway, the Acromat sands very easy so take my comments only as something to consider.
Hope you like what it brings to the party! (grin)
Regards, |
Doron, You obviously know your stuff when it comes to lubricants. Thank you for the information, some of which I once knew but had forgotten. Your last remark is the focus of my question: Do you mean to say that there is some fundamental difference in the way Royal Purple (RP) motor oils are formulated as compared to Redline motor oils which would account for the reported observation that RP 5W30 sounded better than Redline 20W, other than viscosity? My point was that the difference in sonics observed the the OP might have been due entirely to the difference in viscosity between the two oils. Do you think yes, or no? It was after that when I made my ignorant remark about slow motor speed.
You must realize that if you say RP oils are superior to Redline for use in a typical TT, then at least several of us are going to run out and buy RP motor oil. I've got the Redline 20W in my Kenwood L07D. By the way, I'm not interested that much in "stop times". I don't know what it means for a tt platter. A very low viscosity lubricant (I can imagine) might allow for long stop times (at first) while also doing damage to the bearing in the process. |
If any direct comparisons were to be made between the RP and Redline products and I'm not sure they were, varying viscosity's certainly would make them suspect. |
Ok, I'm game. I'll buy the RP XPR 05w-20 race oil and re-run the test(s) with the same weight Redline. |
Don,
I ordered the special Achromat 1200 which was designed for the lip on the Technics 1200....so I suspect the underside is already tapered to accomodate this?
Will post photos when it arrives.
I've also got a glass mat on its way from Japan.
Apparently Victor produced one for their turntables and get this.....the instructions say that the pigskin mat is designed to go UNDER the glass mat...❓👀
This would never have occurred to me...🙈
Of course I'll try it both ways....but I wonder if you've tried a suede mat UNDER your Achromat..❓
Worth a try....those Victor engineers knew their 'onions'....👅👍 |
I also have the Victor pigskin mat that came with the TT-101
but have ever only used it on top.
Perhaps I need to get out more often. |
Banquo, Keep in mind that the recommended Redline viscosity, and this is only for the Kenwood L07D, is straight 20W, not a blend. So, if you can find it, maybe compare that to RP 20W. Or, compare Redline in the 5W-30 weight to the RP 5W-30 you already own. But maybe also wait to hear back from Doron, if he responds to my post.
A quart of any of these oils should last several human lifetimes (let alone TT lifetimes), even for a freak like me who has 5 TT's, but dammit I cannot find my quart of Redline 20W. I am motivated to try it out in the TT101 and maybe also the SP10 Mk3. |
One thing for certain is I don't know the first thing about motor oils. Here is what is available from Redline (from their website) as far as their race oils go:
20WT Race Oil (5W20)
30WT Race Oil (10W30)
40WT Race Oil (15W40)
50WT Race Oil (15W50)
And here is what RP offers in their XPR line (the line Doron recmmended to me):
XPR 3.1 0W-5
XPR 0W-10
XPR 5W-20
XPR 5W-30
XPR 10W-40
XPR 20W-50
As you can see, if I desire the same viscosity between brands, my 'choice' is limited. |
I also have the Victor pigskin mat that came with the TT-101
but have ever only used it on top. On top of what Totem❓ Perhaps I need to get out more often. Hold your horses Totem......I might be able to save you the effort...😎 The Achromat 1200 arrived this morning sporting its rebated underside which fits nicely clear of the Victor edge lip. Multiple comparisons ensued:- 1) Achromat on its own 2) Achromat plus Jico (thin) on top 3) Achromat plus Jico (thin) below 4) Achromat plus Victor Pigskin on top 5) Achromat plus Victor Pigskin below Let me warn you....the Achromat is NOT a perfectly flat item and in all cases where it was used, the 'warp' created was obvious with the tonearm rising and falling noticeably....😫 All comparisons are against the bare Victor platter with the thin Jico mat.... 1) With the Achromat on its own....the bass became less defined, the midrange slightly less transparent whilst the treble harmonics lost some of their 'shimmer' (and 'shimmer' is good 😜❗️). 2) With the Jico mat on top, a slight degrade to the bare Achromat. 3) With the Jico mat below..it seemed surprisingly worse. 4) With the Victor pigskin on top..not much better than the Jico. 5) With the Victor mat below...not much difference to the bare Achromat. I then, for reassurance....again compared the Victor pigskin on bare Victor platter with the thin Jico on bare Victor platter and it is very very close...👅👀 I would still give it (just) to the thin Jico...but could happily live with the Victor. When I receive the glass platter mat...it will be interesting to repeat all these comparisons...😏 |
Halcro,
Did you use the double-back tape to attach the Achromat to the Victor platter? I ask because my mat could not be any flatter! I've checked it with a straightedge.
BTW: Jico just got a little more of my money! (grin) Place an order
Regards. |
Hello,
Agree with comparing apples to apples, viscosity wise, when comparing the two oils.
Here is some data re viscosity of multiple grades oils:
http://www.viscopedia.com/viscosity-tables/substances/engine-oil/
The multiple grade is not crucial in our case because we are dealing with relatively low temperatures (in the 70-80F) but can relate to the viscosity in the chart.
Adding weights and comparing stop times should give some indication but the best proof is in the listening. Less friction will translate to quieter background and lower sound floor.
Hope this helps,
Doron |
Minh,
You could use the 5W20 in both oils.
Good enough for this application, in my mind.
Just make sure to clean and dry the bottom plug/oil pan and the spindle/bearing from the RP well as it tends to adhere to metal parts and maintain its lubricity.
Re the formulation of synthetic oils:
For most oil companies, oil is a by product of refining crude to fuels.
It's a thorn in their side. They buy an additive package from companies like Lubrizol who specializes in this field. The additive package will contain, anti rust and oxidation agents, anti foaming, metal deactivators, viscosity modifiers, etc, etc.
Then, oil companies will package it nicely, put a photo of a tiger or a race car or whatever and sell it with all sorts of marketing claims...
Synthetics are a bit different in the sense that the base stock is manufactured by cracking ethylene to a long chain of hydrocarbons which do not contain impurities like in the case of standard mineral oil.
The main advantage of synthetic base stock is prolonged life and flatter viscosity curve (less change in viscosity as the temperature changes, which is desirable).
Both kinds will be blended with the additive package.
Royal Purple started as an industrial oil blending facility with two main advantages:
1. They filter and clean their base synthetic stock to a high level (ISO cleanliness of 14/13/11) - most important in process compressors and rotating equipment in general.
2. They blend their own additive package and in it, they include their secret recipe to a potent anti wear agent which increases film strength and reduces friction to a very high degree.
Of course the world is full of marketing claims, snake oil and $20,000 speaker cables which makes any claim a suspect,
I just have very good experience with RP in the industrial realm, which instigated my curiosity re my audio hobby, specifically my turntable bearing (both my previous Oracle Delphi and now my TT-101).
Btw, I am not an RP representative.
I am a chemical engineer who deals with mechanical seals and rotating equipment in general. |
Halcro,
The purpose of a mat is to provide a stable surface with a similar impedance of the record, or so they say. Some think the best mats are forms of acrylic, methacrylate (Delrin), carbon, or vinyl. The trick is in preventing vibrations from reflecting back to the record. Achromat does this with bubbles somehow. Perhaps a lead sheet would be more affective.
Beside the obvious problem of weight, lead is soft and manufacturing a flat sheet might be a problem, but I doubt if any material is more affective at slowing vibrations. A lead sandwich or under mat might be ideal.
Regards, |
Fleib, To paraphrase Mike Tyson... Everyone's got a theory until they're punched in the face After listening to multiple different materials and combinations on the Victor DD turntables......I know what sounds best to me....and so far it's what the Victor engineers themselves agreed on, the pigskin thin platter mat. The last mat I will try is the glass one....also designed for these decks. The Walker Proscenium turntable uses a platter made of granulated lead and epoxy I believe...😎 |
The funny or sad fact is that the mat has a large effect on sonics,…. after all the money is spent on the tt, tonearm, and cartridge. It's the salt and pepper of vinyl. |
........or have their ear bitten off. Bon appetit.
Sorry I chimed in.
This has already been done by Pierre Lurne, only with a platter rather than a mat. I happen to have some sheet lead. Might see if it's doable. |
Mat wise, did anyone try the old Oracle groove isolator?
It's a bit smaller than the TT platter but thick enough to be higher than the edge. I have tried carbon fibre (Boston) and Acrylic hard mat and found them hard and bright sounding. The Groove Isolator seems to have a very good tonal balance to my ears without losing details/muffling the sound.
Your mileage may vary. |
Dear Doron, BA mats, brittle sounding or not, are not made of carbon fiber; they are made of graphite. (But I submit this with some trepidation, knowing now that you are an expert on materials science.) On two very different turntables (Lenco and SP10Mk3), I find them to be relatively neutral. On my Kenwood L07D, I find no reason to deviate from the OEM stainless steel "platter sheet", but if you asked me how I feel about metal mats in general, I would say that the BA graphite mat2 beat out the SAEC SS300 metal mat on my Mk3. Go figure. |
Fleib .......or have their ear bitten off. Bon appetit. I hope you didn't think it was I with the hunger pangs...❓👀 I was trying to convey the thought that no-one has yet proposed a scientifically provable theory as to what, how or why the turntable mat plays such an important role in the 'sound' that the stylus extracts from the record groove❓ In exactly the same way that no-one has proven HOW the material of the headshell does (for arms with removable ones)....😏 It is of course tempting to formulate theories in our minds to try to explain these phenomena....but the only conclusive evidence we have for them...is the listening experience (as far as I am aware)❓ Nowhere is this more visible than in the topic at hand.....leather/suede turntable mats. Five years ago when I happened to acquire an original Victor Pigskin mat with my TT-101....I don't believe that there were after-market leather mats available from many sources at all...❓Certainly 30 years ago I had never even heard of them... These days on EBay.....if you type in "Leather turntable mats".....you can find dozens of independent suppliers who all have their own takes on composition, thicknesses and finishes....as Banquo has discovered..😜 So a market has arisen (and it must be a considerable one)...driven by an obvious demand...to enable financial profit for multiple suppliers... And now Jico has entered it 😏 This 'market' could only have grown due to first-hand listening experiences as I have not noticed any great press coverage of this 'discovery' in the printed or on-line journals..❓👀 |
Sorry Lew,
My bad, Carbon Graphite it is. In any case, didn't work for me.
Re material's expert, I'm far from being an expert on anything.
I always say: I learn everyday, I'm going to die stupid in the end, but I'll die trying...:-)
Mat sound, like cables (and maybe this whole hobby) is subjective.
A dark sounding system (define dark) can benefit from a hard mat and a bright system would benefit from a duller sounding mat.
Without references points any impression is subjective.
its just trial and error for any one of us.
Generally, I see audio as a combination of engineering, physics and cooking, all in one hobby...unlike engineering and physics, cooking and taste is a highly subjective matter. Otherwise we would all have the same system.
Not even getting into the fact that we all have very different rooms (and rooms account for very high percentage of the sound).
My personal experience in the context of my system/taste is that softer mats like cork, pig skin, delrin have better sonic results. |
Halcro,
No one has yet to provide a provable theory how or why a mat works?
This stuff might seem like rocket science to you or I, but it's not. The record/platter interface is understood, but platters are made differently and people bring their preferences to the evaluation table.
If you read the literature describing the Acromat, you know that its mechanical impedance is trying to match that of a record so vibrations are drained unimpeded. The bubbles are to prevent the vibrations from reentering the record.
Apparently this works, at least to some extent. Some people are getting good results. This approach is taken directly from Pierre Lurne (physicist). He devised a platter that was (I believe) 10mm of lead sandwiched between methacrylate slabs. Lead is extremely affective at slowing vibrations and the methacrylate was formulated to match the record. The formulation of acrylic and methacrylate can be varied to different hardness.
Rubber or sorbothane is good at damping, but generally isn't a rigid platform - it gives.
A leather top mat can soften the blow so to speak, between the record and a hard platter - metal or glass. It too will give, but if it's thin and LP is hard clamped, it might not compromise detail? You can say the same about sorbothane, but IMO that only goes so far.
With that said, I just ordered a thin leather/suede mat. I'm still going to make a lead mat. I have to figure out how to do it and what to use on the outside. I always liked the Goldmund mat, but they're pretty much gone.
The notion that JVC had this figured out 35 years ago, is akin to burying your head in the sand. Look at all the statement tables back then, NONE had a great mat or platter, at least the interface.
Regards, |
In medicine, it is said that a "specialist" is someone who knows more and more about less and less, until he knows everything about nothing.
Soft mats do have their appeal, but not soft rubber mats. Do you consider Delrin to be "soft"? I've never had one in my possession. TT Weights sells some, I think, and I've been tempted. However, I always thought of Delrin as one of those materials that attempts to mimic the characteristics of vinyl, so as to minimize impedance to energy transfer from the LP, i.e., I thought Delrin was "hard" (in the way that vinyl LPs are hard) vs soft.
Is there anyone here who adheres to the notion of elevating the LP in space, a la the old Transcriptors turntable platter and the new "Resomat"? It's the total opposite philosophically of what we've been discussing. |
I just landed a Luxman PD444. Does anyone here have personal experience with this table? Also, a pointer to the service manual would be much appreciated. There is nothing on Vinyl Engine or anywhere else via web search.
Assuming that it arrives in good working order as advertised, I suppose the first step will be to re-cap the electrolytics and attempt to inspect the condition of the bearing. This may be a challenge, as a poster has written that the bearing is sealed.
It's an interesting design. Luxman literature indicates that its slotless DC servo motor somehow levitates 4/5 of the 2.5kg platter weight without resorting to a permanent magnet around the bearing. Here is an extract from the owner's manual:
"The PD444 employs a slotless, flat DC servo motor that offers a small amount of torque ripple from theoretical viewpoint as well. It is so designed as to obtain an even torque regardless of the rotor position, thanks to the brushless structure with hall elements which detects the rotor position.
In addition to conventional speed control by means of a frequency generator circuit, a so-called "Quartz Lock" system is employed utilizing a PLL system...crystal oscillator. Therefore, the open-loop gain in DC area becomes infinite, which helps suppress external load variations in low frequencies. Also, the rotation speed is locked to the... crystal.
The QL system is effective in the suppression of external load variation from DC area to 1Hz. To reduce those load variations of relatively higher frequencies(5-10Hz), the flywheel of the (heavy) platter is effective.
But coupled to these advantages are such problems as shorter life of the bearing, and longer rise and decay time. Our exclusive "Load-Free Spindle"...solves these problems. The phono motor itself offers the repelling power to the spindle to float the platter, unlike conventional magnet-float systems.
The driving current to the motor is small, and such characteristics as S/N ration and wow and flutter are improved." |
Lew, I use a Resomat and prefer it to direct coupling on my L07D and VPI TNT. However, the Resomat can sound a bit light and tizzy without a clamp or record weight to bring the LP into full engagement with the two full circles of vinyl cones on the mat that mate with the record lead-in and run-out sections. Too much weight or pressure becomes counter-productive, cupping the LP away from the outer circle of cones. To prevent cupping I stack rubber washers on the spindle above and below the Resomat. When the record weight is applied the perimeter cups down.
All of this may seem like too much trouble, but it's really no big deal. |
Lew, re: elevated LPs?
This seems to be popular in Great Britain, I believe the source of the Ringmat. And that company may or may not have produced an earlier version utilizing a number of cork dots (smaller than a quarter) to suspend the record.
Also, B&O made at least one table with radial plastic supports on the platter to suspend the LP.
So I must ask, as I have with other "out of the box" ideas, if it was truly successful would not nearly all manufactures have adopted something similar by now? |
Lewm - Is there anyone here who adheres to the notion of elevating the LP in space.... Lewm - My tonearm and platter are already "in space" I also preferred my records firmly grounded in between. Later in personal conversations with Verdier (prior to his recent passing-RIP) he confirmed to me that his TT was designed to be used with no mat. Halcro
I've also got a glass mat on its way from Japan.
Apparently Victor produced one for their turntables and get this.....the instructions say that the pigskin mat is designed to go UNDER the glass mat...
This would never have occurred to me...
Of course I'll try it both ways....but I wonder if you've tried a suede mat UNDER your Achromat..
Worth a try....those Victor engineers knew their 'onions'.... I have heard of "pheasant under glass" but never pig. Analog can be so much fun...... |
Dave, How much does the Resomat weigh, in comparison to the stainless steel platter sheet on the L07D? One of my reasons for not experimenting with the L07D, besides the fact that I adore its sound already, is the fact that the mass of the platter sheet is figured into its servo design. If I were to sub out the platter sheet, I'd look for something of very similar mass. |
03-16-15: Banquo363
One thing for certain is I don't know the first thing about motor oils. Here is what is available from Redline (from their website) as far as their race oils go:
20WT Race Oil (5W20)
30WT Race Oil (10W30)
40WT Race Oil (15W40)
50WT Race Oil (15W50)
And here is what RP offers in their XPR line (the line Doron recmmended to me):
XPR 3.1 0W-5
XPR 0W-10
XPR 5W-20
XPR 5W-30
XPR 10W-40
XPR 20W-50 @ the Redline, RP guys on this thread (Banquo, Doron, Lewm, others...) Re: the bearing well lubricant discussions... Recently read the synthetic fluid postings here. Found it ironic as my son just bought a used sports car and sent me a bunch of url's to review. they discuss RP and RL as well. like this one ok, nothing to do with this thread, but the similarities are striking. These guys changing out mineral fluids for synthetic in the gearboxes; sort of like you guys with the thrust pad wells ? Anyway you guys reminded me of them. For SP10MKII owners with worn out thrust pad wells. You can get some hereHappy listening |
Fleib, I don't think the record/platter interface is understood as you claim and that's where we differ... If it were....there would not be the plethora of platter materials, shapes and weights nor the cornucopia of platter mats (materials, thicknesses etc). I don't believe there are even two turntable manufactures with identical platter/mat combinations...? And if...as you declare.... The purpose of a mat is to provide a stable surface with a similar impedance of the record, then the majority of turntable and mat manufacturers fail in this endeavour..😱 Some think the best mats are forms of acrylic, methacrylate (Delrin), carbon, or vinyl. And some people DON'T think that.... Some people even think that NO mat is better....and on some platters I have found this to be true... And then, as Lewm points out....some even think that the less contact the record has with a platter...the better😊 If you believe that all these opinions reflect an "understanding" of the record/platter interface....I simply beg to differ...😎 |
Dgarretson, although I've not seen a PD444 in pieces, probably its bearing spindle sides were cut into a shape resembling a helical gear. When the spindle turns, such a gear thread will exert a pumping action on the oil contained in the bearing housing. This pumping pressure will center the spindle (so that a hydraulic film is maintained between spindle and bearing housing), and partially unload the spindle pressure on the thrust-plate (depending on the orientation of the helical cut).
With this kind of internal structure, it would be no great surprise for the bearing to be sealed.
Other turntables incorporated a similar "Archimedes pump" philosophy. For example, Trio-Kenwood's "DL" motor (employed in the KP-880 and later models) had a herring-bone pattern cut into the spindle sides, again for the purpose of pressurizing the oil inside the bearing housing and centering the spindle.
As to why the magnetic route wasn't pursued, for sonic reasons most likely Luxman didn't want full platter levitation, which meant that simpler hydraulic partial levitation was sufficient to protect the thrust-plate from the weight of the platter that they chose to use.
kind regards, jonathan |
Halcro,
If the record/platter interface isn't yet understood or a matter of opinion, why defer to original options offered for your old table? The fact that there were options implies there is/was no one right solution. Perhaps not, but I think this interface is understood better than it was 35 years ago.
Seems to be three schools of thought, damping, impedance matching - preventing reflections back, and coupling or decoupling like Resomat. Admittedly, I didn't consider that one.
I suspect platter mass and rotational imperfections might have something to do with preference. Perhaps cart/arm synergy is the biggest factor.
Regards, |
Lew, The Resomat is almost weightless. It consists of a paper-thin acetate sheet that serves only to fix the locations of the small and lightweight vinyl acetate cones that couple the record through the sheet to the OEM platter. The cones pass through the sheet and their bases rest directly on the TT platter. So the idea with this mat is not to isolate the LP from the platter, but rather to couple it at two radiuses. The mat is available in several versions: short cones or long cones designed to clear the raised lip of an SP-10 platter.
With L07D I'm using a sandwich arrangement. Stillpoints LPI record weight over short-point version of Resomat over TTW Weights 4 lb./4mm solid copper platter over ERS cloth mat over Kenwood steel plate. The Kenwood's tall spindle is just long enough for all of this.
The weight of the copper mat is pretty close to the weight of an original Kenwood perimeter ring. The performance with the copper mat is improved by pressing the button on the L07D PS that was conceived for the perimeter ring.
Jcarr, very helpful & thank you for the info. |
Interesting to consider torque to mass ratio with the Yamaha GT 2000. Stock platter was 5.8kg. Optional platter was 18kg and was used w/o modification. That's almost 40lb. The Goldmund Reference platter was 35lb, was said to be too heavy for a DD table. |
Fleib, I have seen a lot of GT2000s, both in person whilst in various Tokyo audio emporia and on the internet. The ones I have seen all seem to have a relatively "thick" platter, due to peripheral rim thickness more than anything else, but I don't know whether I am looking at the 5.8kg standard or the 18kg optional. Did you find a photo of the latter? That's a huge difference in platter mass for use on the very same motor with the same servo feedback mechanism, unless the motor/servo is switchable so as to accommodate the heavy platter. As Dave mentioned, the L07D power supply does have such a switchable mechanism, to be used when one is using their dedicated record weight and peripheral ring (and in Dave's case, he uses it with his complex platter "sandwich").
WRT your discussion with Halcro re the LP/platter interface, I would say you're both correct. The nature of the interface is "understood", but there is no agreement how best to deal with it in order to achieve max fidelity of sound reproduction. |
Lew,
There are photos of both the GT2000 and 2000x at Vintage Knob. Stock aluminum platter is pretty hefty at nearly 13 lbs. The x platter looks similar, but is gun-metal. The motor shaft on the x is beefed up to 6cm vs 2cm for the 2000, but apparently the rest of the motor was the same.
The heavy platter was an option on the 2000 so I guess the shaft could handle the weight.
How do you think these Yamaha's stack up? |
Fleib How do you think these Yamaha's stack up? There certainly are many GT-2000 owners about, as to how they stack up there was a thread that Jcarr posted regarding a {Japan forum} where a Victor motor designer who had a hand in the GT2000 design pursued the Yamaha and ended up taking it home. I thought it a rather fitting endorsement. Found it Jcarr There is an interesting Japanese webpage by a retired JVC engineer, in which he talks about his involvement in designing the motor drive and controller circuits for the slotless DD motor of Yamaha's GT-2000. note, several pages http://37282.diarynote.jp/200708032337340000/ |
The glass platter mat arrived yesterday beautifully packaged and included an ingenious silicone rubber record puck which squeezes the record onto the the vinyl without adding weight over the spindle..😎 The glass mat is beautifully made and I tested it on its own as well as with the Victor Pigskin mat both under and over it. It was easy to dismiss the silicone puck as being inferior in sound to the heavy Yamaha record weight I usually employ...😊 To cut a long story short....the results were quite similar in all respects to the Achromat with the glass being slightly better.... The clear winner was again the Jico thin leather mat.... As always....YMMV..👀❓ |
Totem395,
Thanks for the info. It seems like torque or lack of, and speed correction circuitry are major contributors to SQ of various DD's. I saw a GT2000 years ago, but never had the pleasure of playing with it. If the motor can power a 18kg platter, one would think it's a bit much for the stock 5.8kg one?
I'm sure it sounds good. I was just wondering about comparisons. An anecdote about a Victor engineer is interesting, but.....
Regards, |
My impression from touring Tokyo audio salons is that the GT2000 is much more commonly seen for sale these days than are some of the other TOTL vintage direct-drive turntables. This can only mean that many more of them were sold vs for example the SP10 Mk3 or the Exclusive P3/P3a. However, I have seen a GT2000X only in those photos on Vintage Knob, never saw one in "real life". Thus I missed the point that the GT2000X has the heavy platter; I thought it was distinguished only by its more massive plinth. All of that said, I have never heard either Yamaha. One criticism I read was of the tonearm. It is apparently made at least in part of plastic, probably some high-tech plastic but plastic, nevertheless. There was an article detailing the fact that those tonearms can develop stress fractures (maybe on Vintage Knob???). I don't know if this applies to all tonearms supplied with the GT2000 and GT2000X or only a particular one.
Does anyone here own a GT2000/X? How about a Luxman or Onkyo TOTL direct-drive? Those last two seem really rare to find these days. |
I have the GT2000 and am quite happy with it, though I have not done direct comparisons with other DD turntables.
The difference between the GT2000 & GT2000X is that the latter has a bigger motor shaft and plinth. The have the same platter, motor, and controller. The 18kg gunmetal platter was optional for both.
Some people like the arm on the GT2000 but many also change it for something else. Yamaha sold two other arms and SAEC made a special version of 407, the 407/GT that can directly replace the existing arm. There are also commercial arm boards available that allow the use of other tonearms. I have no experience with or knowledge of fractures in the tonearm. |
Thanks, Sampsa. Have you compared your GT2000 to any other vintage DD turntables? Have you ever seen either the 18kg platter (hard to believe) or a GT2000X? |
No. I've compared it to a Garrard 401 with the same cartridge (SPU Gold) but with different tonearms and preferred the GT2000.
I haven't seen either the GT2000X or the YGT-1 platter in real life. They're both pretty rare but do occasionally pop up on the net. |
I have now compared the Jico leather mat with the custom rubber mat that comes with the Exclusive P3.
Overall the leather mat has good transparency let down by a softening of the leading edge of instruments and a slight fattening of the sound in the upper bass. would probably be good with neutral/lean SS gear.
The P3 rubber mat is more coherent top to bottom and the music is more involving.
A bit of a PITA is the thicker mat is not flat - it bows where the Jico cattle mark is. Makes every lp look like it is bowed. Sort of defeats the purpose of a mat when it cannot effectively coiuple the lp to the platter.
YMMV
Still have to compare on my P10 and TW Acustik.
cheers |
I concur. First job of a mat is to be flat. Of course, the platter supporting it has to be perfectly flat too. |
I read on Karma that deer hide is better so I got a thin one (< 2mm) figuring a thick one would have too much give. Although it looks to be of uniform thickness results were similar to Downunder. Mild edge warps looked exaggerated and it seemed that repositioning the record didn't correct.
I tried this on top of 2mm SRM acrylic mat that's just a bit too hard IMO, but sounds better w/o the leather. Putting the suede side up seemed to help a bit, but not that much. |
Fleib
Mild edge warps looked exaggerated and it seemed that repositioning the record didn't correct.
The weight of the album did not flatten the warps in the mat? Seeing it is <2mm and pliable you'd think it would.
Or perhaps the diameter of the mat extended past the platter where the wave's were present. |
Totem,
No, the weight of the record didn't seem to do anything, and the pliability of the mat seemed to create the problem, but you've given me an idea. I normally use a reflex clamp, but not in the reflex mode. In other words, just holding the record in place. Perhaps if I dig out a felt washer and reflex the disc, the pliability will be an advantage?
I'll give it a try.
Regards, |
