Good news for those who own the JVC-X 1. I discovered 4 styli which can be used as substitute for the original. By 'pick-upnaalden.com' named as 'JVC DT-X1-MK2'. I purchased the 'Tonar 00740-DE' for 52 euro and am surprised with its quality.
|
Is the tonar stylus body shaped like the x1 original, Nandric, or like the x1 mk2? If the latter, then you have a few more choices: jico makes a mk2 shibata replacement and lp gear has their own 'vivid line' replacement. I have both. The jico is very good, although sadly not nearly as good as the original. I haven't mounted the lp gear one.
Does the tonar have the tension wire? |
Dear Banquo, The modesty is not a qualitity of a person but depends from the circumstances. I first thought that there are no aftermarket styli for the JVC-X1 available and than come 4 of them across by pick-upnaalden in Holland. All of them are marked as 'JVC DT-X1-MK 2'. Neither is with the so called 'tension wire', alas. My comrade Don who is familiar with Jico will investigate what Jico has to offer. My original cantilever is broken in such a way that a new cantilever/stylus combo can be glued on the remainder. So it is probably that I will end with at least 3 new styli. What is anyway certain is : I will never again try to straighten any cantilever whatever. |
Lew, if you're still interested in a budget phono stage let me know. I have some comparative user reports on the top contenders.
Nandric, if you're still looking for X-1 replacement styli TurntableNeedles.com has what I believe to be an Astatic. Like the Jico replacements it's a straight aluminum cantilever with a bonded tip. #673-DQ. ($38) Jico doesn't have the stylus. Regards, |
Regards All, I do not know if it is in this thread or another that somebody modified the Marantz 7c to be specifically used as a MM phonostage. Can someone please point me to it. |
Audpulse, So far as I know, the phono stage in the Marantz 7C in completely original form IS MM-ready. There was no such thing as an MC cartridge back in its day. It probably does develop higher than average gain compared to a typical modern MM phono stage, because of the bass and treble and other contour controls built into it; such filters suck up some gain, so a little excess is needed. |
Lewn, I have the Marantz 7c as a back-up full function preamplifier for over a decade and has only been used once after changing the captive power cord on the unit. But recently I came across what is called a solid state 12AXT tube that totally blew my mind. This tube has no filament and does not need any warm up. Not much to report on that tube at the moment till I install it in the Marantz 7c. With the high gain of the tube and the performance that was demonstrated to me, I think that my search for a dedicated TOTL MM phonostage may be over. I know that I read on one of the Audiogon threads about a modified Marantz 7c that aroused my curiosity but I cannot remember the thread. |
I picked up a Signet MR 5.0 ML. The MR series has the same basic generator as the 440 - 490mH, 790 DC, 3200 ohm imp. I really bought it for the stylus which is beryllium/ML, to replace the 152ML I broke in transplant. The MR series has a 120/440 series plug, but requires a slight plastic trim on the side, to fit.
The Signet only sounded so-so. The DC was off, being around 809 in one ch and 830 in the other. It also has a small metal body. I put the stylus on my 440 and it was excellent, much like the 152 stylus. I was trying to figure out why the MR body is subpar. Just a bad sample or does the metal body have something to do with it? My 440 measures close ch to ch on DC resistance.
All the ATs I've messed with seem to be greatly improved with a boron or beryllium cantilevered stylus. High inductance ones are easier to manipulate. Like Timeltel's 13Ea with a 155LC stylus is greatly improved, and I think without having to change loading. I used to load my stock 440 at 32K to tame the high end. With the exotic stylus it sounds great at 47K.
Heavier aluminum cantilevers resonate in the audio band and often augment response peaks. The exotic ones resonate near the limit, or past the audio band and also have greater detail/resolution. A lower inductance generator like the 150MLX (350mH) will be harder to manipulate. If it's too aggressive I suspect judicious lowering load resistance is the answer. All AT MMs need < 200pF shunt capacitance which is important to keep the high frequency resonance from being lowered and augmenting treble. Regards, |
Dear Audie, Is the 12AXT a vacuum tube or a solid state device? (If it has no filament, it MUST be solid state, actually.) If the latter, do you know for a fact that it can be dropped in a 7C to replace the 12AT7s or the 12AX7s? (I forget which tube type is used in the 7C, thought it was 12AT7.) Where and in what context did the "12AXT" blow your mind?
As to modifying a 7C, sure, there are many ways to upgrade it with modern parts that did not exist back then. But I personally would not mess with the tube types originally chosen, unless I wanted to change the sound altogether. Just my $.02 |
Follow-up: A Google search on "12AXT" brings up nada about any such device. I then tried searching on "12AXT tube", then "12AXT transistor", again with no result except a list of references to the "12AX7" vacuum tube that we all know about. Aud, what's up? Thanks. |
Lew, here it is - a solid state replacement: http://amtelectronicsusa.com/productpage12AX7WS.html
Regards, |
Holy cow! That's illegal! Perhaps the reason I could not find it under "12AXT" is the fact that its name is "12AX7-WS". What a clever idea. Has anyone besides Audpulse heard one of these devices? Based on specs, it should not give any more gain than a 12AX7 vacuum tube, but if one were to replace an aging 12AX7 with a WS, then it would subjectively appear to have more gain. And I was wrong; the OEM Marantz 7C does indeed use 12AX7s (not 12AT7s).
From the blurb, it would appear that AMT has also made solid state replacements for other tube types. |
Fleib, thank you for pointing out the AMT website. You are more than Google.All the descriptions on that site about the product is what I heard during the very short period of listening. The guy said that he has two versions of the product, a high gain one and a low gain. This is the reason why I want to try the high gain one on the Marantz 7c. I do not want my excitement to cloud my judgement but to have an extended home listening. Solid state or no solid state does not matter too much to me.I was not able to detect that it is not a tube. |
Lewn, what is illegal about it ? The guy said that he developed it about six years ago but put it away. Finance was his problem to push it further. He did acknowledge the fact that somebody put a patent on a similar thing but the application is different from what he is doing. He went further to say that the patent has expired but that he has the first right to the technology since his was on his site before the patent was granted. Lew the way I see it is that no circuit change is required and it might solve problems for we guys that are in love with tube phonostage. Reduced noise floor. |
Audie, My use of the word "illegal" was meant to be taken as humor. Nothing more than that.
The device described on the website appears to be electrically identical to a 12AX7 tube (except I did not see a rating for "mu", which parameter best describes the gain of a vacuum tube). Does AMT have high and low mu versions of this product? Do you know the mu values for both or either? |
Lewm, I know nothing about the AMT one but my Tech here in Houston has identical one and that is the one I want to try. As for the mu values I do not know. |
C'mon guys: http://www.jetcityamplification.com/#!retrovalves/ctjr
They're marketed for musicians. http://www.amazon.com/s/ref=nb_sb_ss_i_9_9?url=search-alias%3Dmi&field-keywords=jet%20city%20retrovalve&sprefix=jet+city+%2Cmi%2C207
Regards, |
Fleib, Never having heard one of these devices, I share your skepticism. However, Audpulse apparently has heard the 12AX7 version in his or some other person's Marantz 7C, and he's evidently impressed. That's all we've got to go on. Like you, I've got to think that if they were truly revolutionary from an audiophile standpoint, I would be reading about them on TubeDIY and other such threads. Still, never hurts to keep an open mind. |
Lew, I never herd of them either. Apparently AMT uses matched fets and probably the JetCity as well. I didn't see AMT for sale and I have no idea about any qualitative differences.
Seems like they get mixed reviews on musicians sites, mostly positive as far as I can tell. Some of them loved them and one guy said it eliminated howling and ringing and sounded better the rest of the time. You can buy them direct from Jet City and it won't cost much to find out. The ones in the red pack are high gain.
I'd guess that audiofool tube heads would be the last to accept something like this even if it was better. I don't particularly like those little 12_ tubes and have no use for them, but they might be way better and quieter in a phono pre. Seems to work out for Audpulse. Regards, |
Fleib I have not used the tube in any of my component. What aroused my interest is my lowly Marantz 7c. After changing the captive cord on the unit to iec, I also asked the tech to increase the power supply. It played mm better than stock. But with this solid state device I started thinking maybe the output can gain a significant db without increasing the noise level. That is just the audiophile in me rearing it's ugly head though I see myself as a music lover.This is also the reason why I am searching for the thread about somebody here in this universe who recently modified the 7c to a better unit for mm cartridge. Can you please help to steer me in the right direction. The guy with this device is the same person that will do the modification to the 7c and the device will be tried on the unit without incurring any extra cost for the device. The way I see it, I have nothing to loose. Will definitely report back to this thread as to the performance of the device when tried on the 7c. |
AP, If you're using the line stage section try substituting 12au7 on the output. If you need more gain on phono maybe the high gain Jet City substitute will do it? You'd have to try it. I have no idea if it's appropriate. http://www.diyaudio.com/forums/tubes-valves/67922-marantz-7c-still-good-today.html
Discussion about preamp viability: http://www.diyaudio.com/forums/tubes-valves/20465-marantz-preamp.html
http://www.diyaudio.com/forums/tubes-valves/93159-marant-7c-preamp-diyzone-project.html
Too little gain on phono and too much on line. The line stage seems to be the Rodney Dangerfield part - gets no respect. I think the high gain Jet City pieces are your best hope. You could go out the tape outputs and use it as a phono stage?
Finally - modding and RIAA EQ. http://www.diyaudio.com/forums/tubes-valves/120643-variability-riaa-eq-tube-characteristics.html
Regards, |
Audie, There are many many things that could be done to upgrade a 7C. First of all, replace the selenium rectifiers with Schottky diodes, but in doing so, you need to be sure that the voltages don't change much. Then you can upgrade the filter capacitors in the PS. I agree with Fleib that a 12AU7-like tube would be better in the output stage, but you also need to change some resistors to increase the current flow to the output tube; 12AU7s need much more current than 12AX7, in order to sound best. But I would not even use a 12AU7; I would use a 12FQ7. Much better sounding than any 12AU7. (I've made the comparison in the context of a Quicksilver preamp.) Coupling capacitors can all be upgraded to teflon types or whatever you like. Beyond this, I would need to see a schematic. Anyway, you'd need a schematic in order to revise the circuit for a better output tube, |
Dear Raul
What headshell do you recommend for the Audio Technica AT 170ML OCC cartridge? Thanks |
Are you guys still using 100kohm input impedance as suggested by Raul or switching back to the standard 47kohm |
Don´t waste your time with 100K like I did. Suggested by Halcro and Fleib I switched back to lower values, in fact I´m extremely happy with 20K and enjoying sound quality never before experienced. I no longer miss 47K either but it´s a very good value in general. |
My next mod to my Silvaweld phono stage, which I use for MM cartridges, will be to install a rotary switch to allow switching among different load resistances and to add capacitance. At the moment, I am using 100K fixed load in the Silvaweld. I make no claims that there is any magic associated with a 100K load. Years ago, independent of Raul and before I knew he existed, I proved to myself that 100K was superior to 47K for one and only one cartridge, the Grado TLZ. I have never made comparisons with other cartridges.
Harmon, Raul has left the building in search of Elvis. |
The same with the phono capacitance value, the lower the better. I noticed this two decades ago when changed from 250 pF to 120 pF for one of my best MMs. Now I have a handful of vintage top MM/IM carts and they all seriously benefit from very low values, the total is 40 pF I´m currently using. |
One load fits all? HO carts require more attention to loading than MCs. Two of the three variables of electrical resonance, the LCR circuit that interacts with mechanical response, is under your control, or it should be.
As a general rule vary resistance with bright or dull SQ and keep capacitance low initially. Too bright - lower resistance value and visa versa.
If there is a mid treble dip in response making the cart sound distant, you might have to add capacitance. Adding capacitance will lower high frequency resonance and help fill in the dip by augmenting treble. It will also roll off the extreme high end. Judicious application of capacitance while varying resistance will often result in a minimal addition of capacitance.
This was the case for me with the Ortofon M20FL Super. 55K and approx. 250pF did the trick.
I think you might find that optimal load will vary somewhat from preamp to preamp and for different systems. Some carts, especially those designed for 4-ch, might sound smoother than most at 100K. Many carts are unlistenable at 100K with jagged response and wild frequency response variations. Sometimes using 100K and lots of capacitance will mimic a MC rising high end, but that depends on the cart. Regards, |
Why no variable resistance MM/MI phono stages? There is, as we see, a market. Soundsmith makes a variable resistance MC stage. Can he not just take out the gain stage? |
First, I have only 5 MM carts left so my testimony refers these only. I have no idea how, say a Stanton would perform at very low cap & imp values. And I understand that a cart´s performance depends on the preamp characteristics too. My preamp is different to all others I know on this forum, yours is different to somebody´s etc. Maybe mine and say, Raul´s are "extremes". My preamp gives its best at 40 pF / 20K for the 5 carts. These values are fixed, I would like to have a few other low values too, say 70 pF and 40K. All my 5 MM carts perform better now with much lower imp & cap values. The SHURE ULTRA and the AT-ML180/OCC, especially blossom like mature ladies at their forties, namely at 40 pF/ 20K. AT actually recommends 100 pF to start with (if my memory serves me correctly ?), so why wouldn´t a bit lower value be as good ? I must admit that I was surprised that the ULTRA prefers 40 pF as 250 pF is the "optimum". Now its sound is very very "flat". It has always been fabulous but now it´s stellar. All this is just a funny coincidence ? I wouldn´t know and don´t care because now my carts sound better than ever.
"Many carts are unlistenable at 100K with jagged response and wild frequency response variations." Your words. This is actually what I was trying to say. |
Back in the day there were variable resistance MM stage preamps. That TNT article I linked to previously, Load the Magnets, has a picture of the back of a Luxman C12 with a pot for resistance. That article is a good one for understanding how this works.
Loading a low inductance MM is a very different proposition than a high inductance cart. A TK9 or 10ML has inductance of 85mH. Here's Hagerman's electrical resonance calculator. You'll see it just before the first graph. Play with the values and see what happens: http://www.hagtech.com/loading.html
85mH/600pF still has electrical resonance past the audio band. A 6mm boron cantilever will resonate approximately 27KHz. With a cart like this you have to load down resistance to make it less bright.
With high inductance carts - 681 (900mH), it's trickier if there are response anomalies like the mid treble dip of the M97. In that case you have to maintain 250pF to keep the dip from worsening, and because it's a dull cart, increase resistance load. 62K/250pF is said to be optimal for that one. A few words of caution: The rest of the article describes electrical properties only and is of limited value for determining optimal load. The mechanical response is of greater value in determining overall response. Best response is getting one to compliment the other. 1) initially keep capacitance as low as possible. Remember total capacitance is arm wires (internal and external) + preamp.
2) with a higher inductance cart (usually) add capacitance only to fill in treble dip. Otherwise, it's just lowering high frequency resonance and rolling off the top end.
Regards, |
Harold, When you say you use 20pF of capacitance, I have to assume you are ADDING 20pF to the inherent capacitance of the whole circuit from cartridge leads to phono input. Since the inherent capacitance is typically 100pF to 150pF, depending upon cables, etc, you might consider that the capacitative load seen by your five MM cartridges is more like 120pF to 170pF. Could even be higher. I typically add zero capacitance to the existing capacitance in the circuit, but as noted I've been using 100K as a load.
To add to Fleib's info on phono stages with variable input loading, nearly all the Japanese integrated amplifiers and preamplifiers of the 70s and 80s, and even beyond, provided these adjustments. Many of them even had two phono inputs, one fixed and one with adjustable loading. (See especially Pioneer, Sony, Accuphase, Yamaha,etc.) Also, in the last few years, manufacturers have awakened to this need, and there are now several products that allow selection of load resistance. Not too many yet allow for adding capacitance, that I know of. |
Why no variable resistance MM/MI phono stages? There is, as we see, a market. My Halcro DM-10 Preamp has an inbuilt Phonostage with both variable Resistance AND Capacitance......for the MM Section only..😎 The MC Phonostage has fixed Resistance of 220 Ohms..😊 Displaying an understanding and appreciation of the merits of MM cartridges at the turn of the millennium.....was a brave (and almost unique) position for a high-end amplifier designer....👍 If I could have my wish for an ideal phonostage granted today....it would be for a MM (only) active stage (I would use an SUT for LOMCs) with electronically remote-controlled variable Resistance and Capacitance capability...😍 The changes (particularly for Capacitance) can be quite subtle and need to be heard from the listening position IMHO 😊 In terms of both loadings....every MM cartridge has potentially a different 'ideal' combination...😳 Some of my cartridges....like the Fidelity Research FR-6SE and Garrott P77 like the 100K Ohms loading with minimal Capacitance....whilst others like the Signets and ATs, prefer 40K with a bit extra Capacitance...👀 But this of course assumes that all records are cut 'FLAT'.....which is rarely the case...❓ Using Resistance and Capacitance loadings like 'Tone Controls' from record to record (or even track to track)....can be valid and quite satisfying...😎 Now where is that remote-control....❓👀 |
Lewm, I never said using 20 pF. 40 pF with 20K. I have measured many times that the 100 cm long uninterrupted silver wire from cart leads to phono input has 25 pF at maximum (depends on the actual measurement that´s taking place, it usually varies a bit, more or less as you too may have noticed). My Hi-Fi specialist "removed all capacitance" from the pnono input so there should be practically no capacitance left(?). So I would assume that my preamp´s inherent capacitance is very low´s and to be "safe", I would say that the total value seen by a cart is 40 pF at maximum, including the value of the wire from cart leads to phono input. Please note, I´m a not a technician and can´t measure the actual inherent capacitance of my preamp. How can I do it, would you help me ? Interesting hear your thoughts about anyway. |
Harold, Sounds like you got your hands on some VERY low capacitance cable, is all I can say. There is added capacitance at the input of a tube phono stage; capacitance develops between the grid and the plate and between the grid and the cathode of a vacuum tube. Typical tube phono stages use a 12AX7 tube at the input, because of its high gain. "Miller capacitance" is a statement that the total capacitance at the grid is also a function of gain. Thus, the 12AX7 has quite a high Miller capacitance, up around 150pF by one calculation. You can easily look it up. There's also a little capacitance associated with any connectors in the path and the wire inside the tonearm. If you have a solid state phono stage, the ss input device can also add some capacitance in parallel with the signal. Different types of transistors (e.g. JFETs vs bipolar types) are different in this regard. |
Also, in the last few years, manufacturers have awakened to this need, and there are now several products that allow selection of load resistance. Not too many yet allow for adding capacitance, that I know of. Don't be fooled by the advertising blurb Lewm.....👀 While most of those new phonostages being released DO include adjustable Resistance loading.....they are in fact adjustable loadings for the MC input only..😢❗️with the MM input fixed at 47K Ohms...😱 Sacre bleu..😡 HERE is the brand new Phonostage from TW Acustic which includes loadings from 50 to 1000 Ohms for MC input....whilst MM is stuck on 47K Ohms and has adjustable Capacitance loading from INSIDE the unit...😫😱⁉️ Thanks for nothing.... |
Lewn, I tried to call my Hi-Fi specialist and ask about my preamp´s new inherent life but he doesn´t answer his business mobile (probably on holiday). I will try to contact him later... Yes, top MM ATs recommend 100 -200 pF. See what´s this happy owner, Johnnyb53 has to say about low cap values: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1334624405&openflup&3&4#3, http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1334624405&openflup&5&4#5 and http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1334624405&openflup&8&4#8
Top SHUREs love very low cap values too apparently, as I have experienced in my system over the decades. I´m using very low values at the moment, the total under 200 pF whatever capacitance inside the preamp... or even under 100 pF perhaps ? Both SHURE and AT have blossomed out like mature women. |
Hi Henry, I guess I was thinking specifically of the K&K phono stages. They will build it with adjustable MM loading, if the customer requests it. As I understand it, the load R and C can be selected without opening up the top of the unit. The K&K phono stages are superb by all accounts. Also, doesn't the more expensive EAR phono stage provide for cartridge loading? And the Manley Steelhead definitely does. I think also the latest Parasound by John Curl does. Others may chime in here with additional choices. My Atma-sphere MP1 allows the user to install any value capacitor and/or resistor as a cartridge load, via external screw-terminal binding posts. However, the MP1 circuit is built normally for MC cartridges, with lots of gain; there is an option to reduce gain for MM, if so desired.
Yes, I saw that TW Acustic phono stage at a local show. I like its retro look. Too bad it is not actually retro enough to deal with MM cartridge loading. |
I have been reading through this thread for the last few days, a lot of fun! but I have a question for Flieb...
You mentioned a few times having an electrostatic speaker/amp system, "I had mono OTLs direct driving electrostats at 50KV...". I am so curious, I used to work on 2 megawatt RF sources (used to drive a Fusion energy reactor) and the Output tubes only ad 33kv on the anodes. I am curious what speaker system employ 50 kv?
Thanks, Kevin |
The Project Ref phonostage RS has both adjustable impedance and capacitance with many values and easily accessible. Plus you select either RIAA or Decca curves. And has both XLR/RCA inputs and outputs. Anyone listen to it? Any good? |
Looked up the Project Ref Phonostage and it seems that once again the VARIABLE resistance is for MCs (10-1200 Ohms) with the MM stuck on 10 or 47K Ohms....😢 |
Hi 3ox, I think the Acoustat panels can be driven with much lower voltage, but I'm sure the storage caps were banks of 50KV each. Each amp had 4 cap tubes.
This was around 30 yrs ago and I didn't design the amp or know/understand exactly how it was configured. I do remember building banks of storage caps all hooked up in series. Photoflash caps seemed to make a big difference. Apologies if my description is inaccurate. I'm not a tube designer. Regards, |
... and load capacitance 100pF, 200pF, 300pF, 420pF, 520pF :/ Why always starting with 100 pF, why not lower values like 10 pF, 50 pF, 100 pF, 150 pF, 200 pF ?!? |
Has anyone compared the FR66s to the newer Ikeda IT-407 CR1 tonearm? Any thoughts? In previous years, the Ikeda was available with either copper or silver internal wiring but the recent models don't mention anything about the tonearm wiring. Can anyone comment what type of wiring is used in the latest editions? It would seem intuitive that the later Ikeda IT407 should be a better performer than the FR66s having improved material and bearings over the FR66s but the proof is in the hearing. |
Adding capacitance just moves the resonance freq. higher , in case of overload just a bigger "splash ' in the music. If you can balance the arm just play the damn thing, vinyl doesn't need all this overthinking. |
Adding capacitance moves the resonance frequency lower. |
LOL. Schubert, I like your back to basics thoughts. Obviously you are a fan of classic music but your attitude is kinda punkish. I´m a fan of prog rock but Yes actually had kinda punkish attitude too when they came back with vengeance, "Going for the One" in 1ate 1977 and "Tormato" a year later. And they still were the leading group in prog. That´s rock´n´roll. Let´s just play these damn cartridges ! |
Correct Skriefal, in any event not a great idea. |
Dear 3ox (and Fleib), I think your point was well taken. It is not likely that the Acoustat X speaker, to which Fleib refers, could stand 50kV on its stators for more than a few seconds before a spectacular explosion might occur. Typical DC voltages for ESLs range from as low as 1500V to, maybe, 10kV tops. For example, my Sound Lab speakers probably put about 5kV to 7kV on the stators (best guess), whereas my Beveridge speakers operate at 3200V. |
Should have added that it is entirely possible the Acoustat X operates at circa 10kV, but not 50kV for sure. |