Unsprung TD125 - Sound quality?

[Runningwolf]

Where can the rubber grommets cb-909 be ordered today?
Thanks, I would like to experiment with my 125.

[flavio81]

These are:



I guess you could go to a hardware store and find something suitably similar for cheap.

Seems a great modification to try. I'd guess rumble will be increased a little -- but still falling within pretty acceptable levels-- and sonics might be improved.

[copland35]

The rubber suspension system works really well. The advantages are in the stability of the subchassis. The sprung subchassis has a tendency to torque shift when the motor starts or when the speed is changed. This is something it does whenever there is a change in torque albeit at a visibly imperceptible level. In effect the subchassis is continually being rotated by the motor. The belt, Clutch and the elasticity of the belt provide restoring forces that add up to create oscillations. I found that the rubber suspension effectively removes this movement. It is well damped and gives a broad band decoupling of the chassis from vibration. Effectively nearly all of the energy from the motor gets to the platter. I found there was an increase in purity of the sound through improved pace rhythm attack and timing. Better dynamic expression is apparent especially in complex recordings. The record player is improved in many ways using the rubber suspension. I got my suspension rubbers from Stereo Lab. They are really helpful.
http://www.stereo-lab.de

[flavio81]

I am now using the TD125 with rubber suspensions. I'm just using 3 rubber shoes that are sold for fitting under a chair's tubular legs. They fit perfectly.

The rumble is now audible (if i turn the volume reasonably loud and listen with headphones). It is still not too intrusive but the spring-suspended 125 has no rumble.

The top plate is now less resonating, as i expected, but i'm not too satisfied. I think i should try damping the underside of the top plate if i want to control resonances. Then i can just suspend it with springs as usual.

[copland35]

The suspension rubbers are made of a soft compound and are hollow. They are in fact both compliant and damped. They behave like the plenum suspension units used on trains. They have better performance in the context of turntable suspension than a solid piece of rubber which would tend to have a defined compliance and a more defined resonant frequency peak. The solid rubber will tend to couple the subchassis to the chassis over a broad range of frequencies. The immediate effect will be feedback. If you wanted to use the rubber you would probably need to increase the mass of the subchassis significantly to lower the resonant frequency. The real suspension rubbers are very inexpensive and designed to work in the context of the TD125. I am certain you would experience a superior playback to both the rubber you used and the normal coil sprung suspension. My TD125 is outstanding on the rubber suspension bushes. It has fantastic dynamic range and solidity. It has wonderful imaging. It has tremendous speed stability. It is easy to see why EMT were able to use the TD125 to develop their EMT928 just because the quality of transcription on rubber suspension is plainly excellent.

[Obscurist]

The suspension rubbers are made of a soft compound and are hollow. They are in fact both compliant and damped. They behave like the plenum suspension units used on trains. They have better performance in the context of turntable suspension than a solid piece of rubber which would tend to have a defined compliance and a more defined resonant frequency peak. The solid rubber will tend to couple the subchassis to the chassis over a broad range of frequencies. The immediate effect will be feedback. If you wanted to use the rubber you would probably need to increase the mass of the subchassis significantly to lower the resonant frequency. The real suspension rubbers are very inexpensive and designed to work in the context of the TD125. I am certain you would experience a superior playback to both the rubber you used and the normal coil sprung suspension. My TD125 is outstanding on the rubber suspension bushes. It has fantastic dynamic range and solidity. It has wonderful imaging. It has tremendous speed stability. It is easy to see why EMT were able to use the TD125 to develop their EMT928 just because the quality of transcription on rubber suspension is plainly excellent.

Very interesting stuff to read, I was going to post a new thread about this, but no need for that I guess.

I was considering to put rubber mushrooms in my TD 125, and I asked for advice from a Swiss company called Schopper (who sell an improved version of the mushrooms at a reasonable price, go to http://www.schopper.ch and look under TD124/Spare Parts).

The owner Mr. Joerg Schopper told me that, in his experience, replacing the springs with mushrooms will only work exceptionally well with a tone-arm that has a counterweight that is isolated from the arm stub with a rubber decoupling. Like the original TP-25 (now unobtainable), SME 3009 (too limited choice of cartridges) or Ortofon arms (too expensive for me). Otherwise, he tells me, you'll hear rumble because the motor of the Mk1 TD 125 is not properly isolated from the diecast chassis. I want to ask him if the Jelco SA-750 will be suitable as well, because I seem to remember it has a decoupled counterweight as well.

Furthermore, he said that when you're listening mostly to classical music, and want to put another (non-decoupled) arm on the player, you should leave the spring suspension right where it is...

Well, I have a very broad and eclectic taste in music, ánd I have been looking at the 10-inch Jelco SA-750e a lot lately. That arm is definitely on my shortlist, so if I decide to go for it, I think I'll give the 'shrooms' a try as well. After all, it's a rather cheap and completely reversible experiment. On the other hand, if I decide to buy a Clearaudio Satisfy Carbon, I would have to leave the spring suspension alone...

It may be a while before I get to it, but I'll tey to keep y'all posted on my findings...

[GurraG]

This is very interesting. I am working on a td 125 LB project with the 12" version of the Jelco. I am very curious if rubber suspension would improve the sound. I just bought black Linn springs, and I haven´t yet tried the TT, but this weekend it will be up and running. In due time I´ll make a new (or completely refurbish the present) plinth. At that point in time I may change the suspension as well, since this sounds really interesting.

/Gurra

[sjam]

The top plate is now less resonating, as i expected, but i'm not too satisfied. I think i should try damping the underside of the top plate if i want to control resonances. Then i can just suspend it with springs as usual.

Hi Flavio,
I wondered how your final decision was on the suspension of your TD125. Did you go back to springs?
Regards Sam.

[Obscurist]

Hm...getting rid of the feedback with a heavy plinth is easy. You either buy one or build one. Rumble may be a bit more of a problem. Is there no way to isolate the motor from the subchassis? Did anyone ever try that?

Today I spoke to a guy who uses the most viscous variety of white Damping Grease from Nye Lubricants to remarkable rumble eliminating effect in a Perpetuum Ebner 2020i bearing well. You can order a sample of different kinds of that product from their website. Just search for Damping Grease Sample.

@Gurra: I'm very curious to hear what you think of the 12" Jelco, since it is only the slightest bit more expensive than the 10" one I've been looking at. I haven't started building a new plinth for my TD125 yet, so there's still a possibility of building an LB version. Did you make a new plinth as well? If so, are you willing to share info on (inner) dimensions and construction? And how did you solve the resonance problem of the wider armboard?

[PaulMB]

With both a TD126 and now a TD125 the "floating" of the deck disturbs me. So I've tried to quick and inexpensive mods.

A) On the 126 I found a rubber car radiator hose that jams into the plastic cups, leaving space for the springs inside. I cut lengths so that the hose is just a few MM higher than the edge of the cup. The result is that the vertical "bounce" is very much reduced, while the horizontal "floating" is practically eliminated.
B) Even simpler, on the 125 I've taken a few bits of 10mm thick neoprene and jammed them tightly between the edge of the suspended deck and the plinth. There is thus practically no movement at all.

How does it sound? Seems to sound exactly the same as before. But I don't have "golden ears", assuming anyone does.

[GurraG]

@Gurra: I'm very curious to hear what you think of the 12" Jelco, since it is only the slightest bit more expensive than the 10" one I've been looking at. I haven't started building a new plinth for my TD125 yet, so there's still a possibility of building an LB version. Did you make a new plinth as well? If so, are you willing to share info on (inner) dimensions and construction? And how did you solve the resonance problem of the wider armboard?

I just got things up and running yesterday evening, so I haven´t listened very much, but i can tell you that there is a significant improvement over my td150 with Audio Technicha 1100 tonearm. I bought my 125 lb without a tonearm, so I can´t compare the Jelco to another arm on the same deck. I strongly recommend the arm, it is a joy to handle!

I got the original plinth, with no other modification than a 1" thick solid wood bottom plate instead of the original flimsy thing. I will refurbish or maybe build a new plinth in due time, we´ll see what I´ll do. I got no drawings though, sorry. I would also love to have them.

I haven´t taken care of the resonance issue yet, but my plan is to add adhesive damping material along the underside edges of the armboard, ca 15 mm wide strips to save weight.

This is not the right place to discuss my project however, this is for springs vs. rubber. If there is more to say about my discspinner I suggest we´ll do it here:

My TD 125 LB project

[flavio81]

The top plate is now less resonating, as i expected, but i'm not too satisfied. I think i should try damping the underside of the top plate if i want to control resonances. Then i can just suspend it with springs as usual.

Hi Flavio,
I wondered how your final decision was on the suspension of your TD125. Did you go back to springs?
Regards Sam.

Sam,

I haven't modified the TD125 further because it was sounding so much better with the rubber thingies. But the next step is to fill down the top plate's underside with plasticine and then try the springs again. If the top plate is still resonating then i'll remove the springs and use the audioquest sorbothane feet, 3 of them.

[GurraG]

I just ordered a set of rubber grommets from Stereo-Lab. Looking forward to trying them!

[GurraG]

If you got a TD125 - Get these rubbers!
The music slowed down, let loads of more "air" into the sound.
The bass ha a lot more contour to it.

These are my first impressions after about two hours of listening. I have had no issues at all with rumble.

I´ve got a LB with a Jelco 750D 12" arm mounted.

/Gurra