"I'm very skeptical of the whole genre of audiophile upgrades in general. I'm especially skeptical when I can't find any technical specifics published in regards to an upgrade or modification.

So when Bill Thalmann of Music Technologies brought up the Krebs upgrade for SP10 motors, as he was restoring a number of SP10 boards for us, I asked him point blank- "Do you really think this is going to make a serious difference?" The upgrade is not inexpensive. I trust Bill and he replied in the affirmative, suggesting that I would find the Krebs modifications worthwhile. Even though we already remove the SP10 motor from the stock chassis and put it in a 200lb plus slate plinth, anchored right to the slate, and thus the part of the modification which involved the motor's mounting in the stock chassis would be absent, I agreed to give the Krebs a try.

When my tech installed the modified motor and we sat down to listen, I was prepared to forestall judgement, as Bill had mentioned that the motor would improve after some break in. We need not have worried about that. The change was just overwhelming. Neither of us could believe it was possible to have anywhere near the kind of improvement the Krebs made possible. The definition, focus and just plain impact of the music was very much worth the cost of the upgrade. We now have every SP10 motor we use in our OMA Tourmaline turntable Krebs modified. I can't even imagine running the deck with the original, unmodified motor."

Jonathan Weiss
Oswalds Mill Audio OMA


Hello Richard and Bill,
Wishing you well and enjoying music.

Just a short note to thank you Bill T. for upgraded 2 PS and one Technics SP-10 MK3 table for me and also Richard for encouraging me to upgraded the Technics SP-10 MK3.

I had one Technics SP-10 MK3 table and one PS running for one week before attending THE SHOW & CES in Las Vegas. The performance of the upgraded Technics SP-10 MK3 table and the PS was very noticeable:
---quiet ... black back ground, less back ground noise
---sharp attack
---excellent details delay
---more ambient details
---more dynamics, top and bottom.

I am very happy with the upgrade Technics SP-10 MK3.

BIG thank you,
Tri Mai
Tri-Planer Tonearms.

I received the MK3 last week and was told it would be at two or possibly three months before the full benefit would be realized. With only "out of the box" play I was not prepared for the upgrade Bill Thalmann achieved with the MK3.

Just to make it clear, I have no involvement in the mod other than loving Bill's work and being a happy customer.

I'm still trying to come up with words to describe the improvements, it is not exactly like anything else I've experienced and it took a couple of days to believe and accept.

I will continue to listen and come up with a clear description
(if possible).

Also, Bill and his counterpoint Richard Krebs in New Zealand are working on a similar mod to be performed on the Technics MK2......

The improvements are supposed to be more of the same as I've already experienced. I've had some time to think about this and I guess what I expected was better signal to noise, more black or whatever term you wish to use to describe quietness.

It is a bit quieter but by far the astonishing thing is resolution, big resolution changes and amazing lowering of distortion. It was already the lowest distortion transport I've ever owned and now it's moved another step.

What I keep thinking as a way to describe may not make sense, but I'm going to say it because what I'm hearing I've never experienced before.

Imagine music as very large peaks of sound with valleys on either side. The peaks always satisfied you and dynamics and low level details were as good as you ever experienced.

Then the modified table comes back and you now realize the valleys were full of sand or dust. Now they are sparkling clean and there is another entire level of information down there that has never been before. Going from LP to LP in my library I find information, contrast and space within the music that was never revealed before.

Also the extreme high frequencies are absolutely 3D. They hang in space with their own dynamic and sense of space while maintaining the same perfect speed and timing that was previously there.

Sorry if I come off too flowery, I'm excited because a change at the source is huge for the entire system and this was a huge source improvement. I was not expecting one fourth of what I got.

Albert Porter. Porterhouse Audio.

Hello Richard,
Thought that I would take a moment and provide you with an update on our progress.  We got the modified MK3 back from Bill.  Once installed in a base we gave it a listen. 

The transient attack did return and was much better than the unmodified table.  The sound of the modified table was much smoother top to bottom and the definition was much better.  The bass went noticeably deeper and was much better defined.

Joseph Sammut. Pass Labs.

I received my Technics SP 10 MK3 back from Bill Thalmann last week, after having the Richard Krebs modifications performed. Bill Thalmann had already done his complete electronic overhaul of the turntable and power supply last year, before I bought this turntable from Albert Porter. I really wasn't expecting too much from the modifications, since the turntable was already excellent.

I made several recordings before I sent the Technics away for the modifications, both in analog and digital (reel to reel at 30ips and digital at 24/96) because I thought the differences would be difficult, if not impossible to hear. I really worried that the resolution of either medium (tape or digital) wasn't good enough to reveal the differences.

My Technics is set up with the original obsidian base and feet, Graham Phantom Supreme arm (10"), Benz LPS cartridge, Graham IC-70 balanced cable, and Boulder 2008 phono stage. I play around with mats, but currently using Herbie's Way Excellent Turntable Mat.

In sum, the Technics after modifications is a game changer. I didn't need to hear my pre-modification recordings because the improvements are so dramatic. To begin with, the noise floor is lower and now matches my vacuum hold-down belt drive. And while I thought the noise floor was already low enough, the modifications allow me to hear details deeply, most notably the mechanical action of keys on piano recordings and long, long decays.

Musical lines are easy to hear and follow, even in complex classical works. I believe a low noise floor enhances three-dimensionality and sound stage because you can hear ambient cues so much better - and there are ambient cues in abundance. One of the most dramatic changes is the rich detail in very quiet passages contrasted with thunderous loud passages. This turntable plays music quietly and loudly at a new level of realism for me.

My desire for absolute speed stability, a pet peeve of mine, drove me to check out the direct drive turntables in the first place. My reference belt drive always gave me a vague uneasiness about speed stability - not necessarily wow and flutter - but longer term slowdowns during complex, highly modulated grooves. Maybe a little "rubber band" effect of the belt, that is a continual contracting and expanding of the belt. The Sutherland TimeLine indeed confirmed that my belt drive turntable was challenged in the area of speed stability.

The Technics' speed stability was already amazing and easily trounced my reference belt drive in this respect - both sonically and visually with the Sutherland TimeLine. After modification, speed stability is even better - much, much better and has to be heard to be believed. I hear this on every single record I've played. It's hard to describe this with words. It sounds more like master tapes.

The music sounds relaxed when it should and pounds you when it should. I believe the hallmark of great audio equipment is to let music sound relaxed when it should be relaxed - with a natural ebb and flow of notes that you easily hear with live unamplified music and not so often on reproduced music. Maybe I am wrong, but I think speed stability contributes to this "relaxed" sound.

A harpsichord recording that used to sound a bit "hashey" now sounds natural, rich and pristine. In fact, this very record made me question the speed stability of direct drive before modification, giving some credence to direct drive critics who claim that the bane of direct drive is the constant "hunting" for the correct speed.

I absolutely no longer have this concern about the Technics. In fact, Richard Krebs says his modifications make the job of the servo control much easier, and much less necessary. Maybe this is what I am hearing. Anyway, every record I've played since modification advertises speed stability in the extreme.

There are improvements throughout the frequency range. Bass is thunderous, relentless and with excellent pitch definition. Midrange remains excellent and is maybe the least improved, but still benefits from the lower noise floor and speed stability. Highs are much improved - musical lines presented by instruments in the higher frequencies are easier to follow and more "there".

Thanks to Albert Porter for selling me this turntable in the first place and hosting his Tuesday evening music group where I met Richard Krebs, and thanks to Bill Thalmann for his excellent work. By way of disclaimer, I have no financial ties to any of these men.

Ken McCarty.

(back to top)

SOME DISCUSSION TOPICS
Why do we listen to music?

For us, it is to connect with the musicians. To feel.
In our view, music is designed to elicit an emotional reaction. This is it's reason for being. The upgrade brings this connection closer and deeper.

Some examples, not necessarily great recordings but great emotional content.

What does live music sound like?
To us it has all of the qualities of connection listed here, but if you want to dissect it into its constituent notes, to us it goes like this. Obviously the note has a beginning which should rise at a rate dictated by the instrument. Likewise it should decay in an appropriate manner. What is difficult to achieve with any realism is the center of the note. This is where the note has mass. This is where the emotion lives. One should be able to close ones eyes and imagine walking up to the note frozen in time. You should be able to hold it and it would have weight and a texture. Even a live struck  triangle has this mass feature, but it is very hard to replicate with a stereo. Our upgrade goes a long way to doing this.

The DD, BD debate.
There is an ongoing debate between audiophiles in the Belt drive camp and those in the  Direct drive camp.

The BD  people say that they can hear a DD motor cogging and can hear the servo correction constantly adjusting the platters speed. The DD people say that they can hear speed errors due to belt stretch, or slip and no matter how heavy the platter is, it does not have enough inertia to drive thru heavily modulated passages.

Lets look at these assertions.
Stylus drag and servos.
Some years ago we owned a highly respected expensive DD turntable which had a JVC motor. Platter weight was around 2.5 kg with the mass concentrated on its circumference, so it's moment of inertia was high. This, not the platters weight, is what really counts.

In an effort to improve this TT, we built a heavy duty power supply. Listening tests definitely showed a positive change and out of curiosity we placed an oscilloscope on the power supply's output. To our amazement we saw a distorted picture of the music that was playing at the time. Even high frequencies in the music were present in the power supplies output.
This meant two things.

1) The power supply was not nearly stiff enough
2) The platters speed was being modulated by the music due to stylus drag and the servo was attempting to correct these errors, drawing current from the power supply in the process. The platters inertia was not enough even at high frequencies, so speed correction became necessary. The servo was acting to correct these errors.

Speed variations due to stylus drag are real and significant. This conclusion lead us to search for a DD motor system that had a high inertia platter and a very high torque motor to ameliorate this problem. The SP10 range was the logical choice. There are other brands that also meet there criteria. These motors and their associated controllers have absolute dominance over the high inertia platter, so they have a better chance of taking care of stylus drag issues.

But another problem became evident. There was a pervasive grayness and tension to the sound which never quite went away. Increased resolution of our system only served to highlight this problem. Fifteen years of hunting down the cause has in our view been successful. While we cannot objectively measure this, we believe that the platter does in fact frequently change in speed, we call it jitter, due to speed measuring errors. While jitter is normally associated with digital recording and playback, we are confident that you will agree it is appropriate, once you hear the effect of its removal. The theory is that these errors are not induced by stylus drag but by errors in the motors own speed measurement, which the upgrade addresses. The irony is that the BD people were right all along. The beautiful irony is that there is a fix.

With the motors load burden greatly reduced because it is no longer correcting errors that do not exist, you will now hear increased drive capability. There is more in reserve to push thru musical peaks. This drive virtue is one of the features that drew us to DD technology in the first place. Imagine this being significantly enhanced. Listen to how an orchestra swells in volume for a clear example of this, or how it drives the beat forward in modern music. The music also takes on a stillness that mimics the live event, it becomes grounded.

We should step aside to explain what our goal is when evaluating an upgrade step. We strive for accuracy and musicality.  The problem here is that accuracy is close to being unknowable. Very few of us were there at the recording. We did not hear the mic feed. We do not know the sound characteristics of the lathe or the cutting head. So how can we know what is actually  scribed in the grooves? Even if we are fortunate enough to have a copy of the master tape, we do not know how the tape formulation has changed the sound or for that matter how the reel to reel changes the sound or what the mastering engineer did when transferring to the cutting lathe. The answer here is that we don't know what is there in the grooves.

But what we can listen for is a difference between LP"s. The greater the difference we hear between a range of LP's the higher the intrinsic accuracy of our system and by definition our turntable. This because the system is imposing less  of its own characteristic on the final result. Greater inter LP difference equals greater accuracy. On the topic of musicality, we believe that the modifications dramatically improves speed accuracy, mimicking the relaxed ebb and flow of live music without the nervousness of direct drive jitter.  Timbral accuracy is improved.  Slam and drive is improved.  Again, all of these things mirror live music. So we also know that there is an absolute improvement resulting from the upgrade because the reproduced music sounds more like real music.

We can't know whether the upgrade has resulted in a more faithful reproduction of the original master tapes, but we have to assume it does, since the end result is more like live music and the differences between LP's is greater. Musical beauty exists, if by virtue of good luck or more likely, extremely skillful recording and cutting, the engineer captured a close facsimile of the musical event. This is when we connect.