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Revisiting the Ryan Sound Lab ‘MusicPower’ Plug-Ins....

YNWOAN

YNWOAN

100% Analogue
As some may know, I was a very early adopter (time does fly - this was some eight years ago) of the replacement boards that Kit Ryan, of Ryan Sound Lab (RSL), makes for a number of the older Naim pre-amps; and since then I have been very happy with them - until now!

A few weeks ago I read that Kit had a new loaner set about to tour the U.K. (so potential buyers could try them out). He asked me if I would like to try them and compare the current version of his boards with my older ones. Not really sure what to expect I agreed and a couple of weeks later they arrived at my door. As ever with RSL the boards are beautifully packaged and come with full instructions (including pictures).

The first thing I noticed was how different the newer boards looked. I mean they were still recognisable as being RSL boards but Kit has clearly done a lot of adjustment to relaying the circuit and there are numerous component changes. Here are some pictures:

Below are the RSL replacements for the Naim 323 boards with my older one on the left and the current version on the right. Note that these boards aren’t even called the same thing! Also, the new boards have a jumper on them that allows you to reduce the gain in two steps (I left them at the standard 12x). It’s also interesting to see a tantalum capacitor appearing in the circuit! *



And these are the RSL version of the Naim 729. The new board is at the top and my older one is at the bottom:



These boards are extremely easy to swop over as, once the amps have been turned off, you just pull out the old and plug in the new. And so I sat down to hear, what I expected to be, subtle difference in presentation. Unfortunately, for my wallet, I was wrong and rather than struggling to dissect minutia in the sound the difference was immediately obvious! Before I get to the changes let’s look at what hasn’t changed. What hasn’t changed is the the basic tonality of the sound, the bass isn’t more pronounced, or go lower and the same goes for the upper frequencies. What has changed is the sound has a touch more body, acoustic guitar has a more ‘woody’ quality. There is also more differentiation between tonally similar sounds which makes interplay between instruments easier to follow. The biggest difference is one that’s difficult to describe though. It’s about structure, about how rhythms ebb and flow. Perhaps it’s about the new boards allowing the note shape to develop more completely, but the subjective effect is to make music develop in a more organic and effortless, less ‘hi-fi’, manner. Anyway, once heard, the improvement is difficult to ignore and also difficult to live without (for me anyway). As a result I will shortly be the owner of two sets of RSL ‘MusicPower’ board sets!

If anyone needs background and details about these products (or is wondering what the hell I’m on about) the RSL website is here:

https://ryansoundlab.com/index.php?main_page=index&cPath=1

* I say that it’s interesting to see the tantalum bead capacitor because Naim pre-amps have traditionally made extensive use of these capacitors and they are said to be responsible for much of the ‘Naim Sound’ - both good and bad!
 
Included with the ‘loaner set’ are also the MM and MC boards that RSL do. I don’t use a MM cartridge but I’m going to try the MC boards. I’ve got some very late generation 323/5 K boards to compare them to, and also my resident Paradise phono stage.
 
Ynwoan, interesting indeed. I have v5.6 boards, but without the tantalum fitted at c8!
I have been very satisfied with them. As you say, their ability to reproduce subtle tonal differences is uncanny.
I am now wondering what difference the extra capacitor makes, I need to contact Kit.
 
Brennus - your boards do have the tantalum in the same place but it is the "surface mount" version (they don't stick up like these), so these boards are identical as far as the circuitry. I was initially debating whether there was a sonic difference in the tantalum caps between surface mount and through-hole, so left myself the option of going either way with the v5.6 PCBs. I subsequently decided there was no difference so now go with all surface mount on v5.6a. They take less time to install, are a bit more rugged, and sound just as good.

I'll be adding a description of the evolution of these boards over the past 8 years or so a little later today, hopefully.
 
Regarding evolution since the original Z200 v2.2 boards, I'll make this as brief as I can and focus mostly on those amp boards. (abbreviations: PP=polypropylene; Mylar is polyethylene; PS=polystyrene):

1. 2013: Original RSL boards used film caps: PP cap for input, Mylar cap for output which needed a large 10uf size. I eliminated the aluminum electrolytics in the power supply and the feedback circuit that Naim had. I felt they just had a deadening effect on the sound. The input circuit had to use an FET discrete transistor in a unique arrangement to work properly with a PP cap. Because FETs have notoriously inconsistent bias points, the circuit required me to measure and select a resistor for proper bias after the board was finished - a real pain. I used PS caps for input and stability since Naim had been using them. The LT3082 regulator used ceramic, low ESR caps on the bypass and output pins. It was a big SQ step forward compared to the original Naim boards.

2. 2014: Very soon after release, I had a customer wanting lower gain because his Tannoy speakers were so efficient he couldn't use much of his volume control range. Thus, the fixed gain early board transitioned to the adjustable gain version v2.3. Rest of the circuit didn't change.

3. 2015: All the RSL boards were then changed to use thin film resistors instead of the original thick film types. The thin film types have lower noise, lower distortion, and lower temperature drift. Only problem was that they were originally very expensive. Well, about the time I was looking, someone figured out how to make much lower cost thin film resistors and I converted all my boards over. This is when all the boards got a "5" inserted in their numbers, so Z200 became Z250v5.2a (for some reason, I never changed the Z301 to Z351 but it uses thin film caps too). Small improvements in SQ.
Also note: along the way I tried those "foil" resistors. Ridiculously expensive (about $12 each over here). My impression of them was that they were rather "soft" and actually detracted from the dynamics so I decided against using them.

4. 2017: PS caps almost disappeared overnight from suppliers (they came partially back about 2 years later but that was too late for me). I quickly redid the boards to use Wima PP caps for stability and tone shaping on the Z301 time-aligned buffers. They were also easier to mount and sounded just as good to me. Also, I decided the ceramic cap on the output of the LT3082 regulator was rather harsh sounding, so changed it to a tantalum. This was the awakening of the tantalum interest in my boards after years of discounting their goodness. v5.2c Live and learn.

5. 2018: I was looking to solve a couple of problems, including that nuisance resistor selection and the large number of discrete components that the boards required (and my eyes weren't getting any better over time!) so I tried using an FET input op amp for the circuit. The TI 1641 turned out to be a real find. Designed by the Burr-Brown team who always made the best analog circuits, I converted the output amp to use this and found a significant improvement in control and clarity. My assessment is that the limited gain of the discrete circuit just can't compete with the huge gain and very low output impedance of the op amp. v5.3.

6. 2019: v5.5 I found I could further simplify the circuit by removing a current source that did nothing for the sound. I believe the TI op amp circuit does not suffer from crossover distortion at its output like most other op amps so didn't benefit from the current source.

7. 2019: v5.6 (current version). I came full circle on using tantalums for the output cap. It has a warmth that the PE film cap lacked while losing none of the dynamics. On paper it's not as low distortion but my ears preferred it. Hats off to Naim for starting the trend decades ago. The v5.6a is the same circuit without an option for through-hole vs SMD tantalum capacitors. I generally add a letter to the version number if it's something for production but not a real circuit change.

All the other RSL boards have been switched over to use the TI op amp over time, including the very latest MM and MC boards which just came out January 2021. The SQ is really much better to my ears.

To answer the question of regulators on the Z301 boards, the older boards have all the regulators on the back of the board. It was quite a challenge to have SMD devices on both sides of the boards, but I figured out how to do it. The newest boards don't need to do that, however, so I've been saved from that hassle. As you can sense, improving production methods is as much a driver in updating the circuits as the SQ!
 
Just been checking my boards. I have Z301 v2.3 and Z250 v5.2a and Z150 MC v5.0. Not sure these boards are old enough to warrant a switch to the new ones. Might try the Z500 though.
RSL boards are a major upgrade in my view, I heard a 252/SC and whilst I thought it was just about better than the 32.5/RSL/HC it was not enough to want to pay for it. The RSL boards are that good.
The one thing I would to try is upgrades for the tape output boards. I use these for my headphone amp and I think that maybe they are not pulling their weight.
 
tonyx - just checked the versions you mentioned and suggest that the Z250 and Z150 boards could use the replacement if you're going for the best sound. The latest Z150 just came out and it is easy to hear the improvement. The Z301 boards are probably OK because the unity gain stages seem less sensitive to circuit improvements in my listening.

For the tape out buffers, you can also install the Z301 buffers instead of the 324 buffers, which should help a bit. As just noted, these are not as dramatic a difference as the high gain stages such as the output amps and phono boards. You can find out without buying anything new by simply swapping the Z301 you already have in place of the tape out 324 buffers (since you'll be listening only to the headphones for that test you can forgo the main outputs). Leave the cover off and just power down, swap only those buffers and power back up. See what you think.

Sorry, but I didn't mean to start customers on a typical, endless Naim upgrade path! it's just that over time I had new ideas and kept tweaking the circuits. As you know, the boards you have are already a big step up from the Naim originals so don't feel like you have to rush out and do something right away.
 
RyanSoundLab said:
tonyx - just checked the versions you mentioned and suggest that the Z250 and Z150 boards could use the replacement if you're going for the best sound. The latest Z150 just came out and it is easy to hear the improvement. The Z301 boards are probably OK because the unity gain stages seem less sensitive to circuit improvements in my listening.

For the tape out buffers, you can also install the Z301 buffers instead of the 324 buffers, which should help a bit. As just noted, these are not as dramatic a difference as the high gain stages such as the output amps and phono boards. You can find out without buying anything new by simply swapping the Z301 you already have in place of the tape out 324 buffers (since you'll be listening only to the headphones for that test you can forgo the main outputs). Leave the cover off and just power down, swap only those buffers and power back up. See what you think.

Sorry, but I didn't mean to start customers on a typical, endless Naim upgrade path! it's just that over time I had new ideas and kept tweaking the circuits. As you know, the boards you have are already a big step up from the Naim originals so don't feel like you have to rush out and do something right away.
Click to expand...
Great, thanks Kit. I will give that a try

Tony
 
The loaner set I was loaned (now sent in to the next person) also included the most recent Moving Coil boards and I have also had a chance to listen to them and also compare them to some Naim 323/5 K cards.

Compared to the standard Naim boards (in this case I used very late production 323/5 K ones) the RSL are a significant improvement in every way. In comparison the Naim boards actually sound a bit anaemic and bland. In addition, the RSL have much better tonal shading and focus and are really quite significantly better in every respect. They also have a very nice flowing quality where rhythms are very easy to follow and the music hangs together in an easy and natural way. Combined with their loading flexibility I would say they are an absolute must have for anyone looking to minimise their box count. In fact they could well be the best solution even if one is considering an external phonostage below a few thousand pounds. Overall they are closer to my Paradise than they are to the Naim originals! When all this is combined with their, easily adjustable, loading options I would say these are a ‘must have’ for anyone using, or considering, MC boards fo their Naim pre-amp.



 
Interesting that R29 has been reduced to 49k9, did you notice any bass rolloff? Naim fit anything from 62k to 100k here depending on how they're feeling!
 
Good questions about R29. I did a lot of modeling (LTSpice) and noted how the value of R29 was also influenced by R31. The original Naim K boards I have used 220 ohms vs 240 ohms for R31 and 62k vs 49.9k for R29. The rest of the circuit also makes a difference since the low frequency gain is affected by the actual open loop gain of the amp. Using an op amp in place of the previous simple discrete transistor circuit also brings more accurate low bass response and that influences R29, too, reducing the need to overcompensate at the very lowest frequencies by increasing R29. I measure every board on my Audio Precision system and they are all well within +/- 0.5db from 30 to 20kHz. Below 30Hz, the level falls off about another 1db at 20Hz. This can't be helped with the European RIAA standard, which has a bit of built-in rumble filtering way down there. (The US RIAA version would have it flat all the way down to zero Hz, but I don't build them like that even over here.) I use only 1% resistors, so the whole variation from flat frequency response is due to the 5% capacitor tolerance on the two RIAA caps. Since I measure and listen to all the boards, I can guarantee that performance.
 
@RyanSoundLab I'm slightly confused by the custom set, because the picture shows 4 x boards. For a NAC 12, for instance, do you have to purchase the custom set + the phono boards?
  • 2 x Z250V Line Out Amp boards
  • 2 x Z301 Time-Aligned Buffers
In addition:
  • 2 x Z 150 MC phono boards
Or does the custom set include all of the above?

Also, my NAC 12 has knife edge connectors; would you be able to include male pins to replace those on the mother board?
 
tonyx said:
Great, thanks Kit. I will give that a try

Tony
Click to expand...

So, I have finally got round to this test. As suggested I switched the Z301 boards for the 324/4 which to use the better cards for the tape out. This was useful improvement in sound into the headphone amp, bass was tightened up a bit but most importantly the vocals became clearer and just better. It sounded right. (My headphone amp is a Topping L30 driving DT1770s).
Changing the boards over is quite a pain so it make me think I need another set of Z301. However there is a problem. When the larger Z301 were in place in the tape out slots the were very tight with the Z150MC phone cards, to the extent that the Z301s were pushed forward more than comfortable. This is largely because of the cable linking the main Z301 with the daughter board. The Z301s were difficult to fit in place because of the tightness of the fit, I thought I wasn't going to manage it at first, but I just about made it and did the test. Then I realised if I switched the Z150s with the straight through boards in phono 2 there would be enough space. So I did that and encountered feedback with the boards on phono 2 that I could not get rid of (from the phono source only). Switched the cards back (so Z150s now back on phono 1) and the feedback disappeared. Anyone know what was going on?

Tony
 
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