Ryan Sound Lab (RSL) Preamp Boards for Classic Naim Preamps

[Naim NAC 32.5 equipped with RSL boards]

Updated Preamp Boards Bring New Life for Old Preamps

[Italian version here]

Product name: RSL preamp boards for classic Naim preamps 32, 32.5, 42, 62, 72
Manufacturer: Ryan Sound Lab - U.S.A.
Cost: € around 200.00 USD for a pair of replacement boards
Reviewer: Hartmut Quaschik - TNT Germany
Reviewed: March, 2015


Kit Ryan from Ryan Sound Labs asked TNT-Audio for a review of his replacement boards for Naim NAC32/32.5/42/62/72. Since I am a die-hard Naim aficionado, I took the chance. Kit is a retired naval engineer and long time Linn-Naim user. He began doing his own preamp boards in the 80ies Ė like me, but different from me, he succeeded in building something better, and recently started his own business. You can buy these replacement boards directly from his homepage.

My Naim History

My Naim experience began in 1984. Listening to Naim for the first time was a shock for me. Some might say that I was brainwashed in that Orwell year. Indeed, and it was a positive shock. A dealer setup of Naim NAC32.5, Snaps, NAP110, Linn Kan, Linn LP12, Ittok, Asak delivered an incredible amount of music. It was like deep diving into a flow of rhythm and tunes, while voices had magic and power, and power had control. Of course I bought a copy of that setup.

At the end of the Eighties, I sold my Naim setup, and subscribed to do-it-yourself. I even tried to modify Naim circuits, but with mixed results rather. In many cases, the sound was just different and at the same time some of Naim qualities got lost. In my book, Naim lost that magic in the 90ies. I never made friends with the olive Naim gear, be it 72, 82, Hicap, 140, 180, NAT02, CD2 - all of which I had as loaners from a friendly Naim dealer - because to me those all sounded closed-in and unnatural. I had to wait for the new millennium to see the old quality coming back, but the Reference series is for the very rich only.

Ten years ago, when vintage Naim was cheap on the British second-hand market, I bought old NAC32.5, NAP140/1, and Snaps units, and only did some slight modifications: I modified the Snaps into so-called Snaps2, which means to play in Hicap mode: both regulators feed the preamp, while in the original Snaps the second regulator is reserved for the active crossover NAXO. The power amp was changed to be able to drive all sorts of speaker cables (sort of feed-forward-compensation), and the line output of the preamp was changed in a similar way to be stable under all conditions. Snaps2 makes the sound more open compared to Snaps, whereas a Hicap makes the sound faster. The other changes did not have any effects on the sound. Loudspeakers are Linn Kan clones with original Linn Kan mid-woofers and latest generation Hiquphone tweeters.
My turntable currently is a Technics SL-1200 with Fidelity Research MC-44 low-output moving coil cartridge. Other components are a Samsung DVD player which also can play CDs, a vuplus satellite receiver for radio broadcast, and a Toshiba laptop. As you might have guessed, this all stands nearby the TV in my living room. This setup represents my secondary audio system, and fulfills the tasks of the kitchen radio, since my first floor is actually a big one-room, with open kitchen via dining room to living room.

In my main audio system you would find a big Micro-Seiki turntable, which can handle up to four tonearms, Schroeder and Fidelity Research tonearms, Zyx and Koetsu cartridges, an Oppo BDP 83-SE Nuforce blue-ray and CD player, and very many DIY amps and speakers.

Arrival of RSL loaners

RSL first sent me a parcel containing used and already broken-in boards. These are available as "loaners" for short period evaluation only.

When I got these used and broken-in boards, I began replacing the boards inside my NAC32.5: first phono MC, then line outputs, and at last the line buffers.

With so many boards in the parcel, one could be afraid of making errors, like mistaking the boards. But with Naim, you cannot put a board in the wrong position. Each Naim module has its own distinctive set of spaced connectors at the underside, so a line output module cannot be placed into the slot of an input module.

RSL also delivers an instruction manual with lots of photos showing the exact positions of the boards. Just turn off both power amp and preamp, before changing boards.

First Impressions

Each replacement made an improvement. But this improvement was not of a "more" of the Naim sound, but rather a "more" of what is usually missing in Naim sound. What we know as positive Naim sound remained to full degree: the feeling of rhythm, power, and flow in the music just was like before, but for the first time I could have my cake and eat it, too. In other words, there was an unexpected wealth of undistorted, natural and fine detail, which integrated very well into the original sound. This was exactly what I felt, when I replaced the phono and line-out boards. When I finally replaced the line buffers (those board have to drive the 10k Alps pots), it was a bit more difficult for me. While the new boards showed more resolution, I began to miss the old soft and tubey sound of the original buffers, because the new boards had the "time aligned" feature of the later NAC72 (which is about filtering away the frequencies outside the listening range). It took me some time to get used to the sound of my NAC32.5 with the time-aligned RSL buffer boards. The new buffer boards also had more grip and tightness all over the range. Finally I realized that it was a big improvement,

Astonishingly, the RSL boards, which were already run-in, definitely did not need a warm-up before sounding better than the Naim boards, which had been always-on for months.

According to internet forums, many Naim owners suffer from bad sound from their gear, either because of not being always-on for long enough time, or becoming due for a capacitor replacement. The RSL boards are good news to them. New caps are on the boards, and the preamp sounds great from cold.

Arrival of RSL Boards for Long Time Evaluation

A few weeks later, I had to send back the broken-in boards, and got new boards instead. Now, those brand new boards sounded grainy and wiry out of the box, like cheap hifi. Expect some four weeks for break-in.

Sound Quality

When the new boards had had their running-in time, I began comparing them board against board, by putting back a single pair of Naim boards at a time, so I could hear what harm the original Naim boards could do to the RSLíed 32.5.

First, letís talk about sound differences and try to define ďone stepĒ of sound quality difference in a well-known Linn-Naim environment. We all know that differences between cables are subtle most times, but the difference between a Linn Ittok and a Linn Ekos tonearm, between two different Naim power supplies or between a Denon 103 and a Linn Arkiv is a real improvement step. This sort of difference is what I call "one step" in the rest of this review, and should be familiar to virtually any user of Naim audio electronics.

[RSL moving coil boards]

Naim mc boards 325 revision 5 (470 Ohms, 6800pF) against RSL Z100 mc boards (560 Ohms, 1000pF)

Phono mc amplification is a major strength in Naim amplification. The difference between the boards was not only in quality, but there was also a tonal difference. The Naim boards were definitely warmer and cozier. Rythm and pace was fine with both of them. The RSL boards had a lot more fine detail, as well as better soundstage. With the RSL boards, I had to adjust volume level, as they seem to have slightly less gain. The Naim boards are good as they are, but the RSL are finer. This qualifies for a "one step" improvement for the RSL mc boards.

[RSL moving magnet boards]

Naim mm boards 323 revision 4 against RSL Z102 mm boards

The RSL boards excelled in every respect, dynamics, PRAT, fine detail, sheer bass power and soundstage. When compared, there is no way to go back to the Naim mm boards. The RSL boards push moving magnet playback quality to a new level. The Naim boards are still good, but the RSLs are a lot better. The RSLs are even better in musical terms. For me, this is "one and a half step" improvement for the RSL mm boards.

[RSL variable input boards]

Naim variable gain input card 328 revision 2 against RSL Z401 variable gain input card

In my secondary setup, the CD signal is delivered from a cheap Samsung DVD player. So I expected next to no differences. But I was surprised. After some weeks with the RSL boards, the Naim variable input boards became unlistenable and sounded broken against the RSL boards. This qualifies a "two-step" improvement.

[RSL line stage]

Naim line amplification boards 321 revision 2 against RSL Z200V line amplification boards

The Naim line boards sound muffled and flat, and the sound is closed-in into the loudspeaker. The RSLs have more PRAT, better musical insight and also a good soundstage. The RSL boards had three adjustable gain steps "standard", "-10dB", "-20dB", and I expected less noise and better sound with the lower gain steps, but all settings sounded equally good to me.

This is a no-brainer. Again, this qualifies as a "two-step" improvement, because the RSLís are better in hifi aspects as well as in Naim natural strengths.

Coincidently, the RSL boards I liked best had more circuit changes compared to Naim. The line boards as well as the mm phono boards both have JFETís in the input stage. The mm boards even eliminated the need for an input cap.

Naim input buffer cards 324 revision 3 against RSL Z301/Z302 volume-control buffer cards

The RSLs have a bit more fine detail and sound a bit more modern. This difference is a bit smaller, say, "a half step" improvement.

[RSL input buffer boards with remote control]

Improved User Interface: Remote Control for Volume and Mute

There is one big improvement: the RSL buffer boards come with a tiny remote control, which can set volume up and down in 20 steps, or mute the sound down in two steps. Suddenly my kitchen radio setup gets a remote control. This is really great news for couch potatoes like you and me.

RSL against state-of-the-art

I took my own high-speed, no-feedback, no-coupling-cap, low-distortion full-function preamp (but no MM phono input) from my primary setup to the Naim setup in the living room, and compared it the full monty RSLíed 32.5. Well, there is still room for improvement. However, from my experience, the overall performance of the RSLíed 32.5 is on par with preamps in the 5000 to 10000 EUR/USD class.


If you have only one hifi setup, and do serious listening, you have no option: You have to go full choice. The RSLíed 32.5 is so much better, you would have to buy a new preamp for a high four digit or low 5-digit price to get about the same result.

What you get with an investment of 800 USD is about the sound of a 5000 or 10000 USD preamp. This 1:10 ratio is also the natural ratio between part costs which make up audio gear and retail price. If you buy a preamp for 8000 EUR, there are 800 EUR parts in it, from which 300 EUR make up the sound, the rest is for user interface and fancy champagne-gold fascia. The other money is for manufacturer markup, marketing, distribution markup, dealer markup, customs, VAT, etc. Distribution markup and dealer markup are each about 100% on their sales costs, so they quadruple what the manufacturer gets paid. With RSL, there is no distribution or dealer between manufacturer and customer, so RSL boards are an amazing value for the money.

To make a long story short, these boards buy you an 8000 bucks preamp, and you wife wonít even notice Ė as long as you donít use the remote.

The Bang for Buck question

If you have your Naim preamp in your secondary setup, you have to ask the bang for buck question. You may ask, which boards are must-haves, which are nice-to-have, from your own point of view. This is what I did. My personal conclusion about RSL boards is like this.

Once I got accustomed to the RSL qualities, there is no way to send back all the RSL boards. I asked myself: Which boards are the more important ones, if I want to have the best improvement for my money? For me, it is obvious, that the RSL line output boards are the most important. If you buy some RSL boards, but leave in place the Naim line stage boards, it makes no sense, since the Naim line boards are a real bottleneck, quality-wise.

Then, for CD playback, I would simply buy Naim or RSL jumper boards, if the volume step between CD and phono inputs does not bother you. If I really need variable gain input for CD playback I would go RSL variable line level inputs. Alternatively, for about the same amount of money, I could buy the remote control buffer boards, and use jumper boards for the CD input. Whenever switching to CD, volume is adjusted with one or two clicks on the remote control. Especially, when you have more than one high-level input, e.g. sound from internet radio, laptop or the like, the remote control option makes more sense. If I would use a moving magnet cartridge, I would have to invest in the RSL phono mm boards, which would give me an improvement as big as a better tonearm and better cartridge at the same time.

For MC phono, the RSL boards are a real improvement, but the original boards are still listenable. Since I have my top analogue frontend in my primary hifi setup, I would leave the original boards in place.

As I have both MM and MC cartridges, it makes sense to me to opt for MM phono in my secondary setup, and leave all the expensive cartridges (Koetsu, Zyx, etc.) in my primary setup. This move is motivated by the excellent RSL moving magnet phono boards, which seem to be superior to the RSL moving coil boards. To summarize my own preference: I would take RSL line stage boards, RSL remote control boards, CD jumper boards, and RSL phono MM boards. With choosing only 3 out of 5 pairs of RSL boards there no Naim boards in the signal path any more, and the same time a maximum of improved performance.

[Naim NAC 32.5 with RSL remote control]


Once upon a time, when I was fiddling with Naim amplification, I failed and thought, there is no real improvement. RSL did not fail. They did a great job, and managed to offer boards at competent prices, which bring your old kitchen radio Naim sound to the standards of today.

A final Remark

Kit Ryan informed me in February 2015, that improved MM and MC boards are about to be sold soon.

© Copyright 2015 Hartmut Quaschik - www.tnt-audio.com