Audible illusions Modulus 3A or Klyne 6L

AI Modulus Preamps Are Not Hard On Tubes... To date we have mfg.many thousands of these units and, to the best of our knowledge, premature tube failure has not been a problem. The problem is some "tube rollers" continue to substitute old-style 6DJ8 type tubes in our preamps. These tubes were OK for TV sets and RF applications but not designed for audio purposes. Thus the small plates and weak mica insulators resulting in excess microphonics and noise. However there do exist some NOS brands that are acceptable and exhibit good life; Tungsram is one brand that comes to mind.

Be advised that our tube preamps are open-loop/no-feedback designs. The advantage of eliminating negative feedback is well known. The downside is that the tube we select must be well constructed, have low-noise and good life. In our 30 years experience the best tubes we found that meet our criteria are those mfg.in Russia. In the early 1980's we did use some 6DJ8 tubes produced in the 70's that were well made but, when the supply of good tubes ran out, in 1987 we discovered Russian tubes. Primarily used for their military communications, including transmitters in MIG jets, these tubes were designed for low-noise spec.and reliability. All of our preamps since 1988 have Russian tubes installed.

Regarding our filament-on design, based on his experience with tube equipment in the recording industry, my boss had learned that the main contribution to tube failure was thermal shock to a cold tube. For that reason most recording studios left their tube equipment on. Of course, leaving tubes on does cause premature plate degeneration but he experimented with leaving the filaments on but with some current flowing on the plates. This design has proven to be a big success in prolonging tube life in our circuits.
Unfortunately this circuit design will not prolong the life of old-style, poorly made tubes. Suggest you tube rollers experiment with preamps employing negative feedback and cathode followers. Regards, Jerry/AI's Tech,

Thank you Jerry ! It says it all ! Why to and when not to...

Methodology, you now know everything you probably didn't know before. Take your pick !

Regards !

Wahwah, thankyou. Although I have owned my Audible Illusions preamp for a short period time & leave the preamp powered up most of the time, I have not experienced any tube failure yet.

Reviews are important but the real test of any preamp is to listen to it in your own system and draw your own conclusions. Since the Audible Illusions preamp purchase, friends & family that are very familiar with the previous sonics of my system have noticed a remarkable improvement overall in sound quality. In fact the Audible Illusions makes all previous preamps sound broken. I won't go into a lengthy description of the obvious improvements but it is safe to say I'm in it for the long haul.

This post is a little late but Aesthetix had issues with their 12AX7's in the Calypso preamp. It ate them for lunch and I should know. I spent enough on replacement tubes. However, it you finally got a good pair, it was wonderful. Jim White is a very good designer and easy to talk. I think he builds excellent equipment but it does have quirks.
They're other preamps that eat tubes so to speak. Andr, Aesthetix didn't mention it being hard on tubes or requiring certain tubes.
The AI's in my personal experience are not tube eaters. That's all I can say and it is from personal experience. People jump on these bandwagons for whatever reason.
Andr, sorry, but what you tell is not experience in my book. You need to own one, live with it and then you can talk all you want. People have all kinds of reasons for selling and dealers have all kinds of reasons for dropping lines (usually something to do with profit margin.)
As for not putting NOS tubes in it, it is on the AI websight and a competent dealer would tell you. I would think they should have experience.
As for sound, that's up to each individual to make the call.
A lot of the preamps people bring up in comparison are not there to me. Try comparing side by side, not on memory of what you think something sounded like. It's the only way to know for sure. I've found a lot of other things bring about sound change.
Also, one last comment, Art and his crew have always been excellent with me. Art shipped my L2 to me so it arrived Christmas day! Try that with another manufacturer.
They are a small company and as such, are slower. However, patience is a virtue. They've been around long enough to see a bunch of other companies drop out and to me, they must be doing something right.

I owned the AI M3A for around two years. I never had a problem with the stock Sovteks or a pair of NOS Tungsram. What I didn't like was the high gain and stepped attenuators. Too much tweaking involved. The sound with good vinyl was amazing though. For someone who listens primarily to vinyl I think that they are a great value.