Best Tubes for Audible Illusions 3 Pre-Amp

I have an L-1 and have used Bugle Boys, Tungsram and the Electro Harmonix that AI sells on their site. All are very good and I also agree that I have not had a problem with tube life either.

My favorite is the Tungsram.

Regards,

You should talk to someone who knows, I am just passing along something I remember hearing, and that is that the Audible Illussions unit, through its design, stresses tubes much higher than almost all other designs and therefore severely limits your choices for replacements as many, many tubes will fail in this circuit in a matter of weeks.

This is what I love about this site, So much detailed information from knowledgable sources. Thank you all! Imin2u, I will be waiting for your review on the different tubes you will sample. For the record, I never had a problem with the AI in stressing tubes. I had the same pair in for years. The unit actually sends a small charge through the unit keeping them "warm" so when the unit powers up it does not "shock"the tube. Again all, Thanks.
Basil

One thing to keep in mind - I Never turn the power off on Any component (except the turntable). I never even "mute" the AI 3A. I feel, with all electronics, that it's the warming/cooling./warming effect that kills components. I may be wrong but it works for me.

I must second Imin2U's last comment about keeping hi-fi gear powered up.

The proprietor of one of the high end's more noteworthy and successful tube gear companies explained to me that the studies done in the 1950's on tube wear all confirmed that small signal tubes such as those used in preamps and DAC's last much longer (and as a corollary, also sound better) if powered up 24/7. Basically, he said that, if left powered up 24/7, they either die at some point in the first 250 hours (infant mortality of sorts) or they basically last forever.

I leave all of my equipment except turntable and tube amps powered up 24/7. Over the years, this has included a tubed DAC (Cal Audio) and three tube preamps (Jadis, CAT and Hovland). In fourteen years combined of these tube components being left on 24/7, I have never had to replace a tube (nine years now on the DAC), nor has any of my equipment, tube or solid-state, required service. As for the preamps, when I am not listening to them, I am careful to keep the volume turned all the way down and the mute engaged.

Tube amps cannot be left powered up because the output tubes pass a relatively large amount of current that stresses the tubes, and do last longer if turned on and off.

As a general rule, however, I believe that Imin2u is correct -- it is the thermal cycles that occur when equipment is powered up and down (i.e., repeated expansion and contraction of the components as they heat up and cool down) that kills components, even tubes - it is basic physics.