Hi PB,

Think I tried Fringe, but didn't stick with it. I quite like White Collar, however.

I understand the urge to experiment with tube amplifiers. I grew up building tube amps in my teens for my audiophile father, which is when I caught the hi-fi bug. ONe of the problems with many tube amplifiers is that they do not have 0 output impedance. All solid-state amps have essentially 0 ohms output impedance. With tube amplifiers, the output impedance of the tube amplifier may interact with a speaker's impedance curve, significantly changing the frequency response of the system. Tube amplifiers with output transformers have impedance taps--for 8 ohms, 4 ohms, etc.

In other words, tube amplifiers may not be "linear" with a smooth frequency response across the audible spectrum. That, combined with possible impedance interactions, may introduce audible colorations which you may or may not care for.

At Axiom, we always seek neutral, transparent frequency response from our speakers and the amplifiers, which is why we don't use tube gear. One of our former chief engineers designed tube gear for MacIntosh, as well as solid-state amps for Luxman, H/K and others.

Be careful if you try any single-ended tube amps, which typically are very low-powered--about 6 watts per channel. I just emailed an Axiom customer who was using one to power M22s in a huge room and he drove the little tube amp into distortion, destroying his tweeters and a couple of the midrange/woofers.

In one fascinating A/B comparison that I participate in, of tube vs. solid-state amps of about the same power output--35 watts per channel--the sound quality was essentially identical until they approached their output limits. The soundstage of the tube amp collapsed into almost mono and became distorted. The transistor amp remained excellent until it clipped, and sounded distorted and nasty. When not driven to their limits, the two were essentially indistinguishable. None of us in the room could reliably say which amp we were listening to until they were run past their output limits.

Regards,
Alan


Alan Lofft,
Axiom Resident Expert (Retired)