Which is REALLY the best Conrad Johnson Preamp

I have to say this about the Classic 2 SE, it was the single most noticeable upgrade ever in any of my systems over the years.  I've had a number of very good preamplifiers over the years and this unit walks all over them in terms of sound quality .   Zero listening fatigue with this pre,  I can and often do listen for hours on end.   

This unit gets looked down upon due to lack of remote, but it is all about the sound with this pre.      It's a complete 180 compared to some of my previous preamplifiers.   No balance control or tone controls,  just a power switch, a source selector, and a volume knob....that's  it.      It's a sleeper that will probably get passed over due to its lack of remote which is too bad....  

I have been enjoying my PV8 since I bought it used in 1991. Although I have never had a chance to directly compare it with more modern preamps in my system, my feeling is that it gives up some detail for a warmer presentation; there is very little fatigue in long listening sessions. It has pretty good dynamic slam when called upon. The phono stage (low gain) seems pretty good.

I just noticed last night gentle popping sounds coming from both channels only in the phono stage when I turn up volume. Also, while CDs are sounding quite nice, phono no longer sounds that good, which is a switch from normal order of preference (current tubes have been in at least 5 years). Question: the preamp has two AX7, two 5751 and two 5965. Can I replace just the AX7 to try to fix the phono stage? Also, what do I need to do to properly clean the unit inside and out? What products do you guys recommend for cleaning /maintenance?
Thanks.

Jafant: Thank you. Aspens

i love my ET5 and never heard any cj anything that didn't sound great to me.

For my money, the GAT will sweep the floor.  Maybe all our GAT owners should get together for a love fest.