в продолжении темы.
привожу ниже слова владельца очень известной американской хай-эндной фирмы Tempo Electric, специализирующейся на ламповой технике с бескомпромиссными комплектующими, Joseph Levy:

"In amplifiers, push-pull amps that use EL84 tubes and 5AR4/GZ34 rectifiers are all generally musical and easy to modify. Ditto with 2A3 or 300B SET amps. If your budget is limited, there are many $200-$500 sleepers out there, as well, including the Dynaco PAS-3, ST-35, plus any number of Fisher and Scott amps (look for the ones which use EL84`s). For under 10% of the price, Tannoy Monitor series drivers from the 1960s-80s in custom cabinets can equal or better any $50K speaker on the market today.
Get the basics right and it`s easy after that. Even without tweaks, you`ll still have music.."

последняя фраза особенно важна для тех, кто начинает делать правильные шаги.