Tube Pre+ Transistor Power will burn your power Amp. easily?

LIttle more:

Not all tube pre's have this minimal risk. For instance, if the output is transformer coupled, or balanced. Most tube pre's are single ended.

If you truly have a vintage pre-amp (before 1980's) then you absolutely owe it to yourself to check the coupling caps (input and output) and replace all with modern film types.  Electrolytics will be failing by now, and older films just didn't sound as good. :)

Best,


E

There have been times when I have seen someone cause issues with a solid state amp being ruined by a tube pre but in every case it was due to turning both the preamp and amplifier on at the same time not allowing the voltages of the pre come up first.

@response34

That IS interesting. Since the caps pass AC, it’s possible a very high voltage ( >> 30V) turn on thump could occur. However, honestly that would damage the amp even if off. It would most likely break through most electrolytic coupling caps and if DC coupled, short several transistors. Of course, if a speaker was connected, things could get even worse! :)

Perhaps what tube preamps really should have is a coupling cap + zener diodes to prevent the possibility of high voltages reaching outside.

I ran a Classe solid state amp with a Modulus 3 tube preamp for 20 years and presently run a Stratos  solid state amp with a Rogue rp5 tube preamp.  Your friend doesn't know what he is talking about.

Thanks a lot for your kind response and opinions. In fact, I use a tube pre. to run a SS power for a very long time without problem. But once upon a time, I turn on the volume to squeeze more power to play the Japanese Taiko (big drum) with more solid bass, one side of the MOS FET had been burned together with one side of speaker (the unit handles the high frequency driver).  Judging on such long time experience, I think it should be no problem to use a tube pre and the SS power. But my friend is a Dr., so I have to respect his professional even though I still regard it should be safe or little risk only. I will hear more opinion from audio dealers. Any way, tks again for your precious suggestions.