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


I used to combine with a tube pre + transistor power with the ideal sound which I prefer. But one of my friend told me recently that such kind of combination will burn out power amp. easily if I use a tube pre.

Is this theory or practice true?


faust168
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.  
 I agree with your other responses, I think this is not valid but I'm not certain.  I'd like to find out from an expert just to be certain.
Some consider me to be an expert... the idea that a tube preamp can do anything to a solid state amp in particular is a myth plain and simple. Coupling caps being old has nothing to do with it. Its just a myth and no matter who is trying to propagate it, its still a myth.

Solid state preamps have coupling caps too and are just as failure prone in this regard as a tube preamp.

Well the fact is that all sorts of things can cause amp-dangerous thumps! This is not a solid state/tubes thing, because solid state preamps can easily make thumps! This is why many solid state preamps often have output muting protection relays. Many tube preamps do as well. But a protection relay is just about guaranteed to mess with the sound, so many preamp designers expect the operator to have some common sense and follow the procedure below:

Its just a matter of being careful- when turning on the stereo, always turn on the preamp first and wait for it to stabilize. Then turn on the amp.

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.
Apparently this is an example of having a doctorate but still having no clue about what one is talking about. In this case his opinion is just that and its bunk.