Krell amps and Tube Preamps - enemies?


Wow! I never realized how difficult it would be to add tubes with a KRELL amp. I'm no engineer, and, I don't pretend to be into the "technical" side of the audio world. So I'll try to explain.

It seems that tube Preamps create DC. I've been told that DC will dammage my Krell amp (FPB400cx), and possibly my speakers(Tyler Acoustics Linbrook Sig, System 1 piece). UNLESS, I open the amp up and do something to the "jumpers on the digital board" . This puts some protection into the signal path. The Bad thing is, I'm told, - it also colors or degrades the audible signal coming thru the speakers. So, if I want to use my SS set up, say for SACD or DVD-V/DVD-A, I would have to open the amp up again and reverse the proceedure. This would remove the "blockage" in the signal path. :-( This of course, would have to be re-done when I want to go back to the tube setup. WHAT A PAIN!

Needless to say, this has thrown the proverbial 'wet blanket' on my tube enthusiasm. Is this problem common to ALL SS amps? Or is it just a KRELL thing?

Any thoughts would be helpful.
(This is part of a thread i started on the speaker threads, but i thought i might have more luck here on the "amp' Threads)
Thanks
oldpet

Showing 2 responses by newbee

Rwwear, What would you expect from a newbee who still listens to a 20 year old pre-amp and 10 year old amps? :-)

My point was only that while you might be able to hear the capacitor it might not really make any substantive difference sonically speaking, different perhaps but not better or worse, and if it allows an upstream improvement it would be worthwhile.

If there were such a beast as a SS amp which really sounded like tubes then the manufacturer would get a corner on the SS market (IMHO)! Some solid state amps that I have heard that come close that won't cost an arm and a leg are made by Muse and Plinius... I'm sure there are others. Personally, if I were going to have a SS amp in my system I'd find an older Threshold amp - the SA series. With your speakers the SA3 or SA2's would be great and they are not a problem with tubes - I used them for years w/o problems. I think they may well be the best amps Nelson Pass ever designed. By the way, I doubt that you will hear the insertion of the capacitor in the Krell unless you have everything else in your system optomized, with either a tube or SS pre-amp. Oh, an extra "by the way" DC offset from a CDP shouldn't be a problem - it should stop at your pre-amp, and even if it didn't the volume control would substantially reduce the signal if it did pass.