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
Oldpet - I purchased the RA line stage as a kit which requires doing all the soldering. Most of that is to PC boards and the instructions are very complete. If this is a problem, it is available already built. I now have over 350 hours on mine and the sound has continued to improve. My experience with the Lundahl transformers in my K&K phono preamp is that they will continue to "sweeten up" over several hundred hours.
Oldpet, the bass is just fine. The preamp is transformer coupled; it can't leak DC. Also, since it is a differential parafeed design, there is no DC at the input of the output transformer. That is how they are able to use a high quality mike input trannie wired in reverse for that job. These transformers will not tolerate any DC on their input.
Well gang. I figured I might add some thoughts to this thing I started. There are, after all, several tube preamps which, by design, do not leak DC. (Yay!!!! For all the Krell owners out there.)
I am one day away from taking delivery on a new First Sound, Presence Deluxe MkII. It doesn't leak DC. The designer, Emmanuel Go, through his own experience with krell amps, says that Krell and his preamps are a match made in heaven. Who am I to dispute him :-) Tomorrow we'll see. Thanks to all who contributed.

pt
hi Dave - NO! I was tracking the delivery from ups. (scares me to begin with) and the Pre was "rescheduled" for delivery to 3/24! Six days past the original delivery date! What's up with that? How does that happen? Emmanuel Ships the unit - it has a delivery date - then suddenly the date is move back 6 days. I don't understand. Any ideas? Thanks for asking Dave. Now I'm keeping my fingers crossed for a safe arrival. I'll let you know.

Paul
Well I learned quite a bit from every one regarding Krells and tubes..Thanks to all for the input...

Any idea what would make my amps have a loud electrical discharge, as heard through the speakers, when switching to standby from being on? The tweeters are taking a kicking when this happens.
Yes the amp gets switched to standby first as it is turned on last when system is powered on..
I use a BAT Rex preamp (all tubes, power supply and output stages) with a Krell EVO 402e amp. I did nothing but set up the components. Everything sounds glorious with the best of both worlds: big, rich, sound that is also tight, detailed, dynamic.