2. amps-preamps
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Audio research and krell

So here goes I have a arc ref 5se and I am using a krell Kas 300s and recently I noticed the krell was making some noise when powered off so I made some calls to krell and found out that the older krell amps are not recommended to be used with tubes I have never heard this .so has anyone here heard this .second  question if that's the case what should I move to for a new amp I like the krell sound. Speakers are revel salon 1 transparent cables

tunawishing
sbank's avatar
sbank
3,378 posts
 

@unsound You're correct. The FBP-300 has this. I forgot to mention that. Good callout! Cheers,

Spencer

invalid
1,153 posts
 

I believe krell added that jumper during the production of the ksa 250, because a certain model BAT preamp was causing DC issues, not all BAT models were a problem just one model if I remember right.

tunawishing OP
17 posts
 

Yes that's correct I spoke to krell today the protection started on the fpb amps 

arcguy's avatar
arcguy
26 posts
 

You can use your Ref 5SE into any Krell amplifier ever made.

Many years ago Krell said they would not warrant their amps when used with tube preamps because too many tube preamps did not have auto mute circuits (you had to have it manually muted on turn-on) and too many could output DC--which could blow up the amp. (Counterpoint, Melos, Audible Illusions, Paragon...) Even then, Krell would warrant their amps when used with ARC preamps because they were safe.

Your 5SE has coupling caps that will not pass DC, so you are fine.

arcguy's avatar
arcguy
26 posts
 

Your 300S is over 25 years old and it is likely that some of the capacitors are showing their age. If the two halves are not discharging evenly when you turn it off then you will get some funny noises. If you turn off the 300S (with the 5SE muted) and you hear noise through the speakers, it's coming from the amp.

 

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