Bird Tweet

Blues

New Member
Jun 16, 2020
2
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#1
Have a Krell 700cx and 801 Nautilus B&Ws using Krell Home Theatre preamp. Everything in system unchanged for 15 years. Suddenly now when I turn on amp I get bird tweeting sound from both speakers followed by hum. Checked speakers through other amp and fine. Know outlet is dedicated line meeting amp spec and checked it. Tried different dedicated line meeting spec and still get sounds. Not speakers, not outlet ground loop. Is amp itself the problem the problem? Still happens with all peripherals and preamp turned off. Ideas?
 

Lagonda

VIP/Donor
Feb 4, 2014
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#2
Probably worn out capacitors in preamp section, or problems with the dac chips if you use that part of the Home Theater. My brother had both problems in his KPS 25sc. Try to isolate the amp by playing another source without the Preamp, the capacitors in the older Krell gear just die from all that heat over time. The Fpb amps are also very sensitive to light dimmer noise, i could not use light dimmers when my 700cx was playing.
 
Last edited:

Blues

New Member
Jun 16, 2020
2
0
1
70
#3
Probably worn out capacitors in preamp section, or problems with the dac chips if you use that part of the Home Theater. My brother had both problems in his KPS 25sc. Try to isolate the amp by playing another source without the Preamp, the capacitors in the older Krell gear just die from all that heat over time. The Fpb amps are also very sensitive to light dimmer noise, i could not use light dimmers when my 700cx was playing.
Disconnected preamp and all peripherals so it is just amp and speakers and still get the tweet and hum when I turn amp on. No dimmers anywhere nearby. Are capacitors in a Krell 700cx hard to replace or can you use generic? Don't know much about them
 

Lagonda

VIP/Donor
Feb 4, 2014
1,358
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Denmark
#4
Any good repair shop can do a capacitor exchange, just specify you need the once that can handle the most heat. :rolleyes: I had all capacitors exchange after about 10 years preemptively so i never had the problem myself.
 

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