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System feedback coming thru speakers.....help

I just hooked up my system that I have been building for several months and I am getting some feedback out of the speakers. I ended up hooking up a different speaker and it still is doing the same thing. The speakers are all static-ie and the signal seems weak. Here is my system:
Sonograph SA 400 amp
CJ PV 11 with phono
Thorens TD 160 turntable
Hales T 3 speakers
Nakamichi dragon tape deck
Panasonic DVD S 53 as cd source (for now).
Just had a pair of audio quest bi wire speaker cables made today.

Any ideas?
Additional note: I am in a really old house......like late 1800's. Old wiring, two prong, pre grounding even. Could it be:
Line noise?
Cables touching behind my system?

Any suggestions would be greatly appreciated.

Thank you in advance!

Jason
jdvorak
lloydelee21
1,202 posts
 
HI Jdvorak,

i believe you said when you plugged in just the pre and the amp...with no source plugged or connnected...you could turn the preamp volume way up and there was no noise.

Is this correct?
jdvorak OP
13 posts
 
Lloydelee21, correct. nothing. no hum, no nothing.
lloydelee21
1,202 posts
 
And when you do plug in either of 2 sources...from either of 2 plug outlets...into any of your preamp inputs...there is hum which gets louder with volume. And the feedback hum is in both speakers...and also in a replacement set of speakers using the same 'problem setup'.

- not amp or speakers,
- probably not grounding which does not vary with volume
- Normally, 'feedback' occurs when you are outputting sound, and there is a microphone picking it up and feeding back into the same system. i assume there is no microphone input in your CJ preamp
- is it the interconnect?
- is it possible there is a problem with preamp...but you cannot tell if there is no source attached because (as you said, if u plug in source, turn volume down, feedback goes away).

Try different preamp, or try to see if you can plug the DVD source directly into your amp temporarily...some DVD players have a built-in internal volume control...usually terrible but it should work.
almarg's avatar
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almarg
9,670 posts
 
Try different preamp, or try to see if you can plug the DVD source directly into your amp temporarily...some DVD players have a built-in internal volume control...usually terrible but it should work.
Or try the cassette deck straight into the amp. It has a level control on the front panel.

Regarding the references to feedback and hum, as I indicated earlier I don't think this is a feedback problem or a hum, ground loop, or grounding problem, based on the sonic descriptions that have been provided. My guess at this point is that it is simply a preamp problem.

Regards,
-- Al
jdvorak OP
13 posts
 
Great idea, Almarg! I'm flying back home from biz tonight. I will try in am with dragon.
So, you believe it might be bad tubes?

Note for all: It's not just a "hum". It's a thumping coupled with a static-ie feedback.
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