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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
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.
newbee
4,767 posts
 
This may not be a cure for you, but it was for me. With your amp/pre-amp properly grounded using the 3 prong plugs try adding the 'cheater plug' to the PC of the CD/DVD player. I have an oversensitive integrated that for reasons I haven't yet figured out the only way I can keep it quiet is by using the cheaters on the input source power cords. The only difference from your problem (only :-) is that the hum is constant.

Give it a try. Only takes a few seconds.
almarg's avatar
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almarg
9,670 posts
 
So, you believe it might be bad tubes?
Seems like a reasonable bet to me. If it is a bad tube, it would figure to be either V5 or V6 (both are 12AU7's), since the other tubes are not involved when line-level sources (CD/DVD or cassette) are being used.

Since V4 is also a 12AU7, but only supports phono playback, you might try swapping it with V5 and V6 (one at a time). If either of those substitutions fixes the problem when one of the line-level sources is being used, you've found the bad tube!

Regards,
-- Al
jdvorak OP
13 posts
 
Ok, the plot thickens. When I just hooked up my nakamichi dragon directly to my SA 400 amp, it still does the same problem. Ugh!!! Tried different interconnects as well. It sounds like a bad (distant) radio station when I play a tape.....static, woofer noise, etc.
Could it be the amp?
I know it's NOT the speakers. I tried another set of speakers in this system earlier in the week and they did the same thing, but they work fine back in my mini system in the kitchen.

May e it's time I go back to a boom box! :)
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