System feedback coming thru speakers.....help

If the preamp can make the sound smaller or bigger...but the preamp and amp are silent with no source attached to it no matter how loud you turn the preamp...then it has to be source. And is probably not grounding. i did not think grounding would get louder and softer with volume.

Might be your source or your cable in between your source and preamp. Try a different cable. If same, then try another dvd player. Hope the electrician can help.

I've plugged the DVD into a different source on the pre amp......same results.

What you should try is a different source component, such as the cassette deck. Connecting the same source into a different input of the preamp doesn't prove very much.

I made mention Arlie's of it sounding "fine" at lower level......not the case......just at low volumes more difficult to hear the static/thumps.

That's different. Given that, I agree with Lloyd that the problem is upstream (ahead) of the volume control in the preamp. Meaning that it is being caused by either the CD/DVD player, the interconnect cable between it and the preamp, or by preamp circuitry (or tubes) that are "ahead" of the volume control.

I've included the preamp circuitry that is ahead of the volume control on that list of suspects, even though no symptoms appear when nothing is connected to the preamp inputs, because it is possible that a problem in that circuitry might not manifest itself under zero-signal conditions.

Regards,
-- Al

Lloydelee21, the standard procedure is to disconnect everything except the amp to the speaker wires. Turn on the amp. Do you have any noise? If you have noise with just the amp on, it is your wiring in the house. If not connect the preamp to the amp. Turn on the preamp and then the amp. Any noise? If so, it is your preamp or the interconnect wires. If not, connect one source and turn everything on. If there is noise, it is either that source or the interconnects to the preamp. If not, add the second source and turn everything on. If noise is present, it is that source or the interconnects to the preamp.

Actually, I think it is just a cold solder joint in which ever component you identify as the culprit above.

A p.s. to my previous post. Looking at the information on your preamp at the CJ website, although I realize you said that the tube types at locations 4, 5, and 6 are correct, just to be sure I'll mention that if a 12AX7 or 5751 were placed at the V5 and/or V6 locations, instead of the 12AU7's that are supposed to be there, it might result in the symptoms you have described.

Also, it can be inferred from that information that V1, V2, V3, and V4 are all only relevant to the phono input, not to the line-level inputs (where the CD/DVD player should be connected, of course).

Regards,
-- Al

Hi TPG,

To Jdvorak's credit, the process you descrive is exactly what he has done. He has so far determined there is complete silence with the volume on the preamp loud with teh amp on...providing there is no source connected.

So it appears to be the source of the interconnect. So he needs to connect a new source thru the same interconnect and see. If no noise, it is the source. If noise, it could be the interconnects.

Jdvorak? Any news?