Hello, I have been working on my telefunken opus 7 and been having issues. I am now having trouble with the volume. When I turn the volume all the way down I still get sound and as I turn it up it sounds good at about 30%, but the higher I turn it I get distoration in the sound at about 45%. I have hooked up good external speaker, so I know the speakers are good. What tube efeect the sound?
Thanks
David

Try disassembling the control and cleaning it. Then coat the carbon with di-electric grease (very thin film). It is normal for the sound to be just barely audible when the control is turned down on a lot of old radios. Some turn the sound off and some turn it down really low.

Distortion may be caused by a dirty volume control. It may also be caused by leaky condensers. Check all condensers for leaks, and replace all which have any leakage what-so-ever. Check resistors for drifting, too. Remember to remove each component that you test. Leaving components in the circuitry will throw off readings.

Also check tubes. Occasionally a tube will get gassy or weak, and will perform as you stated (distorts easily).

Thomas