Giscours malfunction

[fjn04]

I assume that by checking cables you also swapped the connections to the amps at the pre?

I assume this is happening both with phono and another source? This would eliminate something in the phono stage as the issue.

If so, then the easiest trouble shooting is to swap the positions L/R of the valves, one set at a time, powering off in between. Start with the rectifiers, then the tubes in the line stage. If you hear the failure switch channels, you know that tube is bad.

If after doing this the problem doesnt flip channels, and all the cable connections are not bad, you know you have another part failure in the line stage that you will have to seek out a reliable repair for. Probably the best place to start with that might be A23.

** If I may just ad one precaution. After you power down the Giscours, I would wait like 5 minutes before powering back on. So following Gortnippers procedure above, also give the preamp that rest before powering back up. So I would shut down, let the tubes cool a few minutes, put 1st set back to original position, flip second set, power back up....