Ran the BeePre for about 4 hours today - lost 95% of the volume in left channel. Details below. Same left channel where I was having the 'hum' before, details at this link:
http://bottlehead.com/smf/index.php?topic=6879.0I was kind of 'breaking in' and the volume level was fairly low as I was working from home - came into the room and couldn't hear anything from the left channel. A little cable swapping and testing indicated that signal into the BeePre was good but the signal out was not. Ear to the speaker, I could hear probably 5% volume of what it should have been, even with only one channel plugged in, so it wasn't bleed from the other channel. So a tiny amount of signal was getting through. All tubes were glowing and the two halves of the amp felt the same temp, everything looked and felt normal, just no sound.
Powered down to let the tubes cool enough to swap, so after 3 minutes when I could handle them, I swapped the EL84s and powered everything back up and both channels are back. It barely had time to cool down. Powered down and swapped them to original positions, everything is fine. Never moved the 300Bs. Chassis is cooling now so I can inspect the bottom and see if anything is cooking or looks odd.
With this low level of signal coming through - any ideas or any suggestions on what I might look for?
