'73 super reverb AB763 layout.

[Doc Stitches]

I accidentally tried to play my Super Reverb with the 5U4GB in place of the adjacent 6L6.... ( several minutes )
Did I do much/any damage to tubes or amp ??
Doc

[loudthud]

Was there anything in the rectifier socket? Did the amp make any sound through the speaker?

If it did make sound, the is possible damage to the 470 ohm screen resistor on the 6L6 socket. Check it with an ohm meter for proper resistance. The 5U4 would get 3.2V on it's 5V heater and will try to pull current through pins 4 and 6 to ground. Did you smell any burning smell?

[Doc Stitches]

Thanks loudthud.
There was a 6L6 in the rectifier socket, and the rectifier tube was in the adjoining socket.
No sound through speaker.
470 ohm screen resistors are OK.
No burning smell at all.
Normal channel is great but vibrato channel is very low on volume..... and the treble and bass pots are not working correctly...I will recheck the wiring. Vibrato channel had these problems before tubes were in wrong.

[loudthud]

It is unlikely that any damage occured if there was no B+. The 6L6 in a 5U4 socket wouldn't even get hot because there would be no power to the heater.

[Doc Stitches]

Thanks, loudthud.

Now if I can get the vibrato channel low volume problem figured out I will be finished with this amp.

I only have ( about 1/10th ) volume at 3 and 10 on the volume dial and lifting the 2 legs of the roach didn't help.

Pin 1 on V2 only has 179v

Doc

[Doc Stitches]

Vibrato channel volume problem solved !.....It was a bad 250pf tone cap in the reverb channel.
Now there is 270v on pin #1 on V2...and not 179v. No more scratchy sounds when turning the knobs.
Thanks to all
Doc