Page 1 of 1

New Tubes for a 79' a112

Posted: Wed May 27, 2015 1:55 pm
by sants
I ended up getting the a112 combo I posted about months ago.

The power tubes are mismatched with a vintage mallard and westinghouse 6ca7. It came with an extra of each but it turns out they bad hence the mismatch.

I put in some JJ's el34's i had lying around. Everything seems to be sounding great but the back of the amp was very hot. I seem to remember my old Matchless Chieftain being hot like this. My deluxe reverb does not get near as hot.

The tubes were not red plating and all seems well. I am concerned after reading some posts about tube voltage being insanely high with new production tubes. I don't really want to mod the amp with an adjustable bias.

Was it only early hiwatts that run new production tubes hot or all vintage models? If I hold on to the amp I will be replacing the caps soon.

Overall the amp sounds great at all volume levels and is punchy. It makes my deluxe reverb sound like a toy in comparison.

Re: New Tubes for a 79' a112

Posted: Wed May 27, 2015 3:32 pm
by Dr.HI-TONE
I would expect a DR112 to generate considerably more heat than a deluxe reverb.
as long as they EL34s are biased properly, then they should be just fine.