Microphonic tubes on Bassman
Sat, 10/05/2013 - 20:22
Hi Skip,
A reissue Bassman I have recently acquired is has very microphonic tubes with an obvious audible ringing. This is the 1st large amp I have had so was wondering what the best solution is I.e what tubes aremost prone to ringing and what the best swap is without sacrificing anythiNg if possible.
Thanks
Gareth
Mon, 10/07/2013 - 23:28
#2
Thanks Skip
Thanks Skip,
It was just V1, replaced and ready to roll. Looking to play with tube variations soon via bassman chronicles recommendations,
Much appreciated,
Gareth
Hello Gareth- Thanks for writing. It is most likely that you have just one microphonic tube.....just one will make it seem like all the tubes are microphonic! There are three preamp tubes in your amp and any one of them could the culprit, but I would start by removing "V1" (the tube farthest from the power tubes) with the amp on. If the amp stops "ringing" then that is the one. If not, remove the other preamp tubes. V1 or V2 are the most likely to be causing the problem. Check out the "Bassman Chronicles" here at BluesHarmonica.com for some tips on specific tube types for your amp...... a bunch of harp dogs (Hi Mark!) spent mucho hours experimenting with all kinds of preamp tube swaps (and other tweaks) for the RI Bassman.