Question for Mo' Bass owners

Clark Dark · #1 08-29-2011, 03:10 PM

Lately I seem to have a decline in volume with my pre-Fender Mo'. My Gecko5 with an OBP-3 cannot even get the red clip light to blink at all (amps pre control around 7>8) when my bass is full on and I plug into the passive/active input instead of the active input. I last changed the 12ax7 a year and a half ago so it might be a weak tube but I'm asking if any owners of this amp experienced the same thing I am and what cured it. Thanks

RickenBoogie · #2 08-29-2011, 03:46 PM

Try cleaning the fx loop jacks with DeOxit, or run a cable in and out a few times. Sometimes that's all you need. If that doesn't work, you may need to take it in to the amp doc.

Clark Dark · #3 08-29-2011, 05:39 PM

I'll try that. If you own a MoBass what's the widely recommended 12AX7 tube as far as you know / or prefer ?

emjay · #4 02-09-2012, 03:26 AM

I just came across your post from months ago. The tube can be going south as well. If it starts to sound like glass breaking, replace it immediately. JJ and new issue Tung-Sol tubes are pretty well recongnized, but I use the vintage tubes from the 60's and 70's in my Mo's, as well as other SWR heads and combos. Some of the best vintage 12AX7 tubes I've used were from Mullard, Amperex / Bugle Boy, Telefunken and RCA - but they can cost well over $100 if they are new old stock (NOS). PM me if you want to get them, as I have far too many for this lifetime.