[Harp-L] Bassman mods

[Mike Best <mike.d.best@xxxxxx>]

Hi all you tech gurus. My main amp is a 59 Reissue Bassman, made in March 2000 according to the date code.

Lately it has developed a weird problem. When I play some high notes the amp emits another note at the same time which is approx an octave lower but not quite. It sounds very discordant. It doesn't happen with all high notes, just some. For example the high A 10 hole blow on an A harp.  I've removed all my effects from the chain and tried different mics and amps and I can confirm the problem lies somewhere within the Bassman

So, first question:  has anyone else ever had this problem and any ideas how to fix it?

Second question:  assuming I end up taking it to an amp tech, while I'm there are there any mods I should be asking him to do to tweak the amp for harp use?  I use a Squeal Killer to control feedback so volume isn't a problem, just wondering whether there are any common mods to improve the tone or whatever

Cheers
Mike