[Harp-L] [Harp On!] Tube Amp Advice PLEASE!

["Heath Mensher @ SOPAC" <heath@xxxxxxxxxxxx>]

Tube Amp Advice Please:

What I have:

A CRATE VINTAGE CLUB 30 Watt Amp. It has:
4 Preamp Tubes: 12AX7's
4 Power Tubes: EL84's
I have a very good amp technician who owes me a favor.

Can someone please tell me what tubes I should swap in or out of this amp to
make it a good Harmonica Amp?
Right now, since it's set up for guitar, I can only get the volume/gain to
about "2" before it feeds back.
FYI, I use a SM58 and/or a Hohner BluesBlaster.

Thanks very much for your tube-swapping answers!
Heath

Heath@xxxxxxxxxxxx