Re: Pro Junior tube swap

[The Bernadettes <mdestefano@xxxxxxxx>]

Dan Todd wrote:

> Happy Holidays to one and all!
> I  just got a new non-tweed Pro Junior (1X10 @ 15 watts) and want to
> boost the harp volume I can get before feedback.  In the archives,
> knowledgeable folks sometimes recommend switching the 12AX7's for
> 12AU7's.  I have never swapped out tubes before.  Is it as easy as: 1)
> unplug amp  2)  remove 12AX7's  3) replace with 12AU7's  4)  plug in
> amp and blow ??
> I also plan to play guitar through this amp.  I see so many other
> guitarists/harmonicists on the list these days. I wonder if my guitar
> sound will lose commensurate treble tones (I play in a Robert Junior
> style -- very few ripping post-Hendrix single string high leads -- more
> of a pre-60's Memphis Sonny Boy ensemble sound, if that makes sense).
> Any suggestions/ directions or tube brand recommendations would be much
> appreciated -- even a reputable online dealer's URL.
> Thanks very much for any help here, and have a great New Year everybody!
> Dan Todd

Dan,
    Yes unfortunately trying to change the gain characteristics of the amp
to optimize it for harp will hurt it somewhat for guitar.  You're gonna have
to kinda compromise a little for both.  I'd go with Bob Maglintes suggestion
of a 12AY7 in the 1st position.  This will help it somewhat for harp and
still be good for guitar, especially if you're going for a smooth, sweet
rhythm guitar tone, (you might actually like it better with a 12AY7 for
guitar.)  Even for harp I wouldn't go with all 12AU7's, this would kill too
much gain and the amp will lose a lot of it's "spank" or "bite".
    As a suggestion from another harp-guitar player, this is what I use for
gigs where I'm playing both harp and guitar, and I'm too lazy to lug two
amps...consider buying yourself a classic, vintage two channel Fender black
or silverface amp such as Deluxe Reverb, Vibrolux Reverb (my fave), Pro,
Super, or Bandmaster.  (P.S. don't get the reissues!!)  This gives you two
separate channels.  Stock, one will be perfect for guitar, then modify the
other channel for harp.  You'll have two separate, dedicated channels with
their own volume and tone controls.  No switching cords, fiddling knobs back
and forth, etc.  You can be playing guitar on a tune and just grab the harp
mic to blow a solo mid-tune without having to screw around with amp
settings.  Something to think about...save your pennies.

Tube dealers:
NOS tubes: KCA...  http://www.kcanostubes.com
                    Angela Instruments...   http://www.angela.com
Current production:
                JJ tubes, Eurotubes...   http://www.eurotubes.com
            various makers, New Tube Store...   http://www.newtube.com
                                    Hoffman Amps...
http://www.hoffmanamps.com

Good luck,
Don D.