Re: Feedback on Fender Blues Junior amp

["Bob Maglinte" <bbqbob917@xxxxxxxxxxx>]

- ----- Original Message ----- 
From: Sandra Laviolette
To: harp-l@xxxxxxxxxx
Sent: Saturday, October 11, 2003 3:32 PM
Subject: Feedback on Fender Blues Junior amp


I rented a Fender Blues Junior amp for a month to see how I like it before
buying it and its OK but I'm having problems with feedback.

I have a shure green bullet mike (new, not vintage with 1/4 inch jack). I
set the volume to 12 (to get a crunchy sound) and master to 1.75 and I get a
good sound but any higher than that on the master and I get feedback. The
amps works fine with a guitar at 12/6. Is this an impedence problem? is it
fixable or should I just consider another type of amp and if so which?

(reverb is at 1, treble 1, bass is 12, mid around 7

Hi Sandra,
When it comes to harp, master volume controls creates FAR more problems than
it solves. If anything, set the MASTER volume control to 12 to completely
negate this circuit, because not only does iot cause more feedback problems,
it makes the harp so damned crunchy that you lose ALL dynamic touch and tone
variety from your chops. Once the master volume is up on 12, I'd roll the
bass back down to anywhere between 6 and 10 (whatever sounds right to your
year), and maybe the middle anywhere between 3 and 6. The treble setting is
you have is usually more ideal when using an Astatic JT30/Hohner Blues
Blaster with a crystal cartridge in it, but with Green Bullets, I find it
usually better setting it between 2 and 3.

One thing you need to bear in mind that guitars are a different animal
entirely, and the signal coming from ANY harp mic is about 50 times STRONGER
than what's coming out of any guitar, and don't be surprised that you can't
get past 3 or 4 on the main volume. Also, if there's a fat switch on it,
keep it in the off positition because it'll be a total feedback problem that
never ends.

The one thing you may want to consider is changing the preamp tube in the
first gain stage (the one nearest to the input jack) from a 12AX7 to a
12AY7, particularly an NOS (new old stock) tube.

My own personal choice for a newer low wattage amp for harp is a Fender Pro
Junior, which I've found is simpler to use and much more harp friendly,
especially the older ones that have the blue painted alnico magnet speakers
in them. There's only a single tone control, and all you need to do with it
turn the tone control ALL the way down.

Hope this helps.

Sincerely,
Barbeque Bob Maglinte
Boston, MA