[Harp-L] Fender Blues Junior - Tube Substitutions For Harp

[mark stafford]

Hi Listers,

I could not find anything in the archives for this although I am sure
it is there somewhere.

If anyone with successful results could kindly respond with
substitutions for the 12AX7's please (you can contact me off list if
you like?). I'm helping a friend who has just purchased a used blues
jr. and I am sure you could save us some valuable time and money so we
can just purchase AT's AY's or AU's...

cheers, great list.

Thanks Kindly, in advance,

Mark Stafford
birdst...@sympatico.ca
http://www.markbirdstafford.com

[John Kerkhoven]

A few years ago, following advice on this list, I swapped a 12AX7 for a 12AU7 to help control feedback on a Seymour-Duncan 84-40. There was a drop in volume, but the feedback was now under control. No troubles since.

This amp comes with 3 12AX7s. I swapped just the first.

Don't know how this transfers to a Blues Jr. YMMV

All the best,

John

[Richard Hunter]

mark stafford wrote:
<If anyone with successful results could kindly respond with
<substitutions for the 12AX7's please (you can contact me off list if
<you like?). I'm helping a friend who has just purchased a used blues
<jr. and I am sure you could save us some valuable time and money so we
<can just purchase AT's AY's or AU's...

Hi Mark, how's things in Toronto?

The usual preamp tube sub for harp is a 12AY7 or 12AU7. The AY7 is a higher gain tube than the AU7. I'd try an AY7 first, then an AU7 if you're still getting too much feedback with too little breakup. Either will give you more breakup before feedback than a 12AX7.

Regards, Richard Hunter

author, "Jazz Harp"
latest mp3s and harmonica blog at http://myspace.com/richardhunterharp
more mp3s at http://taxi.com/rhunter
Vids at http://www.youtube.com/user/lightninrick
Twitter: lightninrick

[John F. Potts]

Mark:

It's not listed on their website, but Eurotubes sells a set of JJ
preamp tubes to voice the BJ for harp. The configuration is: ECC81
(12AT7) in VI - ECC 83S (12AX7) in V2 - ECC 832 (12DW7) in V3.

JP

[Craig (Skip) Effress]

Harp Depot sells the tube set, also.....

[Dan Dial]

I found this chart of 12AX7 tube substitutions a while back. I believe this is
an accurate chart.

There are several sub that will work...you may have to try different ones in
various points to get what you want.

http://cydathria.com/fdm/12AX7_sub.html

Here are some sites I found that have tubes:

http://www.triodeelectronics.com/

*** Triode is an ugly web site, but they have tons of tubes and even more
information on tube amps *** I have ordered tubes from there a couple of times
and have always gotten quick shipment. They have also answered my questions
promptly.

http://thetubestore.com/

http://www.boiaudioworks.com/index.php

Good luck with your Jr.

If anyone is interested, my Harp Gear 35 is for sale.

Dan

[Mojo Red]

This is the exact set that I use in my BJ amp, and they sound wonderful.
JJ Tubes are pretty high quality (formerly Tesla).

Of course, if you combine those tube swaps with a new Webber 12A100 (P12R)
speaker, then your BJ will really be transformed into quite the tone machine.

Harpin' in Colorado,
--Ken M.

________________________________
From: John F. Potts <hv...@bex.net>
To: birdst...@sympatico.ca
Cc: har...@harp-l.org
Sent: Sat, December 11, 2010 6:14:03 AM
Subject: [Harp-L] Fender Blues Junior - Tube Substitutions For Harp