by Dan Torres
of the most sought after old Fender amps were the ones with a Bright
Channel and a normal Channel. The bright channel was so cool and so
crisp, I used to keep about a half dozen brown tolex and Tweed Fenders
on hand just because they had "bright channels."
|So what's the secret? Really
not much. Take a look a drawing #1.
It's a standard amp volume control. Drawing #2 is the
"bright channel" on most of those Fenders. The only
difference is the 47 pico farad (PF) capacitor across the volume
control!! It's a bright switch just turned on permanently. The
'58 and '59 Tweed Bassman has the same thing on the "bright
channel." Its a higher value (1000 pico farad or .001 micro
farads, called M F D) and it is also on the "bright channel"
of 1959 Marshalls.
Since the volume control is in a different part of
the circuit on these amps, the value can be higher. I find that
1000 pf on a Tolex Fender is far, far too bright.
open up your Fender, get a 47 pf capacitor (400-500 volt Available
from Mojo Musical Supply) and put it on the volume control (the two
tabs that aren't grounded.) There you have it - a vintage Bright Channel
anytime you want it! Seems too easy.
out drawing #3. Its the standard Black Face Fender bright switch.
You can see that it is just a larger capacitor and a switch to turn
it on and off. Again, pretty simple.
want to hop it up a bit, and get that vintage crisp tone, check out
drawing #4. It has the 47 pf cap added on the volume control (I do
this on just about every amp I modify,) and the bright switch cap
has been changed to a higher value for more boost. It's not necessary,
but makes for some real great sounds.
have a Deluxe, or Deluxe Reverb or any of the older Fenders with no
bright switch, I've included a drawing (#5) for a 1 meg push-pull
pot (Available from Mojo Musical Supply). Again, another mod I do
just about every time. The right push-pull pot will fit right into
the Fender, use the same bolts, and your knob (if it is a set screw
type knob) fits right back on. Throw the old pot in a little bag and
tape it in the bottom of the amp for restoration to stock later on.
extremely simple tricks will bring an amp to life like nothing you
ever heard before. Real simple, unbelievably cheap (capacitors are
about 25 cents,) and some great vintage sounds from your Fenders.
These tricks will work on any tube amp with a volume control. It is
entirely within "the rules" to mess around with the capacitor
values and types.) You can't destroy your amp, the worst you can do
is short the volume control to ground and just turn the amp off. You
can't create a dangerous situation.
|Ok, here's the warning rap. Read it every
|Warnings and disclaimer
Tube Amplifiers, all components and related products are electrical
products with extremely high voltages that if mishandled or
if used carelessly or for improper purposes, can cause life
hazards and serious personal injuries. Such equipment is dangerous
even when turned off or unplugged.
You shouldn't be working inside the amp unless you know
what you are doing.
Don't work on an amp plugged in.
Always discharge the filter capacitors before starting work.
If you don't know how, contact us for a reprint on how to do
it ("What the Hell are filter caps?")
Solder neatly, and use the smallest amount of solder you
Be careful, but have fun.
|Copyright © 1996 by Dan Torres
|All rights reserved
|Licensed by Sparpco Inc.
|A division of Sparpco Inc.
|1630 Palm Ave San Mateo CA 94402
Tube Amps by Dan Torres the "Never-ending Book"
|Contact Mojo Musical Supply for information on how to get your very own
Tube Amps" is available from Mojo Musical Supply. Dan
Torres is one of the most sought after tube amp experts in the
world. Dan has just finished the definitive book on Tube Amp Technology.
The new project from the Torres shop is a line of moderately priced
full custom tube amplifiers with lots and lots of new ideas and
|This article was created, researched and written
by the author. The ideas and/or opinions contained therein are
solely those of the author, and have not been verified or tested
by Mojo Musical Supply in any manner. Caution is advised when
dealing with electronic and electric materials or valuable musical
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