Modding the normal Fender
         channel for tweed sound?



Strato:
 
Some (maybe all?) of the Brown Fenders use 220K
plate load resistors. This will definitely change thetone
by making the channel more likely to break 
up at lower levels.
 
Just changing the tone caps to .022s and possibly
increasing the midrange resistor to 10 or 15K
can make a significant change in channel one.
 
Another thing I like to do is the "equal weighting"
mmod...this puts both channels in phase and allows
reverb and trem on both channels.
 
To do this, disconnect the wire from the coupling cap at
the output of channel 1, and connect it 
to the output of the same coupling cap for channel 2.
 
Mike K
KCA NOS Tubes
http://www.erols.com/bluestat/

I think I might just add a 100K midrange pot to the
tone stack. When you turn it up it removes the bass and
treble tone controls and gives the gain a boost.

         Lew Collins   (Lewguitar@aol.com)
    Date:
         5/3/2001 6:01 AM
 Subject:
         Here's what I'd do:



1. Put reverb and trem on both channels...a must!
2. Replace mid and bass tone stack with .02 &
.02...Orange Drops work well for this.
3. Replace 250pf treble disc cap with silver mica...that's
what the tweed Bassman used: silver mica.
4. If you have a midrange pot replace it with 25K. If
you only have a 6.8K mid resistor, make it 10K or
15K.
5. Replace the .047 coupling cap with a .02.
6. Maybe double the feedback resistor for a little
ballsier tone.
7. Do you have a bright switch or just a bright cap? if
you have a switch, replace the cap with a 47 pf on the
volume control and another 47 pf on the switch.
8. Enjoy your new amp!

I'd say it also depends WHICH 'tweed' sound you
want, because they vary greatly. If you're thinking of
the hotter end of the spectrum, a tweed Deluxe preamp
might work well in that amp. You've only got Vol, Bass
& Treble to play with anyway, so it's awkward trying
to configure a three-knob Bassman style tone stack in
your Normal channel anyway. A Deluxe-style preamp
would instantly hot-up the amp, with much more gain
in that channel, and would only use two pots (for Vol
and Tone), so you'd have one left to play with -- or
ignore.
 
I've done this in a couple amps, most recently a 1970
Super Reverb, simply by carefully pulling out the
channel as was (save parts for restoring if necessary!)
and rebuilding it as per the tweed Deluxe schematic you
can find in many books and on this site. It was
astoundingly hot in that Super, and because I'd done
the equal weighting with rev and tremolo on both
channels, you could also jumper them and blend the
two sounds. I don't have that amp any more, sadly: it
was a temporary 're-build and pass on' project.
 
A notion I'd heard more recently that would have been
good, though, considering the huge gain jump this mod
gives many amps, is to put a Master Vol in the leftover
third pot which just governs that channel. Even if you
think master volumes are the Devil's plaything, that
would give you a lot more flexibility for balancing clean
and crunch sounds between your two channels.
 
Brinsley Schwarz is writing an article about how to do
that very thing (tweed Deluxe channel plus master) for
the next issue of my magazine, The Guitar Magazine
(UK) which will be on the shelves here mid-June, in the
USA a couple weeks later I suppose. I'm not just trying
to get in a plug, but I don't have all his specs and
diagrams in yet so I don't know how to tell you about it
otherwise!