[sdiy] slightly OT: best tube tremolo? table radio amps revisited

[Don Tillman]

   > Date: Mon, 17 Jul 2006 09:58:26 -0700 (PDT)
   > From: dave at westphila.net
   > 
   > The tremelo/vibrato found in the brown fenders sounds really
   > good.  It splits the signal into high and low frequency bands and
   > modulates them 180 degrees out of phase.  Uses 3 12AX7 tubes to
   > do it but it's much more interesting to my ear than the plain
   > bias vary tremolo.

The "classic" Fender tremelo is a neon bulb and photocell in the
preamp.

Before that Fender used the high/low frequency band arrangement you
mention.

On the very earliest models Fender implemented tremelo by modulating
the bias on the output tubes.

The Vox AC-30 has a variant of the Fender dual band tremelo which ends
up being something between a tremelo and a phase shifter.

And some Magnatone models actually use vactrol / vacuum tube phase
shift stages.  (In an interview a few years ago, guitarist Robert Cray
mentioned using these amps specifically for their tremelo.)

Fun, fun!

  -- Don

-- 
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com