Fender Super Twin distortion channel mod

Jazz P Bass · 10-16-2009, 06:54 PM

A customer brought in a Fender Super Twin CBS amp. He wanted to know if anything could be done to the distortion channel to make it sound better.
Curiously, I could not find the correct schematic for his amp.
The closes that I could get was the Super Twin Reverb from Schematic Heaven. Minus the reverb it was spot on.
Apparently Fender tried to fix the original crappy channel with another crappy one.
On the cathode of V3, after the 4.7K cathode resistor they changed the circuit from just a 3.3K resistor to a 2.2K R paralled by a diode into a coil (marked 01194 4 on the scheme).
I changed the 2.2K resistor to a 1 meg ohm. It changed the whole channel for the better.
It is not a heavy metal distortion, kind of a soft distortion.
Customer was happy. Thought I would pass it along.

10-16-2009, 06:54 PM	#1
Jazz P Bass Senior Member Join Date: Dec 2008 Location: Wernersville, PA Posts: 739	Fender Super Twin distortion channel mod A customer brought in a Fender Super Twin CBS amp. He wanted to know if anything could be done to the distortion channel to make it sound better. Curiously, I could not find the correct schematic for his amp. The closes that I could get was the Super Twin Reverb from Schematic Heaven. Minus the reverb it was spot on. Apparently Fender tried to fix the original crappy channel with another crappy one. On the cathode of V3, after the 4.7K cathode resistor they changed the circuit from just a 3.3K resistor to a 2.2K R paralled by a diode into a coil (marked 01194 4 on the scheme). I changed the 2.2K resistor to a 1 meg ohm. It changed the whole channel for the better. It is not a heavy metal distortion, kind of a soft distortion. Customer was happy. Thought I would pass it along.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Fender Twin Amp - Gain channel sucks, clean channel has limited Bass	TerryCline	Maintenance, Troubleshooting & Repair	5	07-16-2009 06:45 PM
Fender Super Twin	Sparky664	Guitar Amps	2	04-03-2009 11:33 PM
135W UL Twin normal channel mod to Bass Guit. Channel	darrellcheng	Mods & Tweeks	2	01-27-2009 03:23 AM
Funky distortion circuit discussion - fender 'super twin' amp	tele_guitarist	Theory & Design	4	08-13-2007 06:33 PM
Super Twin distortion?	drewl	Maintenance, Troubleshooting & Repair	3	07-11-2006 03:22 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)