ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

 
Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

Weird Marshall Combo


 
10/14/1998 4:36 AM
Liam
email
Weird Marshall Combo
Just got a badly burnt Marshall in for repair. Anyone know what it is? Here's the details.  
 
Bluesbreaker cabinet w. Plexi control panel  
2 x 12AX7, 2 x EL84  
2 x 12 Pre Rola Greenbacks  
Solid state rectifier  
2 Channels, disgusting RC network tremolo  
Volume controls BEFORE the driver (BIG HISS!!)  
 
Grill cloth is brown basket weave, so it's probably '67-'69. The circuit approximates a 2022T, but they never made a 2022 combo as far as I know, so what the hell is it? Any ideas would be much appreciated.
 
10/15/1998 8:52 AM
Richie
email

Liam:This does sound like an oddball,Looks like you figured some things out,the grill cloth,around 68,the speakers before[1970] they made the 1973[model 18 watts with trem] and looked like a bluesbreaker,but they had a rectifier tube and 3 12ax7s,unless they changed it at one point,to a ss rectifier and ss trem circut,then it would have the same tube config. as the 2022t.Marshall also around that time offered options,and special mail order items that were not listed in the books.Does the speakers have a date code? This may have been some special order for someone.Are the controls and inputs setup like the bluesbreaker? Or are they seperated? They made the Artiste model too,it looked like a bluesbreaker, but tubes were different.I have seen some of their amps in books,but looked at a bunch of shows to find them,and have never seen any.This reminds me of the piggyback bassman in the Pittman book,this is the only one anybody has seen.It don't have a stamp or model no#. anywhere?Maybe some other Marshall freaks can figure it out. Good luck [Richie]
 
10/19/1998 5:32 AM
Liam
The speakers are '66, but the amp must have been made later. I've decided it must be a 2022 prototype, because the chassis has the hole for a 3rd tube blanked off, and so is probably a 1973. I reckon it's a prototype because it's full of factory installed errors - like the trem circuit is hooked up wrong, and one half of the PI is hooked to pin 1 instead of pin 2 of a 6BQ5!! I've fixed ot all up, but it seemed a shame to change something that had been wrong for that long.  
 
The controls are split up like a 2022.  
 
I was really surprised to find this is a Class A circuit, and that the cathode bias set-up is ridiculously hot even by Class A standards.
 
   Page 1 of 1