Thomas Organ amp help

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Thomas Organ amp help

Postby beaulieu on Thu Jan 23, 2014 3:49 pm

I have a Thomas A-1 amp. I have installed 1/4 input and output. Vol pot. I have "tweaked" a few comp. but I wonder if someone can look at the pics and give ideas? You can only turn the vol to 1 then it starts to compress. amp has 2 el 84's 6ca4 and a 12au7 and an ax7. I am sure one of you guys already knows what parts I need to change/remove. I have a 100k vol and no tone controls. see pics and thanks in advance. Mark
Image
Image
Mark
69 "Real"Plexi 1992
73 1987
68 1987/86 build NOS parts
12000 series build NOS parts
2554 (Black)Jubilee
7 4x12 cabs left LOL
71LesPaul deluxe
2 Charvels
2 GSXR 1000's
2 PitBUlls (pets)
MXR pedals
NOS Amp parts(Marshall)
beaulieu
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Re: Thomas Organ amp help

Postby Papa Dog on Thu Jan 23, 2014 4:46 pm

let's see if we can find a schematic.
Looks like it well could turn into a decent sounding low wattage amp.
BTW, you said you had made some "tweaks?"
might help to know what you changed and why.
There Ain't No Such Thing As A Free Lunch.

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"To talk of many things:
Of shoes--and ships--and sealing-wax--
Of cabbages--and kings--"
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Re: Thomas Organ amp help

Postby beaulieu on Thu Jan 23, 2014 5:09 pm

Hi there..Thanks I changed a resistor (NFB?) 100k changed 2 capacitors to mustard caps going to the el84's. Trying to talor the sound a little. I found that it might be the same as a 4732 silvertone. I know Marshalls and am trying to use that knowledge to this amp. It says Thomas A-1 on the back and says C.A. tone cabinet. I have some of it figured out like the transformer wires and would like to remove comp that aren't needed and tweak from there. I did change the filter caps but amp still has a hum. Mark
Mark
69 "Real"Plexi 1992
73 1987
68 1987/86 build NOS parts
12000 series build NOS parts
2554 (Black)Jubilee
7 4x12 cabs left LOL
71LesPaul deluxe
2 Charvels
2 GSXR 1000's
2 PitBUlls (pets)
MXR pedals
NOS Amp parts(Marshall)
beaulieu
Squire
 
Posts: 740
Joined: Sun Jul 08, 2007 4:29 pm
Location: Western Md


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