The Canadian Guitar Forum banner

1 - 4 of 4 Posts

·
Premium Member
Joined
·
143 Posts
Discussion Starter #1
I am fortunate to have such a great amp tech in my area ( Jack Ellis) who has been working on and building amps since the 1960's. He specializes in building and repairing the older (larger ) church organs in the lower mainland of BC. He also has built several amps over the years including this one I have posted (and purchased). He built three of these combo's years ago as that is all he could build due to the limited amount of chassis / parts available from a lesser known Hammond organ.
Here are the amp details in Jacks words:

Power amp from Hammond L100 organ with only minor mods including the original Hammond 2 spring long tank and circuitry unchanged.
Preamp and control panel built new to interface with the Hammond amp. Front end and tone stack similar to Fender but custom tweaked. 12AX7 added to amp chassis provides 1st stage preamp plus tremolo oscillator.
Tremolo uses output bias modulation rather than the newer LDR/Neon light found in most Fender amps because of the smoother modulation envelope and consistency over the speed range.
EL84s in class-A cathode bias push pull configuration. EIA Power rating of 15 watts according to Hammond.
Dual 10 inch Jensen alnico speakers from a Hammond F100 organ.

Tonally, it is definitely in the blackface camp with just a nice edge when pushed ( drive) to the max. Weighs in at just over 30 pounds. It will become a studio work horse for me as I think I will give it a retirement home here and keep it at home.
ellis 1.jpg
ellis 2.jpg
ellis 3.jpg
 

·
Registered
Joined
·
1 Posts
Cool amp. I was always under the impression that you couldn't do a bias vary trem with cathode bias - wonder how he implemented that?

AJ
 

·
Premium Member
Joined
·
143 Posts
Discussion Starter #3
If I had the knowledge technical knowledge of Jack Ellis I am sure I could explain. He is one of those people that can build literally from scratch. He did mention the tremolo takes a slight volume drop when in use due to the way it sits in the circuit, but I never solo with the trem on so works out real well.
 
1 - 4 of 4 Posts
Top