1974 Marshall Super Twin 100 (Super Lead / Super Bass) 100-Watt Amp Head

Description

1974
Marshall Super Twin 100
is one of the most amazing amps never put into production.
This
Super Twin 100
combines a
Marshall Super Lead
,
Marshall Super Bass
, and
blackface Fender Twin Reverb
for vintage spec soaring leads, undeniable presence, and bowel shaking lows.
The back story on this amp is that it started its life as a 1974 Plush P1000S, which was let out to pasture. As the decades passed, it wound up in the hands of Steve McKinley of Atlanta Tube Amp. Reviewing its schematics, it was built to compete with the Fender Twin Reverb of its day but with all its circuit changes, it didn't have the same magic.
It was first painstakingly modified to pre-CBS blackface Fender Twin Reverb specs and it sounded beautiful but with all the possibilities during its "open heart surgery", it was on to greatness!
The initial
preamp gain stages
were made
switchable
between
Twin Reverb
(Normal) and
Super Lead
and/or
Super Bass
. Next, a
passive effects loop
was installed
with a volume control
(with nothing plugged in, it acts as a 2nd Master Volume). In addition, the
Negative Feedback Loop
(NFB)
was made
switchable between Fender and Marshall specs
. Also, a
Jumper Switch
was installed to combine both channels for massive tonal control (no jumper cable needed). Borrowing from Vox circuits, a
Tone Cut
was installed for a "late in the circuit" tone control. The Tone Cut control can be pulled out and then it acts as a
Master Volume
. The Reverb and Tremolo add their touches (reverb tank not pictured but is normally installed on the inside cabinet roof). The
Rob Robinette Humdinger Heater Hum Pot
was installed. It's an adjustable heater artificial ground used to adjust the resistance value between ground reference and the two heater wires to even out their voltage and minimize 60Hz hum. You simply adjust the pot by ear for the least hum.
The
preamp tubes
were carefully chosen for pristine tone and the
power tubes
are a matched quad of JJ 6L6s. (preamp V1 JJ ECC81, V2 Marshall ECC83, V3 Electro Harmonix 12AT7, V4 Electro Harmonix 12AX7, V5 Chinese 12AX7, and V6 JJ ECC81).
When set up for
Super Bass
(plugged into Super Bass channel with Bass preamp and NFB switches up), it has clean warmth for days, a grand canyon of lows and sounds divine. I rarely can turn it up passed three because it shakes the room!
When in
Super Lead
(plugged into Super Lead channel with Lead preamp and NFB switches up, Jumper Switch on but Super Bass controls turned to zero), the signature warm, loud, and clear leap out. When you pull out the Tone Cut to engage the
Master Volume
, you can turn up the preamp Volume for coveted golden vintage Super Lead gain that cuts like a light saber through paper. When you want more glorious low end, simply dial up the Super Bass controls for superhuman fullness and flip up the Super Bass preamp switch. Time stops as you're in tone heaven.
Last, but not least, in
Twin Reverb
(both preamp and NFB switches down), bask in the glow of the landmark gold standard of the blackface Fender Twin Reverb. Everybody should have a Twin Reverb and this one sounds heavenly.
As you can imagine, this
Super Twin 100
is a
jaw droppingly good sounding amp
with tonal capabilities most amps could only dream of.
Steve is already planning his next amp build is why this is for sale.
If you're already familiar with the vintage Marshall Super Lead / Super Bass experience, you don't need it explained. For those of you who don't, human words don't even come close to describing it.
Amp head with power cord and footswitch only. Ampeg cabinet not included.
See demos of this amazing amp on the Atlanta Tube Amp Facebook page.
https://www.facebook.com/profile.php?id=100064030963385
Get this extraordinary Marshall Super Twin 100 before someone else does.