Ampeg VT22 Front & Back ViewsThe Ampeg VT22 aka: "The Twin Killer." This is likely an early 1970s vintage. I've had it
since 1986 and it has not had much use.
This amp puts out 120 Watts RMS of tube power through a pair of EV SRO 12" speakers.
This is probably the loudest production combo amp ever made. With it's high input impedance
( 5.6 Megaohms ) and extremely high input sensitivity ( .011mVac ) this amp rips up to max power
quickly and will push peak of over 250Watts easily (see the Spec pictures below). Compare this to
an 80Watt Fender Twin with an input impedance of 68Kohms and an input sensitivity of .100 mVac.
Keep in mind that an original Gibson PAF humbucker put out about .070mVac and a stock Strat pup
about .040mVac. (For comparison, a DiMarzio Super Distortion cranks a whopping .185mVac ) You
can see that pretty much any axe is going to completely drive the VT22 and never really push a Twin to
it's full capability
For complete info on the EV speakers, click here. I had intended to sell the speakers separately for
$400 and keep the amp when I still had the Ampeg 4-12 cabinets. It is clean and LOUD with a lot of
control over the tone it produces (see Front Panel Controls pictures below).
The VT22 is original, except for the speakers, output tubes, one 12AX7A preamp tube, the AC Outlet,
and the Standby neon light. The AC outlet was cracked and I found an exact replacement. The Standby
light was broken when I got the amp.
The amp got weak back in 2000, three of the original Magnvox 7027 tubes tested marginal, and one
was bad. I replaced them with a set of matched Ruby Tubes 7027A. My cost for Ruby Tubes was $17.95
each, retail is $31.50, if you can find them. The 12AX7A replacement is a generic tube, $5.00 (I lost the
original when the power tubes were changed.)
The tolex covering and speaker grill cloth are in very good shape with only minor wear and scratches. The
faceplate and controls are also in good shape with some minor corrosion. The casters (wheels) are very
sturdy and easily removable.
I'm asking $650, buyer pays shipping and insurance from Santa Rosa California. This amp weighs
about 160lbs and will be very difficult and expensive to ship. I suggest picking it up in Santa Rosa
or paying me to deliver it to you.
Front Panel Controls
Each channel has a Volume pot and three position (3-pos) Sensitivity (input level) rocker switch. The
Treble, Midrange, Bass and Reverb pots control both channels. The 3-pos Ultra Hi switch expands the
range of the Treble control. The 3-pos 1 2 3 switch above the Midrange pot selects different taps and
capacitor combinations from an internal Torroidal Inductor changing the midrange "peak."
Front Panel Switches
There's a bit of corrosion on the switch hardware and the silk screening is faded.
The back panel. There's a tube locator guide showing the tube type for each tube location.
From left to right:
* there's a strap at both ends for winding the AC cord,
* a 6amp fuse (the 85W Twin Reverb uses a 2 & 1/2 amp fuse!),
* the Hum Balance control (already adjusted),
* two External Amp 1/4" phone jacks to power two other power amps with the VT22's preamp
signal (does not interrupt the VT22 power amp section),
* the Reverb lock. A metal band expands to push the springs up against the top of the can so they
won't bounce during travel,
* the Speaker and External Speaker jacks wired in parallel,
* the Speaker Impedance Switch, with taps for 8, 4, and 2ohms. The total impedance of the main
speaker or the combination of Main and Extension. If you plug two 8 ohm cabinets in you set the
switch to 4 ohms.
SpecsThese are specs from the Ampeg company for the later version with 3 12DW7 tubes instead of the
earlier version with the 6K11.
SchematicShown smaller than actual size. The legend section to the right is shown actual size. I also have the V4
schematic which is bigger and easier to read. You can find lots of other amp and stompbox schematics
by clicking here.