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INTRODUCTION
Congratulations! You are now the proud owner of The Percolator 2W 1x8 Combo from Zeppelin
Design Labs. The Percolator has been designed for electric guitar, cigar box guitar and harmonica.
Intended to be used in a variety of situations from a bedroom practice amp, to a small stage gigging
amp, to a small studio amplifier, the Percolator should give you a lifetime of great tone. With only 2
watts at full volume, the Percolator offers some serious cranked up tone at bedroom levels. Unlike any
other production guitar amp, it has an all-tube signal path and uses only one (NOS) Compactron tube.
The single volume knob allows for warm, rich, clear tones at lower levels and aggressive, overdriven
tones at higher levels — all at a moderate volume.
Like all ZDL products, the Percolator was designed by musicians and audio enthusiasts, using only the
best components. Each combo is hand-built right here in our lab by the owners of the company, giving
each one its unique character. All of our products are thoroughly tested and inspected to make sure
they meet our requirements before they are sent out to the customer. We make sure that each amplifier
is the best it can be before you play it! We’d love to hear your feedback about any of our products.
Send an email, or post on the ZDL forum.
In order to get the most out of your Percolator, please read this manual before you begin rocking out.
SOME HISTORY...
The Percolator was designed around a single tube developed by GE in the early 1960’s under the
brand name “Compactron.” Compactron tubes have multiple amplifier sections in one bottle. The tube
in the Percolator has two triodes and one sharp cut-off pentode. That’s the same topology as the Fender
Champ, but in one bottle! This tube was never intended to be used in an audio circuit (it was originally
designed for use in various parts of a TV circuit), but it works and sounds great in a guitar amplifier.
Since this tube is rarely, if ever, seen in guitar amps, it offers a rather unique tone.
Compactrons were developed in a time of fast technological growth. In the early 1960’s transistors
were becoming more stable and practical for use in more demanding circuits. They also were
much smaller and didn’t require as much power (via heating filaments). The tube market was being
challenged and threatened by this new solid state competitor. The GE corporation (which was one of,
if not the most prolific tube developers in the world at the time) was well invested in their miniature
tube line and wasn’t too interested in making the transition to transistor development. So to compete
with transistors and give tubes a few more years in the market, the engineers at GE developed the
Compactron that could take the place of several tubes with just one bottle. It was the tube equivalent
to the integrated circuit. They were mostly designed for use in the color TV market, but some of
them did find their way into radios and hifi amps. Ampeg even used a Compactron in some of their
preamp circuits. GE made a big push to promote and use these tubes in their products, but eventually
transistors did win the technology battle and tubes were altogether replaced in televisions, leaving
large stockpiles of unused Compactrons in warehouses. The last Compactrons were made in the
early 1990’s and are still readily available today as “new old stock” (NOS) items. The Percolator,
with its single Compactron tube, givesus a chance to re-purpose a piece of tube history, while
offering unique tonality in this modern market.
