Voodoo Lab Amp Selector User Manual page 5

guitar amp. This insures that your guitar pickups will see the correct
load and therefore sound their best. Using a buffer amplifier is
what allows us to drive multiple amplifiers and a tuner without
excessively loading your guitar and destroying your tone.
Each amplifier output is coupled using a high quality shielded and
sealed transformer. Isolating each output with a transformer is what
breaks the ground paths between amplifiers. Without this, current
would flow through ground loops causing your amps to hum. In
addition, we have developed a proprietary matching technique to
drive the transformers. By carefully matching impedances and
component values we are able to greatly improve the performance
of the transformer. The result is a true, super accurate sound without
any loss of tight low-end response.
The Tuner output provides a copy of whatever goes into Input-A.
This is a non-isolated slave output for a variety of purposes. It is
always active regardless of amp switching status. Typical uses would
be to drive a tuner, direct out for recording, or to chain additional
Amp Selectors.
Individual level controls allow you to conveniently balance volumes
of each amp. Normal position is about 3 o'clock. At maximum they
will provide a very small amount of boost. Any significant volume
changes should be done with the level controls on your amp itself.
In normal operation, the amp select buttons simply toggle each amp
output on and off. Check out the Operation section of this manual
for programmable switching options.