6
Explanation of Controls
You may be wondering why the Twin Tube Blue uses a 16-volt AC transformer
instead of a common 9-volt DC adaptor or even a battery. The Twin Tube Blue relies
on an internal transformer to obtain the high voltage the dual triodes require. The
transformer cannot work on DC voltage. One alternative would be to run the tubes
on low voltage in “starved plate mode.” Here, the tubes are used like a clipping diode
and do not actually amplify. Though starved plate voltage is used in some inexpensive
tube stomp boxes, it is not true tube amplification. The circuitry in the Twin Tube Blue
enables the tubes to work like the tubes in the preamp section of a high quality tube
amplifier. Another alternative would be to supply a dedicated AC power cord and an
internal high voltage transformer or a DC-to-DC switching converter. However, these
options would make the Twin Tube Blue larger, heavier and more costly. With the Twin
Tube Blue you are getting true tube tone AND tube amplification with minimal size,
weight and cost.