Chapter Five: Power Amplifier; Tone And Volume Of The Power Amplifier; Master Volume; Presence - Diezel Einstein Owner's Manual

Chapter Five: Power Amplifier
5.1 Tone and Volume of the Power Amplifier

5.1.1 Master Volume

As the name suggests, this controls the overall, volume of the amplifier. There is also a
second, selectable master volume control, which allows volume adjustments via remote
control device while playing.

5.1.2 Presence

The presence knob controls frequencies over 3kHz. Treble is produced and dispersed in a very
small beam from the speaker, so be sure to position yourself in the projection area of the speaker
when making adjustments.

5.1.3 Deep

The Deep Control is an active bass control contrary to conventional bass controls. It
controls the frequencies around 120Hz without influencing the overall dynamic range of the
power amplifier. Diezel GmbH. is not responsible for disintegrating speaker cabinets.
5.2 Power Amplifier Tubes

5.2.1 Function

As the name suggests, the power amp section is the part of the amplifier that produces
output power, measured in watts. Preamp signals are sent to the power amp(s), which amplifies
this signal to a level that is acceptable for loudspeakers. Guitar amplifiers utilize several different
types of power amps, which differ in output power and tone. We chose the tube type power
amplifier for its tried and true performance and familiar tonal behavior.

5.2.2 Selection

Diezel GmbH. installs the most reliable and best sounding tubes that are currently available in
sufficient quantities. So it is possible that tube brand and tube type will change during
production. You can fine-tune your Einstein by having different type and brands of tubes
installed, however, it is imperative that the amp is biased properly. Einstein utilizes 4 power
tubes, organized in 2 pairs with dual bias possibility. This allows use of 2 different pairs of
power tubes, either the same or the different types. Yes, this means that in a 4 - tube Einstein,
you can mix 6550's with EL34's, or 6L6's with KT88's etc. Cool!
A quick and a general overview of the most common tube types for the Einstein:
EL34/6CA7: aggressive, slender low end, higher total harmonic distortion Recommended bias:
30-35mA
5881/6L6: great tube for clean sounds, good blues tone, also strong bass and excellent clarity.
Recommended bias: 25-35mA
6550: very loud, very good dynamics, strong low end, amazingly percussive. Recommended
bias: 40-60mA
KT88/KT100: similar to 6550, but very punchy with great clarity and warmth. Expensive.
Recommended bias: 35-50m