Chapter Four: Two Pre-Amplifiers
4.1 Pre-Amplifiers and their Jobs
The Diezel Einstein comes equipped with 2 different and totally independent preamps.
This allows the artist to play through nearly all musical-styles without having to make
major changes to his/her amplifier. The preamps are voiced todeliver the most
wanted guitar tone flavors: Clean, Crunch, Heavy, Lead. This design concept delivers
stellar guitar sounds with excellent playability, warm dynamics and razor sharp
equalization possibilities. The tone controls work in an unusually wide range, so a little
adjustment does quite a lot. As with so many things, less is often more. We suggest
you start exploring the channels with all controls set to 12:00 o’clock, and the master
volume just slightly cracked open. (To avoid hearing damage)
4.1.1 Channel One (low to medium gain)
Clean Tone is a very sensitive subject, because there are so many different ideas on
how a clean amp should sound like. Clean tonal textures require much higher
dynamic range than distorted sounds. From hard and percussive sounds to soft,
warm, and blossoming tone. Einstein was designed to offer as many of the clean
varieties as possible. Your choice of guitars and pickups will have a large part in this
equation.
Channel one has three modes, selectable by a toggle switch near the channel one
gain knob. The modes pre-select different gain stages in the pre-amp, allowing this
channel to span the range from extreme clean to a heavy crunch. A player that does
not require a clean channel can use these modes for alternate distortion sounds.
4.1.2 Channel Two (high gain)
This channel is voiced for single notes, or for very heavy and massive rhythm
guitar. Due to its slight midrange accent and very high gain, it possesses a good
punch, will play with ease, and gain authority to rule any stage, or studio. The “less
is often more” rule applies here
also.
4.2 Pre-amplifier Tubes
The pre-amps are equipped with 12AX7 tubes in all positions. The pre-amp tubes are
not designed to produce high power output. Therefore, their life expectancy ismuch
higher than that of the power amplifier tubes. This is not to undermine their utter
importance in overall sound and response ofthe amplifier. Also, annoying defects like
crackling noises and low dynamics are directly related to defective pre-amp tubes.
Like all other tubes, 12AX7 tubes come in many different gain stages, and offer a
wide variety of tonal behavior. Our choice for production was made to ensure a wide
variety of tones, with low noise and good
reliability.
4.2.1 Microphonics and Bad Noises
The overall performance of pre-amp tubes is easily influenced by external
mechanical factors. Malfunction in these external components will manifest
themselves by a sudden, high-pitched feedback sound. The input stage is especially
suspect to these phenomena. If one encounters microphonic tube behavior, then the
first tube should be checked as a rule. Pre-Amplifier tubes can also cause a hum or
other bad noises, like crackling or ticking.
