Tiptop CB808 User Manual

Introduction.

The CB808 is Roland's TR-808 cowbell sound generator adapted for modular
synthesizer use. The front panel contains all of the controls found on the original
TR-808 drum machine, allowing you full control over the sound’s volume levels to
mix with other drums, and accent levels. In addition to that, the CB808 includes a
pitch-modulating LFO with control over the LFO rate and modulation depth.

About the Making of the CB808.

The CB808 is a one-to-one clone of the original circuit found in Roland's TR-808
drum machine. During the design phase, we created additional features only when
implementation would not compromise the original signature sound, add excessive
costs, or sacrifice panel space. Cloning a circuit that was designed and produced
in the early 80's was not an easy task. A variety of obstacles including availability
of the original parts, the modern SMT manufacturing process, the differences in
+/-12V Eurorack power versus the +/-15V of the original 808, and far many more
were addressed in the creation of this module. To learn more about the process
of remaking the sound generator in this series please refer to the BD808 user guide.

Let’s get started.

To start using the CB808, just plug a gate signal into the GATE IN and plug the
CB OUT to your sound system and set the LEVEL half way.

Dynamics and Gain.

Level Explained:

The CB808 offers an enhanced output gain stage over the original 808 design.
This addition allows the output signals to get very hot so that anything flowing
from the module will be overdriven, generating additional harmonics through
distortion and clipping of the sound. This capability is one of the most useful ways
to get more sounds out of this circuit. This effect is easily noticeable by sending
the audio output with both LEVEL and ACCENT set to max into line level instruments
such as computer audio interfaces, outboard multi-effects, mixers, and even low
level devices like guitar pedals, mic preamps etc. This enhanced gain stage will also
make any synthesizer module operate at peak levels while adding interesting
harmonics or digital artifacts in the case of digital processing modules.

On the other hand, if all you want is a nice, clean 808 sound, setting
the range of the LEVEL knob somewhere between 0 to 70% will cover that.

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