Roland TB-303 with Devilfish Mod

via this auction
"The Devil Fish is a modification to the TB-303 - a synthesiser/sequencer produced by Roland in 1981/82, which has played a crucial role in the development of electronic dance music.

Features include:
• CV and Gate inputs.
• CV input to turn on Slide.
• CV input for Accent.
• CV input for Filter Frequency.
• Output for Accent.
• Audio In to filter.
• Audio In to frequency modulate the filter.
• Audio Out from filter (pre-VCA).
• Overdrive pot to control the level of oscillator going to the filter: zero to 66.6 times normal level.
• Separate control of Main Envelope Generator times in accented and non-accented notes.
• Volume envelope is no longer fixed, and can be varied from 16 msec through 3 seconds – and to no decay at all, i.e. for notes which last indefinitely.
• Soft Attack control gives attack times between 0.3 and 30 msec. (TB-303 attack was ~3 msec.)
• Slide time is variable to five times longer than normal.
• Variable Filter Tracking causes the oscillator CV to control the filter frequency.
• Internal Filter FM: a unique approach of AC coupled Filter FM from the audio output of the VCA.
• The Muffler is a unique post-VCA soft-clip distortion circuit which retains bass response.
• Push-button to manually activate Accent.
• Filter can be switched to self resonance.
• Accent Sweep has three modes and can be disabled.
• Filter Cut Off pot range doubled to 5 kHz max, and widened to include much lower frequencies.
• Env Mod pot range extended to include zero and go as high as three times the normal maximum.
• Bass response is improved.
• Lithium battery for at least ten years battery backup, so there is no need to install C-cell batteries.
• The six TB-303 knobs Tuning to Accent are mounted 1.5mm higher, making them easier to turn.
• The Devil Fish can still sound like a TB-303."