Acid Breaks

What it is

A TB-303 is a monophonic bass machine with a resonant filter and sixteen steps of memory, and it has been reinvented as a lead instrument roughly every four years since 1987. This is the breakbeat version of that. Bomb The Bass and Renegade Soundwave were putting acid lines over funk breaks in London in 1988, and a decade later the Thursday Club and TCR crowd did it again on purpose, at 140 rather than 118. The scene overlapped heavily with nu skool breaks, shared the same clubs, and in a lot of cases the same records: what separates an acid breaks track is that the 303 pattern is the tune, so the drums are programmed thin and dry to leave the filter sweep room to be heard. When the 303 rests, there is very little going on.

What it sounds like

Dry drums and a screaming filter. The break is high-passed, compressed and short, with the room tone taken off, because reverb behind an acid line turns into mud within four bars. The 303 is distorted at the input rather than the output, so the squelch keeps its edge. Hats sit on offbeat sixteenths and stay quiet. Underneath, a clean sub sine holding one note for whole bars while the 303 moves over it. The overall picture is narrow and loud in the middle, with the top end reserved almost entirely for the filter resonance.

Key elements

• The 303 as the leadSixteen steps with accents and slides, filter cutoff swept by hand over eight or sixteen bars. The accent pattern is the composition here, more than the note pattern is.
• A break with the room taken offGated, high-passed at 200Hz and short. Anything ringing behind the 303 fights the resonance, so producers strip the break back until it is closer to a drum machine than a recording.
• One sub noteA sine holding the root while the 303 does the moving. Two basses in the same octave cancel, so the 303 gets everything above 150Hz and the sine gets everything below.
• Distortion before the filterOverdrive on the way into the low-pass rather than after it. It thickens the harmonics the filter then sweeps through, which is why a clean 303 into a distortion pedal sounds different from this.
• Space to hear the sweepWhole bars where the arrangement drops to drums and the acid line alone. A sixteen bar filter sweep only reads if it has that frequency band to itself.

How to get them

• Write the accents firstProgram sixteen steps with about five accented and two or three slid, then leave the notes alone. Move the accent placement rather than the pitches when the pattern gets boring, because that is what a 303 responds to.
• Sweep by hand over sixteen barsRecord the cutoff move live on a knob rather than drawing a ramp, and keep the take with the uneven bits in it. Resonance at about three quarters, envelope modulation just under half.
• Gate the breakPut a gate on the loop with a 1ms attack and a 60ms hold, keyed off its own signal, then high-pass at 200Hz. You want the transients and none of the tail.
• Split the bass job in twoLow-pass a sine at 120Hz for the root note and high-pass the 303 at 160Hz. Sidechain only the sine to the kick. Trying to make a 303 do sub duty at 140 is what makes these tracks disappear on a big system.
• Keep the hats quietClosed hats on offbeat sixteenths at velocity 40 or under, and one open hat a bar. The high end belongs to the filter, and a bright hat pattern will mask the exact thing the track is about.
• Arrange around the acid, not the drumsBring the 303 in filtered shut, open it over sixteen bars, drop the drums for four while it screams, then bring everything back. The drum arrangement should be almost static underneath.

Reference points

Bomb The Bass and Renegade Soundwave for the 1988 version, then Rennie Pilgrem, TCR, Uberzone and the Thursday Club nights for the later one. Named as reference points for the sound, not as endorsements.