808 Conga (Pinged)
This is an 808 style conga patch made using a pinged filter as a sound source. The conga has a bright and saturated initial attack, with a short dull tail. Read some notes about the 808 conga here.
1: Switch the VCF to NT2 (Notch). You can also try BP4. You what something with a steep curve that emphasis a narrow range of frequencies.
2: Tune the Filter:
Raise the Q slider all the way up: the filter should start self oscillating.
Plug a tuner into the VCF out jack.
Tune the filter with the frequency slider.
Use the guide below to help select a tuning within the 808’s conga range. The 808 has 3 conga sounds (low, mid, high). Each is the same with different tunings and decay times:
High Conga: Low = F#4, Centre = G4 +35 cents, High = A#4 -42 cents.
Decay Time: 80 ms.
Mid Conga: Low = B3 +21 cents, Centre = C#4 +18 cents, High = D#4 -6 cents.
Decay Time: 100 ms.
Low Conga: Low = E3 +2 cents, Centre = F#3, High = A3.
Decay Time: 180 ms.
3: Patch ENV-B to VCF audio in. Setup ENV-B to output a short click.
4: Lower Q until the filter stops resonating, and patch the VCF out to Main 1.
5: Adjust Q while firing the manual trigger button. Higher values will ring out too much. Lower values will have too much click. It should have a bright resonant body, and a short clunky tail.
Optional Variations:
Try sending velocity to filter resonance so louder notes will be brighter and lower velocity notes will be more clicky.
Further Reading
A short blog post on how to recreate the 808 Conga.
Pg. 6 has a brief description of the combined tom/conga circuit (LT/LC (MT/MC, HT/HC)).
Pg. 7 has a block diagram (top right, between the SD and BD).
Pg. 9 the circuit (centre).
Pg. 14 has a chart displaying the frequency, and decay times (LC, MC, HC).
Erics Synths EDU DIY Kick Drum user manual.
For a good explanation of how a bridged-T oscillator works, check out Pg 9 through 12 of the user manual for the Erics Synths EDU DIY Kick Drum.