808 Conga
The 808 has 3 conga sounds (low, mid, high). Each is the same with different tunings and decay times. It has a bright and saturated initial attack, with a short dull tail. Read some notes about it here.
1: Tune VCO-A according to the tuning guide below. Then turn VCO-A sine up in the mixer.
High Conga Tuning: Low: F#4, Centre: G4 +35 cents, High: A#4 -42 cents
Mid Conga Tuning: Low: B3 +21 cents, Centre: C#4 +18 cents, High: D#4 -6 cents
Low Conga Tuning: Low: E3 +2 cents, Centre: F#3, High: A3
2: Turn the VCF level up to around 2:00 or 3:00 (65% to 75%). Don’t let the signal go too far into the red.
3: Tune the VCF to the same frequency as VCO-A.
Make the filter self-oscillate by raising Q all the way up. Plug a tuner into the VCF out. Use the frequency dial to tune. Lower Q back down.
4: Switch the VCF to notch (NT2).
5: Raise Q 10 or 15% to brighten up the sound, but don’t let the signal get too saturated.
6: Create a subtle pitch drop by modulating the filter frequency with ENV-B by turning up VCF FM-1. Only raise it by about 10%. The pitch drop shouldn’t be too immediately noticeable. Don’t exaggerate it. Don’t let it boing.
7: Patch ENV-B to VCA-A. Keep rise at 0. Make the envelope very plucky. The sound shouldn’t ring out. Refer to the guide below for target decay times.
High Conga Decay Time: 80 ms
Mid Conga Decay Time: 100 ms
Low Conga Decay Time: 180 ms
8: Turn on soft clipping and add a small amount of overdrive. Set the amount so the initial attack gets boosted and then has less effect on the tail. You don’t want the whole sound to get overdriven. The goal is to have a bright attack, and a duller, less saturated tail. Check that the output light goes red at the attack, then quickly goes darker.
9: Optionally: Patch trigger out to VCO-A sync, and set it to hard sync. This can help create a more consistent attack click.
Optional Variations:
Try sending velocity to filter resonance so louder notes will be brighter and lower velocity notes will be more clicky.
Control pitch with velocity.
Exaggerate the pitch drop. Increase the filter frequency’s envelope modulation.
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.