NLC Doof Drum Module - Build notes

These are my build notes for the Nonlinearcircuits Doof drum module.
It's Eurorack format.
This is a very different circuit from the 808 & 909 clones doing the rounds today.
Can't believe I would ever tire of those sounds but its great to have something different.
This circuit uses a trimmed down NLC dual OTA VCO and the VCA from the NLC matrix mixer
(a future build).

 I built the OTA VCO over a year ago.
http://djjondent.blogspot.com.au/2015/03/nonlinear-circuits-dual-ota-vco-build.html
That VCO used a OTA or Operational transconductance amplifier.

The topology is common enough in many drum synths: Trigger circuit, envelope follower, VCO, VCA.

Get started with some tanning. It's the Aussie way.

Firstly the virgin PCBs & faceplate:


First get those !Cs in.
Now the rest of the SMDs
I'm using a 10K on the RL ... LED resistor
Stuff in the through hole stuff:
pOTS & jacks next.

Now the LED. Get the orientation right. The anode is the long lead.


initial tests:
Initially, with a headphone, I found the volume very low and the LED didn't light up.
The LED resistor I used was a 10K. This is for super bright LEDs.
I swapped it for a 1K and noticed a sudden increase in volume & that the LED lit up.
I decided to do another swap. This time for a 510 R.
Much much better !!!
Very loud and the LED lights up nicely thanks.
:-)

Links:
1. NLC Build Notes
2. Muffs : adjusting output level of the Doof
3. NLC blog spot