ADDAC104

Following our ADDAC103 T-Networks this new module is also inspired by Twin T-Networks circuits used in many legendary drum machines. A simple 4 voice module with frequency controls for each of the voices. This new module also features CV inputs with attenuverters for each voice Frequency. Due to the specificities of the circuit and to keep the module at a low price these inputs are not calibrated to 1v/octave.

At each voice input there’s a gate to trigger converter so any input source is possible.
Audio inputs can also be used as an input, in this case and due to the nature of the gate to trigger converter, each voice can be used as very destructive filters.

The top 2 channels feature a higher frequency range, the bottom 2 channels feature a lower frequency range.

Features;
4 Voices each with:
Frequency control with CV input and attenuverter Frequency Range Switch, Low/Mod/High
Trigger Input
Audio Output

Summing Mix output with Volume control

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This module is also available as a full DIY kit.

Specs:
8Hp
2.5cm deep
50mA +12v
50mA -12v

Note: All specifications and features are subject to change without previous notice.

In case you're wondering: Sure! We can get you a custom coloured front panel for the ADDAC104.
It has an additional cost and takes 4 to 6 weeks to be ready.

A custom colour panel can be done in either Red, Green, Blue, White, Silver Gray, Yellowed Silver, and Dark or Light Bronze.

Print colour varies between Black, White, or Red, Yellow, Blue and Green. We recommend lighter-tone print for darker panels, and vice-versa.

Please note: we don’t stock custom coloured panels. For every custom order we need to make a single panel order from our panel provider. This explains the panel price and lead time.

This module is also available as a DIY Kit from Thonk, Exploding Shed, Soundofyou.eu and Synthcube.
 
Here's the detailed step by step Assembly Guide Pdf:
http://media.addacsystem.com/diy_guides/ADDAC104_DIYkit.pdf

Troubleshooting

Usually there are 3 building mistakes with the ADDAC104 DIY builds:

.1 - The vactrols polarity is reversed.
First, get familiar with the lm78l05 pinout (here); locate the output pin and the ground pin and check with your multimeter if the output pin delivers a voltage around 5v. To do this, set the multimeter to DC voltage and point the black probe to ground pin and the red probe to the output pin. If you read a voltage around 5v the LM78l05 is fine.

.2 - The user did not calibrate the trimmers properly.
To calibrate the trimmers, keep in mind that these are 20-turn trimmers and they only affect the vactrols on a very short range of turns. First set the switch to middle or low position, turn the potentiometer full clockwise and start turning the trimmer that is related to that channel. Turn it anti-clockwise until you hear the “bongo” sound. If you turned the trimmer all the way to the end and nothing happened, started turning the trimmer clockwise. Since your potentiometer is fully clockwise, tune to the highest pitch possible on the trimmer.

.3 - The user plugged the power in reverse and the lm78l05 is dead.
Check again vactrol polarity; if the vactrols are reversed nothing will work.