ob1techno/valvs

A cascading quad tube VCA module in Eurorack format.

valvs's Issues

VCA1 CV pot positioned incorrectly

Needs nudging to the right a little to line up with the rest. Also needs correcting on the panel.

Cascaded signals need to be inverted.

Needs an op-amp inverter stage.

LED Polarity?

Hi. There is no indication on the PCB of the LED polarity. Cathode in square or round?
This is the black PCB supplied by Pusherman.

Missing supplier link in BOM

The v1.01 BOM is missing a supplier (Mouser) link for the 750R 1/2W resistors.

Bypass the Ferrite SMD components ?

I want to build this module but I can't find which ferrite smd components were used. Can I bypass these components by only soldering a bridge on the pads? If these components must be used, do you have the reference for the ferrites used?

All pots backwards

Having issue with high background noise that seems to depend on other LEDS/screens in other modules

so I've built the module half a year ago and but haven't tested it extensively or even calibrated it really. Now today I set up a new rack and tested everything. On my unit, there seems to be an issue with very noticeable background noise that seems to depend on the other modules connected to the same PSU/near it. Specifically, when I unplug modules with oled screens and modules that have many LEDs, the background noise is considerably less.
I never noticed this in my old rack, might have been there already though since I didn't get to use the module much until now.
Do you think this could be caused by the power supply being strained (my new rack has a relatively small PSU for it's size), some RF thing or the tuning/calibration of the unit?