THERE !!!
ok, have fun now, that should fix
Not on the doepfer power cable!
This is on the Belton Brick (aka "brick") itself where it connects to the pcb.
I just soldered it onto the pins on the opposite side of the pcb to the brick.
No, it's just on the power supply for the brick.
Numbering of pins on the brick, as it sits moounted in the module, start at 1 at the top.
Last two pins at the bottom are 12 & 13.
I use a ceramic 10u which is perfect. If you have an electrolytic check voltages for orientation.
(I forget, but if you get stuck I'll check)
as far as I can work out, it's the brick that generates the noise, and this gets out into the analog circuitry of the module.
10u capacitor from pin 12 to pin 13 of the brick.
Noise fixed.
Now I've got this going I think it's a really nice little sequencer.
Great feature set, with the triggers and step length control.
...but without a fix it wouldn't run, the input on the op amp where the clock comes in had been left floating by the designer and with a genuine TL072 the clock in stops functioning as charge builds up. Added 3M3 resistor to ground (back of board) and it comes to life. (probably with a cheap "fake" op amp the problem does not manifest, lower input impedance)
Voltage range of out put is 0-10V, so needs to be used with an attenuator. (I added voltage divider on output for 0-5V)
There's no protection against reverse connection, no 100n caps near the op amps for stability...but it works.
It doesn't go far into the audio range, and timing on the CV lags the clock, imperceptably but enough to confuse one of my quantisers (some quantisers have a setting for this reason)
Easy build and the only special component is the rotary switch.
Befaco Stmix 4-Channel Stereo Mixer Module
Has anyone tested them - know what the befaco is like noise-wise?
-- converted
Not heard any noise. It's just the usual op amps in a mixer with only 1:1 amplification so would take some serious bad design choices to make it noisy.
Nice module. Using left input only gives you mono. Aux in is handy.
