Ambika not making sound


#1

Hello! Just put together an svf ambika, and I get orange lights on all the voice cards. The mobo lights and menu flash as usual and I can see the oscillators working on the mobo leds. I midi’d it up with my octatrack and I can see it’s receiving the midi data, it’s just not giving out sound. I’m using a (input) 120VAC 60hz 17w (outtput) 9VAC 1500mA power supply. Is this too much power output?


#2

I get a solid data led but I don’t get any note flashes.


#3

No. 17W / 1500mA is the maximum power/current. It won’t shove those 1500mA down the circuit’s throat, I guarantee you :slight_smile:


#4

After flashing the mobo again, I can hear a waveform oscillating at a very low volume, but I can’t seem to get it any louder than it is. I have the vfc, resonance, and mix volume all the way up.


#5

After re-flashing everything and inspecting the mobo, I think my capacitors bit the dust which is why it’s not feeding audio. Gonna swap them out and see if it makes a difference.


#6

The best way to test things like this is to actually inspect the signal at various points in the circuit. If you have a multimeter, trace the signal from the DAC all the way to the outputs and see where it “disappears”.

If you don’t have access to a scope, you can make a small “probe”: Connect the GND wire of an audio cable to your Ambika GND and solder a 1k (or larger) resistor to the other wire. Connect the cable to a cheap active speaker system (e.g. a cheap computer speaker or similar - better not kill your expensive hifi system with unexpectedly loud signals). Now you can touch various points on the PCB with the other end of the resistor and “listen” to the signal there. This is surprisingly effective to find out where the signal disappears. The resistor is mainly for protection and can be anything from 1k to 100k.


#7

There is a corroding residue seeping out of the capacitors, so I’m gonna keep it simple for now. I appreciate the response though.