I just build the x0xi0 and i started the test. It works until the VCO2 and for this one i don't get the waves. I double check all the parts and the welds.Everything looks ok. I'm stuck... Any ideas are welcome
1) Check the power supply voltages on the x0xi0 Top PCB.
a) IC401 Pin 8 = ~12V (if not correct, first thing is to check wire connected to Pad 9 on x0xi0 Top PCB)
b) IC401 Pin 3 = ~5.3V (if not correct, first thing is to check wire connected to Pad 6 on x0xi0 Top PCB)
2) Check CV input.
a) if possible put the unit into KEYBOARD mode so you can play the keys manually.
b) play low C and high C alternately while checking DC voltage at Pad 13 on the x0xi0 Top PCB. It should be alternating between 2V and 3V
c) if not correct first thing is to check the wire connected to Pad 13 on the x0xi0 Top PCB
3) Check the wire connected to Pad 4 on the x0xi0 TOP PCB.
4) Check SAW waveform first.
a) If all above is ok, then check the saw wave output at the junction of R411 and Q405.
b) then if ok then check square wave at the junction of R408 and Q406.
The "gate-on" switch causes all audio to stop and then the audio sometimes recovers, but the gate is still not held open.
There's two different Mode's, and it can be confusing until you figure out exactly what's going on. It's described in a little detail on page 90 of the test procedure.
1) make sure you have the VCA SUSTAIN control at max
2) make sure the MODE switch is in Mode 1.
3) turn the ENV2 DEPTH control to minimum to turn off any VCA modulation from ENV2.
it shows the orientation of Q403 the opposite of what's printed on the board. I presume the board is correct?
correct, it goes as actually shown on the PCB.
and page 61 section 7 TOP PCB INSTALL : "Connect the green wire from pad Z on the x0xi0 I/O PCB to pad V on the x0xi0 Top PCB". It's pad Z to pad Z, right?
i still have VCO2 problem. I have only a click. In my x0xi0 kit, i had Q402 and Q404 : C1815 instead of C536. Are they equal ?
yes, all kits now come with 2SC1815GR.