x0xi0 Full Kit - Install & Troubleshooting

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fudog
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by fudog »

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Last edited by fudog on Sun Jan 26, 2014 6:25 pm, edited 1 time in total.

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maxtim
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by maxtim »

I have finished the build and started the test procedure (section 10)
All checked out OK until step 9 – VCO & Noise Source summed output
I am not getting anything at Pad T on the x0xi0 Top PCB

I am using a digital oscilloscope.

I have checked an verified all the power supplies
Digital at Pin 16 of U16 = 5.07V
Headphone amp at pad N on the x0xi0 Rear PCB = 5.99V
Reference voltage has been set at 5.33 volts via TM6
Pad 9 on the xoxi0 top PCB has been verified at 11.87V
Pad D on the x0xi0 top PCB has been set to 11.9 V via TM203
VCO1 p-p voltages are 6V saw and 4V square
VCO2 p-p voltages are 4.24V saw and 4.08V square
The noise source output is p-p of 6.8V average
I verified the level controls for VCO1, VCO2 and noise

BUT nothing at Pad T
:?:

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maxtim
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by maxtim »

Answer:

The amplitude of the signal at this test point is much lower than that of the prviouse test point(s).
I did not re-adjust my oscilloscope, beacuse I was expecting a signal of the same peek to peek volatages as what I saw before, except now, mixing together.
Turn on the VCO OD switch and they will come through strong and clean!

Thank you bcbox for getting this sorted.
I appreciated it BIG TIME

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

hi guys,
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
Thks for your help

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maxtim
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by maxtim »

rubakpo, if you have double-checked all of the part values and orientation of the VCO2 components, and verified all of your solder connections, then start looking at the inputs and outputs to and from the VCO2 circuit. Use the schematics and follow the letters and numbers for the interconnects. Check those wires between the PCAs that relate to the VCO circuit, as they can be pulled off while working with the x0xb0x x0xi0.

Here is where I am at with my next hurdle in getting all of the verifications completed.

:?: The "gate-on" switch causes all audio to stop and then the audio sometimes recovers, but the gate is still not held open. :?:

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

ThK for your reply, i'm not alone...
the voltages are all ok
i checked every wires of vco2 , there are ok, but it still not work.
vco1 waveforms are ok, noise waveform is ok.
when i put sw404 on sync position (right), i have a waveform (VCO1 ?). no waveform when sw404 is on left side
When i play a sequence, there is only a clic on each note in hearphone.
what happen ?

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dnigrin
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by dnigrin »

Brian, small inconsistency in the build documentation for the full kit (version 2.0 that's on your site now). On page 37 (http://alphazone1.com/x0xi0/install/full_section4.html), it shows the orientation of Q403 the opposite of what's printed on the board. I presume the board is correct?

Thanks...

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

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?

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

hi,
i still have VCO2 problem. I have only a clic. In my x0xi0 kit, i had Q402 and Q404 : C1815 instead of C536. Are they equal ?

bcbox
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by bcbox »

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?
correct.
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.

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

Thank you very much Brian for reply, i feel depressed...
I check
1) power supply voltages
a) IC401 Pin 8 = -11,9
b) IC401 Pin 3 = ~5.3V

2) Check CV input.
b) low C 1,79 V
high C 2,59 V

c) wire connected to Pad 13 Ok

3) wire connected to Pad 4 Ok

4) Check SAW waveform first.
a) saw wave output at the junction of R411 and Q405 OK
b) square wave ??? a sort of clik (i can listen in vco out) modulate with octave pot...

bcbox
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by bcbox »

i feel depressed...
no, you'll get it, it's just the damn VCO, not too complicated!
You may have a bad component. I'll take some reference voltage measurements tonight in the VCO2 circuit and you can test and figure out what's bad.

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

thank you ,
i check and i re-check everything.
i can ear VCO1 in VCO out.
VCO2 still not working (only clics)

when i plug hearphone in headphone out or mix out, i have nothing. it's another problem...

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

- Now i have vco1 in hearphone and vco out, but....
- i can hear far away vco1 in HP, but with a big click (gate or something...)
- still have vco2 pb.
- i found a short between left and right hole of qQ409 on x0xi0 board, is it normal? (board pb?)
- on X0XB0X mainboard schema for X0Xi0, POINT K is plug on C20 or it's on C21 in full install doc, where will i plug it?
thanks, i don't give up now

rubakpo
 
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Re: x0xi0 Full Kit - Install & Troubleshooting

Post by rubakpo »

today, i compare Voltages and shapes from VCO1(X0XB0X) and VCO2 (X0XI0).
Q405 = Q28 = saw
Q406= Q8 = square
i have good waveforms in Q28 and Q8 (X0XB0X), and bad in Q405 and Q406 (X0XI0)...Ok
in Q405, i have a lot of modulation from 5,6 to 10V. Or in Q28, i have modulation from 8,16 to 8,18V (0,2V)
in Q406, i have a lot of modulation too, from 5,7 to 7v. Or in Q8, i have only 0,4v modulation.
So, maybe it's something wrong going inside the 2 transistors? Am i right ?? I haven t found yet...

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