xoxshop.de no sound (UPDATE)

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

i don't have a sound scope so i will try the inexpencive headphone method.
the led`s blink and the buttons are working too but it dosen`t start/stop.

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mmm
 
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Re: xoxshop.de no sound, sequenzer not working, pls help!!!

Post by mmm »

fearandloathing138 wrote:i changed the 7805 voltage regulator and now the led`s work!! the voltages of the psu seems right.
its possible to switch the modes of xoxbox but i still have no sound. i can't hear any sound in keyboard mode and when i press start in random mode, the led`s don`t start running.
Wait a second.

Are you sure you're in the correct mode? The xoxbox starts running automatically in random mode; the start button is not required here.

It appears there are two types of switches for Mode and Bank/Channel: For one of them the "zero" position is with the flat side to the top; for the other one it's toward the bottom. Naturally all switch positions are off by 180 degrees between those two models.

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

i put the fader caps on to navigate threw the menu.
in keyboard mode the led light up when i press the associate key. (all led`s are working)
in random mode only the tempo led blinks but there is no sound at all. :(

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

do i need a polyester capacitor to probe the saw wave?

edit:
i switched the direction of the ba6110 and get click sounds on the headphones out.

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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

antto wrote:so, sequencer works? leds blink, buttons respond, start/stop responds?

to test why there's no sound, the usual procedure is:
follow the audio signal from the oscillator, thru the filter, to the vca and mixer, to the output, see where it vanishes
ideally this is done with a scope, but if you don't have one - you can use the "inexpensive headphones" method described in the build manual

so, start by probing at the vco, the waveform switch is a good place to probe, you can see if you got saw and square there
i tried to follow the signal with the inexpensive headphone method from the manual but i didn't got the saw/square wave at the waveform switch. i only got a very scratchy/distorted sound.
when i press start in keyboard mode the patterns don't start running.
is the ba6110 chip in the right position on the photo? i turned it around and got strange click sounds on the headphone output.
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ba6110 right position?
ba6110 right position?
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try to probe the signal at the waveform switch
try to probe the signal at the waveform switch
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antto
 
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Re: xoxshop.de no sound (UPDATE)

Post by antto »

the BA6110 looks properly oriented in the pic
but if you had it backwards - it may have been busted

in keyboard mode - the RUN/STOP isn't supposed to work
in that mode, you press the keyboard buttons and the synth plays the corresponding notes (you can use the UP/DOWN buttons too, and the ACCENT button) .. that's all

now, you didn't hear anything, but i want you to do the test once again
this time, in keyboard mode - press some button on the keyboard (upper C for example) and make sure the LED also responds when you press it

see, when you swtich the x0xb0x on - the oscillator may be oscillating at some uber low note (so low that if you probe it - you might hear nothing or just some slow pops)
so you have to either play some "sane" note first or a pattern, in order to have the cpu set the vco to some reasonable frequency

so, test it again this way, and see if you can at least hear a sawtooth
have in mind that the square wave on the 303/x0xb0x is not exactly a square, so don't be shocked.. it's a sort of pulse with one edge softer, and frequency-dependant PW

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

antto wrote:the BA6110 looks properly oriented in the pic
but if you had it backwards - it may have been busted

in keyboard mode - the RUN/STOP isn't supposed to work
in that mode, you press the keyboard buttons and the synth plays the corresponding notes (you can use the UP/DOWN buttons too, and the ACCENT button) .. that's all

now, you didn't hear anything, but i want you to do the test once again
this time, in keyboard mode - press some button on the keyboard (upper C for example) and make sure the LED also responds when you press it

see, when you swtich the x0xb0x on - the oscillator may be oscillating at some uber low note (so low that if you probe it - you might hear nothing or just some slow pops)
so you have to either play some "sane" note first or a pattern, in order to have the cpu set the vco to some reasonable frequency

so, test it again this way, and see if you can at least hear a sawtooth
have in mind that the square wave on the 303/x0xb0x is not exactly a square, so don't be shocked.. it's a sort of pulse with one edge softer, and frequency-dependant PW
so i did the test again in keyboard mode and pressed some buttons (leds responds) but there was no change in sound.
i think this weird scratchy sounds comes from scrubbing the pins of the headphones with the pins of the wave switch.
the sound also don't change when i switch the waves ... :(

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

i tried to get signal in this mode, but the only thing i can hear is the crunchy sound when the tips of the pins touch.
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antto
 
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Re: xoxshop.de no sound (UPDATE)

Post by antto »

okay
again, in keyboard mode, press a C note and measure the voltage (DCV) of the CV output (on the rear)
then press the upper C note and measure again

also, do you get all the proper voltage at J4 on the mainboard? (12V and 5.33V)

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

keyboard mode C note on CV output - 4,65V
C` - 4,33V
on j4 i get: 5,32 V and 11,14 V ( i can only adjust 5,32V with the trimpoti on the PSU)
is there a problem with the PSU (11,14V)?

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antto
 
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Re: xoxshop.de no sound (UPDATE)

Post by antto »

hm
the 12V that's a little bit lower than usual (same goes for the 5.33V, if you can't get it any higher than that)
the 12V usually somewhere like 11.86V

the pitch CV also looks bad
you should get 1V, 2V, 3V, 4V, etc on the C notes

perhaps, check the IO board for any signs of weirdness - anything getting excessively hot, bad solder joints, bad orientation of components, bad values of components
also, do the voltage measuring tests which are suggested in the build manual during the power supply section building, see if you got any weirdness then

hm..

EDIT: also, is your adapter proper? check what it says on it (you need 9V AC) and measure it with the multimeter in "VAC" mode

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

i did the measurment on the PSU again and got these voltages:
Adapter: 10,5 VAC
Power jack : 10,4 VAC
Capacitor: 30,6 VAC, 14,13 VDC
7805: 10,5 VAC, 5,01 VDC
IC 21: 5,98 VDC, 12,6 VAC
Pin 8 IC: 5,32 VDC
J4: 5,32 VDC, 11,87 VDC

is there a problem with the capacitors?

as next step i will check the io board.

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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

anything strange here?
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acidbuzz123
 
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Re: xoxshop.de no sound (UPDATE)

Post by acidbuzz123 »

anything strange?
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antto
 
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Re: xoxshop.de no sound (UPDATE)

Post by antto »

~30.6 VAC on both C3 and C5?

other than that, on the IO board J4 - you get proper 12V (11.87V - that's the normal value)
but on the other side of J4, you said you get lower voltage 11.14V .. weird
re-measure that, and if it's still not 11.87V - perhaps check the cable: switch off the x0xb0x and measure the resistance at the two ends on the cable... normally it should be very small (a few ohms max)
if you get more than a few ohms - check the actual resistance of the multimeter (by just touching its two probes together)
my cheap multimeter gives about 4 ohms that way

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