i eed help! everyhting was werking b4 jumpers, now no sound

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crazylarry
 

i eed help! everyhting was werking b4 jumpers, now no sound

Post by crazylarry »

ok:

first of all the only thing i did different was different color leds.

now, i tested everyhting along the way as i went. the vco seemed to work ok. i put a scope on the resonance pins, and saw the wave changing, and i also put it on the s1 pins to see the saw and square wave.

i got confused about what was going on with the testing on teh vca and the envelope. im not really sure how that is supposed to work. i ahve a multi meter, but i was jsut confused on where to put the pins. i wanst sure where and when to check the voltages. with r146 and d36 etc.

so, i finished all the soldering, and put on all the jumpers. i can get the thing inot keyboard mode and random mode, and can see all my leds lighting up, but i get no sound out. now im at home, away form my scope and dont hear anyhting in the headphones on the s1 or the resonace.

what mode should i be in to test? should i disocnnect all teh jumpers except for teh power? can someone help exlplain where i can test some voltages to see where my problem lies. i will love you forever if i can get this fixed. ill be online all night, so im ready for help. ask any questions you need for clarification.

Larry-

Guest
 

Post by Guest »

first make sure the jumpers are all aligned correctly
measure the voltages on the mainboard to verify
that 6v 5.3v 12v and 5v get to the right pins

then check for sound at the waveform switch
check for sound at resonance pot
check for sound on volume pot
check for 12v gate signal on d35
check for sound on mixout
check for sound on headphone out

crazylarry
 

Post by crazylarry »

how do i check the volts on d35. thats where i think i BANNED up. i didnt really uinderstand that part of the fab man for testing.

also, checking for sound, i was using ipod headphones. will that work? i was trying to jsut touch the tip to say pin 1 or 3 on the wave form switch. is that right?

crazylarry
 

Post by crazylarry »

also, dont know if this helps or not, but i put my x0x into random mode, then plugged in the cv out of teh xox box and then put it to cv in on my sh101 synth, and it played it perfectly. i did the same for gate, and its working fine. what does that mean? what is working correctly for that to work, and where should i check to see whats not working.

also, my usb does noting when i plug it into my puter

L-

crazylarry
 

Post by crazylarry »

also, here are some voltage readings while the synth is running in random pitch mode:

J4 pin 1:5.33 3: 11.84
J7 pin 1: nothing 3: nothing jumper is installed correctly
J6 pin 1:ranges from about .8 to 2.4 3: ranges from 6.5 to about 11.3
J5 pin 1:nothing 3:5.96
big jumper pin 1:0 3-6:5.02 9:2.53 11 and 12: .01 nothing on teh rest

does this help at all?

Guest
 

Post by Guest »

sounds like your gate is working
just to verify you can connect your meter to d35 and check
put one probe to ground and the other to the side of d35
that doesnt have the black stripe
it should go from 0 to 12v

then check the collector of q1
it should go to about 1.2v when the gate is on

do these checks in keyboard mode
so you can hold down a key to keep the gate on

crazylarry
 

Post by crazylarry »

i get nothing when its in kb mode, but if its in random mode, i get all different val;ues for d35, which leads me to belive its working ok. i get a range of values on q39 as well from almost 0 to about 2.4

i also tested with headphones the vco, vcf etc, and want to test the last pin on the volume knob. where is a good place to ground teh sleeve for the volume knob? i was using r152 for the others, but it doesnt work for volume knob. btw, i can get audio while the x0x box is running from the sqr/saw wave switch, and the resonace place on vr4.

im getting no voltage out of jumper 7, thats probably my problem, right? since that is the main output voltage? what can i test around there?

L-

Guest
 

Post by Guest »

you can ground to the case of the volume pot

its odd that keyboard mode doesnt work
set the tempo to ridiculously slow
when you do the q39 and d35 tests
this will make the voltages more stable

crazylarry
 

Post by crazylarry »

that worked. however, i am still not getting any voltages at j7. i think that j7 is what sends to the output. i am getting sound through the headphones at the volume pot, but i dont hear the volume going up or down when i turn the pot. should i?

my new question is: where are some other places to check for voltages after the volume pot, since that seems to be the last place i know my synth is working. thanks in advance for any help!!!! im desperate to get this thing working!!

L-

Guest
 

Post by Guest »

glad to hear you have sound at the volume pot
check out the posts under

Number 057 mostly done... headphone amp issues

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