A noobs homebuilt x0xb0x with no sound [SOLVED]

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Morglurg
 
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A noobs homebuilt x0xb0x with no sound [SOLVED]

Post by Morglurg »

[UPDATE: Now works, thanks to a new atmega162 :D]

Hey everyone!

I'm an electronics novice that has built the xoxshop.de-kit, which seems very good. But i'm failing in the final stage (no sound):

The x0xb0x lights up. One can change programs and stuff. I'm testing in keyboard mode.

TESTING SO FAR
[*]VCO seems ok
[*]VCF seems ok
[*]GATE maybe, there's 12V at D35 as long as tangent is pushed, but 0.3V when it's not.
[*]BA6110 has values close to
1 / 5.3v /
2 / 5.3v /
3 / 0.0v /
4 / 0.0v /
5 / 0.0v /
6 / 5.3v /
7 / 5.3v /
8 / 5.3v /
9 / 12v /

LEADS (maybe)
[*]Faint clicks can be heard in the headphone output.
[*]The leds over the keyboard light up a bit (half a second maybe, very noticeable) after the button is pressed.
[*]In random play, the tempo encoder doesn't change the tempo

MISTAKES
Q3 was soldered in backwards, but now replaced. This did not change anything.
Probing with low quality headphones, sometimes I heard a loud "POP", possible shorting? This was after the problem though.

I'm really thankful for any tips and guidance, since I'm keen on getting my x0xb0x to work.
Last edited by Morglurg on Sat May 31, 2014 4:27 am, edited 1 time in total.

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54656f
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by 54656f »

Hi,

I have exactly the same situation.
I found out that you can override the BA6110 with jumper. If You didn't solder the BA6110 directly to the pcb and used the socket the sh0p provided then You can easily connect pin 1 to pin 6 and pin 7 to 8. After this questionable mod I got a x0x-like sound from line out and headphones. Both are a bit weak and also there's a sustain in the sound like someone pressing the pedal all the time.

I think they've got a bad batch of BA6110s. Mine is labeled BA6110 402 155.

Morglurg
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

Hi!

How interesting (and wierd!) that we have the same problem! I'm a bit scared to use that method though, is it safe for the rest of the synth?

Mine is labeled the same!

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antto
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by antto »

yes, using the SIP socket is a good idea

make sure you have put the BA6110 in IC15B and not in IC15A
also make sure you don't get the orientation wrong

but if you have sound before that (all the way thru the filter) then the problem would be in the vca/vca_envelope/volume/mixer

you can check if you got control voltage (envelope) to the vca when playing notes
(i'm not too sure about this part, but here it goes)
probe the voltage at pin1 on the IC15A slot (yes, it should be easier since it's free in your case)
you should have zero when not playing notes, and then, when you play notes it should change
if you still get zero - the problem is with the envelope most likely

Morglurg
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

Thank you for the reply! Very valuable to me!

The orientation of my ba6110 seems correct. The "notch" is pointing "north".

I probed hole 1 (the northernmost) of IC15A like you said, and when i struck a keyboard button it was 0.5V and nothing while no note struck. Is this normal/good.

Morglurg
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

54656f wrote:Hi,

I have exactly the same situation.
I found out that you can override the BA6110 with jumper. If You didn't solder the BA6110 directly to the pcb and used the socket the sh0p provided then You can easily connect pin 1 to pin 6 and pin 7 to 8. After this questionable mod I got a x0x-like sound from line out and headphones. Both are a bit weak and also there's a sustain in the sound like someone pressing the pedal all the time.

I think they've got a bad batch of BA6110s. Mine is labeled BA6110 402 155.

Just did this! And it worked just like you said.
Unmistakable "SWISH"-sound from the filter and its envelope. But unlimited sustain as you said.

sound here: http://ge.tt/8e9b3he1/v/0?c

Is it the BA6110 then, that is bad?

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antto
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by antto »

my multimeter also gives a voltage around 0.5V when playing notes, so i guess the envelope itself is fine

you could try to see if there's audio coming out of the VCA, using inexpensive headphones, probe between the two outmost pins on the volume pot, or between ground and the middle pin (and the volume set high) and see if you hear anything there

you could also try to search thru the forum about similar issues (no sound after VCA, etc)

Morglurg
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

antto wrote:my multimeter also gives a voltage around 0.5V when playing notes, so i guess the envelope itself is fine

you could try to see if there's audio coming out of the VCA, using inexpensive headphones, probe between the two outmost pins on the volume pot, or between ground and the middle pin (and the volume set high) and see if you hear anything there

you could also try to search thru the forum about similar issues (no sound after VCA, etc)
Thanks a lot for your support! xoxshop.de gave me a new ba6110, so maybe that will solve stuff! But i'll have a look at your tip, in case it's something else!

Morglurg
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

antto wrote:my multimeter also gives a voltage around 0.5V when playing notes, so i guess the envelope itself is fine

you could try to see if there's audio coming out of the VCA, using inexpensive headphones, probe between the two outmost pins on the volume pot, or between ground and the middle pin (and the volume set high) and see if you hear anything there

you could also try to search thru the forum about similar issues (no sound after VCA, etc)
There's sound at the volume pot also. But the whole synth behaves sluggishly and unreliable. Lag (delay] when striking notes, no tempo changing in random play and more. Seems the whole "computer control" is way off ;)

Morglurg
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

I tried connecting to with BANNED. It was visible under hardware and ports at port 32.

But connecting when connecting it it said ping:bad and then nothing more happened. Any ideas?

Phew, a lot of wierd things here, bear with me.

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antto
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by antto »

weird

i'm going out of ideas

as a potentially useless experiment, you could try setting the baudrate in BANNED to 9600, 6400, 4800.. see if it connects with any of those (i doubt)

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54656f
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by 54656f »

Sure we have weird things! I had one connection missing on I/O pcb, one faulty 2sc1583 replaced with two matched trannies (temporarily I hope) and faulty BA6110 (now two jumpers)... While searching the Vca problem I replaced the ICs 9, 11 and 12.

Keyboard mode midi out worked for a while, but not anymore. And the usb is a bit silent. I haven't got the usb to get recognized at all (osx). Have to check the usb on another computer before any other diagnose. One bad solder fixed already, but I think there might be something else, perhaps the resonator?

So far it has been fun and rewarding learning process ;-)

Morglurg
 
Posts: 14
Joined: Sun Apr 27, 2014 8:20 am

Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

54656f wrote:Sure we have weird things! I had one connection missing on I/O pcb, one faulty 2sc1583 replaced with two matched trannies (temporarily I hope) and faulty BA6110 (now two jumpers)... While searching the Vca problem I replaced the ICs 9, 11 and 12.

Keyboard mode midi out worked for a while, but not anymore. And the usb is a bit silent. I haven't got the usb to get recognized at all (osx). Have to check the usb on another computer before any other diagnose. One bad solder fixed already, but I think there might be something else, perhaps the resonator?

So far it has been fun and rewarding learning process ;-)
Man, at least we don't have to be worried about what we're doing on our free time ;). Interested in the IC:s, how did you test those?

Yes, xtal1 and 2 might be worth looking at (but how?).

Cheers!

xlarge
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by xlarge »

There have been a couple of uc's sold with the wrong fuses making them running at 2mhz instead of 16mhz.
And there is no way of checking that unless you read the fuses from the uc (or just set them right ofc).

Morglurg
 
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Re: A noobs homebuilt x0xb0x with no sound [support]

Post by Morglurg »

xlarge wrote:There have been a couple of uc's sold with the wrong fuses making them running at 2mhz instead of 16mhz.
And there is no way of checking that unless you read the fuses from the uc (or just set them right ofc).
Which part do you mean with uc? It sounds like it is possible that the clock rate is too low on some component...

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