x0x no sound

Discuss x0x construction and related issues

Moderators: altitude, adafruit_support_bill, adafruit, hamburgers, phono

Please be positive and constructive with your questions and comments.
User avatar
mmm
 
Posts: 516
Joined: Tue Apr 24, 2012 1:51 am

Re: x0x no sound

Post by mmm »

Bepi wrote: Fri Oct 28, 2022 6:07 am Also: I can’t find why some x0x are called banned…I’ve tried to find info about that with no luck!
That seems to be a function of the forum software: It automatically "bans" certain words (and also prohibits links that contain those words). Probably some anti-spam feature that went wrong.

User avatar
Bepi
 
Posts: 16
Joined: Sun Oct 16, 2022 6:11 am

Re: x0x no sound

Post by Bepi »

Thanks for the explanation!
Btw i bought the x0x kit from a site that starts with w and ends with yx if that helps
(Hoping that this will bypass the word banning system lol)

User avatar
mmm
 
Posts: 516
Joined: Tue Apr 24, 2012 1:51 am

Re: x0x no sound

Post by mmm »

So let's start with a few basic things, like the question whether a CV for the oscillator is actually generated.

Switch the unit to "random" mode and observe (with the oscilloscope) the voltage at pin 7 of IC 11. Vertical resolution should be around 2V or 5V per unit, horizontal resolution around 250 ms. Please take a pic of the scope screen and post it.

User avatar
Bepi
 
Posts: 16
Joined: Sun Oct 16, 2022 6:11 am

Re: x0x no sound

Post by Bepi »

Hi!

Here it is:

https://ibb.co/vQ4nzLV

User avatar
mmm
 
Posts: 516
Joined: Tue Apr 24, 2012 1:51 am

Re: x0x no sound

Post by mmm »

Please describe exactly the grounding situation; where do you obtain the ground for your probe? What kind of probe do you use? (a picture might help here as well)

User avatar
Bepi
 
Posts: 16
Joined: Sun Oct 16, 2022 6:11 am

Re: x0x no sound

Post by Bepi »

I’m not in laboratory now, i will take some photos of the grounding points i’m using
What grounding points you suggest to use?
The probe is a (really old but new old stock) 10megaohm hewlett packard if i remember correctly

User avatar
Bepi
 
Posts: 16
Joined: Sun Oct 16, 2022 6:11 am

Re: x0x no sound

Post by Bepi »

Update:
The grounding point i was using was center pin of J4.
Turns out that the probe was broken by the way, sorry.
I have another one that is new and seems to be working fine checking with a signal generator.
Then I tried again to take the same measurements you asked me before and i can’t see any kind of signal coming out from pin7 of IC11.
Pic of the probe:
https://ibb.co/yNhqGhm

User avatar
mmm
 
Posts: 516
Joined: Tue Apr 24, 2012 1:51 am

Re: x0x no sound

Post by mmm »

Can you measure the voltages on J4 with the oscilloscope (of course DC coupled)? I want to rule out that we have a measuring problem.

User avatar
Bepi
 
Posts: 16
Joined: Sun Oct 16, 2022 6:11 am

Re: x0x no sound

Post by Bepi »

Tried on pins 1 and 3 of J4
Nothing on screen…

User avatar
mmm
 
Posts: 516
Joined: Tue Apr 24, 2012 1:51 am

Re: x0x no sound

Post by mmm »

OK, then try this again with the voltmeter.
Since you got voltages on the BA6110 I would suspect a general measuring problem with the oscilloscope here. Since the oscilloscope is obviously key to debugging in this particular situation we need to rely on its measurements.

User avatar
Bepi
 
Posts: 16
Joined: Sun Oct 16, 2022 6:11 am

Re: x0x no sound

Post by Bepi »

Voltages on multimeter:

J4
Pin1: 5.3v
Pin3: 11.8v

User avatar
mmm
 
Posts: 516
Joined: Tue Apr 24, 2012 1:51 am

Re: x0x no sound

Post by mmm »

That's perfect.
And that also means that something is wrong with your oscilloscope setup or your probes. I suspect that there is no proper ground path between the xox and the oscilloscope. So we need to get this sorted out first.

Can you make a pic (or two pics) of the complete (oscilloscope) measuring setup? I'd like to see how the probe is attached to J4 and where the ground reference is coming from. Also a pic of the complete front panel of the oscilloscope as set up for this particular measurement.

I'm certain that once we've figured that out we'll make quick progress.

Post Reply
Please be positive and constructive with your questions and comments.

Return to “Making x0x”