Analogue-sequencer

Hi Colin,

After some time I managed to construct P3-035. At first boot I had the impression something was working however no display :(

Cause no contrast, so tuning VR1 did the trick ;) 

Now I am facing another challence as all P3 functionality seems to work no midi data is sent out.

Any suggestions on solvng this are highly appreciated

Best Regards,
Frank

Hi Frank, 

> Now I am facing another challence as all P3 functionality 
> seems to work no midi data is sent out.
> 
> Any suggestions on solvng this are highly appreciated

Do you have a logic tester or oscilloscope ?
First thing to check would be the MIDI output pin on the CPU itself.
That's pin 11, remembering the P3 CPU is upside down on the board.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com

Well, managed to get a scope (old one but is working fine). When I hook it up to pin 11 I see a difference when stopping or starting a sequence. However i do not get a clear squarewave as it seems to be a vague one. Can you outline what I should see?

Best Regards,
-Frank

Frank,

Which board revision have you got ?

Are there two transistors Q3 and Q4 for the MIDI output stage ?
Like this: http://www.sequentix.com/build/v1.5/images/cnst-main-small.jpg

Or is it the earlier version where the CPU pin 11 is connected directly to
R5 then to MIDI out ?
Like this: http://www.sequentix.com/build/old/images/Mainboard.jpg

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com

> -----Original Message-----
> From: analogue-sequencer@yahoogroups.com 
> [mailto:analogue-sequencer@yahoogroups.com] On Behalf Of 
> syntaxdevelopment
> Sent: 23 May 2009 20:41
> To: analogue-sequencer@yahoogroups.com
> Subject: [analogue-sequencer] Re: P3 Sequencer 035 up and 
> running ==> No Midi?
> 
> Well, managed to get a scope (old one but is working fine). 
> When I hook it up to pin 11 I see a difference when stopping 
> or starting a sequence. However i do not get a clear 
> squarewave as it seems to be a vague one. Can you outline 
> what I should see?
> 
> Best Regards,
> -Frank
> 
> 
> 
> ------------------------------------
> 
> Yahoo! Groups Links
> 
> 
>

Hi Colin,

I'm having revision board v1.4.

Best Regards,
-Frank

Hi Colin,

As I'm not using PCB DIN mounts I mirrored connections (stupid me!). So I switched connections now my midi out is working. This will do the trick for midi in as well, I'm sure.

Anyway thanks for your everlasting support!

Best regards,
Frank

--- In analogue-sequencer@yahoogroups.com, "syntaxdevelopment" <syndev@...> wrote:

>
> Hi Colin,
> 
> I'm having revision board v1.4.
> 
> Best Regards,
> -Frank
>