HI Ken
I've asked around and am having little luck trying to sort this one.
Do you think it could be a problem with transistors here ?
________________________________
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Thursday, December 6, 2012 11:14 AM
Subject: Re: [cgs_synth] CGS77 - Serge VCF
Are you not able to compensate for this using the trimmer? Also make sure
your FREQ CV pot input is set to the center of its travel when you do the test.
I really don't know why this is happening. I can only guess, but it seems
that the CV mixer output voltage is too low - too "negative", requiring you
to turn the pot that far around before you reach the point where the expo
converters can respond. Is it the double sided or single sided version?
Ken
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
[Non-text portions of this message have been removed]
I've asked around and am having little luck trying to sort this one.
Do you think it could be a problem with transistors here ?
________________________________
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Thursday, December 6, 2012 11:14 AM
Subject: Re: [cgs_synth] CGS77 - Serge VCF
Are you not able to compensate for this using the trimmer? Also make sure
your FREQ CV pot input is set to the center of its travel when you do the test.
I really don't know why this is happening. I can only guess, but it seems
that the CV mixer output voltage is too low - too "negative", requiring you
to turn the pot that far around before you reach the point where the expo
converters can respond. Is it the double sided or single sided version?
Ken
>CW is wired to 0V__________________________________________________________
>
>
>________________________________
> From: "sasami@..." <sasami@...>
>To: cgs_synth@yahoogroups.com
>Sent: Thursday, December 6, 2012 10:13 AM
>Subject: Re: [cgs_synth] CGS77 - Serge VCF
>
>
>Â
>Have you wired the CW terminal of the pot to -VE or 0V?
>Ken
>
>>Hi Ken
>>
>>I am just troubleshooting the BOG panel and am having problems with the
>Serge VCF.
>>
>>When i move the Freq Pot the filter does not kick in until about the
>'1o'clock' point on the pot's travel.
>>
>>Below that point , nothing.
>>
>>Everything else seems to be working , all ins and outs doing what they should.
>>
>>I have swapped the LM3900 and this has had no effect.
>>
>>[Non-text portions of this message have been removed]
>>
>>
>>
>>------------------------------------
>>
>>The CGS Modular Synth home page: http://www.cgs.synth.net/
>>Yahoo! Groups Links
>>
>>
>>
>>
>__________________________________________________________
>Ken Stone sasami@... otherunicorn@...
>Modular Synth PCBs for sale <http://www.cgs.synth.net/>
>Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>
>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
[Non-text portions of this message have been removed]