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2015-03-13 by Stephen Richards
2015-03-13 by Ken Stone
On Fri, Mar 13, 2015 at 5:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hi KenI have a CGS VCO that is not giving any output on the Saw to Sine and a very quiet output on the Sine out.Where else should i start looking ? CA3140 ?It's not the LM3900 , or BC547 is swapped those out already.
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2015-03-13 by Stevie Richards
On 13 Mar 2015, at 5:16 pm, "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com> wrote:
Check the 22k trimmer to the sine and saw/sine section is set.Ken
If that isnt' it, make sure you are getting a 5V sawtooth. Check the resistors around the area if you are not, in particular those associated with the 311 and the output TL072.On Fri, Mar 13, 2015 at 5:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hi KenI have a CGS VCO that is not giving any output on the Saw to Sine and a very quiet output on the Sine out.Where else should i start looking ? CA3140 ?It's not the LM3900 , or BC547 is swapped those out already.
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2015-03-16 by Stephen Richards
Hi KenI have a CGS VCO that is not giving any output on the Saw to Sine and a very quiet output on the Sine out.Where else should i start looking ? CA3140 ?It's not the LM3900 , or BC547 is swapped those out already.
2015-03-16 by Ken Stone
On Mon, Mar 16, 2015 at 1:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:It ended up being a broken track from the original builder , there is a whole lot of broken tracks and links on this board ; it was the one they missed.Now it's fixed , i've had a chance to look at the sine on the scope , the shape is all hills and no dales. Like a sine wave halved and push together with all the others. Would changing the LM394 have anything to do with this ?
From: "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com>
To: cgs_synth@yahoogroups.com
Sent: Friday, March 13, 2015 5:16 PM
Subject: Re: [cgs_synth] CGS 48 VCO question
Check the 22k trimmer to the sine and saw/sine section is set.Ken
If that isnt' it, make sure you are getting a 5V sawtooth. Check the resistors around the area if you are not, in particular those associated with the 311 and the output TL072.On Fri, Mar 13, 2015 at 5:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hi KenI have a CGS VCO that is not giving any output on the Saw to Sine and a very quiet output on the Sine out.Where else should i start looking ? CA3140 ?It's not the LM3900 , or BC547 is swapped those out already.
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2015-03-16 by Stephen Richards
It ended up being a broken track from the original builder , there is a whole lot of broken tracks and links on this board ; it was the one they missed.Now it's fixed , i've had a chance to look at the sine on the scope , the shape is all hills and no dales. Like a sine wave halved and push together with all the others. Would changing the LM394 have anything to do with this ?
From: "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com>
To: cgs_synth@yahoogroups.com
Sent: Friday, March 13, 2015 5:16 PM
Subject: Re: [cgs_synth] CGS 48 VCO question
Check the 22k trimmer to the sine and saw/sine section is set.Ken
If that isnt' it, make sure you are getting a 5V sawtooth. Check the resistors around the area if you are not, in particular those associated with the 311 and the output TL072.On Fri, Mar 13, 2015 at 5:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hi KenI have a CGS VCO that is not giving any output on the Saw to Sine and a very quiet output on the Sine out.Where else should i start looking ? CA3140 ?It's not the LM3900 , or BC547 is swapped those out already.
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2015-03-16 by Ken Stone
On Mon, Mar 16, 2015 at 1:49 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hi Ken , No , Im not expecting it to be good ; ive seen it many times on mine but this sounds very different to the other VCO right next to it.Ive trimmed it to as good as i can get it.
From: "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com>
To: cgs_synth@yahoogroups.com
Sent: Monday, March 16, 2015 1:10 PM
Subject: Re: [cgs_synth] CGS 48 VCO question
The sine wave is affected by that trimmer. Don't expect it to be particularly good.On Mon, Mar 16, 2015 at 1:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:It ended up being a broken track from the original builder , there is a whole lot of broken tracks and links on this board ; it was the one they missed.Now it's fixed , i've had a chance to look at the sine on the scope , the shape is all hills and no dales. Like a sine wave halved and push together with all the others. Would changing the LM394 have anything to do with this ?
From: "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com>
To: cgs_synth@yahoogroups.com
Sent: Friday, March 13, 2015 5:16 PM
Subject: Re: [cgs_synth] CGS 48 VCO question
Check the 22k trimmer to the sine and saw/sine section is set.Ken
If that isnt' it, make sure you are getting a 5V sawtooth. Check the resistors around the area if you are not, in particular those associated with the 311 and the output TL072.On Fri, Mar 13, 2015 at 5:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hi KenI have a CGS VCO that is not giving any output on the Saw to Sine and a very quiet output on the Sine out.Where else should i start looking ? CA3140 ?It's not the LM3900 , or BC547 is swapped those out already.
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2015-03-16 by Stephen Richards
Hi Ken , No , Im not expecting it to be good ; ive seen it many times on mine but this sounds very different to the other VCO right next to it.Ive trimmed it to as good as i can get it.
From: "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com>
To: cgs_synth@yahoogroups.com
Sent: Monday, March 16, 2015 1:10 PM
Subject: Re: [cgs_synth] CGS 48 VCO question
The sine wave is affected by that trimmer. Don't expect it to be particularly good.On Mon, Mar 16, 2015 at 1:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:It ended up being a broken track from the original builder , there is a whole lot of broken tracks and links on this board ; it was the one they missed.Now it's fixed , i've had a chance to look at the sine on the scope , the shape is all hills and no dales. Like a sine wave halved and push together with all the others. Would changing the LM394 have anything to do with this ?
From: "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com>
To: cgs_synth@yahoogroups.com
Sent: Friday, March 13, 2015 5:16 PM
Subject: Re: [cgs_synth] CGS 48 VCO question
Check the 22k trimmer to the sine and saw/sine section is set.Ken
If that isnt' it, make sure you are getting a 5V sawtooth. Check the resistors around the area if you are not, in particular those associated with the 311 and the output TL072.On Fri, Mar 13, 2015 at 5:09 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hi KenI have a CGS VCO that is not giving any output on the Saw to Sine and a very quiet output on the Sine out.Where else should i start looking ? CA3140 ?It's not the LM3900 , or BC547 is swapped those out already.
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