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steiner VCF weak levels

2004-03-06 by peng3002

Just finished the Synthacon VCF and it kind-of works. I get very weak
signal at the output (about 1/4 of what it should be)(kinda sounds
like putting a signal through a mixer without the op amp). The
resonance and all the controls seem to function properly. Any ideas
anybody?

scratchin' my head,
Peng

Re: steiner VCF weak levels

2004-03-07 by jeff brown

You need to increase the negative feedback resistor for the TL071. The schematic shows an optional link (or an external level pot) and a 47k resistor. I left the 47k in and replaced the link with a 300k resistor (found by experiment). This gave a reasonable output level in both of my Synthacon filters. I also added attenuators to the audio inputs. If you don't have input attenuators, you might want to try a 500k output level pot in place of the above mentioned 300k fixed resistor. Hope this helps.

Jeff

----- Original Message -----

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From: peng3002
To: cgs_synth@yahoogroups.com
Sent: Saturday, March 06, 2004 7:27 PM
Subject: [cgs_synth] steiner VCF weak levels

Just finished the Synthacon VCF and it kind-of works. I get very weak
signal at the output (about 1/4 of what it should be)(kinda sounds
like putting a signal through a mixer without the op amp). The
resonance and all the controls seem to function properly. Any ideas
anybody?

scratchin' my head,
Peng

See the following URLS for the CGS Modular Synth home page:
Main: http://www.cgs.synth.net/
Secondary: http://otherunicorn.0catch.com/synth/

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Re: steiner VCF weak levels

2004-03-07 by peng3002

Replaced the level pot link with a 390K. Works great. Now, the
frequency pot mods...

thanks for the help,
Peng

--- In cgs_synth@yahoogroups.com, "jeff brown" <guitaricon@c...>
wrote:

Show quoted textHide quoted text

> You need to increase the negative feedback resistor for the TL071.

The schematic shows an optional link (or an external level pot) and a
47k resistor. I left the 47k in and replaced the link with a 300k
resistor (found by experiment). This gave a reasonable output level
in both of my Synthacon filters. I also added attenuators to the
audio inputs. If you don't have input attenuators, you might want to
try a 500k output level pot in place of the above mentioned 300k
fixed resistor. Hope this helps.

>
> Jeff
> ----- Original Message -----
> From: peng3002
> To: cgs_synth@yahoogroups.com
> Sent: Saturday, March 06, 2004 7:27 PM
> Subject: [cgs_synth] steiner VCF weak levels
>
>
> Just finished the Synthacon VCF and it kind-of works. I get very

weak

> signal at the output (about 1/4 of what it should be)(kinda

sounds

> like putting a signal through a mixer without the op amp). The
> resonance and all the controls seem to function properly. Any

ideas

> anybody?
>
>
> scratchin' my head,
> Peng
>
>
>
> See the following URLS for the CGS Modular Synth home page:
> Main: http://www.cgs.synth.net/
> Secondary: http://otherunicorn.0catch.com/synth/
>
>
>
> --------------------------------------------------------------------

----------

> Yahoo! Groups Links
>
> a.. To visit your group on the web, go to:
> http://groups.yahoo.com/group/cgs_synth/
>
> b.. To unsubscribe from this group, send an email to:
> cgs_synth-unsubscribe@yahoogroups.com
>
> c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of

Service.

>
>
>
> [Non-text portions of this message have been removed]

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steiner VCF weak levels

steiner VCF weak levels

Re: steiner VCF weak levels

Re: steiner VCF weak levels

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