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2018-01-09 by John Hollis
I find it is necessary to greatly attenuate a VCO output (say the sine wave from a A-111-1) to prevent distortion. I have adjusted the trimmers to get a full range sweep for an ADSR. Is there an input resistor that could be changed to remove the need for 2 x A-183-1 dual attenuators, or am I thinking about this incorrectly? Thanks John
2018-01-09 by yahoo@doepfer.de
Hello, each of the four VCAs is equipped with a 47k input resistor (R1, R12, R23, R34). If you increase the values of these resistors (or add a trimming potentiometer to each resistor) the input signal is attenuated. You find the position of the resistors in the attached picture. Best wishes Dieter Doepfer > -----Ursprungliche Nachricht----- > Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com] > Gesendet: Dienstag, 9. Januar 2018 12:50 > An: yahoo@doepfer.de [Doepfer_a100] > Betreff: [Doepfer_a100] A-132-4 Input Signal Level > > > I find it is necessary to greatly attenuate a VCO output (say the > sine wave from a A-111-1) to prevent distortion. I have adjusted > the trimmers to get a full range sweep for an ADSR. > > Is there an input resistor that could be changed to remove the > need for 2 x A-183-1 dual attenuators, or am I thinking about > this incorrectly? > > Thanks > John > > > > ------------------------------------ > Posted by: John Hollis <john@hollis.je> > ------------------------------------ > > > ------------------------------------ > > Yahoo Groups Links > > > [Non-text portions of this message have been removed]
2018-01-09 by Bakis Sirros
attachments on the group emails are not allowed. maybe upload the photo in the files/photos section of the group ?
From: "yahoo@doepfer.de [Doepfer_a100]" <Doepfer_a100@yahoogroups.com>
To: Doepfer_a100@yahoogroups.com
Cc: john@hollis.je
Sent: Tuesday, January 9, 2018 2:34 PM
Subject: AW: [Doepfer_a100] A-132-4 Input Signal Level
Hello,
each of the four VCAs is equipped with a 47k input resistor (R1, R12, R23,
R34). If you increase the values of these resistors (or add a trimming
potentiometer to each resistor) the input signal is attenuated. You find the
position of the resistors in the attached picture.
Best wishes
Dieter Doepfer
> -----Ursprungliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
> Gesendet: Dienstag, 9. Januar 2018 12:50
> An: yahoo@doepfer.de [Doepfer_a100]
> Betreff: [Doepfer_a100] A-132-4 Input Signal Level
>
>
> I find it is necessary to greatly attenuate a VCO output (say the
> sine wave from a A-111-1) to prevent distortion. I have adjusted
> the trimmers to get a full range sweep for an ADSR.
>
> Is there an input resistor that could be changed to remove the
> need for 2 x A-183-1 dual attenuators, or am I thinking about
> this incorrectly?
>
> Thanks
> John
>
>
>
> ------------------------------------
> Posted by: John Hollis <john@hollis.je>
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
[Non-text portions of this message have been removed]2018-01-09 by yahoo@doepfer.de
That's why I've sent a CC to John's email address directly. Best wishes Dieter Doepfer
> -----Ursprüngliche Nachricht----- > Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com] > Gesendet: Dienstag, 9. Januar 2018 13:47 > An: Doepfer_a100@yahoogroups.com > Betreff: Re: AW: [Doepfer_a100] A-132-4 Input Signal Level > > attachments on the group emails are not allowed. > > maybe upload the photo in the files/photos section of the group ? > > From: "yahoo@doepfer.de [Doepfer_a100]" <Doepfer_a100@yahoogroups.com> > To: Doepfer_a100@yahoogroups.com > Cc: john@hollis.je > Sent: Tuesday, January 9, 2018 2:34 PM > Subject: AW: [Doepfer_a100] A-132-4 Input Signal Level > > > > > Hello, > > each of the four VCAs is equipped with a 47k input resistor (R1, R12, R23, > R34). If you increase the values of these resistors (or add a trimming > potentiometer to each resistor) the input signal is attenuated. > You find the > position of the resistors in the attached picture. > > Best wishes > Dieter Doepfer > > > -----Ursprungliche Nachricht----- > > Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com] > > Gesendet: Dienstag, 9. Januar 2018 12:50 > > An: yahoo@doepfer.de [Doepfer_a100] > > Betreff: [Doepfer_a100] A-132-4 Input Signal Level > > > > > > I find it is necessary to greatly attenuate a VCO output (say the > > sine wave from a A-111-1) to prevent distortion. I have adjusted > > the trimmers to get a full range sweep for an ADSR. > > > > Is there an input resistor that could be changed to remove the > > need for 2 x A-183-1 dual attenuators, or am I thinking about > > this incorrectly? > > > > Thanks > > John > > > > > > > > ------------------------------------ > > Posted by: John Hollis <john@hollis.je> > > ------------------------------------ > > > > > > ------------------------------------ > > > > Yahoo Groups Links > > > > > > > > [Non-text portions of this message have been removed] > > > > > > > > >
2018-01-09 by John Hollis
Hi Dieter, Thanks for the PCB layout. I needed 2M2 to get it clean! I guess it’s looking into a fairly high impedance. The results are great. My Simmonds SDSV patch now sounds perfectly 1981. Best wishes, John
> On 9 Jan 2018, at 12:30, <yahoo@doepfer.de> <yahoo@doepfer.de> wrote: > > Hello, > > each of the four VCAs is equipped with a 47k input resistor (R1, R12, R23, > R34). If you increase the values of these resistors (or add a trimming > potentiometer to each resistor) the input signal is attenuated. You find the > position of the resistors in the attached picture. > > Best wishes > Dieter Doepfer > >> -----Ursprungliche Nachricht----- >> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com] >> Gesendet: Dienstag, 9. Januar 2018 12:50 >> An: yahoo@doepfer.de [Doepfer_a100] >> Betreff: [Doepfer_a100] A-132-4 Input Signal Level >> >> >> I find it is necessary to greatly attenuate a VCO output (say the >> sine wave from a A-111-1) to prevent distortion. I have adjusted >> the trimmers to get a full range sweep for an ADSR. >> >> Is there an input resistor that could be changed to remove the >> need for 2 x A-183-1 dual attenuators, or am I thinking about >> this incorrectly? >> >> Thanks >> John >> >> >> >> ------------------------------------ >> Posted by: John Hollis <john@hollis.je> >> ------------------------------------ >> >> >> ------------------------------------ >> >> Yahoo Groups Links >> >> >> > <A132_4_b.gif>
2018-01-09 by christian ienni
heh, i remember someone in a Keyboard magazine from ~35ish years ago describing it as "that Simmons sheep-kicked-in-the-gut drum sound". :-)
From: "John Hollis john@hollis.co.uk [Doepfer_a100]" <Doepfer_a100@yahoogroups.com>
To: yahoo@doepfer.de
Cc: Doepfer_a100@yahoogroups.com
Sent: Tuesday, January 9, 2018 8:16 AM
Subject: Re: [Doepfer_a100] A-132-4 Input Signal Level
Hi Dieter,
Thanks for the PCB layout. I needed 2M2 to get it clean! I guess it’s looking into a fairly high impedance.
The results are great. My Simmonds SDSV patch now sounds perfectly 1981.
Best wishes,
John2018-01-09 by John Hollis
If only voltage controlled sheep were rack mountable…
> On 9 Jan 2018, at 19:23, christian ienni ienni23@yahoo.com [Doepfer_a100] <Doepfer_a100@yahoogroups.com> wrote: > > > heh, i remember someone in a Keyboard magazine from ~35ish years ago describing it as "that Simmons sheep-kicked-in-the-gut drum sound". > > :-) > > > From: "John Hollis john@hollis.co.uk <mailto:john@hollis.co.uk> [Doepfer_a100]" <Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>> > To: yahoo@doepfer.de <mailto:yahoo@doepfer.de> > Cc: Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com> > Sent: Tuesday, January 9, 2018 8:16 AM > Subject: Re: [Doepfer_a100] A-132-4 Input Signal Level > > > Hi Dieter, > > Thanks for the PCB layout. I needed 2M2 to get it clean! I guess it’s looking into a fairly high impedance. > > The results are great. My Simmonds SDSV patch now sounds perfectly 1981. > > Best wishes, > John > > > > >