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Thread

A-124 tweak tic tic.

2013-02-14 by ctujoao

Hello there, 

Love the A-124. But now, how to make it even better?  

I got the self oscillation modifications done. Work best with a pot added that let all the screaming goodness slowly coming in. 

You can tap the HP or LP on each leg of the mix potentiometer. 
I've personally replace the "cv1" in - never used, always goes for cv2 with attenuation- with an "LPout".

One thing that would be nice would be to CV control the crossfader between HP/LP, but that sounds like a lot of work, and with the extra out mention before, I can do that downstream. 

Then, there's the resonance... And how to get control over that wild thing. 

The signal that flows between the legs of the potentiometer is weird; it lives at around 5.8V when the pot is CCW, and at 5.4V when CW. However there's significantly more current going through (form 165mA to 350mA). 
I've got no idea how that work, could someone point out where to start? 

And since I'm not a messiah, but a very naughty boy, I added a jack in the signal path at the potentiometer, just to see: when an LFO, env...  is added in parallel with the original signal flowing through the pot, you can swipe the resonance wildly (full res to actually no sound, like silencing the filter, no gain) 
Same thing: if someone wise can explain, I'll be grateful. 

THanks.

Re: A-124 tweak tic tic.

2013-02-20 by ctujoao

Thanks for the answer. 
Of course these measurement don't make sense. I didn't even click. 
Could have I misread milli and micro, certainly so. 

VCAs, and control, I'll read more about that then. 

I could not resist, since it's my lesson of the  day: 

http://groups.yahoo.com/group/Doepfer_a100/photos/album/1096362407/pic/2138570574/view




--- In Doepfer_a100@yahoogroups.com, <yahoo@...> wrote:

Show quoted textHide quoted text

>
> For all these modifications VCAs are requried. One VCA for the CV control of
> the feedback path and two opposite controlled VCAs for the LP/HP panning
> (nothing but the A-134 with the two inputs wired to the LP and HP outputs).
> One cannot simply add a voltage somewhere in the circuit to obtain CV
> control.
> 
> If your module consume 165...350mA something is completely wrong! Usually
> the A-124 takes less than 30mA.
> 
> Best wishes
> Dieter Doepfer
> 
> 
> > -----Ursprüngliche Nachricht-----
> > Von: Doepfer_a100@yahoogroups.com
> > [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von ctujoao
> > Gesendet: Donnerstag, 14. Februar 2013 23:40
> > An: Doepfer_a100@yahoogroups.com
> > Betreff: [Doepfer_a100] A-124 tweak tic tic.
> >
> >
> > Hello there,
> >
> > Love the A-124. But now, how to make it even better?
> >
> > I got the self oscillation modifications done. Work best with a
> > pot added that let all the screaming goodness slowly coming in.
> >
> > You can tap the HP or LP on each leg of the mix potentiometer.
> > I've personally replace the "cv1" in - never used, always goes
> > for cv2 with attenuation- with an "LPout".
> >
> > One thing that would be nice would be to CV control the
> > crossfader between HP/LP, but that sounds like a lot of work, and
> > with the extra out mention before, I can do that downstream.
> >
> > Then, there's the resonance... And how to get control over that
> > wild thing.
> >
> > The signal that flows between the legs of the potentiometer is
> > weird; it lives at around 5.8V when the pot is CCW, and at 5.4V
> > when CW. However there's significantly more current going through
> > (form 165mA to 350mA).
> > I've got no idea how that work, could someone point out where to start?
> >
> > And since I'm not a messiah, but a very naughty boy, I added a
> > jack in the signal path at the potentiometer, just to see: when
> > an LFO, env...  is added in parallel with the original signal
> > flowing through the pot, you can swipe the resonance wildly (full
> > res to actually no sound, like silencing the filter, no gain)
> > Same thing: if someone wise can explain, I'll be grateful.
> >
> > THanks.
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>

AW: [Doepfer_a100] A-124 tweak tic tic.

2013-02-20 by yahoo@doepfer.de

For all these modifications VCAs are requried. One VCA for the CV control of
the feedback path and two opposite controlled VCAs for the LP/HP panning
(nothing but the A-134 with the two inputs wired to the LP and HP outputs).
One cannot simply add a voltage somewhere in the circuit to obtain CV
control.

If your module consume 165...350mA something is completely wrong! Usually
the A-124 takes less than 30mA.

Best wishes
Dieter Doepfer

Show quoted textHide quoted text

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von ctujoao
> Gesendet: Donnerstag, 14. Februar 2013 23:40
> An: Doepfer_a100@yahoogroups.com
> Betreff: [Doepfer_a100] A-124 tweak tic tic.
>
>
> Hello there,
>
> Love the A-124. But now, how to make it even better?
>
> I got the self oscillation modifications done. Work best with a
> pot added that let all the screaming goodness slowly coming in.
>
> You can tap the HP or LP on each leg of the mix potentiometer.
> I've personally replace the "cv1" in - never used, always goes
> for cv2 with attenuation- with an "LPout".
>
> One thing that would be nice would be to CV control the
> crossfader between HP/LP, but that sounds like a lot of work, and
> with the extra out mention before, I can do that downstream.
>
> Then, there's the resonance... And how to get control over that
> wild thing.
>
> The signal that flows between the legs of the potentiometer is
> weird; it lives at around 5.8V when the pot is CCW, and at 5.4V
> when CW. However there's significantly more current going through
> (form 165mA to 350mA).
> I've got no idea how that work, could someone point out where to start?
>
> And since I'm not a messiah, but a very naughty boy, I added a
> jack in the signal path at the potentiometer, just to see: when
> an LFO, env...  is added in parallel with the original signal
> flowing through the pot, you can swipe the resonance wildly (full
> res to actually no sound, like silencing the filter, no gain)
> Same thing: if someone wise can explain, I'll be grateful.
>
> THanks.
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

Re: A-124 tweak tic tic.

2013-02-20 by NetPierre

In case you want to make more tweaks to your A-124, check out Nick Keller's DIY/Modification-page at Analoguehaven:

http://www.analoguehaven.com/usercomm/diy/#vcf

Have fun!

Pierre Serné / PatchPierre
http://patchpierre.blogspot.com


--- In Doepfer_a100@yahoogroups.com, "ctujoao" <ctujoao@...> wrote:

Show quoted textHide quoted text

>
> 
> Thanks for the answer. 
> Of course these measurement don't make sense. I didn't even click. 
> Could have I misread milli and micro, certainly so. 
> 
> VCAs, and control, I'll read more about that then. 
> 
> I could not resist, since it's my lesson of the  day: 
> 
> http://groups.yahoo.com/group/Doepfer_a100/photos/album/1096362407/pic/2138570574/view
> 
> 
> 
> 
> --- In Doepfer_a100@yahoogroups.com, <yahoo@> wrote:
> >
> > For all these modifications VCAs are requried. One VCA for the CV control of
> > the feedback path and two opposite controlled VCAs for the LP/HP panning
> > (nothing but the A-134 with the two inputs wired to the LP and HP outputs).
> > One cannot simply add a voltage somewhere in the circuit to obtain CV
> > control.
> > 
> > If your module consume 165...350mA something is completely wrong! Usually
> > the A-124 takes less than 30mA.
> > 
> > Best wishes
> > Dieter Doepfer
> > 
> > 
> > > -----Ursprüngliche Nachricht-----
> > > Von: Doepfer_a100@yahoogroups.com
> > > [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von ctujoao
> > > Gesendet: Donnerstag, 14. Februar 2013 23:40
> > > An: Doepfer_a100@yahoogroups.com
> > > Betreff: [Doepfer_a100] A-124 tweak tic tic.
> > >
> > >
> > > Hello there,
> > >
> > > Love the A-124. But now, how to make it even better?
> > >
> > > I got the self oscillation modifications done. Work best with a
> > > pot added that let all the screaming goodness slowly coming in.
> > >
> > > You can tap the HP or LP on each leg of the mix potentiometer.
> > > I've personally replace the "cv1" in - never used, always goes
> > > for cv2 with attenuation- with an "LPout".
> > >
> > > One thing that would be nice would be to CV control the
> > > crossfader between HP/LP, but that sounds like a lot of work, and
> > > with the extra out mention before, I can do that downstream.
> > >
> > > Then, there's the resonance... And how to get control over that
> > > wild thing.
> > >
> > > The signal that flows between the legs of the potentiometer is
> > > weird; it lives at around 5.8V when the pot is CCW, and at 5.4V
> > > when CW. However there's significantly more current going through
> > > (form 165mA to 350mA).
> > > I've got no idea how that work, could someone point out where to start?
> > >
> > > And since I'm not a messiah, but a very naughty boy, I added a
> > > jack in the signal path at the potentiometer, just to see: when
> > > an LFO, env...  is added in parallel with the original signal
> > > flowing through the pot, you can swipe the resonance wildly (full
> > > res to actually no sound, like silencing the filter, no gain)
> > > Same thing: if someone wise can explain, I'll be grateful.
> > >
> > > THanks.
> > >
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> >
>