Modular Synth Panels

How is the spread CV on the bridechamber panel for the CGS CMOS VCF pansl wired up? I don't see anything on the CGS site and tried to do some searching here but couldn't turn up anything.

Thanks!

Jack to left lug of pot

So should each of those 2 junctions go through a 200K resistor (in other words 2 resistors or 1 resistor with 2 wires connected to the other end)?

Thanks!

--- In ModularSynthPanels@yahoogroups.com, Scott Deyo <contact@...> wrote:
>
> Jack to left lug of pot
> Middle lug via 200k resistor (haven't tested this yet, but should be a
> good value) to two places:
> CVSN of Filter B
> Junction of Junction of 100k and 2k2 resistors that go to pin 2 of
> Filter A CV inputs op-amp
> Right lug to ground
>
> So, the effect should be, putting 5V in, with pot turned all the way
> up, Filter A should go down around 2V5-worth of frequency, and Filter
> B should go up an equal amount.
>
> Scott Deyo
> contact@...
> The Bridechamber
> www.bridechamber.com
> Jealous Edison Record Kompany
> www.jealousedison.com
>
>
>
>
> On Feb 11, 2010, at 5:14 PM, joshdaigleusa wrote:
>
> > How is the spread CV on the bridechamber panel for the CGS CMOS VCF
> > pansl wired up? I don't see anything on the CGS site and tried to do
> > some searching here but couldn't turn up anything.
> >
> > Thanks!
> >
> >
> >
>

Each through a resistor. 

Thanks again!

--- In ModularSynthPanels@yahoogroups.com, Scott Deyo <contact@...> wrote:
>
> Each through a resistor.
>
> Scott Deyo
> contact@...
> The Bridechamber
> www.bridechamber.com
> Jealous Edison Record Kompany
> www.jealousedison.com
>
>
>
>
> On Feb 12, 2010, at 3:32 PM, joshdaigleusa wrote:
>
> > So should each of those 2 junctions go through a 200K resistor (in
> > other words 2 resistors or 1 resistor with 2 wires connected to the
> > other end)?
> >
> > Thanks!
> >
> > --- In ModularSynthPanels@yahoogroups.com, Scott Deyo <contact@>
> > wrote:
> > >
> > > Jack to left lug of pot
> > > Middle lug via 200k resistor (haven't tested this yet, but should
> > be a
> > > good value) to two places:
> > > CVSN of Filter B
> > > Junction of Junction of 100k and 2k2 resistors that go to pin 2 of
> > > Filter A CV inputs op-amp
> > > Right lug to ground
> > >
> > > So, the effect should be, putting 5V in, with pot turned all the way
> > > up, Filter A should go down around 2V5-worth of frequency, and
> > Filter
> > > B should go up an equal amount.
> > >
> > > Scott Deyo
> > > contact@
> > > The Bridechamber
> > > www.bridechamber.com
> > > Jealous Edison Record Kompany
> > > www.jealousedison.com
> > >
> > >
> > >
> > >
> > > On Feb 11, 2010, at 5:14 PM, joshdaigleusa wrote:
> > >
> > > > How is the spread CV on the bridechamber panel for the CGS CMOS
> > VCF
> > > > pansl wired up? I don't see anything on the CGS site and tried
> > to do
> > > > some searching here but couldn't turn up anything.
> > > >
> > > > Thanks!
> > > >
> > > >
> > > >
> > >
> >
> >
> >
>

I apologize if this is posted twice - I have a difficult time with Yahoo groups sometimes and finding recent posts. Posting again because it doesn't seem to have made it through.

Ok, I'm building this now and am confused. I think Ken has his schematic wrong for the CV section:

http://www.cgs.synth.net/modules/pic/schem_cgs49_twf.gif

This schematic shows the CV "+" inputs summing into the non-inverting input, pin 3, and the CV "-" input going into the inverting input, pin 2. If you look at the traces on the board this is reversed: The single "CV-" input goes to pin 3, the non-inverting input, and the summed "+" CV inputs go to the inverting input, pin 2, with the 2K2 resistor in the negative feedback loop between the output and pin 2.

So, correct me if I'm wrong, please, but I'm going to venture that this mod will not work as suggested then, right, because we can't throw another input onto the non-inverting input of the TL072, can we? If, as suggested, I add a wire, through a 200K resistor, to the intersection of the 100K input resistor for the CV- input and the 2K2 pull-down resistor, ultimately feed into into the non-inverting input summed along with the "CV-" input, this won't work, will it? Am I off? The way I've understood op-amps is to sum/mix multiple inputs into an op-amp this has to happen via input resistors which sum into the inverting input, with the non-inverting input tied to ground.

So, does this mean we either have to sacrifice the CV Invert switch or not have the spread functionality?

--- In ModularSynthPanels@yahoogroups.com, "joshdaigleusa" <taviny@...> wrote:
>
> Thanks again!
>
> --- In ModularSynthPanels@yahoogroups.com, Scott Deyo <contact@> wrote:
> >
> > Each through a resistor.
> >
> > Scott Deyo
> > contact@
> > The Bridechamber
> > www.bridechamber.com
> > Jealous Edison Record Kompany
> > www.jealousedison.com
> >
> >
> >
> >
> > On Feb 12, 2010, at 3:32 PM, joshdaigleusa wrote:
> >
> > > So should each of those 2 junctions go through a 200K resistor (in
> > > other words 2 resistors or 1 resistor with 2 wires connected to the
> > > other end)?
> > >
> > > Thanks!
> > >
> > > --- In ModularSynthPanels@yahoogroups.com, Scott Deyo <contact@>
> > > wrote:
> > > >
> > > > Jack to left lug of pot
> > > > Middle lug via 200k resistor (haven't tested this yet, but should
> > > be a
> > > > good value) to two places:
> > > > CVSN of Filter B
> > > > Junction of Junction of 100k and 2k2 resistors that go to pin 2 of
> > > > Filter A CV inputs op-amp
> > > > Right lug to ground
> > > >
> > > > So, the effect should be, putting 5V in, with pot turned all the way
> > > > up, Filter A should go down around 2V5-worth of frequency, and
> > > Filter
> > > > B should go up an equal amount.
> > > >
> > > > Scott Deyo
> > > > contact@
> > > > The Bridechamber
> > > > www.bridechamber.com
> > > > Jealous Edison Record Kompany
> > > > www.jealousedison.com
> > > >
> > > >
> > > >
> > > >
> > > > On Feb 11, 2010, at 5:14 PM, joshdaigleusa wrote:
> > > >
> > > > > How is the spread CV on the bridechamber panel for the CGS CMOS
> > > VCF
> > > > > pansl wired up? I don't see anything on the CGS site and tried
> > > to do
> > > > > some searching here but couldn't turn up anything.
> > > > >
> > > > > Thanks!
> > > > >
> > > > >
> > > > >
> > > >
> > >
> > >
> > >
> >
>

Of course, I didn't think of that, so I asked Ken:

I'm planning to build one of these, but with my own 1U panel. Yes, 1U.
It will have three pots, the mode switch, and three jacks per filter
section. No spread feature, though. I'm waiting for Ken's PC board to
become available again.

Richard Brewster
http://pugix.com

Scott Deyo wrote:

>
>
> Of course, I didn't think of that, so I asked Ken:
>
> "Pin 3 is not a summing node. You can feed a second signal into it via a
> second resistor. The two -CV will AVERAGE with each other, not sum. In
> other
> words, stuff will happen, and it will probably be good enough. The -CV
> won't
> be quite as sensitive as on the other unit, though it probably won't
> be that
> noticable. It will be in keeping with the general "roughness" of the
> module
> though, and that is part of its charm. "
>
> You'd think I'd learn to stop doing mods. At least it only effects one
> of the filters, and it's not a 1V/oct, precise filter anyway.
>
> Scott Deyo
> contact@... <mailto:contact@...>
> The Bridechamber
> www.bridechamber.com <http://www.bridechamber.com>
> Jealous Edison Record Kompany
> www.jealousedison.com <http://www.jealousedison.com>
>
>
>
>
> On Mar 17, 2010, at 8:38 PM, joshdaigleusa wrote:
>
>> I apologize if this is posted twice - I have a difficult time with
>> Yahoo groups sometimes and finding recent posts. Posting again
>> because it doesn't seem to have made it through.
>>
>> Ok, I'm building this now and am confused. I think Ken has his
>> schematic wrong for the CV section:
>>
>> http://www.cgs.synth.net/modules/pic/schem_cgs49_twf.gif
>> <http://www.cgs.synth.net/modules/pic/schem_cgs49_twf.gif>
>>
>> This schematic shows the CV "+" inputs summing into the non-inverting
>> input, pin 3, and the CV "-" input going into the inverting input,
>> pin 2. If you look at the traces on the board this is reversed: The
>> single "CV-" input goes to pin 3, the non-inverting input, and the
>> summed "+" CV inputs go to the inverting input, pin 2, with the 2K2
>> resistor in the negative feedback loop between the output and pin 2.
>>
>> So, correct me if I'm wrong, please, but I'm going to venture that
>> this mod will not work as suggested then, right, because we can't
>> throw another input onto the non-inverting input of the TL072, can
>> we? If, as suggested, I add a wire, through a 200K resistor, to the
>> intersection of the 100K input resistor for the CV- input and the 2K2
>> pull-down resistor, ultimately feed into into the non-inverting input
>> summed along with the "CV-" input, this won't work, will it? Am I
>> off? The way I've understood op-amps is to sum/mix multiple inputs
>> into an op-amp this has to happen via input resistors which sum into
>> the inverting input, with the non-inverting input tied to ground.
>>
>> So, does this mean we either have to sacrifice the CV Invert switch
>> or not have the spread functionality?
>>

Sigh... The shame of non-standard spacing. I shed a salty, salty tear
for standard spacing, Richard. My grey lil' heart breaks.
But I want to see pics and hear sounds and watch your modular grow,
nonetheless.

Scott Deyo
contact@...
The Bridechamber
www.bridechamber.com
Jealous Edison Record Kompany
www.jealousedison.com

On Mar 18, 2010, at 5:51 PM, Richard Brewster wrote:

> I'm planning to build one of these, but with my own 1U panel. Yes,
> 1U.
> It will have three pots, the mode switch, and three jacks per filter
> section. No spread feature, though. I'm waiting for Ken's PC board
> to
> become available again.
>
> Richard Brewster
> http://pugix.com
>
> Scott Deyo wrote:
>>
>>
>> Of course, I didn't think of that, so I asked Ken:
>>
>> "Pin 3 is not a summing node. You can feed a second signal into it
>> via a
>> second resistor. The two -CV will AVERAGE with each other, not sum.
>> In
>> other
>> words, stuff will happen, and it will probably be good enough. The -
>> CV
>> won't
>> be quite as sensitive as on the other unit, though it probably won't
>> be that
>> noticable. It will be in keeping with the general "roughness" of the
>> module
>> though, and that is part of its charm. "
>>
>> You'd think I'd learn to stop doing mods. At least it only effects
>> one
>> of the filters, and it's not a 1V/oct, precise filter anyway.
>>
>> Scott Deyo
>> contact@... <mailto:contact@...>
>> The Bridechamber
>> www.bridechamber.com <http://www.bridechamber.com>
>> Jealous Edison Record Kompany
>> www.jealousedison.com <http://www.jealousedison.com>
>>
>>
>>
>>
>> On Mar 17, 2010, at 8:38 PM, joshdaigleusa wrote:
>>
>>> I apologize if this is posted twice - I have a difficult time with
>>> Yahoo groups sometimes and finding recent posts. Posting again
>>> because it doesn't seem to have made it through.
>>>
>>> Ok, I'm building this now and am confused. I think Ken has his
>>> schematic wrong for the CV section:
>>>
>>> http://www.cgs.synth.net/modules/pic/schem_cgs49_twf.gif
>>> <http://www.cgs.synth.net/modules/pic/schem_cgs49_twf.gif>
>>>
>>> This schematic shows the CV "+" inputs summing into the non-
>>> inverting
>>> input, pin 3, and the CV "-" input going into the inverting input,
>>> pin 2. If you look at the traces on the board this is reversed: The
>>> single "CV-" input goes to pin 3, the non-inverting input, and the
>>> summed "+" CV inputs go to the inverting input, pin 2, with the 2K2
>>> resistor in the negative feedback loop between the output and pin 2.
>>>
>>> So, correct me if I'm wrong, please, but I'm going to venture that
>>> this mod will not work as suggested then, right, because we can't
>>> throw another input onto the non-inverting input of the TL072, can
>>> we? If, as suggested, I add a wire, through a 200K resistor, to the
>>> intersection of the 100K input resistor for the CV- input and the
>>> 2K2
>>> pull-down resistor, ultimately feed into into the non-inverting
>>> input
>>> summed along with the "CV-" input, this won't work, will it? Am I
>>> off? The way I've understood op-amps is to sum/mix multiple inputs
>>> into an op-amp this has to happen via input resistors which sum into
>>> the inverting input, with the non-inverting input tied to ground.
>>>
>>> So, does this mean we either have to sacrifice the CV Invert switch
>>> or not have the spread functionality?
>>>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

Shame? No the pride! It's not that non-standard, just smaller pots.
It's the MOTM jack grid for the whole panel. Your 3-jack bracket works
great. Like this:

http://pugix.com/synth/cgs-super-psycho-lfo/

Richard

Scott Deyo wrote:

> Sigh... The shame of non-standard spacing. I shed a salty, salty tear
> for standard spacing, Richard. My grey lil' heart breaks.
> But I want to see pics and hear sounds and watch your modular grow,
> nonetheless.
>
> Scott Deyo
> contact@...
> The Bridechamber
> www.bridechamber.com
> Jealous Edison Record Kompany
> www.jealousedison.com
>
>
>
>
> On Mar 18, 2010, at 5:51 PM, Richard Brewster wrote:
>
>
>> I'm planning to build one of these, but with my own 1U panel. Yes,
>> 1U.
>> It will have three pots, the mode switch, and three jacks per filter
>> section. No spread feature, though. I'm waiting for Ken's PC board
>> to
>> become available again.
>>
>> Richard Brewster
>> http://pugix.com
>>
>> Scott Deyo wrote:
>>
>>> Of course, I didn't think of that, so I asked Ken:
>>>
>>> "Pin 3 is not a summing node. You can feed a second signal into it
>>> via a
>>> second resistor. The two -CV will AVERAGE with each other, not sum.
>>> In
>>> other
>>> words, stuff will happen, and it will probably be good enough. The -
>>> CV
>>> won't
>>> be quite as sensitive as on the other unit, though it probably won't
>>> be that
>>> noticable. It will be in keeping with the general "roughness" of the
>>> module
>>> though, and that is part of its charm. "
>>>
>>> You'd think I'd learn to stop doing mods. At least it only effects
>>> one
>>> of the filters, and it's not a 1V/oct, precise filter anyway.
>>>
>>> Scott Deyo
>>> contact@... <mailto:contact@...>
>>> The Bridechamber
>>> www.bridechamber.com <http://www.bridechamber.com>
>>> Jealous Edison Record Kompany
>>> www.jealousedison.com <http://www.jealousedison.com>
>>>
>>>
>>>
>>>
>>> On Mar 17, 2010, at 8:38 PM, joshdaigleusa wrote:
>>>
>>>
>>>> I apologize if this is posted twice - I have a difficult time with
>>>> Yahoo groups sometimes and finding recent posts. Posting again
>>>> because it doesn't seem to have made it through.
>>>>
>>>> Ok, I'm building this now and am confused. I think Ken has his
>>>> schematic wrong for the CV section:
>>>>
>>>> http://www.cgs.synth.net/modules/pic/schem_cgs49_twf.gif
>>>> <http://www.cgs.synth.net/modules/pic/schem_cgs49_twf.gif>
>>>>
>>>> This schematic shows the CV "+" inputs summing into the non-
>>>> inverting
>>>> input, pin 3, and the CV "-" input going into the inverting input,
>>>> pin 2. If you look at the traces on the board this is reversed: The
>>>> single "CV-" input goes to pin 3, the non-inverting input, and the
>>>> summed "+" CV inputs go to the inverting input, pin 2, with the 2K2
>>>> resistor in the negative feedback loop between the output and pin 2.
>>>>
>>>> So, correct me if I'm wrong, please, but I'm going to venture that
>>>> this mod will not work as suggested then, right, because we can't
>>>> throw another input onto the non-inverting input of the TL072, can
>>>> we? If, as suggested, I add a wire, through a 200K resistor, to the
>>>> intersection of the 100K input resistor for the CV- input and the
>>>> 2K2
>>>> pull-down resistor, ultimately feed into into the non-inverting
>>>> input
>>>> summed along with the "CV-" input, this won't work, will it? Am I
>>>> off? The way I've understood op-amps is to sum/mix multiple inputs
>>>> into an op-amp this has to happen via input resistors which sum into
>>>> the inverting input, with the non-inverting input tied to ground.
>>>>
>>>> So, does this mean we either have to sacrifice the CV Invert switch
>>>> or not have the spread functionality?
>>>>
>>>>
>>
>> ------------------------------------
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>
>