Modular Synth Panels

Hi Scott and others -

Couldn't find the right message to reply to, so I'll start a new
thread. The volume of replies is getting out of hand anyway.

While sliders are cool, I'm definitely solidly in favor of knobs on my
klee. I think Clickmrmike has seen my roland jd-800, which I've had
since they were introduced back in the early 90's. 54 sliders. While
these are considered to be some of the best sliders ever put on a
performance instrument, at any point after the first year or so the
chances of having all 54 sliders working correctly, even after
rigorous cleaning, are minimal at best. With just 16 sliders, your
chances get better, but there are still going to be problems - and
this is a "will be problems" situation, not a "might have problems"
thing.

Sure, 16 spectrol pots are going to cost a bit, but they will be
foolproof, and probably work perfectly with no problems for a lifetime
(or at least my lifetime, or rather what's left). And actually 16
spectrols isn't that much - I built a milton once with 64 pots - not
spectrols, but pretty close in price. Heck, the doomsday has 18
spectrols on it. And even alpha pots are a bit more reliable than most
faders in my experience.

So Scott, if a panel with holes in it is in the line-up, I'll buy one,
if it appears in time, otherwise I'll finish up this fpd file and bite
the bullet. By the way, my design is actually based originally on my
old milton panel, just with a lot of stuff moved around/changed, etc.
I don't have the size handy, but clickmrmike has my old panel - how
big is it? That one was based on Jeff Pontius's design which is in the
files here. It's the full bells and whistle design, btw, based on the
designs of clickmrmike and Will and Bill. The current design 16 pots
in a row) requires the smaller knobs, although there's room to
stagger/offset the pots and actually use the larger ones - I haven't
really got my head around that yet though.

BTW, this isn't meant in any way to put down the slider fans - I think
the slider klees I've seen and heard are fantastic - it's just my
personal choice to use knobs. Call me old fashioned, call me a fuddy
duddy, as long as you call me.

Steve

Hear hear, Steve! Well, that's three of us. Anyone else want to come
out of the woodwork? :)

> Hi Scott and others -
>
> Couldn't find the right message to reply to, so I'll start a new
> thread. The volume of replies is getting out of hand anyway.
>
> While sliders are cool, I'm definitely solidly in favor of knobs on my
> klee. I think Clickmrmike has seen my roland jd-800, which I've had
> since they were introduced back in the early 90's. 54 sliders. While
> these are considered to be some of the best sliders ever put on a
> performance instrument, at any point after the first year or so the
> chances of having all 54 sliders working correctly, even after
> rigorous cleaning, are minimal at best. With just 16 sliders, your
> chances get better, but there are still going to be problems - and
> this is a "will be problems" situation, not a "might have problems"
> thing.
>
> Sure, 16 spectrol pots are going to cost a bit, but they will be
> foolproof, and probably work perfectly with no problems for a lifetime
> (or at least my lifetime, or rather what's left). And actually 16
> spectrols isn't that much - I built a milton once with 64 pots - not
> spectrols, but pretty close in price. Heck, the doomsday has 18
> spectrols on it. And even alpha pots are a bit more reliable than most
> faders in my experience.
>
> So Scott, if a panel with holes in it is in the line-up, I'll buy one,
> if it appears in time, otherwise I'll finish up this fpd file and bite
> the bullet. By the way, my design is actually based originally on my
> old milton panel, just with a lot of stuff moved around/changed, etc.
> I don't have the size handy, but clickmrmike has my old panel - how
> big is it? That one was based on Jeff Pontius's design which is in the
> files here. It's the full bells and whistle design, btw, based on the
> designs of clickmrmike and Will and Bill. The current design 16 pots
> in a row) requires the smaller knobs, although there's room to
> stagger/offset the pots and actually use the larger ones - I haven't
> really got my head around that yet though.
>
> BTW, this isn't meant in any way to put down the slider fans - I think
> the slider klees I've seen and heard are fantastic - it's just my
> personal choice to use knobs. Call me old fashioned, call me a fuddy
> duddy, as long as you call me.
>
> Steve
>
>

eh, count me in amongst the knobbies as well. anything to look like
Tangerine Dream.

>Hear hear, Steve! Well, that's three of us. Anyone else want to come
>out of the woodwork? :)

Now - I've been keeping my mouth shut because I swore I wouldn't build
one of these things. But Will - yes, I'm blaming him again - has his
own idea about it... fueled, I think by comments by clickmike and gino
(thanks a lot guys <G>). So yes - I give in - but we'll want a knobby
one for sure. So that's five knobbies and counting?

(God save me - tangerine dream or clockwork orange?) Bill and Will




--- In ModularSynthPanels@yahoogroups.com, Jason Proctor <jason@...>
wrote:

>
> eh, count me in amongst the knobbies as well. anything to look like
> Tangerine Dream.
>
>
>
> >Hear hear, Steve! Well, that's three of us. Anyone else want to come
> >out of the woodwork? :)
>

although i have heard rumours that thomas white is doing a rotary
panel for the Klee just like his MFOS one. i think i'd prefer that
over just about anything else...

>Now - I've been keeping my mouth shut because I swore I wouldn't build
>one of these things. But Will - yes, I'm blaming him again - has his
>own idea about it... fueled, I think by comments by clickmike and gino
>(thanks a lot guys <G>). So yes - I give in - but we'll want a knobby
>one for sure. So that's five knobbies and counting?
>
>(God save me - tangerine dream or clockwork orange?) Bill and Will

On 5/17/08, sduck409 put forth:

>
>Sure, 16 spectrol pots are going to cost a bit, but they will be
>foolproof, and probably work perfectly with no problems for a lifetime
>(or at least my lifetime, or rather what's left). And actually 16
>spectrols isn't that much - I built a milton once with 64 pots - not
>spectrols, but pretty close in price. Heck, the doomsday has 18
>spectrols on it. And even alpha pots are a bit more reliable than most
>faders in my experience.

I prefer virtual sliders on a Mac and virtual knobs on a PC ;)

Speaking of pots, for non-MOTM-format use, is there anything between
$1 Alpha carbon pots and $9 Spectrol/Bourns cermet/conductive-plastic
pots?? Or is that it??

I'm also looking for a line of decent switches -- less expensive
than NKK but not complete crap.


Thanks :)

--- In ModularSynthPanels@yahoogroups.com, Mark <yahoogroups@...> wrote:

>

>
> Speaking of pots, for non-MOTM-format use, is there anything between
> $1 Alpha carbon pots and $9 Spectrol/Bourns cermet/conductive-plastic
> pots?? Or is that it??
>
> I'm also looking for a line of decent switches -- less expensive
> than NKK but not complete crap.
>
>
> Thanks :)
>

Actually I use the spectrol 249's, which are about 5$ from mouser.

I guess I caused a little scrum eh ? Go pots ! Though knobs are too goddamm expensive.
We need to do something about that too.

A good rule is for CV and control I'll use Alphas or Allen Bradley, high mechanical
reliability and for Audio I use reliable conductive plastic or cermet like Bourns. There
needs to be a middle ground on pot but the only real middle ground is to bulk buy a lot ot
somehow find a good overstock dal.

> >
> > Speaking of pots, for non-MOTM-format use, is there anything between
> > $1 Alpha carbon pots and $9 Spectrol/Bourns cermet/conductive-plastic
> > pots?? Or is that it??
> >
> > I'm also looking for a line of decent switches -- less expensive
> > than NKK but not complete crap.
> >
> >
> > Thanks :)
> >
>
> Actually I use the spectrol 249's, which are about 5$ from mouser.
>

I'm a slider supporter for the Klee since I feel on this particular
sequencer it is important to have the clearest possible visual
indication as to what is going on. However, if I don't have choice I
will go for knobs IF it is 8U or less with room for large knobs.

--- In ModularSynthPanels@yahoogroups.com, Jason Proctor <jason@...>
wrote:

>
> although i have heard rumours that thomas white is doing a rotary
> panel for the Klee just like his MFOS one. i think i'd prefer that
> over just about anything else...
>
>
>
> >Now - I've been keeping my mouth shut because I swore I wouldn't build
> >one of these things. But Will - yes, I'm blaming him again - has his
> >own idea about it... fueled, I think by comments by clickmike and gino
> >(thanks a lot guys <G>). So yes - I give in - but we'll want a knobby
> >one for sure. So that's five knobbies and counting?
> >
> >(God save me - tangerine dream or clockwork orange?) Bill and Will
>

Well, 3 against 5 so far... But since my slider vote counts for 500....
; p

I think a lot of Klee PCBs are out there, and if there are less
expensive, non-FPE panels maybe more will sell, so maybe I'll just do
both.

On the back of the pot version I'll have to silkscreen a little
something extra, so they might be a little more expensive.
Hardy har har, just kidding.

Cheers,
Scott Deyo
The Bridechamber
contact@...
http://www.bridechamber.com
Jealous Edison Record Kompany
http://www.jealousedison.com

On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:

> I'm a slider supporter for the Klee since I feel on this particular
> sequencer it is important to have the clearest possible visual
> indication as to what is going on. However, if I don't have choice I
> will go for knobs IF it is 8U or less with room for large knobs.
>
> --- In ModularSynthPanels@yahoogroups.com, Jason Proctor <jason@...>
> wrote:
> >
> > although i have heard rumours that thomas white is doing a rotary
> > panel for the Klee just like his MFOS one. i think i'd prefer that
> > over just about anything else...
> >
> >
> >
> > >Now - I've been keeping my mouth shut because I swore I wouldn't
> build
> > >one of these things. But Will - yes, I'm blaming him again - has
> his
> > >own idea about it... fueled, I think by comments by clickmike and
> gino
> > >(thanks a lot guys <G>). So yes - I give in - but we'll want a
> knobby
> > >one for sure. So that's five knobbies and counting?
> > >
> > >(God save me - tangerine dream or clockwork orange?) Bill and Will
> >
>
>
>

I have 4 sets of Klee PCBs.

I plan on building one table top version w/sliders (maybe 2) & then the rest will be built with whatever Scott offers. I personally think sliders offer a better visual indicator than knobs & they are far easier to tweak in groups, making them better suited for sequencers than knobs..... to each his own. Regardless, Scott will be getting my money either way. I am extremely excited about this project!

-Jim


----- Original Message ----
From: Scott Deyo <contact@...>
To: ModularSynthPanels@yahoogroups.com
Sent: Sunday, May 18, 2008 8:21:05 AM
Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders

Well, 3 against 5 so far... But since my slider vote counts for 500....
; p

I think a lot of Klee PCBs are out there, and if there are less
expensive, non-FPE panels maybe more will sell, so maybe I'll just do
both.

On the back of the pot version I'll have to silkscreen a little
something extra, so they might be a little more expensive.
Hardy har har, just kidding.

Cheers,
Scott Deyo
The Bridechamber
contact@...
http://www.bridechamber.com
Jealous Edison Record Kompany
http://www.jealousedison.com

On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:

> I'm a slider supporter for the Klee since I feel on this particular
> sequencer it is important to have the clearest possible visual
> indication as to what is going on. However, if I don't have choice I
> will go for knobs IF it is 8U or less with room for large knobs.
>
> --- In ModularSynthPanels@yahoogroups.com, Jason Proctor <jason@...>
> wrote:
> >
> > although i have heard rumours that thomas white is doing a rotary
> > panel for the Klee just like his MFOS one. i think i'd prefer that
> > over just about anything else...
> >
> >
> >
> > >Now - I've been keeping my mouth shut because I swore I wouldn't
> build
> > >one of these things. But Will - yes, I'm blaming him again - has
> his
> > >own idea about it... fueled, I think by comments by clickmike and
> gino
> > >(thanks a lot guys <G>). So yes - I give in - but we'll want a
> knobby
> > >one for sure. So that's five knobbies and counting?
> > >
> > >(God save me - tangerine dream or clockwork orange?) Bill and Will
> >
>
>
>

On 5/17/08, adaaxs put forth:

>I guess I caused a little scrum eh ? Go pots ! Though knobs are
>too goddamm expensive. We need to do something about that too.
>
>A good rule is for CV and control I'll use Alphas or Allen Bradley,
>high mechanical
>reliability and for Audio I use reliable conductive plastic or
>cermet like Bourns. There
>needs to be a middle ground on pot but the only real middle ground
>is to bulk buy a lot ot
>somehow find a good overstock dal.

Who sells Allen-Bradley??

--- In ModularSynthPanels@yahoogroups.com, Mark <yahoogroups@...> wrote:

>
> On 5/17/08, adaaxs put forth:
> >I guess I caused a little scrum eh ? Go pots ! Though knobs are
> >too goddamm expensive. We need to do something about that too.
> >
> >A good rule is for CV and control I'll use Alphas or Allen Bradley,
> >high mechanical
> >reliability and for Audio I use reliable conductive plastic or
> >cermet like Bourns. There
> >needs to be a middle ground on pot but the only real middle ground
> >is to bulk buy a lot ot
> >somehow find a good overstock dal.
>
> Who sells Allen-Bradley??
>

Aside from what mostly appear to be surplus on the web, Digi-Key carry PEC (Precision
Electronic Components) pots. Every bit as Mil-spec as Allen and Bradley.

http://digi-key.dirxion.com/Main.asp?
from=emailafriend&pagenav=&bookid=2&pageindex=1843

now that ive finished my klee, have absolutely no regrets about doing pots
instead of sliders. the improvisational strength of the klee lies in the
manipulation of the switches (all of them) as well as the manual load button.
IMO it is far more important to design a panel in which the switches and manual
load button are easily accessible. the klee is not a set-it-and-forget it
sequencer, but i hardly touch the programming pots while im recording.

the biggest disadvantage of designing for sliders is that the panel/subpanel
will probably be slider pot make/model specific. maybe if scott designs these
around one particular slider, he can bundle the sliders with the panel and sell
them all together.





--- James Elliott <johans121@...> wrote:

> I have 4 sets of Klee PCBs.
>
> I plan on building one table top version w/sliders (maybe 2) & then the rest
> will be built with whatever Scott offers. I personally think sliders offer a
> better visual indicator than knobs & they are far easier to tweak in groups,
> making them better suited for sequencers than knobs..... to each his own.
> Regardless, Scott will be getting my money either way. I am extremely excited
> about this project!
>
> -Jim
>
>
> ----- Original Message ----
> From: Scott Deyo <contact@...>
> To: ModularSynthPanels@yahoogroups.com
> Sent: Sunday, May 18, 2008 8:21:05 AM
> Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders
>
> Well, 3 against 5 so far... But since my slider vote counts for 500....
> ; p
>
> I think a lot of Klee PCBs are out there, and if there are less
> expensive, non-FPE panels maybe more will sell, so maybe I'll just do
> both.
>
> On the back of the pot version I'll have to silkscreen a little
> something extra, so they might be a little more expensive.
> Hardy har har, just kidding.
>
> Cheers,
> Scott Deyo
> The Bridechamber
> contact@...
> http://www.bridechamber.com
> Jealous Edison Record Kompany
> http://www.jealousedison.com
>
>
> On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:
>
> > I'm a slider supporter for the Klee since I feel on this particular
> > sequencer it is important to have the clearest possible visual
> > indication as to what is going on. However, if I don't have choice I
> > will go for knobs IF it is 8U or less with room for large knobs.
> >
> > --- In ModularSynthPanels@yahoogroups.com, Jason Proctor <jason@...>
> > wrote:
> > >
> > > although i have heard rumours that thomas white is doing a rotary
> > > panel for the Klee just like his MFOS one. i think i'd prefer that
> > > over just about anything else...
> > >
> > >
> > >
> > > >Now - I've been keeping my mouth shut because I swore I wouldn't
> > build
> > > >one of these things. But Will - yes, I'm blaming him again - has
> > his
> > > >own idea about it... fueled, I think by comments by clickmike and
> > gino
> > > >(thanks a lot guys <G>). So yes - I give in - but we'll want a
> > knobby
> > > >one for sure. So that's five knobbies and counting?
> > > >
> > > >(God save me - tangerine dream or clockwork orange?) Bill and Will
> > >
> >
> >
> >
>
>
>
>

+1 vote for sliders.

Visual feedback and fine control is really important - anyone worried about them not lasting forever, buy some spares!

Julian

--- On Sun, 18/5/08, Scott Deyo <contact@...> wrote:

> From: Scott Deyo <contact@...>
> Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders
> To: ModularSynthPanels@yahoogroups.com
> Date: Sunday, 18 May, 2008, 2:21 PM
> Well, 3 against 5 so far... But since my slider vote counts
> for 500....
> ; p
>
> I think a lot of Klee PCBs are out there, and if there are
> less
> expensive, non-FPE panels maybe more will sell, so maybe
> I'll just do
> both.
>
> On the back of the pot version I'll have to silkscreen
> a little
> something extra, so they might be a little more expensive.
> Hardy har har, just kidding.
>
> Cheers,
> Scott Deyo
> The Bridechamber
> contact@...
> http://www.bridechamber.com
> Jealous Edison Record Kompany
> http://www.jealousedison.com
>
>
> On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:
>
> > I'm a slider supporter for the Klee since I feel
> on this particular
> > sequencer it is important to have the clearest
> possible visual
> > indication as to what is going on. However, if I
> don't have choice I
> > will go for knobs IF it is 8U or less with room for
> large knobs.
> >
> > --- In ModularSynthPanels@yahoogroups.com, Jason
> Proctor <jason@...>
> > wrote:
> > >
> > > although i have heard rumours that thomas white
> is doing a rotary
> > > panel for the Klee just like his MFOS one. i
> think i'd prefer that
> > > over just about anything else...
> > >
> > >
> > >
> > > >Now - I've been keeping my mouth shut
> because I swore I wouldn't
> > build
> > > >one of these things. But Will - yes, I'm
> blaming him again - has
> > his
> > > >own idea about it... fueled, I think by
> comments by clickmike and
> > gino
> > > >(thanks a lot guys <G>). So yes - I
> give in - but we'll want a
> > knobby
> > > >one for sure. So that's five knobbies
> and counting?
> > > >
> > > >(God save me - tangerine dream or clockwork
> orange?) Bill and Will
> > >
> >
> >
> >


__________________________________________________________
Sent from Yahoo! Mail.
A Smarter Email http://uk.docs.yahoo.com/nowyoucan.html



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

From: Julian Ware

To: ModularSynthPanels@yahoogroups.com

Sent: Monday, May 19, 2008 1:32 PM

Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders

+1 vote for sliders.

Visual feedback and fine control is really important - anyone worried about them not lasting forever, buy some spares!

Julian

--- On Sun, 18/5/08, Scott Deyo <contact@bridechambe r.com> wrote:

> From: Scott Deyo <contact@bridechambe r.com>
> Subject: Re: [ModularSynthPanels ] Re: Klee panel - knobs vs sliders
> To: ModularSynthPanels@ yahoogroups. com
> Date: Sunday, 18 May, 2008, 2:21 PM
> Well, 3 against 5 so far... But since my slider vote counts
> for 500....
> ; p
>
> I think a lot of Klee PCBs are out there, and if there are
> less
> expensive, non-FPE panels maybe more will sell, so maybe
> I'll just do
> both.
>
> On the back of the pot version I'll have to silkscreen
> a little
> something extra, so they might be a little more expensive.
> Hardy har har, just kidding.
>
> Cheers,
> Scott Deyo
> The Bridechamber
> contact@bridechambe r.com
> http://www.bridecha mber.com
> Jealous Edison Record Kompany
> http://www.jealouse dison.com
>
>
> On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:
>
> > I'm a slider supporter for the Klee since I feel
> on this particular
> > sequencer it is important to have the clearest
> possible visual
> > indication as to what is going on. However, if I
> don't have choice I
> > will go for knobs IF it is 8U or less with room for
> large knobs.
> >
> > --- In ModularSynthPanels@ yahoogroups. com, Jason
> Proctor <jason@...>
> > wrote:
> > >
> > > although i have heard rumours that thomas white
> is doing a rotary
> > > panel for the Klee just like his MFOS one. i
> think i'd prefer that
> > > over just about anything else...
> > >
> > >
> > >
> > > >Now - I've been keeping my mouth shut
> because I swore I wouldn't
> > build
> > > >one of these things. But Will - yes, I'm
> blaming him again - has
> > his
> > > >own idea about it... fueled, I think by
> comments by clickmike and
> > gino
> > > >(thanks a lot guys <G>). So yes - I
> give in - but we'll want a
> > knobby
> > > >one for sure. So that's five knobbies
> and counting?
> > > >
> > > >(God save me - tangerine dream or clockwork
> orange?) Bill and Will
> > >
> >
> >
> >

____________ _________ _________ _________ _________ _________ _
Sent from Yahoo! Mail.
A Smarter Email http://uk.docs. yahoo.com/ nowyoucan. html

You know - it strikes me that aside from whatever visual-clue
advantages there may be to sliders and longevity advantages there my
be to knobs, there are probably panel design issues too. Knons take
up less room vertically, and sliders less horizontally - make sense?
So I wonder how this would ultimately affect panel design. I wonder
which would make more overall sense in a MOTM-style panel. Or maybe
there's no particular advantage one way or the other. Ideas?

Are there some MOTM designs out there?

Bill (& Will)

--- In ModularSynthPanels@yahoogroups.com, "krisp" <krisp14u@...> wrote:
>
> I'm on the sliders list X 2
>
> cheers
>
> paul
>
> ----- Original Message -----
> From: Julian Ware
> To: ModularSynthPanels@yahoogroups.com
> Sent: Monday, May 19, 2008 1:32 PM
> Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders
>
>
> +1 vote for sliders.
>
> Visual feedback and fine control is really important - anyone
worried about them not lasting forever, buy some spares!
>
> Julian
>
> --- On Sun, 18/5/08, Scott Deyo <contact@...> wrote:
>
> > From: Scott Deyo <contact@...>
> > Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders
> > To: ModularSynthPanels@yahoogroups.com
> > Date: Sunday, 18 May, 2008, 2:21 PM
> > Well, 3 against 5 so far... But since my slider vote counts
> > for 500....
> > ; p
> >
> > I think a lot of Klee PCBs are out there, and if there are
> > less
> > expensive, non-FPE panels maybe more will sell, so maybe
> > I'll just do
> > both.
> >
> > On the back of the pot version I'll have to silkscreen
> > a little
> > something extra, so they might be a little more expensive.
> > Hardy har har, just kidding.
> >
> > Cheers,
> > Scott Deyo
> > The Bridechamber
> > contact@...
> > http://www.bridechamber.com
> > Jealous Edison Record Kompany
> > http://www.jealousedison.com
> >
> >
> > On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:
> >
> > > I'm a slider supporter for the Klee since I feel
> > on this particular
> > > sequencer it is important to have the clearest
> > possible visual
> > > indication as to what is going on. However, if I
> > don't have choice I
> > > will go for knobs IF it is 8U or less with room for
> > large knobs.
> > >
> > > --- In ModularSynthPanels@yahoogroups.com, Jason
> > Proctor <jason@>
> > > wrote:
> > > >
> > > > although i have heard rumours that thomas white
> > is doing a rotary
> > > > panel for the Klee just like his MFOS one. i
> > think i'd prefer that
> > > > over just about anything else...
> > > >
> > > >
> > > >
> > > > >Now - I've been keeping my mouth shut
> > because I swore I wouldn't
> > > build
> > > > >one of these things. But Will - yes, I'm
> > blaming him again - has
> > > his
> > > > >own idea about it... fueled, I think by
> > comments by clickmike and
> > > gino
> > > > >(thanks a lot guys <G>). So yes - I
> > give in - but we'll want a
> > > knobby
> > > > >one for sure. So that's five knobbies
> > and counting?
> > > > >
> > > > >(God save me - tangerine dream or clockwork
> > orange?) Bill and Will
> > > >
> > >
> > >
> > >
>
> __________________________________________________________
> Sent from Yahoo! Mail.
> A Smarter Email http://uk.docs.yahoo.com/nowyoucan.html
>

Not having looked at the Klee design too much yet, I just did a
different design that has two rows of 10 sliders (60mm ones, not too
short), jacks along the bottom and room for 8 or so pots/ knobs, and it
was 4U.

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

On May 19, 2008, at 2:45 PM, wjhall11 wrote:

> You know - it strikes me that aside from whatever visual-clue
> advantages there may be to sliders and longevity advantages there my
> be to knobs, there are probably panel design issues too. Knons take
> up less room vertically, and sliders less horizontally - make sense?
> So I wonder how this would ultimately affect panel design. I wonder
> which would make more overall sense in a MOTM-style panel. Or maybe
> there's no particular advantage one way or the other. Ideas?
>
> Are there some MOTM designs out there?
>
> Bill (& Will)
>
> --- In ModularSynthPanels@yahoogroups.com, "krisp" <krisp14u@...>
> wrote:
> >
> > I'm on the sliders list X 2
> >
> > cheers
> >
> > paul
> >
> > ----- Original Message -----
> > From: Julian Ware
> > To: ModularSynthPanels@yahoogroups.com
> > Sent: Monday, May 19, 2008 1:32 PM
> > Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders
> >
> >
> > +1 vote for sliders.
> >
> > Visual feedback and fine control is really important - anyone
> worried about them not lasting forever, buy some spares!
> >
> > Julian
> >
> > --- On Sun, 18/5/08, Scott Deyo <contact@...> wrote:
> >
> > > From: Scott Deyo <contact@...>
> > > Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs
> sliders
> > > To: ModularSynthPanels@yahoogroups.com
> > > Date: Sunday, 18 May, 2008, 2:21 PM
> > > Well, 3 against 5 so far... But since my slider vote counts
> > > for 500....
> > > ; p
> > >
> > > I think a lot of Klee PCBs are out there, and if there are
> > > less
> > > expensive, non-FPE panels maybe more will sell, so maybe
> > > I'll just do
> > > both.
> > >
> > > On the back of the pot version I'll have to silkscreen
> > > a little
> > > something extra, so they might be a little more expensive.
> > > Hardy har har, just kidding.
> > >
> > > Cheers,
> > > Scott Deyo
> > > The Bridechamber
> > > contact@...
> > > http://www.bridechamber.com
> > > Jealous Edison Record Kompany
> > > http://www.jealousedison.com
> > >
> > >
> > > On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:
> > >
> > > > I'm a slider supporter for the Klee since I feel
> > > on this particular
> > > > sequencer it is important to have the clearest
> > > possible visual
> > > > indication as to what is going on. However, if I
> > > don't have choice I
> > > > will go for knobs IF it is 8U or less with room for
> > > large knobs.
> > > >
> > > > --- In ModularSynthPanels@yahoogroups.com, Jason
> > > Proctor <jason@>
> > > > wrote:
> > > > >
> > > > > although i have heard rumours that thomas white
> > > is doing a rotary
> > > > > panel for the Klee just like his MFOS one. i
> > > think i'd prefer that
> > > > > over just about anything else...
> > > > >
> > > > >
> > > > >
> > > > > >Now - I've been keeping my mouth shut
> > > because I swore I wouldn't
> > > > build
> > > > > >one of these things. But Will - yes, I'm
> > > blaming him again - has
> > > > his
> > > > > >own idea about it... fueled, I think by
> > > comments by clickmike and
> > > > gino
> > > > > >(thanks a lot guys <G>). So yes - I
> > > give in - but we'll want a
> > > > knobby
> > > > > >one for sure. So that's five knobbies
> > > and counting?
> > > > > >
> > > > > >(God save me - tangerine dream or clockwork
> > > orange?) Bill and Will
> > > > >
> > > >
> > > >
> > > >
> >
> > __________________________________________________________
> > Sent from Yahoo! Mail.
> > A Smarter Email http://uk.docs.yahoo.com/nowyoucan.html
> >
>
>
>

I think it's a trade-off either way - both choices have pros and cons.
You make your choice. Or build one of each. I'm going with knobs, but
faders are great too.

Sure, I've got a 8u motm (sort of) panel worked up mostly - it's based
on the one from your web page though. Although it'll work, I'm not
terribly happy with it, and have visions of rotary klee knobs ala
Thomas White's sequencer. Thomas hasn't started work on his yet, but
gave me permission to mod his design, which was nice, although I
probably would have anyway. Having some sort of rotary design in 6u is
a lot more appealing to me than the straight line 8u. Or some sort of
8x8 ovoid pattern - got to get working on this.

--- In ModularSynthPanels@yahoogroups.com, "wjhall11" <wjhall@...> wrote:
>
> You know - it strikes me that aside from whatever visual-clue
> advantages there may be to sliders and longevity advantages there my
> be to knobs, there are probably panel design issues too. Knobs take
> up less room vertically, and sliders less horizontally - make sense?
> So I wonder how this would ultimately affect panel design. I wonder
> which would make more overall sense in a MOTM-style panel. Or maybe
> there's no particular advantage one way or the other. Ideas?
>
> Are there some MOTM designs out there?
>
> Bill (& Will)
>
>

Hey Scott,

Uncle Krunkus has a nice looking panel if you want something to
reference, it might be a bit bigger than most but I personally don't
mind if it's a larger panel. The more space the merrier :)

http://electro-music.com/forum/phpbb-files/klee_build_7_807.jpg

--- In ModularSynthPanels@yahoogroups.com, Scott Deyo <contact@...> wrote:
>
> Not having looked at the Klee design too much yet, I just did a
> different design that has two rows of 10 sliders (60mm ones, not too
> short), jacks along the bottom and room for 8 or so pots/ knobs, and it
> was 4U.
>
> Scott Deyo
> The Bridechamber
> contact@...
> http://www.bridechamber.com
> Jealous Edison Record Kompany
> http://www.jealousedison.com
>
>
> On May 19, 2008, at 2:45 PM, wjhall11 wrote:
>
> > You know - it strikes me that aside from whatever visual-clue
> > advantages there may be to sliders and longevity advantages there my
> > be to knobs, there are probably panel design issues too. Knons take
> > up less room vertically, and sliders less horizontally - make sense?
> > So I wonder how this would ultimately affect panel design. I wonder
> > which would make more overall sense in a MOTM-style panel. Or maybe
> > there's no particular advantage one way or the other. Ideas?
> >
> > Are there some MOTM designs out there?
> >
> > Bill (& Will)
> >
> > --- In ModularSynthPanels@yahoogroups.com, "krisp" <krisp14u@>
> > wrote:
> > >
> > > I'm on the sliders list X 2
> > >
> > > cheers
> > >
> > > paul
> > >
> > > ----- Original Message -----
> > > From: Julian Ware
> > > To: ModularSynthPanels@yahoogroups.com
> > > Sent: Monday, May 19, 2008 1:32 PM
> > > Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs sliders
> > >
> > >
> > > +1 vote for sliders.
> > >
> > > Visual feedback and fine control is really important - anyone
> > worried about them not lasting forever, buy some spares!
> > >
> > > Julian
> > >
> > > --- On Sun, 18/5/08, Scott Deyo <contact@> wrote:
> > >
> > > > From: Scott Deyo <contact@>
> > > > Subject: Re: [ModularSynthPanels] Re: Klee panel - knobs vs
> > sliders
> > > > To: ModularSynthPanels@yahoogroups.com
> > > > Date: Sunday, 18 May, 2008, 2:21 PM
> > > > Well, 3 against 5 so far... But since my slider vote counts
> > > > for 500....
> > > > ; p
> > > >
> > > > I think a lot of Klee PCBs are out there, and if there are
> > > > less
> > > > expensive, non-FPE panels maybe more will sell, so maybe
> > > > I'll just do
> > > > both.
> > > >
> > > > On the back of the pot version I'll have to silkscreen
> > > > a little
> > > > something extra, so they might be a little more expensive.
> > > > Hardy har har, just kidding.
> > > >
> > > > Cheers,
> > > > Scott Deyo
> > > > The Bridechamber
> > > > contact@
> > > > http://www.bridechamber.com
> > > > Jealous Edison Record Kompany
> > > > http://www.jealousedison.com
> > > >
> > > >
> > > > On May 17, 2008, at 4:39 PM, andrewlistmayer wrote:
> > > >
> > > > > I'm a slider supporter for the Klee since I feel
> > > > on this particular
> > > > > sequencer it is important to have the clearest
> > > > possible visual
> > > > > indication as to what is going on. However, if I
> > > > don't have choice I
> > > > > will go for knobs IF it is 8U or less with room for
> > > > large knobs.
> > > > >
> > > > > --- In ModularSynthPanels@yahoogroups.com, Jason
> > > > Proctor <jason@>
> > > > > wrote:
> > > > > >
> > > > > > although i have heard rumours that thomas white
> > > > is doing a rotary
> > > > > > panel for the Klee just like his MFOS one. i
> > > > think i'd prefer that
> > > > > > over just about anything else...
> > > > > >
> > > > > >
> > > > > >
> > > > > > >Now - I've been keeping my mouth shut
> > > > because I swore I wouldn't
> > > > > build
> > > > > > >one of these things. But Will - yes, I'm
> > > > blaming him again - has
> > > > > his
> > > > > > >own idea about it... fueled, I think by
> > > > comments by clickmike and
> > > > > gino
> > > > > > >(thanks a lot guys <G>). So yes - I
> > > > give in - but we'll want a
> > > > > knobby
> > > > > > >one for sure. So that's five knobbies
> > > > and counting?
> > > > > > >
> > > > > > >(God save me - tangerine dream or clockwork
> > > > orange?) Bill and Will
> > > > > >
> > > > >
> > > > >
> > > > >
> > >
> > > __________________________________________________________
> > > Sent from Yahoo! Mail.
> > > A Smarter Email http://uk.docs.yahoo.com/nowyoucan.html
> > >
> >
> >
> >
>

wjhall11 wrote:

> Knobs take up less room vertically, and sliders less horizontally - make
> sense?

Um, no? Unless you're going with bare slider shafts, good slide pots with
functional cap-knobs are going to take up just as much room. Same goes
for the back of the panel, the Alpha slide pots I'm using are just as wide
as the *super sexy* alpha rotary pots I'm using for the glide knobs.

I've had to adjust my 3U rack slider panel design a half dozen times to
make room for slider caps. It's driven me slightly buggy.

Paul

Oh - well - great point. I've never made something with sliders. So
then the faders take up as much space horizonatally - or nearly so -
but they're more "graphic" per some earlier comments. One of the
advantages of faders on mixers is how you can manipulate them -
pushing or pulling groups of them togeher. Would this be applicable
to the Klee? I'm really just considering the merits of either
approach. My personal bent has been toward knobs... but I'm wondering
how I might approach a slider panel layout -

--- In ModularSynthPanels@yahoogroups.com, "plord" <plord@...> wrote:
>
> wjhall11 wrote:
> > Knobs take up less room vertically, and sliders less horizontally
- make
> > sense?
>
> Um, no? Unless you're going with bare slider shafts, good slide
pots with
> functional cap-knobs are going to take up just as much room. Same goes
> for the back of the panel, the Alpha slide pots I'm using are just
as wide
> as the *super sexy* alpha rotary pots I'm using for the glide knobs.
>
> I've had to adjust my 3U rack slider panel design a half dozen times to
> make room for slider caps. It's driven me slightly buggy.
>
> Paul
>

The circular design is amazing, actually. It makes a lot of sense.
I wonder how it would be adapted to the Klee. Bill





- In ModularSynthPanels@yahoogroups.com, "sduck409" <sduck409@...> wrote:

>
> I think it's a trade-off either way - both choices have pros and cons.
> You make your choice. Or build one of each. I'm going with knobs, but
> faders are great too.
>
> Sure, I've got a 8u motm (sort of) panel worked up mostly - it's based
> on the one from your web page though. Although it'll work, I'm not
> terribly happy with it, and have visions of rotary klee knobs ala
> Thomas White's sequencer. Thomas hasn't started work on his yet, but
> gave me permission to mod his design, which was nice, although I
> probably would have anyway. Having some sort of rotary design in 6u is
> a lot more appealing to me than the straight line 8u. Or some sort of
> 8x8 ovoid pattern - got to get working on this.
>
> --- In ModularSynthPanels@yahoogroups.com, "wjhall11" <wjhall@> wrote:
> >
> > You know - it strikes me that aside from whatever visual-clue
> > advantages there may be to sliders and longevity advantages there my
> > be to knobs, there are probably panel design issues too. Knobs take
> > up less room vertically, and sliders less horizontally - make sense?
> > So I wonder how this would ultimately affect panel design. I wonder
> > which would make more overall sense in a MOTM-style panel. Or maybe
> > there's no particular advantage one way or the other. Ideas?
> >
> > Are there some MOTM designs out there?
> >
> > Bill (& Will)
> >
> >
>

Here's a pic of a circular Klee design:

http://electro-music.com/forum/phpbb-files/klee250_576.jpg

There's a movie of it somewhere, IIRC.

There are a lot of different takes on panels in this electro-music thread.  I think my ugly panel is in there somewhere:

http://electro-music.com/forum/viewtopic.php?t=21954

Here's Fonik's (using sliders), which was used as the pic in the build doc:

http://electro-music.com/forum/viewtopic.php?t=25821

 

Cheerios,

Scott (S)

 

 

-----Original Message-----
From: wjhall11
Sent: May 20, 2008 1:42 AM
To: ModularSynthPanels@yahoogroups.com
Subject: [ModularSynthPanels] Re: Klee panel - knobs vs sliders

The circular design is amazing, actually. It makes a lot of sense.
I wonder how it would be adapted to the Klee. Bill

- In ModularSynthPanels@ yahoogroups. com, "sduck409" <sduck409@.. .> wrote:
>
> I think it's a trade-off either way - both choices have pros and cons.
> You make your choice. Or build one of each. I'm going with knobs, but
> faders are great too.
>
> Sure, I've got a 8u motm (sort of) panel worked up mostly - it's based
> on the one from your web page though. Although it'll work, I'm not
> terribly happy with it, and have visions of rotary klee knobs ala
> Thomas White's sequencer. Thomas hasn't started work on his yet, but
> gave me permission to mod his design, which was nice, although I
> probably would have anyway. Having some sort of rotary design in 6u is
> a lot more appealing to me than the straight line 8u. Or some sort of
> 8x8 ovoid pattern - got to get working on this.
>
> --- In ModularSynthPanels@ yahoogroups. com, "wjhall11" <wjhall@> wrote:
> >
> > You know - it strikes me that aside from whatever visual-clue
> > advantages there may be to sliders and longevity advantages there my
> > be to knobs, there are probably panel design issues too. Knobs take
> > up less room vertically, and sliders less horizontally - make sense?
> > So I wonder how this would ultimately affect panel design. I wonder
> > which would make more overall sense in a MOTM-style panel. Or maybe
> > there's no particular advantage one way or the other. Ideas?
> >
> > Are there some MOTM designs out there?
> >
> > Bill (& Will)
> >
> >
>

________________________________________
PeoplePC Online
A better way to Internet
http://www.peoplepc.com

I was using sliders w/ built-in indicators -- no knobs. ModCan uses
them too, I believe.
That way I can fit them fairly close together.

I do really like the circular sequencer designs, though. The one Scott
linked to was really nice!
I'll try to do a layout this week.

Pot pro: may be a little less expensive.
Pot con: Sliders would be on their own PCB, for easy connection.

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

On May 19, 2008, at 11:19 PM, wjhall11 wrote:

> Oh - well - great point. I've never made something with sliders. So
> then the faders take up as much space horizonatally - or nearly so -
> but they're more "graphic" per some earlier comments. One of the
> advantages of faders on mixers is how you can manipulate them -
> pushing or pulling groups of them togeher. Would this be applicable
> to the Klee? I'm really just considering the merits of either
> approach. My personal bent has been toward knobs... but I'm wondering
> how I might approach a slider panel layout -
>
> --- In ModularSynthPanels@yahoogroups.com, "plord" <plord@...> wrote:
> >
> > wjhall11 wrote:
> > > Knobs take up less room vertically, and sliders less horizontally
> - make
> > > sense?
> >
> > Um, no? Unless you're going with bare slider shafts, good slide
> pots with
> > functional cap-knobs are going to take up just as much room. Same
> goes
> > for the back of the panel, the Alpha slide pots I'm using are just
> as wide
> > as the *super sexy* alpha rotary pots I'm using for the glide knobs.
> >
> > I've had to adjust my 3U rack slider panel design a half dozen
> times to
> > make room for slider caps. It's driven me slightly buggy.
> >
> > Paul
> >
>
>
>

I recently completed construction and initial testing of the CGS tube VCA
using a 1SH24B tube. I built it in MOTM-format using a panel and
bracket from Bridechamber.

The version I built is different than the original circuit. In order
to avoid damaging the PCB from excessive unsoldering, I did not first build
a stock unmodified version for comparison purposes.

This is taken from posts I made to the cgs_synth and tubesynthdiy
yagoogroups where I went into more detail as far as my reasons for
doing things. Since no one posted any corrections, I'd thought I'd
go ahead and post it here.

From what others had said, there were three issues: the output was
noisy, there was a "high-pass effect" or "loss of bass", and there
was a "thump" during the attack of the EG when used as a VCA. This
is a list of changes designed to address those issues:

I eliminated the two signal diodes, the two LED's, and their 1.5K
resistors. I connected a 1.2K 1/2W resistor between Pin 1 of the
cathode-heater and ground.

I added a a 47uF axial electrolytic cathode bypass capacitor between
pin 2 of the tube (connected to the negative rail) and ground. Do
not connect it to the ground side of the cathode or the in-rush
current could burn out the heater.

I replaced the TL072 with an OP275. I eliminated the stock 100nF
bypass caps, and underneath the PCB, added two .1uF ceramic caps with
heat shrink tubing going from ground, with the capacitors as close as
possible to the power pins on the socket. I eliminated the 47pF cap
on the output, and replaced it with a resistor lead. I did not add
the gain resistor. While 330 Ohm is the minimum specified resistor
for output protection, I replaced it with 1K (outside the feedback
path) to have the same output impedance as MOTM.

I increased the two 220nF coupling caps to 470nF.

I decreased the CV input resistor to 50K so a 0-5V EG it has about the same
range as the Gain knob.

I wired up the SPDT bias switch -- using properly shielded cable -- to two
settings:

For a "clean" setting, I added a 20K multi-turn trimmer to the
board. There is an area with some writing without any traces to the
right of the -Ve hole for the stock 330K resistor, where I drilled
two extra holes. The trimmer is wired as a rheostat between -Ve and
the switch.

For a "distortion" setting, I connected a 475K resistor between
ground and the switch.

The suspression grid was connected to the negative rail.

I used Bournes conductive plastic 50K linear pots for all four knobs.

While it likely varies from 1SH24B to 1SH24B, the tube I have
installed is more than a bit microphonic. Clicking the bias switch
is enough to produce ringing. So I stuffed some anti-static foam in
between the tube and the board to minimize vibration.

I think that's it.


These modifications seem to have worked very well. I don't notice
any noise on the output.

On the clean setting, with a roughly 10Vpp input potted all the way
up, the distortion is barely noticeable. Three things are happening
as the value of the variable resistor is adjusted lower: the grid
becomes more negative, the level of the AC signal decreases, and the
frequency of the high-pass filter increases. As such, there is some
loss of bass, which rolls off gently at the lowest audible
frequencies. With or without a signal, the grid bias is equal to
-15V, due to the low impedance. I would suggest using a 100K
multiturn trimmer instead -- that way you could adjust a "clean"
setting with the input potted down a bit for slightly better bass
response (although the high-pass effect of the original circuit was
due to a lack of cathode bypassing, as the corner frequency of the
stock values of 220nF and 330K in parallel with the grid resistance
was below the audible range). You also might want to try even larger
values for the coupling caps. I used AVX BQ yellow box caps, which
go up to 1uF, but you should double-check the lead spacing.
http://avx.com/docs/catalogs/bf-bq.pdf

The distortion setting produces obvious distortion, and can produce
oscillations and other noises at various input and feedback settings.
The low frequency response is well below the audio range (so the module will
just about work as a depth control for a fast LFO). The AC voltage
on the grid is about 3.3 RMS. With a signal the grid measures around
-17.6 VDC (it varies with its frequency), and without a signal the
bias is around -14.1V.

While the LPF in the CV circuit is the same as the stock circuit, the
cathode bypass cap improves the transient response of the tube
itself. It seems likely that rapid changes in voltage on the control
grid (eg. an envelope with a steep attack) would cause a sudden
demand for plate current enough to deplete the cathode, which then
bounces back causing an unwanted noise.

There is a bit of a pop or click with a fast envelope, although it is
not any worse than most solid-state VCA's. Changing the signal grid
bias, and switching between the two settings, also effects its CV
response. As such, it is possible to all but eliminate any bleed,
such that there is only a boost at the initial transient for punchy
basses and leads. I found this while experimenting with different
values. It would increase the distortion from the "clean" setting,
but it would still be a very nice feature. I might add that if I can
find a suitable SP3T switch.

Regardless of the signal level on the grid, or the bias switch
setting, the output of the tube, and therefore the module, is a bit
below 1V RMS, as it seems that is the saturation limit of the tube.
So while the signal on the grid is much higher for the distortion
setting, the difference results in just that -- distortion. In fact,
the "clean" setting measures just a bit more, although the
"distortion" setting sounds louder to to the additional harmonics.
Now 1V RMS is only about 2.8Vpp. Although it is enough on the
board, I might change the gain and feedback resistors to 2K
(resulting in about 5.6Vpp) if it seems too low to work well with my
other modules.

For those building this in other formats that might have he extra
space, putting a bias rheostat on the panel would be a nice feature.
Using a reversing attenuator for the second input/feedback control is
another option, as negative feedback is also useful.

So with these modifications there is very little noise, sufficient
bandwidth, and it works fine both as a "regular" VCA and a
distortion/waveshaper module.

I am open to questions and comments.

Wow, good work Mark!

Thanks for all the info -- very handy.

Cheers
Scott Deyo
The Bridechamber
contact@...
http://www.bridechamber.com
Jealous Edison Record Kompany
http://www.jealousedison.com

On May 21, 2008, at 2:35 PM, Mark wrote:

>
> I recently completed construction and initial testing of the CGS tube
> VCA
> using a 1SH24B tube. I built it in MOTM-format using a panel and
> bracket from Bridechamber.
>
> The version I built is different than the original circuit. In order
> to avoid damaging the PCB from excessive unsoldering, I did not first
> build
> a stock unmodified version for comparison purposes.
>
> This is taken from posts I made to the cgs_synth and tubesynthdiy
> yagoogroups where I went into more detail as far as my reasons for
> doing things. Since no one posted any corrections, I'd thought I'd
> go ahead and post it here.
>
> From what others had said, there were three issues: the output was
> noisy, there was a "high-pass effect" or "loss of bass", and there
> was a "thump" during the attack of the EG when used as a VCA. This
> is a list of changes designed to address those issues:
>
> I eliminated the two signal diodes, the two LED's, and their 1.5K
> resistors. I connected a 1.2K 1/2W resistor between Pin 1 of the
> cathode-heater and ground.
>
> I added a a 47uF axial electrolytic cathode bypass capacitor between
> pin 2 of the tube (connected to the negative rail) and ground. Do
> not connect it to the ground side of the cathode or the in-rush
> current could burn out the heater.
>
> I replaced the TL072 with an OP275. I eliminated the stock 100nF
> bypass caps, and underneath the PCB, added two .1uF ceramic caps with
> heat shrink tubing going from ground, with the capacitors as close as
> possible to the power pins on the socket. I eliminated the 47pF cap
> on the output, and replaced it with a resistor lead. I did not add
> the gain resistor. While 330 Ohm is the minimum specified resistor
> for output protection, I replaced it with 1K (outside the feedback
> path) to have the same output impedance as MOTM.
>
> I increased the two 220nF coupling caps to 470nF.
>
> I decreased the CV input resistor to 50K so a 0-5V EG it has about
> the same
> range as the Gain knob.
>
> I wired up the SPDT bias switch -- using properly shielded cable --
> to two
> settings:
>
> For a "clean" setting, I added a 20K multi-turn trimmer to the
> board. There is an area with some writing without any traces to the
> right of the -Ve hole for the stock 330K resistor, where I drilled
> two extra holes. The trimmer is wired as a rheostat between -Ve and
> the switch.
>
> For a "distortion" setting, I connected a 475K resistor between
> ground and the switch.
>
> The suspression grid was connected to the negative rail.
>
> I used Bournes conductive plastic 50K linear pots for all four knobs.
>
> While it likely varies from 1SH24B to 1SH24B, the tube I have
> installed is more than a bit microphonic. Clicking the bias switch
> is enough to produce ringing. So I stuffed some anti-static foam in
> between the tube and the board to minimize vibration.
>
> I think that's it.
>
> These modifications seem to have worked very well. I don't notice
> any noise on the output.
>
> On the clean setting, with a roughly 10Vpp input potted all the way
> up, the distortion is barely noticeable. Three things are happening
> as the value of the variable resistor is adjusted lower: the grid
> becomes more negative, the level of the AC signal decreases, and the
> frequency of the high-pass filter increases. As such, there is some
> loss of bass, which rolls off gently at the lowest audible
> frequencies. With or without a signal, the grid bias is equal to
> -15V, due to the low impedance. I would suggest using a 100K
> multiturn trimmer instead -- that way you could adjust a "clean"
> setting with the input potted down a bit for slightly better bass
> response (although the high-pass effect of the original circuit was
> due to a lack of cathode bypassing, as the corner frequency of the
> stock values of 220nF and 330K in parallel with the grid resistance
> was below the audible range). You also might want to try even larger
> values for the coupling caps. I used AVX BQ yellow box caps, which
> go up to 1uF, but you should double-check the lead spacing.
> http://avx.com/docs/catalogs/bf-bq.pdf
>
> The distortion setting produces obvious distortion, and can produce
> oscillations and other noises at various input and feedback settings.
> The low frequency response is well below the audio range (so the
> module will
> just about work as a depth control for a fast LFO). The AC voltage
> on the grid is about 3.3 RMS. With a signal the grid measures around
> -17.6 VDC (it varies with its frequency), and without a signal the
> bias is around -14.1V.
>
> While the LPF in the CV circuit is the same as the stock circuit, the
> cathode bypass cap improves the transient response of the tube
> itself. It seems likely that rapid changes in voltage on the control
> grid (eg. an envelope with a steep attack) would cause a sudden
> demand for plate current enough to deplete the cathode, which then
> bounces back causing an unwanted noise.
>
> There is a bit of a pop or click with a fast envelope, although it is
> not any worse than most solid-state VCA's. Changing the signal grid
> bias, and switching between the two settings, also effects its CV
> response. As such, it is possible to all but eliminate any bleed,
> such that there is only a boost at the initial transient for punchy
> basses and leads. I found this while experimenting with different
> values. It would increase the distortion from the "clean" setting,
> but it would still be a very nice feature. I might add that if I can
> find a suitable SP3T switch.
>
> Regardless of the signal level on the grid, or the bias switch
> setting, the output of the tube, and therefore the module, is a bit
> below 1V RMS, as it seems that is the saturation limit of the tube.
> So while the signal on the grid is much higher for the distortion
> setting, the difference results in just that -- distortion. In fact,
> the "clean" setting measures just a bit more, although the
> "distortion" setting sounds louder to to the additional harmonics.
> Now 1V RMS is only about 2.8Vpp. Although it is enough on the
> board, I might change the gain and feedback resistors to 2K
> (resulting in about 5.6Vpp) if it seems too low to work well with my
> other modules.
>
> For those building this in other formats that might have he extra
> space, putting a bias rheostat on the panel would be a nice feature.
> Using a reversing attenuator for the second input/feedback control is
> another option, as negative feedback is also useful.
>
> So with these modifications there is very little noise, sufficient
> bandwidth, and it works fine both as a "regular" VCA and a
> distortion/waveshaper module.
>
> I am open to questions and comments.
>
>
>

On 5/21/08, Scott Deyo put forth:

>Wow, good work Mark!
>
>Thanks for all the info -- very handy.

Thanks :) Does this mean you are going to offer a primate synthesis
version?? ;)

Imho, the biggest change is the cathode bypass cap. If you have
one (without a bypass cap) you could test it by sending a signal in
the low audio range, turning up the gain pot, and checking the
cathode for an AC voltage. If you have a scope with two channels and
find a signal on the cathode out of phase with the input signal, then
that would demonstrate negative feedback.

Anyway, I might roll all my posts together -- including all the
explanations -- and put it up on the CGS forum on Electro-Music.
Although, that might take longer to type than it did to build the
module :)