[sdiy] OT - Double emails happening...

[Ray Wilson]

Hi All

Could it be that we are sometimes inadvertently putting the synth-diy
address in the To... and the CC... so that the email system thinkns it is
doing the right thing by sending two emails to the list?

Just a thought.

Ray

-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Thomas Holley
Sent: Saturday, October 18, 2003 10:39 PM
To: harrybissell; Ray Wilson
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Keyboard Control


Thanks for the links and the insight into keyboard controllers. This is an
immense help. I will update my progress if I don't blow something up first.

Thomas
----- Original Message -----
From: "harrybissell" <harrybissell at prodigy.net>
To: "Ray Wilson" <rayw at csd.net>
Cc: "Thomas Holley" <thomasholley at adelphia.net>;
<synth-diy at dropmix.xs4all.nl>
Sent: Saturday, October 18, 2003 8:48 PM
Subject: Re: [sdiy] Keyboard Control


> Hi Ray (et al)
>
> I did it differently... I take the output from the current source... and I
> ground the
> resistor matrix through the keys.
>
> You are picking off the voltage to the 'bus buffer'.
>
> I did the grounded key so that I could get two CV from the keyboard. I
used
> two current sources, and inverted the upper one so that I had low note /
high
> note
> priority
>
> H^) harry
>
> Ray Wilson wrote:
>
> > Hi Guys
> >
> > Just a note on this. I feed the current from the top end of the keyboard
and
> > I still get low note priority because when more than one key is pressed
you
> > are essentially bypassing all of the intervening resistors and since the
> > current is constant (in the design I use) you get the voltage that is
> > dropped across the low side of the resistor ladder.
> >
> > Ray
> >
> > -----Original Message-----
> > From: owner-synth-diy at dropmix.xs4all.nl
> > [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of harrybissell
> > Sent: Saturday, October 18, 2003 3:03 PM
> > To: Thomas Holley
> > Cc: synth-diy at dropmix.xs4all.nl
> > Subject: Re: [sdiy] Keyboard Control
> >
> > Yes, you are right. By taking the output from the low side you will
> > also get low note priority (which I for one, insist on :^)
> >
> > H^) harry
> >
> > Thomas Holley wrote:
> >
> > > Thanks Harry,
> > >  I have the keyboard controller arranged so that the current source is
to
> > > one end (HI) of a resistor ladder and the other end (LO) referenced to
> > > ground. The keyboard is from an old broken ensonique with little
spring
> > > contacts on each key. I have it so when the key is pressed the contact
> > > grounds that point in the resistor ladder. The reference voltage for
the
> > > controller is taken from the top of the resistor ladder where the
current
> > > source connects (copied from an old ARP patent). With this arrangement
I
> > > think the current source should then go on the low (left) key side to
give
> > > the highest voltage reference to the high (right) keys. Is this right
or
> > do
> > > I have it turned around?
> > >
> > > Thomas
> > > ----- Original Message -----
> > > From: "harrybissell" <harrybissell at prodigy.net>
> > > To: "Thomas Holley" <thomasholley at adelphia.net>
> > > Cc: <synth-diy at dropmix.xs4all.nl>
> > > Sent: Saturday, October 18, 2003 1:57 PM
> > > Subject: Re: [sdiy] Keyboard Control
> > >
> > > > Hi Thomas
> > > >
> > > > Higher pitches (to the right side of the keyboard) get higher
> > > > voltages...
> > > > so the current source should go on the highest note side...
> > > >
> > > > H^) harry
> > > >
> > > > Thomas Holley wrote:
> > > >
> > > > >     I have a rather fundamental question. In a keyboard controller
> > > > > resistor ladder, does the high voltage side go to high pitch key
or
> > > > > the low pitch key. I have been tinkering with an old keyboard and
> > > > > soldered up a 100 ohm resistor between each key for a nice ladder
when
> > > > > it finally dawned on me that I had not a clue which side to put
the
> > > > > current source on and which one to ground. Thanks for your help
Thomas
> > > >
> > > >
>
>