[sdiy] Keyboard Control

[ethan tripp]

any way i could get ahold of the plans for that?

-et-

On Saturday, October 18, 2003, at 07:58  PM, 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
>>>
>>>
>
>
>