[sdiy] Arpeggiator1 / Arduino UNO

[Rick Jansen]

The Elektor Formant book2 has a digital keyboard schematic, where a key pressed results in 
a 6-bit value, derived using priority encoder chips (74LS148):

<http://dropmix.xs4all.nl/rick/Emusic/Arpeggiator1/img/formant2_CV_DAC.jpg>

here they use a ZN426 8-bit DAC, of which they use the lower 6 bits to generate the output 
voltage.

The next page has a schematic for a classic R-2R circuit, but if that is really a 
practical circuit I don't know.

r.

On 10/04/2015 15:34, Roman Sowa wrote:
> It's actually 8-bit AD558 DAC with 1/2 LSB INL, using upper 6 bits. So
> at worst case one semitone error is 1/8, that's 12.5 cent, or about 6
> cent if they used AD558K grade. In reality it may turn out better as
> this is maximum error.
>
> Roman
>
> W dniu 2015-04-10 o 15:14, MTG pisze:
>> The Pro One uses a 6-bit DAC, admittedly just for the keyboard, one step
>> per semitone.
>>
>> On 4/10/2015 2:24 AM, Rick Jansen wrote:
>>>
>>> Even an 8-bit (ZN426) DAC would have been good enough, it will give
>>> you 256 discrete voltages. If you choose the reference voltage and
>>> scaling right you will end up with a 83.3 mV per note characteristic..
>>>
>>> Rick
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>