4051 mux problem?

[Rob Brzykcy]

BTW, you CAN use a tl082 in a single supply configuration using a voltage
divider network..
opamp cookbook has examples of this, as do most textbooks..

Rob

-----Original Message-----
From: Grant Richter <grichter at execpc.com>
To: Fraser, Colin J <Colin.Fraser at scottishpower.plc.uk>; 'Stewart Pye'
<stew at uq.net.au>; synth-diy at mailhost.bpa.nl <synth-diy at mailhost.bpa.nl>
Date: Monday, July 26, 1999 12:58 PM
Subject: Re: 4051 mux problem?


>I agree, the refresh timing is not as critical as I made out.
>It would be critical to using a MIDI-CV unit for drum triggers,
>the idea being when two triggers are activated simultaneously,
>is there a perceptible "flam" effect.
>
>For using such a device purely for drum voice control,
>it would probably be better and cheaper to use an octal
>latch for the output. That way all the triggers are updated
>at the same time.
>
>Just thinking out loud.
>
>----------
>> From: Fraser, Colin J <Colin.Fraser at scottishpower.plc.uk>
>> To: 'Stewart Pye' <stew at uq.net.au>; synth-diy at mailhost.bpa.nl
>> Subject: RE: 4051 mux problem?
>> Date: Monday, July 26, 1999 3:17 AM
>>
>> > -----Original Message-----
>> > From: Stewart Pye [mailto:stew at uq.net.au]
>> > Sent: 23 July 1999 21:29
>> > To: Grant Richter; synth-diy at mailhost.bpa.nl
>> > Subject: Re: 4051 mux problem?
>> >
>> >
>> > At 11:31 AM 23/07/99 -0500, Grant Richter wrote:
>> > >On most micros, a timer can be used to generate
>> > >an interrupt. This is the interrupt service routine I spoke
>> > >of. The MIDI input would generate an interrupt of higher
>> > >priority, so the refresh will hold off until the MIDI
>> > >routine clears.
>> >
>> > That would be nice if the PIC16F84 had interrupt priority. I
>> > thaught the
>> > next best thing was to poll the timer overflow flag. There is
>> > only going to
>> > be a small variation in timer overflow detection time.
>> > <100us for sure.
>>
>> On my midi - cv convertor I didn't use a timed interrupt to refresh the
>> sample and holds.
>> The main loop processes incoming data if the input buffer is not empty,
>> otherwise it cycles round all the outputs, refreshing the caps.
>> The main loop also updates any changing output immediately, as well as
>> writing the value into ram for the refresh loop.
>>
>> Unless you need a precise timing interval for LFO generation or suchlike,
>I
>> don't see any reason why your S&H refresh rate needs to be so precise.
>>
>> Colin f
>