help me mod a lag processor

Robot robot at
Wed Aug 21 22:17:03 CEST 1996

I've tried and tried to post this damn thing to the list and I hope this
time I get through.  I've unsubbed and resubbed over and over again.  I
can't figure out what the problem is.

Anyway here it is AGAIN!  Sorry if anyone got a repeat.  I haven't even
gotten any responses.

Hi folks,

This is my first post on diy.  First of let me say that I'm not very
experienced with electronics and circuit design, so please don't flame me if
I sound like someone who has no idea what they're talking about (because I
probably don't). I am, however, VERY curious and like to learn. I'm quite
excited to learn more about the inner workings of electronic gear. So with
that in mind, here's my first big question to everyone.

After buying a Kenton Pro-2, I realized it doesn't do portamento.  Seeing as
how I really like portamented mono leads, I asked around how to make up for
this lack.  Someone on Analog Heaven was quite helpful and I discovered a
new use for the lag processor on my ARP 2600.  Unfortunately the 2600 has
only one and not a very slow one at that.

So here I am set out to build a lag processor to use as a dedicated
portamento for the Pro-2 CV's.  I dug around and found a few very standard
one in, one out lag processor designs with a single potentiometer to select
the slew amount.

Now I'm thinking it would be nice to have a unit with some sort of trigger
or gate to switch the portamento on or off (so as to have it glide on
desired notes instead of all the time) as well as a CV input to control the
slew rate (to do cool stuff like sequencing different glide rates per note).

Unfortunately I'm not savvy enough to know how to mod a design to allow
this. If anyone would care to help me with this I'd greatly appreciate it.
I'm sure it's something simple compared to most of the complex circuit
designs out there but as I said before, I don't understand this stuff well
enough yet to tackle this without someone's help.

Thanks in advance.

PS I'll most likely go with the portamento design in the Terence Thomas book.
- -robert           | |___   ____   ____ _____
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                  |_____/ \___\  |_|   | |__/    / -studio- \
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