[AH] Re: [sdiy] Room 211... Envelope Follower or Pitch to Voltage on a chip?

[Rude 66]

we have a Serge pitch to voltage converter that works quite well, especially
on instruments like horns, flutes, etc. don't know if they still make it, or
how many thousands of $$ it'll cost..;-)

ruud

----- Original Message -----
From: "harry" <harrybissell at prodigy.net>
To: "Cynthia Webster" <cynthia.webster at gte.net>
Cc: "Diy" <synth-diy at dropmix.xs4all.nl>; "Analog Heaven"
<analogue at hyperreal.org>
Sent: Monday, July 15, 2002 1:29 AM
Subject: [AH] Re: [sdiy] Room 211... Envelope Follower or Pitch to Voltage
on a chip?


> Hi Cynthia....
>
> Pitch to voltage conversion is quite difficult. It might be easy to
convert
> something like an electric drill or blender, that has a fairly predictable
and
> repetitive pitch.  Other sounds that are not 'monophonic' are usually
impossible
>
> to convert (what is the 'pitch' of a C7 chord...?)
>
> There are two common ways... the tachometer circuit and the ramp/hold
circuit.
> The tachometer is slow to acquire a pitch, and will track slowly. its fine
for a
> motor
> because the motor can't change speed instantly anyway... and is usually
running
> for a long time.
>
> The Ramp/Hold will acquire a voltage within two cycles of the incomming
> frequency...  but you need to be sure that there are only two zero crosses
> per cycle. this is very difficult in real life.
>
> For the "musique concrete" sort of thing your friend is doing... I'd
recommend
> the Korg MS-20 circuit.  It has a built in trade off for speed of
acquisition
> and the
> output ripple(it is a tach circuit)... and the pulse generation method is
VERY
> clever
> and has a wider range than most tach circuits.
>
> The PV-1  (by Bob Moog - used with permission, me, and distributed by EFM)
> is a circuit board that uses the ramp/hold method. It can convert any
clean
> waveform
> by itself...and with some additional circuitry you could do Guitar, Voice,
etc.
> There
> will be a delay of two cycles... for guitar that might be 24ms... a long
time
> IMHO.
>
> H^) harry
>
> Cynthia Webster wrote:
>
> > Hi All!
> >
> > I was at this crazy event last night, essentially someone rented out an
> > entire motel Lock, Stock & all 30 rooms - upstairs and down, in a
balconied
> > courtyard surrounding a swimming pool, and had a different artist
performing
> > their works in each room.  A great Idea actually!
> >
> > They charged $20 bucks a head for folks to make he rounds and buy drinks
and
> > hot dogs while viewing lots of crazy art projects over a 24-hour period.
> > Quite a scene, as It was certainly "a Happening" and I was somewhat
honored
> > to help my friend Bob with his feedback piece in room 211...
> >
> > He had contact mics placed around the room, which fed into his board and
> > then on to his Macintosh laptop running Super Collider software -  and
then
> > out into the room via amplifiers and speakers.  It was a casual and
friendly
> > clean room that was mostly un-attended.  The message on the door read
> > basically.  "Hey, do what you want in here, watch tv, play some records,
> > or even take a shower if you like - just know that your sounds are being
fed
> > into multiple delayed feedback loops and amplified out to the rest of
the
> > world!
> >
> > I was soldering some last minute connectors for his project, and showing
> > folks what could be done with Train whistles and rubber mallets on
flower
> > vases filled with contact microphones!  it was interesting to see just
> > how many people were attracted to a crate full of vinyl records to muse
> > through and play.  Of course the sound from the TV and the turntable
were
> > seriously altered.  (i.e. Wacked!)  :)
> >
> > Bob said that he'd like to eliminate the laptop and build a stand alone
box
> > to do this patch that he has been perfecting lately...
> >
> > (*this*  was of course music to my ears!) and I pulled-out out my art
tablet
> > and started to draft out an analog equivolent of what the software was
> > doing...
> >
> > it turned into reams and reams of paper!
> >
> > What with all of the pre-amps, envelope following, filtering, and
granular
> > synthesis (LFOs controlling VCA & VCFs chopping), I ultimately concluded
> > that what he really needed was four or six ARP 2600's running side by
side
> > to do the piece!
> >
> > This all leads me to ask you fellow friends and Do it Yourselfers -
> > If anyone makes a combo pre-amp, envelope follower on a Chip kind'a
thing?
> >
> > or I was thinking to use Don Tillman's famous FET preamp
> >
> > http://www.till.com/articles/GuitarPreamp/index.html
> >
> > and wonder if there are VCA/Envelope Follower chips, or sub-assemblies
> > anywhere?  As the needs of this all in one box - Analog for laptop
solution
> > are quite complex!
> >
> > Aside from CEM Curtis and SSM Chips-  what else is (Currently) out
there?
> >
> > The logical next step would be to seek the ultimate Pitch-to-Voltage
circuit
> > as well.  (I was wondering if anyone has tried using a car tachometer
chip
> > to do pitch to voltage conversion)?
> >
> > The main idea here is to make many channels of this patch thing for my
> > friend so he can use many microphones - without a room whole full of
> > modulars.
> >
> > Ha!  I feel a bit like like John Henry must've felt against the Iron
Horse!
> >
> > Ideas certainly appreciated by all.
> >
> > Cynthia
>
> --
> Jihad Terrorism Conspiracy New World Order
> Revolution Black Helicopters Freedom of
> Speech First Amendment Rights: Carnivore Bait
> go ahead and READ my e-mail I have nothing to
> hide... how about YOU ???
>
>