[sdiy] meter meter on the wall

[steven_thomas]

Hi Grant ..yes you are right..the meter was bipolar. Looking at some synthi
specs..

trapezoid output:  +/- 3V dc max
Meter Input:        Control Voltage: +/-1V dc
                            Signal Mode: 4V p.p.
Reverb Mix  cv:  +/-  2V
The Joystick could also put out +/- 1.5V dc

cheers
steve

> In the Putney/Synthi the meter is offset to mid-range for the control
> voltages so it can show plus/minus.
>
> I recall the control voltage range in those as +/- 2 volts, even the
> envelope, so when you turn the attenuator up, the bottom moves as well as
> the top. No a bug - a feature!
>
> In most synths, envelopes start at zero and go up, but in the
Putney/Synthi
> the envelope is bipolar also. Part of the charm of those eccentric beasts.
>
> > From: "steven_thomas" <steven_thomas at ntlworld.com>
> > Reply-To: "steven_thomas" <steven_thomas at ntlworld.com>
> > Date: Thu, 22 Feb 2001 14:33:56 -0000
> > To: "BRADSHAW" <E.K.Bradshaw at newcastle.ac.uk>,
<synth-diy at node12b53.a2000.nl>
> > Subject: Re: [sdiy] meter meter on the wall
> >
> > Hi Ed,
> > well I too have a meter in my modular setup that I haven't wired up
> > yet. I have the synthi A/VCS3
> > service manual and looking at the meter schematics..it does basically
what
> > you suggest..a rectifier setup for the  signal voltages,  a DC follower
for
> > control voltages (assuming they are all positive in your setup)
> > some resistors to adjust for whatever F.S.D. is on your meter. Plus a
switch
> > for monitoring either signal
> > or control voltages on the meter. In the synthi a couple of transistors
are
> > used ..but I guess modern op-amps will be best for the buffering.
> > Hope this helps.
> > cheers steve thomas
> > ----- Original Message -----
> >
> > From: BRADSHAW <E.K.Bradshaw at newcastle.ac.uk>
> > To: <synth-diy at node12b53.a2000.nl>
> > Sent: Tuesday, February 20, 2001 10:03 PM
> > Subject: [sdiy] meter meter on the wall
> >
> >
> >> I don't suppose any one can help me out.
> >>
> >> I want to put a synthi A style meter on an output module - my
> >> question is - what sort of thing do I deep to control it?  my own
> >> minimal-tech guess would be: Buffer - rectifier - voltage
> >> divider/trimmer - galvonmeter.  Is any of this remotely right?
> >>
> >> thanks for any help.
> >>
> >> Eddd
> >>
> >> E.k.bradshaw at ncl.ac.uk
> >>
> >
> >
> >
>
>
>