[sdiy] meter meter on the wall

[Grant Richter]

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
>> 
> 
> 
>