EMS Trapezoid Generator PCB/Layouts?

ericcoleridge · Joined: Jan 16, 2007 Posts: 889 Location: NYC

Just wondering if anyone on the forum has a Trapezoid Generator Layout they could share.

I've got a couple ADSRs, but I'd like to build an AD/AR and/or a EMS-style Trapezoid Generator if I can find a PCB layout.

I'm aware of J. Haible's Trap Gen (but no layout Sad

):

http://jhaible.heim.at/matrix_fx/jh_matrix_fx_trapezoid_vca_sch.pdf

Ricko · Posted: Thu Dec 27, 2007 10:50 am Post subject:

If you are looking for an unusual EG, you could try the ETI4600 envelope generator. Instead of ADSR it has

Start level
Delay
Slope 1
Hold Level
Hold delay
Slope 2
Final level
and a switch for expo/linear. So it can simulate the EMS trapezoid in manual mode (not free run)

Available at RCS Australia (still after 33 years!) http://rcsradio.com.au/

See
http://users.tpg.com.au/rcspcb/oldtonow.txt
and the file is
et 601G $ 22.00 892 MUSIC SYN Transient Gen/r 1974Feb

The schematics are available online around the place.

synth_ollie · Joined: Sep 11, 2006 Posts: 149 Location: sweden

here´s another unusual env. gen that maybe could be of
interest to someone

http://www.synrise.de/diy/mse/mse.htm

forbin · Posted: Mon Feb 16, 2009 5:06 pm Post subject:

The last link from Ollie lead me on to this:

http://www.silcom.com/~patchell/synthmodules/multisegenv.html

Which is a very neat design from Jim Patchell -- pretty complicated though!

simmeau · Posted: Tue Feb 17, 2009 1:03 am Post subject:

Of course there is the MFOS dual AR which has repeat on it. It would be really nice to have something that just sends a gate/trig at end of cycle.

numbertalk · Posted: Tue Feb 17, 2009 7:31 am Post subject:

The Buchla 281 clone project does this:

http://www.electro-music.com/forum/topic-23218.html

simmeau · Posted: Tue Feb 17, 2009 2:53 pm Post subject:

Wow the 281 does look amazing. I was thinking more like a standalone end of cycle trigger that you could use with whatever EGs that you have. The trap generator schematic is also on the EMS mods page:
http://www.hinton-instruments.co.uk/ems/vcs3env.gif

e-grad · Joined: Sep 12, 2008 Posts: 142 Location: Berlin

ericcoleridge · Joined: Jan 16, 2007 Posts: 889 Location: NYC