Message 635
From:  sasami@hotkey.net.au 
Date:  Mon Feb 9, 2004  5:54 am
Subject:  RES04 construction/testing report.

Finally I got around to trying out my RES04 PCB. 

Here are my findings 

-The board works as is without correction/modification.
An LM3900 works fine in the position for the MC3401.
All transistors on the board have pin-outs that correspond to the original
epoxy type transistors. This means they have the emitter in the direction
shown on the 2N4248 with the symbol in its outline. The PN4248 I have are
reversed - i.e. EBC from the flat face, rather than CBE as used on the PCB.
As such, you will need to install any affected transistor substitutions in
backwards with reference to the PCB. You will need to refer to the data for
the transistors you are using.

DTRIM is used to set the inital cycle speed. Turn RISE and FALL to the
fasted positions. Adjust DTRIM until you get 4.00 volts on pin 4 of the
LM3900 (NOT the one marked MC3401).I did this with END patched to CYCLE, 
while listening to the Window out pulse. This was so I could tun it to 
the same frequency of one of my genuine modules.

The other trim pot? It is probably to stabilise the HOLD function. I haven't
dealt with this yet.

There is provision of the PCB for adding a LED to monitor the Envelope Output. 
The connections are labelled LA (LED Anode) and LC (LED Cathode).

I added an emitter follower to the Window Out to drive a second LED. This
helps because the Window Out pulse is more or less independent from the rest
of the envelope generator, apart from being affected by the speed. It stays
lit when the cycle is over.

Pads
A = start input
B = Window pulse output
C = envlope output
D = End pulse output
E = cycle input
F = Hold input
G = Duration CV
H = Window size CV
LA = LED Anode
LC = LED Cathode

Q = not used
U = not used (0v)

W = 0v
X = +12v
Y = +6v
Z = not used (-12v)

To use it as a VCLFO, patch end to cycle, and feed your CV into duration.

Ken


Message 636
From:  sasami@hotkey.net.au 
Date:  Mon Feb 9, 2004  11:06 am
Subject:  Re: [resergence] RES04 construction/testing report. 

The other trim pot is to stabilise the HOLD function. Too high, the signal
drifts, too low and the signal "pulses". I plugged the ENV out into a VCO,
triggered hold while in an envelope, and adjusted the trimput using the VCO
tone as a guide.

Ken