Cgs synth

Hi there everybody!
i've loaded about 10 different boards from Ken in the past couple of
months, despite my best efforts, everything basically works great.

only 2 small probs -
on the super psycho the leds won't light. this is due to the
A1015 transistors i pulled out of an old tv set.
i'm in Japan, everything here is marked by japanese code.
which is no problem, but i would like to know -
what are the critical values that make the BC557s suitable for the
job?

the gate sequencer sometimes skips step 1. it depends on the settings
and seems to do it more often at slower speeds. ive fitted the extra
diode near the reset input, left off the cap from 1 to 3 on the LM358.
have i missed something?
thanks
btw - i wired in the cv-adapter for the gate sequencer on the weekend.
i like it!!

>on the super psycho the leds won't light. this is due to the
>A1015 transistors i pulled out of an old tv set.

BC557 is a general purpose PNP silicon transistor with an hfe of over 110.
Just about any general purpose PNP should work. The possible causes for it
now working would be transistors installed with the connections mixed up
(they don't always follow the outline on the PCBs) or the LEDs themselves
being backwards. Some LEDs mark the anode with the shorter lead/flat side,
just to be confusing!

>the gate sequencer sometimes skips step 1. it depends on the settings
>and seems to do it more often at slower speeds. ive fitted the extra
>diode near the reset input, left off the cap from 1 to 3 on the LM358.
>have i missed something?
>thanks

Odd! Perhaps add 100n directly across pin 18 to pin 18 of the 4017 to
improve its power supply decoupling. Failing that, look at the sequencial
switch for the clock modification I did to stop the 4516 from skipping steps.

Ken
_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>