ASM-1 Construction

gstopp at fibermux.com gstopp at fibermux.com
Thu Oct 31 18:51:30 CET 1996


     The 2N4391 fits exactly as the silkscreen outline on the circuit board 
     shows. The 2N4856 does NOT - at least the ones I have are metal cans 
     rather than plastic half-cylinders so it was data-book time when I 
     soldered them in.
     
     Regarding using the fancy matched pairs instead of the separate cheapo 
     transistors, I still haven't got a setup I can play with! Sheeesh I 
     designed the dumb thing and I still don't have one set up! Okay I'm 
     working on it guys. When I do get my boards back up and running I'll 
     do some stability testing.
     
     The LM358's are single-supply op-amps which is why I use them in the 
     EG's as gate input comparators to drive the CMOS. I'm not sure what a 
     TL082 will do in that location as the power pins are at +5 and ground 
     (damn! another thing I should be able to try easily!). In all other 
     dual-op-amp locations the TL082 works fine and is in fact recommended 
     because it was designed using them.
     
     I take full responsibility for errors and/or omissions in the parts 
     lists. Usually when I build something I just start flinging parts 
     together like some kind of hypnotized robot. Thanks for the feedback!
     
     - Gene


______________________________ Reply Separator _________________________________
Subject: ASM-1 Construction
Author:  Dan Higdon <hdan at charybdis.com> at ccrelayout
Date:    10/28/96 11:07 PM


I know someone posted a message about this a while back, but I don't have 
it any more.  How does the 2N4391 fit into the board?  I assume that since 
the pins and the holes match up so nicely, and the components all seem to 
fit together easily, that it goes in the "natural" way.  Is this right?
(I sure hope so, or I'll get to test my de-soldering skills. :-)
     
Also, is there any more information about using a MAT-02 instead of 2 
transistors?
How is the stability?  Will I even notice a difference under "normal" studio 
usage?
I haven't installed those parts yet, and I don't want to blow around 30 bucks on
some MAT-02s if I don't have to.  (That's 4 of them at around $7.50 each)
     
One more thing - is it OK to use TL082s for all of the opamps?  In particular, 
there are two kinds of opamps mentioned in the envelope generators.  The 
LM358(?), which is used as a comparator is the one I want to replace.
     
I must say that this is my first plate-through board, and I am impressed. 
Those parts installed with NO trouble, and soldering was a breeze.  Just a few 
parts to order (the parts list was short 2 4.7uf caps, and one 0.1uf bypass in 
one
of the oscillators), then I get to order all those pots and jacks.  Eeeee!
     
     
Thanks,
hdan
     




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