[sdiy] Transistor pair swaparounds...

[René Schmitz]

Hi Aaron,

Aaron Lanterman wrote:

> Can these things be swapped around without ill effects? Or will trying 
> to put a 2SC1583 into a circuit designed for a MAT or vice versa cause 
> horrible badness (other than a 2SC1583 having lower specs than a MAT...)

Generally yes. Some things you need to watch out for are the maximum 
permissible Vceo voltages which can be as little as 20V for the 3046 and 
3086. Also the collectors of some of the integrated pairs are only 
insulated by a diode, thus one special emitter (or the bulk terminal) 
has to be kept below all other collector voltages by at least a diode 
drop. (It makes sense to read datasheets, but I guess your students will 
do that anyway.)


> P.S. I had my first student to send me a draft schematic send me a 
> schematic (redundancy specialists, who specialize in redundancy) - he's 
> trying a HP/LP cascade, like the MS-20, but based ofn a vactrol approach 
> modeled off of the Buchla LPG, but with resonance... ;)

Hmm, I hope he has some nonlinearity to limit the amplitude of the 
selfoscillation there. Or else the opamps will get to the rails and this 
will sound very harsh.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159