[sdiy] Transistor help

[Kevin Lightner]

>
>This seems to be based on the schematics, which indicate matched 
>devices only on the earlier schematics. (The later schematic only 
>showed a circled M for the differential pair, and not the ladder 
>itself.)

The schematics are off in many places.
 From straight errors, to omitted or later included parts, substitutes, etc.

>
>>I have 11 (count 'em!) Minis in and they ALL have a colored dot on 
>>their transistors, which the other same numbered transistors don't 
>>have. The reason, often overlooked, about the very early Minis is 
>>that their electrolytic caps are older and of different values when 
>>new anyways.
>>400uf, instead of the later 470. 80uf instead of 100uf and so on.
>>Their carbon resistors are often *way* off too.
>>I often measure the 820 ohm resistors at 1K-1.2K.
>
>Interesting. I presume these are from different "eras"?

Yeah. From the high 2000's to the mid 9000's at the moment, though 
I've seen much earlier and later ones several times. Most minis that 
visit here are in the 3000-6000 range. Funny too: I have two units 
that are very close to the same serial number around 3500, but the 
earlier numbered one has switchable AC power, while the later one 
doesn't.
Maybe Moog had a LIFO ordered assembly line? :)


-- 
Regards,
Kevin Lightner

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