API 553 : gain trim variants?

Hi all,
I have recently bought a second original API 553 eq to finally complement the one I already have. Now it seems that there are some differences between the two, related to gain trim.
The one I bought now differs (or has been modified) from the schematics I found on a thread in this forum (I have no understanding of electronics, I just compare the schematic to the indications on the pcb of the API):
It has pin 7 shortened and a resistor is strapped on pin 11 (common 'gain adjust' pin for other API eqs), normally not in use according to the original schematic, and connected to R14, of which the traces are cut on both sides. Another traces is cut too (between C3/R3 and C5/R11) and replaced by a connection between C3/R3 and R14. The output of the 2520 is also guided to the other end of R14. Ok, a bit difficult without pictures.
Anyway, this modification seems quite common, my old 553 seems like it had the same traces cut but then in a later stage it was apparently restored (only diff with original schematic is that R13 is not put on the board).
Can anyone explain me what this modification does and if I should rather get my old 553 modified or undo the modification on the new one if I want to use them both in a modern lunchbox (next to my 512c pair and aphex cx-1 pair, talking about a killer combination )

Thanks in advance,
Bram

Hi Bram,
I'm not an API expert, so i can't answer your question. There are perhaps a few people here who can help you without the schematic, but just as much chance you won't get an answer.
There are plenty of people here who can help IF you would provide a schematic or a link to one.
Good luck.
Sleeper

The Datatronix PCB is a little different
then the standard PCB. Maybe thats what
you are running into !!?? Also don't worry
about using the gain trim pins in a modern
lunch box.

GARY