Crate PA^-FX Box Mixer

[jjimsu]

I have a crate ps6-fx, Model SLM-06A450-01 Rev D, Ser # 230-66800-300-0
I need a schematic for this amp. I've got it apart and didn't notice the two ea Transistors NPN and the two PNP. I don't know where they go. Please help.

 

[Enzo]

Hi.
First off this belongs down in the Live Sound section under PA systems. it will probably be moved there.

You need PS6-fx or PA6-fx? Your title and your test disagree. I am not aware of a PS6, but PA6 and PA8 are legit model numbers.

Assuming PA6, I think this schematic covers the power amp in the several variations of this model series:
http://bmamps.com/Schematics/crate/Crate_PA-6,_PA-8_Schematics.pdf


Meanwhile, there are also layout drawings and parts lists. For the full file, CALL Loud Technologies near Seattle, and ask for the drawings.

 

[turk 182]

i guess checking supply polarity at the device location isn't the right way to figure out which device type goes where.
maybe i'm overlooking or forgetting something but we are talking bi polar output transistors no?

 

[JMFahey]

NPN transistors have base 0.65V more positive then emitter and collector from 30 to 60V more positive (actually the rail voltage value) so if you measure such voltages on PCB pads, you confirm NPN .

PNP is the same but with negative voltages.

That's the way to confirm which goes where.

 

[Mooly]

Moved to PA forum.