Another Discrete Op-Amp (Pics)

Are the transistors marked 2gp and 4gp ? Sometimes there are dual diodes in the three leg package.

Thanks for the picture what does the module do?

three chip caps

deposited resistors(are they laser trimmed?)

Not thur holes but side to side connections made by the pins and two top connection things

Looks easier to reverse than the older stuff.

It's the Input OP-Amp from A*P*I (L225 in this case).
The sidechain Input have identical surrounding components using a quarter of a TL084.

The SO23 are marked
6 x "KB" with "J" rotated 90 degree
2 x "C2W"
2 x "KJE" with "J0" rotated 90 degree

any infos on this parts ?
searched for hours today with no result ...

Please, schema!!!!

w00, ckt be nice indeed

I think it has been mentioned here that those are used as balanced line receiver in an APIII mixer...

ye, on the recent 8200 1u rack jobbie... :thumb:

searched for hours today with no result ...

Click to expand...

Verrry important link to SMD Codebook

any infos on this parts ?

Click to expand...

Sure...

KB= Motorola MMBT8099L 80V GP npn

Hmm... can't match up those other numbers...?

HTH!
Charlie

[quote author="rafafredd"]I think it has been mentioned here that those are used as balanced line receiver in an APIII mixer...[/quote]

Yes, they are used as balanced line receivers, here the (reversed) audio and sidechain input of the 225L compressor:

better pictures from the scanner (but still can't catch the SMD codes) :evil:




btw: the pin marking on the potted module is wrong, the pin labeled OUT is not connected, the 2nd GND pin is the output.

KB= Motorola MMBT8099L 80V GP npn Thanks Charlie for the link I had a few more smd links on an older machine but lost the hard drive.

We could make a guess C2W are dual diodes and KJEs PNP. and see if it makes sense if traced out. One thing is I would think older API module just changed to SMD.

I can't see the numbers on the board. marking them would help alot

Some guesses, on the three Semi SMD side the out looks like it goes to two emitter Rs then the SMD above it might be a dual diode .

The many SMD side the bottom right two SMDs might be the output pair.

Many SMD side bottom left two the input pair

I will update the scans with marked transistors / diodes when I'm home from work this evening.

How can I measure those "deposited resistors" ?

I would trace where the resistor leads go to on a SMD device solder point and then probe at the exposed devices solder pads. This mght have errors because of other devices in circuit being in parallel cause the readings to be possable lower.

But the readings will give use some idea of the value and we can do some math.

[quote author="Gus"] This mght have errors because of other devices in circuit being in parallel cause the readings to be possable lower.
[/quote]

You could break the paths...

[quote author="rafafredd"]You could break the paths...[/quote]
I have to repair and use this part again :?

anyway, updated the scans, the sot23 parts are labeled now.
I have to work at a video shooting the next days but after that I will try to trace this little module.

Anyway, if you trace the pcb and draw the circuit, we can see the resistors that are in parallel and will probably be measuring strnage values... I think the group will end with a very close, if not perfect schem...

don't know if this makes sense, but here is what I was able to trace and measure:

I'll move this thread to "The Drawing Board" - I think it belongs there..

Jakob E.

[quote author="[silent:arts]"][quote author="rafafredd"]You could break the paths...[/quote]
I have to repair and use this part again :?

anyway, updated the scans, the sot23 parts are labeled now.
I have to work at a video shooting the next days but after that I will try to trace this little module.[/quote]

I have a number of dead 2510's that I am in the process of repairing. I drew out a schematic last night and found two output SOT-23 transistors were bad in addition to a biasing transistor for the output stage. I'm not 100% sure of a couple of the etched resistor values at this point. I'm ordering parts to fix and test these and should know next week what the values actually are.
When I found out these cost $75.00 to replace, I decided to rip a few apart and see what's inside. A few bucks will put these back to new.
PM me if you want to get a scan of my drawing or discuss parts. I don't want to infringe on any rights by making it public.