Backline 600 schematic

[dumbo]

HELP !!
Looking for a schematic diag. of a backline 600 - 300W
uses 3 C5242 & 3- A1962 as outputs.
All were blown - replaced - now output waveform has no neg. side
check drivers & diodes with meter - seem to be ok
What is the ne555 for? - is it part of the protection circuit?
Thanks

[Jazz P Bass]

Are you sure about that NE555.
I thought GK used the NE571 compander IC.
It is for compression.

[Jazz P Bass]

Backline 600 power amp schematic

Here is an older post with the power amp schematic.
Post: http://music-electronics-forum.com/t16020/

[52 Bill]

I don't think that's the right schematic for a Backline 600. Too old.

[dumbo]

Yup - just checked it again - I also thought it was a little odd - figured that by configuring it as a triggered monostable it could operate the shut down circuit. - just a thought - that's why I need the schematic - no ne571 on board.
Thanks

[dumbo]

No it's not. - output section consists of 6 transistors - 3 npn & 3 pnp
Thanks

[pontiacpete]

is this it?

[dumbo]

That's it :-) Thank you so much - Now we can rock!!

[Enzo]

Instead of looking for more bad semiconductors, try looking for open resistors.

[drewl]

Like the man said.
When those transistors short, they usually take out the emitter resistors, check them all.

[Chris537]

Any Chance you would have a Backline600 amp with the 206-0181-A4 board? or would it be the same or close as the 206-0240-A4? I replaced a input jack and foot switch on this with a half a$$ previous job so i have my run for my money and having grounding issues when guitar cord is plugged in but nothing when input cord is unplugged. kinda of a weird issue. but a schematic would help to fix some fried traces from poor prev solder jobs from who knows... Thanks guys! Trying to salvage a nice piece.

Chris537

[don6470]

Hello I´m looking for the same schem pontiacpete left in #7 answer, but it doesn´t get open, could you pleeaasee help me?, thankss!!!

[nickb]

600 Power amp

[don6470]

Hey thanks! sorry to disturb again, but i think that one doesn´t fit, i believe the right one sais "206-0240-b1" could it be a little different?

[nickb]

Hey thanks! sorry to disturb again, but i think that one doesn´t fit, i believe the right one sais "206-0240-b1" could it be a little different?

Sorry, that's the closest I have. Hopefully it will be close enough to help you along. You can always email support@gallien.com and ask them