Tweet
Here I am, asking for a schem, again. Sorry.
Where can I obtain a schematic for this amp?
Thank you.
JC
Where can I obtain a schematic for this amp?
Thank you.
JC
-
-
Is that a Fender? -
No, it's an Acoustic.
What part are you servicing? WHich power amp card is in it, 170074 or 170080? Are the preamp and EQ cards 170078 and 170076 respectively?Education is what you're left with after you have forgotten what you have learned.Comment
-
Enzo,Originally posted by Enzo View Post
I don't know yet. It had a cold and broken solder joint where the power transistor's card meets the rest on the power card, and a loose cable in the preamp card, but the amp still doesn´t work.
The amp powers up and there's little hum coming out from the speaker, that's all for the moment.
serial number: 12501554
Power amp card: 170080
Preamp card: 170078A
EQ card: 170076A
JCComment
-
It's in the power amp or around it I belive. I get a good signal in the headphones that responds to the EQ pots, from the preamp out jack.
There is very little sound coming out from the speaker when I plug the signal generator in the power amp input jack, but only when the generator output level is sent to it's maximum level.Comment
-
The fault is in the power amp board.
I have a transistor that is gone, a 40409 RCA, so I will replace it's companion too, the 40410. I'm guessing these are the drivers, but a schem would help for sure. There is a little component placed between these two transistors that looks like a diode, with a white case and no marks, that I don't know what it is or what it does in the circuit.
I've been searching for a schem with no luck. Maybe someone from you have serviced one of these amps and remember what part of the amp I'm talking about. I'm trying to avoid changing all the transistors in the board.
One of the power transistor's collector from one side had a broken solder point and the 40409 belongs to that side of the power amp section.Comment
-
It's fixed.
I just wonder if a cold solder joint in a power transistor's collector may blow it's driver.
¿Is this possible?Comment
-
Depends. If the output rail tries to draw all its current through the base of the output device, which the driver tries to provide.
Do you no longer need drawings? Send an email to tmenzo at msn dot com if you do, and I will scan it in.Education is what you're left with after you have forgotten what you have learned.Comment
-
No, it's ok Enzo, truly.
Thank you very much.Comment
-
Acoustic 125 Pre Amp
Greetings,
I have a guitar in need of pre amp ... please advise
Thanks,
Bruce
480-516-2455
bew1@cox.net
bwashbur@insight.comComment
-
e-b, I think you need to start a new thread on this topic - maybe in one of the guitar tech forums.
Here, at the end of a non-related thread, it's not likely to get much useful attention.
Hope this helps!Comment
-
-
Becoming worthless
If you are going to take the time to type... why don't you participate instead of leaving your website URL?Originally posted by acousticcontrolcorporation View Post
How about just sharing some info like the rest of us.
Otherwise your just another annoying free commercial here and that is not in the true spirit of AMPAGE.Comment
Comment