Hello,
My first post.
I'd like to thank the creators and maintenance of this forum !
Sorry, my english is not to good ...
This is a great post, I'v learned a lot, that's why I leave here my comments. Always remember a post can be readed many years later and still be updated. Thanks to Douglas an others who really are into it. I wish I could have a good repair teacher. Most of the knowledge I have is coming from "try, error, learn, error, learn, try,..."
Regarding this amplifier, I am just repairing one who has 5 issues ! most of them on channel 1 (left)
4 of them are repaired:
- The Rca imput conector was damaged: Changed. Maybe moved to hard and it disconnected from the board.
- The jack imput was also "disconnected" from the board: repaired.
- The +-15v was completely burned: repaired but I'v changed the resistor for a higher value, higher wats, they get very hot, is it normal ? Zenner diodes new.
- one IC on CH 1 damaged: repaired, new one.
Number 5 is that channel 2 works well but channel 1 is only working half his volume. I have good signal until the volume pot, after I can't find out yet where the problem is. I suppose it has to do with the feedback connection. Probably the IC. Or could it be some of the final transistor ? I don't know how to find out. Any help is welcome !
The fact is that it's not easy to get to mesure the transistors, and some components: the boards are very close and it's difficult to insert a probe.
I'v changed some condensers with wrong values: low capacitance, high ESR.
I must say it looks a nice amp but could have been designed a little better... +- 15v with diodes is not the best way, isn't it ?
Yes Mastergamgee, some times you have to make a break, ... or you'll break something !! Hahaha. I hope you got it repaired. Can you tell if you repaired it ?
Regards.
My first post.
I'd like to thank the creators and maintenance of this forum !
Sorry, my english is not to good ...
This is a great post, I'v learned a lot, that's why I leave here my comments. Always remember a post can be readed many years later and still be updated. Thanks to Douglas an others who really are into it. I wish I could have a good repair teacher. Most of the knowledge I have is coming from "try, error, learn, error, learn, try,..."
Regarding this amplifier, I am just repairing one who has 5 issues ! most of them on channel 1 (left)
4 of them are repaired:
- The Rca imput conector was damaged: Changed. Maybe moved to hard and it disconnected from the board.
- The jack imput was also "disconnected" from the board: repaired.
- The +-15v was completely burned: repaired but I'v changed the resistor for a higher value, higher wats, they get very hot, is it normal ? Zenner diodes new.
- one IC on CH 1 damaged: repaired, new one.
Number 5 is that channel 2 works well but channel 1 is only working half his volume. I have good signal until the volume pot, after I can't find out yet where the problem is. I suppose it has to do with the feedback connection. Probably the IC. Or could it be some of the final transistor ? I don't know how to find out. Any help is welcome !
The fact is that it's not easy to get to mesure the transistors, and some components: the boards are very close and it's difficult to insert a probe.
I'v changed some condensers with wrong values: low capacitance, high ESR.
I must say it looks a nice amp but could have been designed a little better... +- 15v with diodes is not the best way, isn't it ?
Yes Mastergamgee, some times you have to make a break, ... or you'll break something !! Hahaha. I hope you got it repaired. Can you tell if you repaired it ?
Regards.