anyone familiar with a DC300 original

[pucho812]

looking at a DC300.  I have a working channel, but channel 2 has no output and blows the fuse for the DC(+) on  channel 2.

sifting through the manual and hard to find an original dc300 schematic.

IF anyone has one,  would it be possible to get a copy...

fuse for DC(+)  on the channel 2 side pops... so must be a shorted transistor but not sure where yet.

 

[JohnRoberts]

google has multiple dc300 schematics

quasi complementary output stage

Pink probably has it memorized.

JR

 

[pucho812]

they do but for some reason the are all dc300A or dc300AII but no dc300 I have been able to find.... 

 

[gridcurrent]

http://groupdiy.com/index.php?topic=61243.0

 

[pucho812]

thanks

 

[pucho812]

now to try and navigate the rats nest that is the internal wiring... 

 

[peterc]

Pucho

There are a few repair and upgrade articles on the web, mainly for the 300a and 300II. From memory, one of the recommendations is to swap out the ceramics and put in some npo/cog types.

Or even poly caps.

I have a 300  mkIi in my storage rondavel (hut) for a rainy day project........

Peter

 

[pucho812]

output transistors were replaced due to  failing testing. Unit still  blew  the d.c.(+)  fuse after replacing the failed output transistors.  However those output transistors can cause problems for components further up the chain so time to focus there.