CA9 Schematic needed

andrewlebon

Member
2008-02-13 2:25 pm
some pics of CA9

SUPPLY IS 120 VOLTS DC+/-
 

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I think their schematics like Crest CA9, 12, 18 but cut off class G cascode stage.
Fully complementary input, darlington Vas and triple EF3 output.
Some pro-amp in my country like this, they used +/-95VDC rail. But output devices are 2SC5200/2SA1943 (ON semi devices not sell in my country, if you want use it, shipping from Digikey or Mouser, and prices are expensive.)
 
Hello Walkalone,

Do you have schematics of this amps? the original Crest is quiet complicated. to much for DIY....:)

Regards,

Angeltech

I don't have detail schematic of Crest CA class AB. But like i said, they're simply original Crest class G and cut off cascode stage in output stage.
Crest CA9, CA12, CA18... all they're class G.
We know, class G is a cascode stage, upper in class B output stage.
 

andrewlebon

Member
2008-02-13 2:25 pm
You can trace the original board for a schematics, anyway hows the opeartion of it?
Hello Angeltech
greetings yes traced orignal boards sound is very clear and powerful
has vi limiter and all protections once amp is working new compact pcb will be designed
stay tuned little busy with some amps
warm regards
andrew lebon