soundcraftsmen pcr 800 schematics

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hi im a beginner here ,but im lookin for info,schems,advices,mods of course,about the pcr800,i have a pm860 too thats fine and working,but the pcr turn on the led clip in chanel B at very low signal input so i dont use for that,i bought this amp as is,i have electronics skills and equipment so, if somebody can help....
thanks Arturo
artcarmo@gmail.com
 
I have some readings that may be help for the pcr800
DC at output B (bad one) -35mV
DC at output A -113mV
The PSU about +/- 64 (i have a ligth in series with ac mains) and +/- 13 .the chanel A its little warm than B . all this with no load and no signal at input.Thanks
 
Well since a have noting to loose....i swap the outputs and ,surprice, the problem goes to the channel A...looking in the forums (one post from stell4given) i notice that the clip sistem in the SC is very good ,and almost tll about something wrong in the output....i will test the hitachis tomorrow
 
Yup the 135's seem to die before the 50's do. which explains why i have extra stock of J50's and no 135's left!

make sure to check the gate limiting zener diode string. if that string dies, an over voltage will take out the mosfets!

Also you will not the lack of Drain/Source resistors in these amps! the mosfets should be carefully matched for best performance.

There was a guy here that was selling some new 135/J50 fets for a very good price.

Once you get the amp up and running, tell me what you think of it. I love these little amps. very smooth. never harsh, a little shy on the lowest octaves of bass but clean. these were rated better then the Adcom 555's of the day buy Audio magazine.


Zeonrider, email sent with the schematics.


Zc
 
Thanks for the advice on zeners,yea hard to find the 135...any suggest for matching (if i find) i dont have any like "super criket " only a tester with hfe.... and i atach the procedure i use to test the mosfets.any other advice? thanks
 

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Hi i been a little off on my pcr but this is because i cant find parts,anyboby with opinion in NTE2393???for the K135.....Sun, the foam of mine's get disintegrated years ago,in fact i never see one of this in my pcr,i try to put different types but dont work well,so my pm is "open to dust" now,but besides this i dont see more trouble than "dusting regular"...so if you get one let me know where to buy..... :D
 
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