DC Servo MOSFET Amplifier

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#762
Prasi,
So i have been listening to them all day. They are very easy to listen to,Clean & quiet. The bass is well controlled and will go deep if the material is there. All in All very nice, with lots of power for those of us who like to Rattle the walls.!!

Rick
 
#764
prasi said:
I had a good look at both of the boards, cant find any thing amiss (BTW nice soldering), dont have eagle eyes.
Non-working board:
1.Pl check the pin 2 and 3 of op amp for any short, which may not be an issue anyway. try reflow of joints if you haven't done that already.
2. see if any of the transistor is exchanged, MPSA 42 to 92, BC327 to 337, IRFP9240 to 240, etc. + you may like to see if any of the semi is dud.

Working board.
1. like I said resistor values check based on the schematic for expected value (if any of the resistor are in parallel.

hope that someone like Mr. Mile is able spot something.
how is the DC offset behavior , might give some indication if the problem like with servo ckt.
Click to expand...

Hi Prasi,

What cap did you plan for C10 and C11? That is on the low voltage circuit. You have it marked as 100u but it is a large footprint.

Thanks, Terry
 
#766
still4given said:
Hi Prasi,

What cap did you plan for C10 and C11? That is on the low voltage circuit. You have it marked as 100u but it is a large footprint.

Thanks, Terry
Click to expand...

I wanted to see if using higher value there could give better supply to i/p ckt like 470u being used in Bimo mod of FX-8. (But I never actually got around to testing it)
Just my thought, Mr. Mile's ckt uses 100u.
reg
Prasi
 
#767
prasi said:
I wanted to see if using higher value there could give better supply to i/p ckt like 470u being used in Bimo mod of FX-8. (But I never actually got around to testing it)
Just my thought, Mr. Mile's ckt uses 100u.
reg
Prasi
Click to expand...

Actually, Mile didn't use a big cap on the low voltage section.
 

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#768
still4given said:
Actually, Mile didn't use a big cap on the low voltage section.
Click to expand...

Ok my bad. It was my addition. Also added individual electrolytic caps on D of mosfets as a little reserve. Got the idea from one of the slewmasters. Amp will work just fine if one doesnt populate those electros as per Mr. Mile's orginal design.
 
Last edited:
#776
DEAR RESPECTED PLEASE SEND US PCB FOR F100 UPGRADED TO ATOM 600 ON YEAR 2015 BY MISLER MILES APEX. WE ARE HAVING PROBLEM WITH POWER SUPPLY OF THIS VERSION OUR LAB IS BARD DUE TO NOT HAVING THIS POWER SUPPLY WITH PROTECTION SCHEMETIC AND PCB LAY OUT.

LET US HELP WITH IT PLEASE.

AWAITING REPLY
 
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