Marantz MA9S2 choke input power supply

post #14, this is a low power supply for the front ends, and so i have no problems with his calculations. seems typical..
i suspect that the front end of the amp this psu supplied is class A so that loading is pretty much constant...
best way is to get to look at the actual unit, if i were doing it, based on the schematics, i will know what to do..

It seems that you know what to do... I suggest looking at the actual schematics in question first.... that might be the starting point?

Did you miss my post where I clearly stated that you overlooked the fact... that the choke in question supplies the full current grunt needed by the amplifier PCBs? I even posted a little photo...
 
no, i saw what you posted, but i have a different idea, i have seen so many different Japanese design's from repairing Japanese amps in the 80's that are similar to this Marantz, so it will be useless to argue with you about what you are talking about...sorry, i will not slug it out with you, waste of time...
 
Fellas,

Have a better look... the choke supplies current to the main amplifier section. This is why my calculations pointed to a 12A rating... the worst-case power consumption/output, 4-ohm load.

The inductance could be calculated only if the amp is examined under load on a test bench.

I think I've provided enough info here, for something that should not really be encouraged... ripoff of the original design.
View attachment 1153453

Do you mean choke supplies current for amplifier output?
 
no, i saw what you posted, but i have a different idea,
Based on what? Your experience?? Did yous see the size of that choke?? Drawing from your experience, do you think Marantz would use it just for the pre-amp section??
i have seen so many different Japanese design's from repairing Japanese amps in the 80's that are similar to this Marantz
Woah... Impressive! Did you bother to look at their schematics?
, so it will be useless to argue with you about what you are talking about...sorry, i will not slug it out with you, waste of time...
Of course, it would be useless... you did not bother to check the circuit diagram, went on showing here how you are experienced and know so much, and then admitted the choke calculations are correct... for a pre-amp section - which is WRONG.
 
no, no, no.....
Yes Yes Yes

Still refusing to follow the red arrow??

1678781468748.png
 
We only know the inductance (2x180mH ) but do not know the wire gauge and toroidal core.Any ideas?
Looks like R803,R804 are 1R, 1/2W. That puts some limit on what the current through the choke is likely to be. BTW, have a pair of those power amps here. Haven't gotten around to opening them up to look inside yet, though. SQ is very good. Better in some ways than Benchmark AHB2.
 
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Hi. I am now finishing the output. Could you please tell where center tap of the power supply caps are connected? Are they connected to chasis gnd?
 

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