SUMO Power Amp

[Arcolette]

And here follows the 8 Ohm plot:

[Arcolette]

And finally the plot for the no load condition:

[fscarpa58]

well Arcolette

there are to distinct uncorrekated point.

first the max amplitude of output signal on your sim
results to be about 32 Volts (hence 64W) while in my
sim it is about 36V (80W).

This is only due to the opamp device in two way
1) supply voltage : I have +- 21.5 since I measured
these values in both my amp (along with a float of 47 Volts)
2) opamp model


Then there is the switching problem.
It is not a problem of load. Yes I know that changing the load
you have a completely different behavior, the amp id designed so.

Rather, it is like you have a 300 Ohm resistor. I don't figure out why but try to set your resistor to 75 Ohm andlook at the results.

maybe this is only the result of different model.
As I said you, the only possible procedure is to set up correctly the amp based on the performance.

This is another methos more simple than the previous:
-set the load to 4 Ohm.
-set R38 very low in such a way the devices never cut off.
-go to the clipping condition (32 Volts or better if you succeded
in rise that value to 35-36V)
-start rising the value of r38. the central part of the current
will decrease. go on rising and stop when at the threshold of cut off.

now the amp is correctly set up.


Federico

[fscarpa58]

Does anybody know a replacement for the MPSu55 that's used in the Sumo Nine.?

sdman

try the NTE189 (or EGC189)

Federico

[sdman]

Would be interesting to see the schematic of the Thorens
TEM3200. I see that they are using a driver xfm on the input side.
This way they get complete isloation.
Would like to see the translated version mentioned in post #76.

sdman

P.S. I used an on-line translator but it was with mixed results.

[aparatusonitus]

Originally posted by sdman
Does anybody know a replacement for the MPSu55 that's used in the Sumo Nine.?

sdman

I guess that BD526/528/530 from Motorola would fit nicelly.

Best, Ivo

[fscarpa58]

Originally posted by sdman
Does anybody know a replacement for the MPSu55 that's used in the Sumo Nine.?

sdman

BD238
SK3200
2SA818

from an equivalences search

hope this help

Federico

[djk]

http://www.onsemi.com/pub/Collateral/MPSW55-D.PDF

[tiefbassuebertr]

Originally Posted by Jan Dupont;278913 post #10

Some CROWN amps has the same...

Interesting. Please let me know some models - thank you.

here a circlotron circuit:
http://www.amplimos.it/images/CIRCLOTRON_50W.bmp

BTW - who knows the currently link from
http://www.audio-circuit.dk/images/s...ll-pwr-sch.pdf ??

[Jan Dupont]

Interesting. Please let me know some models - thank you.

tief;
That was back in 2003
I don't recall the models, but you can do a search on their Legacy amp pages