Dear All,
Any one has a schematic for SUMO POLARIS II?
What mosfet replacement for this amp?
tks
PS: is this schematic the same with Polaris 310
http://www.diyaudio.com/forums/solid-state/63289-sumo-polaris-310-a-4.html
Any one has a schematic for SUMO POLARIS II?
What mosfet replacement for this amp?
tks
PS: is this schematic the same with Polaris 310
http://www.diyaudio.com/forums/solid-state/63289-sumo-polaris-310-a-4.html
A friend tell me, that his device of this model have a more distorted left channel (in opposite to the right channel).
By comparing the fig. 4 and 5 under
Sumo Polaris II power amplifier Measurements | Stereophile.com
there is to see in the diagrams the same as what would be accordingly the description of the listening test.
Occurs this crossover distortion by a design error ?
Who can upload the schematic ?
Maybe similar to the model "NINE PLUS" ?
HIFIDIY-<SUMO>Circlotron - Powered by Discuz!
SUMO "the Nine"
Thank you very much
By comparing the fig. 4 and 5 under
Sumo Polaris II power amplifier Measurements | Stereophile.com
there is to see in the diagrams the same as what would be accordingly the description of the listening test.
Occurs this crossover distortion by a design error ?
Who can upload the schematic ?
Maybe similar to the model "NINE PLUS" ?
HIFIDIY-<SUMO>Circlotron - Powered by Discuz!
SUMO "the Nine"
Thank you very much
The unit Stereophile reviewed was damaged and was not representative of production units. A baseline Polaris will not have appreciable crossover distortion. It is not similar to the 9.
My Sumo Polaris has been in almost continuous use for 30 years, and in the last week was giving an awful "graininess" -- notably in vocals (was listening to some Palestrina). Apparently, the distortion adjust is out of whack. Thanks @tief for putting me onto that Stereophile article.
Attachments
The Stereophile article is illuminating in several respects, not the least of which is the shoddy construction. My Sumo upon further examination was missing the transformer screw as cited in the article.
More interesting -- take a look at this picture -- only one of the MOSFETs had any silicon paste -- and the one which did fell off when I removed it from the heatsink!
More interesting -- take a look at this picture -- only one of the MOSFETs had any silicon paste -- and the one which did fell off when I removed it from the heatsink!
Attachments
Replacing the PCB in the chassis -- the V+ lug from the thermal switch just fell out -- had to be resoldered. Well, the amp is 30 years old...