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Marantz model 250 and 1200 compatibility

Marcantz

Marcantz

Member
Hello ,
i have a Marantz model 250 with a weak right channel (idle current ) , i have a Marantz model 1200 with a working right channel , could i put the complete (heatsink , output transistors and power board ) 1200 right channel to replace the bad one on my model 250 .
I think it will not work .... Too easy ....
Thanks for your replys.

Marc
 
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Should work.. Same amp, but they did make several versions of the driver board, but they wire the same.
 
Thank you Mike !
I am a newbie but i know that the model 250 is 125w per channel and the 1200 is 100w per channel ...
The transformers have different part number on the service manual.
 
Transformers and main caps are a bit smaller account for the difference in power.
 
After looking at the service manual , it seems that the big capacitors are the same for the model 1200 and the 250 , 20 000 mfd 60v
 
You'll have to open them up and look. Been a while since owning them or working on either. Use to bi-amp with a 1200, doing preamp and one amp and the 250 as the second amp. Could have sworn the caps in the 1200 were smaller. Manuals aren't always correct, and changed are made in production.
 
Hello, 1200, 1200B, 240, 250, 250M share the same power amp. The difference in the nominal output power is only defined by a small voltage difference of the power supplies.
Although, I know 3 driver board versions, heatsink and connectors are all the same.

Helmut
 
Thanks Helmut ,
i think my 250 is a very early version and my 1200 is mark 2 (serial number between 3500 and 5900).
Do you think that i have to change some parts due to small voltage difference or just check the DC offset and bias ?
 
ChrisMarantz ,
when i look at the Marantz 1200 service manual addendum , i can read that mark1 is below 3500 , mark2 from 3500 to 5900 and mark3 (1200B) above 5900 .
 

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My 2 cents....Fix and refurb the original boards... swapping things around is a band aid....
 
jstang ,
you are 200% right ....
But , first i am a newbie and not able to repair by myself .My 250 is at my tech shop since october 2010 and he didn't found the issue for the right channel developing idle current so now i have the solution to give the tech my 1200 working right channel to replace the bad one or recover my 250 amp as i gave him 2 years ago..... Non working .
Since a complete channel is not so heavy , i could send it to someone all around the world , who have a model 250 and could repair it and if you Audiokarma's know this person , please let me know because since i bought this amp on the US bay , i never heard it .
 
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Marcantz said:
ChrisMarantz ,
when i look at the Marantz 1200 service manual addendum , i can read that mark1 is below 3500 , mark2 from 3500 to 5900 and mark3 (1200B) above 5900 .
Click to expand...

If you look at the chart it only shows 2 amplifier boards:

200-1026-100 used on serial numbers 0-5900

200-1071-200 used on serial numbers 5901 and above

There isn't any Mk3 board, there are just 2 versions.

I agree that repairing the damaged board it the right way to go.
 
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