2. amps-preamps
  3. 1401304597

Audio Research D70 mark1 + schematic

Hallo ! I´m trying to repair a D70 from 1983 . It has a 6DJ8
which determine the "workingpoint" for itself and the following two 6FQ7 tubes for each channel . This poweramp has no solid state parts and the cathodes of the 6DJ8 have two 1,5k resistors connected to each cathode ...... not 110 ohm and 511 ohm as mark 2 . I would very much like to find a schematic for this version of the D70 . ( The two 6FQ7 tube
in each channel have just two 6K powerresistors from their cathodes to earth ...... no other resistors as in version mark2 ) Regards Stewen
stewen1

Showing 4 responses by daveyf

daveyf's avatar
daveyf
3,004 posts
 
Stewen 1, do post again once you have had a chance to listen to the amp. I will be VERY interested to hear your thoughts.
IMO, this amp is one of the very best low power amps that ARC made and is still HIGHLY competitive with the latest offerings.
daveyf's avatar
daveyf
3,004 posts
 
Stewen1, I believe IF your D70 uses the 6FQ7's then it is a mk 2 version.
You could check with ARC themselves, they are VERY helpful when it comes to the amp and still service it. I don't believe Pmotz is correct in his assessment of ARC service.
daveyf's avatar
daveyf
3,004 posts
 
Stewen 1, I don't think there are multiple versions of the Mk2. My D70 was updated at the factory to Mk2 status, which the factory still has record of.
You might check with ARC, as previously suggested, to get more info on your amp....just give them the serial #.
daveyf's avatar
daveyf
3,004 posts
 
Stewen 1, I wonder if you have an earlier version i.e a Mk1 that was semi-converted to a Mk 2 by someone other than ARC?
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