Early Audio Research Dual 100 Schematic?

[Unimog]

Does anyone have a schematic for the early Audio Research Dual 100? These were manufactured around 1970 on two chassis, one for the power supply and one for the amplifier. Any assistance would be very much appreciated.

 

[rayma]

Does anyone have a schematic for the early Audio Research Dual 100? These were manufactured
around 1970 on two chassis, one for the power supply and one for the amplifier.

There may not be an official schematic available, but the amplifier circuit was very much the same
as their later models, the D51, D75, D76, and D150. Have you tried contacting ARC directly?

 

[mr2racer]

Here is the dual 100; http://www.arcdb.ws/DUAL100/DUAL100.html

But it doesn't in include a schematic

I found an original manual on eBay in the completed listings section. It sold for .99! It lists two schematics in the manual. If that's the case it should still be available from Audio Research.

 

[Unimog]

Thank you, mr2racer, for posting the link.

Yes, I am looking for the schematic for the all-tube Dual 100, which is entirely different from the later amplifiers. A photo is included below.

Unfortunately, I believe all the manuals on ebay are for the solid state 100-watt amplifier.

I have requested assistance from ARC and am waiting to hear back.

Thank you all for your assistance.

 

[Unimog]

I should have said above that at least the power supply is very different from later models.

I would love to know what all those tubes are doing.

 

[audio king]

Most Audio Research power amps are considerably more complicated than other manufacturers products. Their Cross-Coupled inverters add a lot of tubes,and their willingness to regulate almost every voltage in the unit really bumps thing up in term of complexity. This is one of their earliest models, with all-tube regulation for each channel,and that adds a LOT of extra tubes. And heat!

This is one of my dream amplifiers,but it's unlikely that I'll ever find one.

Are you just curious or do you actually have one of these?

 

[Unimog]

It took a little while but Audio Research responded and was able to answer all of my questions. It was very nice to have such a good interaction with a manufacturer over a long-discontinued product.

 

[rayma]

It took a little while but Audio Research responded and was able to answer all of my questions.
It was very nice to have such a good interaction with a manufacturer over a long-discontinued product.

I'll be that they still have some of the parts for it, too.

 

[rayma]

I should have said above that at least the power supply is very different from later models.
I would love to know what all those tubes are doing.

I think that the 6CA7/EL34 and related smaller tubes regulate the screen voltage of the output tubes.
In their later models, a 6550 tube does that using Zener diodes, instead of the small regulator
tubes in the Dual 100.

 

[audio king]

It took a little while but Audio Research responded and was able to answer all of my questions. It was very nice to have such a good interaction with a manufacturer over a long-discontinued product.

Were they able to provide a schematic? If so,I'd love to see it

 

[rayma]

Were they able to provide a schematic? If so,I'd love to see it

The amplifier section is pretty much the same as the D75. The power supply is all-tube,
including the rectifiers and the screen regulator tubes.