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    Building, troubleshooting and testing of these amplifiers should only be
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Audio Research D115 repair

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Guenth

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Joined 2023
#1
Hello does anyone have any detailed photos of the top and bottom circuit boards of an Audio Research D115mk11. Specifically I'm lookin for where the op amps, pass transistor and V17 tube socket are mounted. These were all removed from an Amp I just bought and I want to restore it back to original. There may be a small circuit board somewhere that had the op amps mounted on it? There are all kinds of parts and circuit modifications on this amp.. I need some clear photos to see how the original was. I do have the schematic but a board layout would save hours of time. Thanks anyone that can help. Guenth
 
#2
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#4
Thanks TonyEE I did see some pictures from SkiFi before but they didn't have clear shots like these. I'll screen shot them before they are gone. I'm a little slow to respond. I haven't had time to get in my shop for a few months ! Limono I know it will be hard to fix but I must do it !
 
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#5
Best of luck to you! I’m still in the process of doing a D70 MKII, its smaller sibling, I started here:
D

Thread 'Audio Research D70 MKII'

Some might call me a glutton for punishment, but I have taken on one of these that’s sickly and that has even had modification attempts! I’m nearly at the point of digging into the power supply. It’s great to have schematics available online, but I’m struggling with identifying ZD12. It‘s labelled as a ZD20, but I’m clueless at exactly what that specific Zener is. Would anyone know?
I’ve rebuilt all the voltage regulators except the bias -42V so far and replaced all the nine pin tube sockets that someone had installed with an “improved version”.
What a pain to work on!
 
#7
Check resistors around regulator circuits and opamp too to be sure . I changed all capacitors ( it needed it ) all zeners ( because I was told they eventually go bad ) but it didn't fix the issue of wandering bias . It was OK for sometimes and than regulator tubes started arcing. I gave up and took it to a friend who is more patient and still has some hair to pull. After a couple of weeks of ON and Off attempts he found the resistor was intermittent. I paid him $500 and he said the repair was still a gift. While it's not Ref75SE ( my favorite ARC amp ) I liked it quite a,lot.
 
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