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PostPosted: Sun Mar 19, 2017 7:57 pm 
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Joined: Sun Mar 18, 2007 5:39 pm
Posts: 8
Location: Toronto, ON, CA
Hi,
Purchased a Scott amp with everything working well and now I am replacing the 7591 power tubes for the first time. Does anybody have any advice on how to do this? I have a voltage meter and a plastic screw driver. Thank you for any responses ahead of time.


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PostPosted: Sun Mar 19, 2017 8:37 pm 
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Joined: Sat Jul 04, 2009 6:08 pm
Posts: 18451
Location: Montreal, QC, CA
vanexel37 wrote:
Hi,
Purchased a Scott amp with everything working well and now I am replacing the 7591 power tubes for the first time. Does anybody have any advice on how to do this? I have a voltage meter and a plastic screw driver. Thank you for any responses ahead of time.


Which specific model number?


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PostPosted: Sun Mar 19, 2017 9:41 pm 
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Location: Toronto, ON, CA
The 299D. Wow that was absent minded of me to forget to mention the model.


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PostPosted: Sun Mar 19, 2017 10:09 pm 
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Location: Montreal, QC, CA
I only have schematics for the 299D; 2 different ones depending on the serial number, but unfortunately, no service manual.


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PostPosted: Mon Mar 20, 2017 2:48 am 
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Joined: Sun Dec 28, 2008 7:49 am
Posts: 1727
Location: Fairport Beach (in Pickering), ON, CA
Google is your friend:

http://hhscott.com/cc/fixed.htm
https://groups.google.com/forum/#!topic ... 4Ksp8PNUso

You say everything is working well so I trust ALL the electrolytic caps have been replaced. They start going bad at 20 years old and are well past their expiry date at 50+ years old.

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Tom

Collecting vintage tube Pilot (Pilotone) HiFi gear.


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PostPosted: Mon Mar 20, 2017 5:11 am 
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Joined: Sun Mar 18, 2007 5:39 pm
Posts: 8
Location: Toronto, ON, CA
The electrolytic caps have been replaced. I see where to adjust the voltage and balance on the 4 power tubes, want to know where the positive test points for each power tube are for the amp(seems like logically it would be just below the adjustment screws)? There is also another testing area which I don't know how to use with rcas and a switch(shown in the picture as well).
Or do I have to open the bottom of the amp to do the biasing?
Thanks


Attachments:
Scott-299D-Top-View-of-Restored-Chassis.jpg
Scott-299D-Top-View-of-Restored-Chassis.jpg [ 74.08 KiB | Viewed 328 times ]
aa5a6437-b8de-451f-a0c1-2caebd16bbc3_zpsnmn6wnuq.jpg
aa5a6437-b8de-451f-a0c1-2caebd16bbc3_zpsnmn6wnuq.jpg [ 83.54 KiB | Viewed 328 times ]
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PostPosted: Mon Mar 20, 2017 6:18 am 
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Joined: Thu Jan 13, 2011 11:29 am
Posts: 527
Location: St.Catharines, ON, CA
schematic


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