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PAS 2
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As a lot of PAS 2 units, this was used a lot and it shows on the Phono pre-amp PC board.  I resoldered all the lands and points on the foil side, checked all the resistors and put in new Mylar capacitors.  This was not a full upgrade which would have included new metal foil 5% resistors as well.

I salveged a line amp board out of another unit to get a better condition board. I checked the resistors and added polyester and poly caps to the board. In a full upgrade all the resistors again here would be replaced with 5% metal film resistors.
Here are the under sides of the boards on a factory wired unit I rebuilt.  You can tell from the rivets holding the PC boards in place.  Notice the poly caps on the line amp to get the corrected values with the caps on top.  Diodes are used to replace the tube rectifier. This will give slightly better V+ and the Dynaco design runs the tubes below mean values so this is not a problem.
This is the top view of the boards in the first picture now installed back into the set. Notice the old selenium rectifier and two large green electrolytic caps in the filament dc supply.  When this picture was taken I was still awaiting the new power supply board from triode Electronics. Tone controls are always left in unless specified by the owner. I also recommend a new sealed ALPS Volume control potentiometer for quieter action and better tracking. All switches and controls are cleaned.  The can cap will be replaced with the caps on the new power supply board.
This unit went out with brand new Sovtek 12AX7 tubes. If your budget allows, higher quality tubes can be added if requested.
Back side of the pre-amp. All the RCA jack inputs are cleaned and burnished to provide a good contact. It is not recommended to used gold plugs with these as dissimilar metals can cause problems with corrosion and or poor contact over time. Use a good quality nickel of nickel chromium plugs.   Unless you are running a very high grade amp and reference speakers it will not be worth the cost to replace the jacks with gold jacks as you will not be able to hear the difference anyway.
Front the PAS 2 all cleaned and ready to go.  It was hard to get a good picture here and it looked a lot better in person than it shows on this picture.

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Copyright (c) 2007 R. David Adams. All rights reserved.

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