Dynaco PAS Rebuild
The Dynaco PAS series of preamplifiers are wonderful blank slates for modifications, upgrades and really hold their resale value. This is the result of getting my mitts on one.
The story behind this one was my business partner and I needed to get ahold of a chassis for dimensions and stuff for making main and phono board upgrades for it.
We really underestimated the damand for these as we bid what we thought was a reasonable amount on pretty much every one that came up on Ebay, but were always out bid... usually by several times what we had maxed our auto-bidder out at!
We lucked out when we put the call out for one at a forum full of Dynaco fans and there were some klunkers laying in basements, collecting spiders. That was fine, all we needed really was the cabinet and chassis. But ours came with a working PA-211 power transformer as well.
The PAS As Received
Front pic from the seller:
Innards pic from the seller:
Someone drilled "extra" vent holes in the top and had it re-powdercoated. Sad thing was, they didn't even de-burr the holes. They had to go. A little autobody expertise on my part fixed that.
The faceplate came with one heckuva ding too (I knew all this before I bought it and the seller was most forthcoming - this 'ding' pic is from him too), so I decided a new faceplate was in order.
I had some 1/8" aluminum kickplate kicking around (ha, ha, ha) and after grinding the I-beam retainer off the rear (not a fun task... aluminum turns to scalding, spattering goo rather than grind off easily. Have to treat it like hard plastic when using abrasive discs, then you're fine), it was simple to drill and cut the holes.
Finish was attained by hand brushing with 100 grit emery cloth and a sanding block.
Some rub-on lettering and Varathane semi-gloss clear coat....
But, wait, there's some knob positions missing!!! Yup! Tone controls are out. These weren't very good and even Dynaco knew that (that's why they came out with the PAS3x, which had special tone pots that defeated the tone stack entirely at centre position). So is the soundstage control and filter switches. I kept the main selector, tape monitor (a handy switch for recording... allows you to instantly monitor the recording device output without breaking the signal chain or creating a feedback loop), volume and balance (sometimes it's needed) and re-positioned them in a more logical order.
NEXT ---> Page 2, Stripping and Fitting.