macaltec said:
Please enjoy the refurb, their is lots of support on the net. Once its up to snuff, while very enjoyable, is far from a modern piece. There are unusable inputs on the preamp in stock condition. They can easily be modded for regular use. The circuit boards leave a lot to be desired, plus are very old by now. If you have the red colored boards, I find they clean up as close to new as possible with a substance called "print coat solvent" from electronics parts providers. The boards sholud be removed, stripped of all parts, cleaned and re assembled. By the time you do this and replace all the caps, resistors, etc., you will have spent more than its worth when you consider kits available out their for this application. I would just redo the power supply, bias supply and coupling caps as a learning experience and the buy a kit from Audio by Vanalstine. Their super pas III kit is perfect. It uses the same tube lineup, 12X4 rectifier, 12XA7A in both line and phono board. Plus it replaces all the components and boards themselves, as well as the entire power supply. Both the power supply and boards are not copies of the original, they are WAY improved. I think the entire kit is up to 300-350 now, but it replaces EVERYTHING, sockets and all and reuses the transformer. The rehab of your unit will give you all the experience you will need to build such a kit, The instructions are EXTREMELY simple and easy to do. The preamp was on stereophiles recommended components for years. Plus, you get an excellent phono section to boot. I have restored several PAS pres and have built two of these AVA kits. They are well worth the money. Alternatively, buy just the power supply kit from Curcio audio for a large improvement if you know you want to keep the stock boards. Curcio also sell well regarded pas mods, but they are all seperate, one for the power supply, one for line, one for phono. All three are fairly expensive, but they are highly regarded. I have never built a curcio unit, but many have, check the dynaco doctor forum for details their. For the money, it is hard to beat all you get with the AVA kit. Very simple assembly. By the way that is the best 4 dollar purchase I've heard of in a while!macaltec said:
If you wish to keep the original circuit its up to you. While the AVA mod will smoke it badly, you can enjoy the basic upgraded circuit and still improve its functionality. Re wiring some of the selector switch can give additional inputs, and the tape-input switch can also be converted to an additional input. Another useful mod is to move the power transformer outside on the back as the AVA mod has you do. More cooling to the transformer, and get a lot of heat out of the box. Also, disconnect the filters and loudness switches, as well as the tone controls. If you are keeping the original boards and circuits, you might get the curcio power supply which is regulated and way stiffer, plus it replaces the bias stuff as well. The stock transformer is adequate, but the filaments really pulls it down. An additional transformer can be mounted on the back just for the filaments...this will take a big load off the transformer. Also, replace the pilot light with a LED. I like green. Looks cool and draws much less than the little light bulb supplied. There is also a guy on Ebay that will sell NEW versions of the original board.Southern said:
macaltec said:
Russellc said:
. I'll have to do some more research as it looks pretty simple to work on.