Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: eleventeen on May 13, 2013, 01:23:11 pm
-
(http://i172.photobucket.com/albums/w32/ttm4/pilotSA232_zps1850dd25.gif)
Pilot SA 232 power amp, stereo 6BQ5 w/Mullard GZ34 & relatively recent looking RCA 6BQ5s x 4 qty. This is a pix stolen from ebay and has an added volume control. The one I got is cherry, with metal cage.
Pilot FA-690 mono tuner/preamp, in enclosure
Pilot #100 multiplex adapter, in cage
$20. for all. All stock. Haven't fired it up yet to see it works, but all the heaters came on and nothing smoked.
The power amp is way too nice to strip for transformers. They are beauties, though.
-
It's fun to find stuff like this. Thirty years ago I worked with a woman whose husband was an electronics geek. He passed away and she sold much of his stuff. She let me have the Dynaco PAS-2 tube preamp and Stereo 70 power amp set that he had built for $15. I enjoyed that setup for many years and finally sold the set for $700 a few years ago.
-
Nice find! Those transformers look great.
-
They sure do, they look one "grade" oversize; the power trans looks like a Twin Reverb tranny and the outputs look like they could handle a pair of 6L6. As is they are only handling EL84/6BQ5 and I suspect that contributes mightily to great bass response and headroom in general. I'm much more inclined to get this working as it is than tearing it apart, though. I also got the tuner and the multiplex adapter, I just haven't had time to variac 'em up yet. Which could be being overly cautious because the ex-owner just turned them all on and I tried to get a radio signal for 10 mins. Still...it's one of those things....if you KNOW you should bring up long-idle tube gear slowly on a variac, then it will blow up if you don't. If you DON'T know about variacs and stuff, then just turn the thing on and you'll never have a problem!
-
Thought I would supply a better picture. Mine is maybe one step below this condition, the gold paint isn't glossy, but it's all there. No rust. There are actually globs of wax on the bottom plate which may have been cooked out of the transformers. This thing sat inside a console for most of its life so it may have run hot. The top surface of the amp chassis has kind of a tough grime which I am reluctant to attack since it might erase the printed tube-name designations. Any ideas? Windex? Alcohol worked on the edges but it took enough pressure so that I'm concerned about wearing off the print. Could also leave it there. The power tranny (and the outputs, as well) is pretty darn impressive for a dual-EL84/6BQ5 amp. It's about the size of a Twin Reverb.
(http://i172.photobucket.com/albums/w32/ttm4/pilot_sa232_nice_zps6a7af226.gif)
-
Mineral spirits is a good cleaner, especially if there is any oily or greasy or waxy dirt buildup. Denatured alcohol is another good cleaner. Neither should lift or dissolve the lettering, but test in an inconspicuous first.
Is the chassis painted or anodized?