Well, it is getting on in years and safety is always number 1. But, you should check the filter caps to see how warm they are after about 20 minutes after start up. They should still be relatively cool certainly not very warm or hot. Are you running the unit without the cabinet? If you can do that it really helps to keep the amp at a lower temp as the outside cab also becomes a heat shield and makes the amp run a lot hotter than without direct heat radiation by going topless. Without the cover you can also check the power tubes for signs of red plating which is not a good thing. The power supply caps and coupling caps can start to wear out faster now that you are using it as the high voltages will be able to find its way through weak spots on the insulation and eventually cause a failure. So, you have to be on the lookout for that. Failure is usually preceded by some horrible noise like a hum that gets increasingly louder and if you are luck a blown fuse.
I have not seen an amp do that but i once was witness to the power supply cap failing on a Dynaco MK3 and that scared the bejesus out me. It was quite loud and it made an even worse mess.
That was the name I forgot! Madison Fielding! I have whats left of a mono 6v6 PP amp that was made by Madison Fielding and sold under various brands like RS. The one I have was branded "HiFi". It was a kit. But exactly like the RS and Madison.
. Absolutely gorgeous rehab job on both -- they sound pretty decent, too. PP 6V6 so about 10 watts (mono integrateds)
RSamps by Mark Hardy, on Flickr
P1300002 by Mark Hardy, on Flickr
Thanks for posting the picture. Those are just like the "HiFi" branded one I have. The one I have isn't so pretty, or complete anymore though. I was thinking of using the chassis for a stereo 6v6 SET amp if the PT is up to it.These passed through here en route from their seller to their (ultimate) owner -- who himself is an AK member of some repute
The SAF-40 runs its output tubes really hard -- I wouldn't recommend plain-vanilla EL84s in one (FWIW). 7189s or the beefy Soviet/Russian variant thereof (6П14П-ЕВ -- I think) will be OK. The latter, IMO, are pretty decent, not too hard to find and not terribly 'spensive, either.
There's one of those here, too -- but it actually belongs to AKer joZmo.
Come to think of it, there's an SAF-24 here, too -- That's pp 6BM8 (or is it 6GW8... I forget!?!) for ca. 8 wpc. It's cosmetically none too pretty.
It is a definite possibility although i can't say for sure. If the amp is original, a dead give away is the use of Suzuki pio coupling caps or sometimes white sleeved Cherry? pio caps.
Yes, the SAF-24 series, I would bet, were all Japanese-made. They have that look to 'em (and those nasty grey coupling capacitors, too). Certainly the SAF-24C here was -- as was the aforementioned SAF-40. I believe the AF-12s were as well, not 100.0% sure, though.
Earlier on, in the 1950s*, Radio Shack used the name "Realist", but were forced to change it by the company that made the "Stereo Realist" stereo camera.
http://www.radioshackcatalogs.com/history.html
Scan0025 by Mark Hardy, on Flickr
