mike stehr Posted September 24, 2002 Share Posted September 24, 2002 I have a old Magnavox single-ended amp.(6CA4,6EU7,6BQ5's) And am currently going through it replacing and upgrading parts. I gave up looking for a schematic, but it's real simple and I have pretty much figured it out. This unit has six Solar brand ceramics in the unit, one strapped across the ac line in, .01 +80 -20% 1400 volt, two for coupling to the output tubes, .01 + - 20%, another pair on the input jacks .01 (no tolerance printed on caps), and another pair on the 6EU7 driver tube. With each capacitor going from cathode to plate on each side of the 6EU7. The value listed on the 6EU7 driver valve ceramic caps are 47M Z5F. Z must be tolerance (5 volts?), I think. I was thinking maybe they are 47 microfarad, but they are the size of the head of a thumbtack, so that isn't it. Usually these old caps are terminated by MMF micromicrofarad or picofarad, but these just have one M. I guess its safe to assume that all the other caps are in microfarad, but this 47M cap has me miffed. Considering the size, wouldn't these be 47 picofarad? THANX! Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted September 25, 2002 Share Posted September 25, 2002 Mike, I'm in the same boat with my Eico. These people use terms like mmf, pf, .047uf. I'm shopping for parts trying to re-cap it and it seems I'm always thinking there's a Zero missing somewhere. Or a decimal point fell off somewhere. Probably just me, I guess. A micro-micro is a millionth of a millionth, looks to me like. Seems to me like the industry is using that term to refer to the quantity I would call a "milli-micro", a thousandth of a millionth. Picky, picky. Tom Quote Link to comment Share on other sites More sharing options...
jazman Posted September 25, 2002 Share Posted September 25, 2002 Mike, Try writing to the seller and builder of this SE EL84 Magnavox amp on ebay recently. It seems like exactly what you have. SE EL84 Magnavox amp KLipsch out Quote Link to comment Share on other sites More sharing options...
mike stehr Posted September 25, 2002 Author Share Posted September 25, 2002 There Jazman, I emailed the guy. Let's see if he replies, and what he has to say. That amp is exactly like mine, minus the gold paint, blue trannies, terminal block, switch, and indicator light. Thanks for the link, looking at his unit gives me some ideas for mine. (I wish he had shown pics of the wiring.) Tom, Don't you have the schematic for the HF-81? They list the values for the caps, micromicrofarad is picofarad. At least it does for the schematics on HF-12. (I'm using .033 Microfarad for coupling to the power tubes in my HF-12 units, the .047 microfarad caps I tried seemed to rob all the highs.) It just didn't sound right, IMO. But this is just a subjective opinion from a newbie tube gomer, so take it with a grain of salt. YMMV. Quote Link to comment Share on other sites More sharing options...
jazman Posted September 25, 2002 Share Posted September 25, 2002 Mike, Glad you sent him an email. When I first saw that amp for sale on ebay I thought of your project and search for schematics, not knowing you still had not found them. He's in the SF Bay area. Good luck. Klipsch out. Quote Link to comment Share on other sites More sharing options...
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