Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: eleventeen on July 26, 2010, 10:47:16 pm
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This is among my all time favorite pieces of gear: Uses 6 qty 6L6's as pass elements! When I was in electronics class in high school (late 60's) there were 2 racks of surplus broadcast gear with one of these in it, and I lusted after it. 325-500 VDC at 400 mils, would be the cat's meow for a tuber.
This one came with 4x 6L6's & 2x 12AX7, too. That's about $30. Coulda shoulda.
(http://i172.photobucket.com/albums/w32/ttm4/lambda.jpg)
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Next time!
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It's actually somewhat rare to find a nice lab-grade supply for 350+ volts that isn't a 10-20 ma supply, scarcely enough to run a preamp stage or two; and isn't an 85 lb Kepco which is a good piece but will cost a fortune to ship. (prolly 10.5" - 12.25" rack space) This particular one was an opportunity because 1: The seller seriously underestimated the hit he is going to take on shipping (only charged $31...it wil cost him nearly double that) and the thing had 4 out of 6 qty 6L6's, 3 of them GB or better; the ones I see NEVER have any tubes in them, and 3: it appears to be in quite nice shape.
True, you don't need a regulated supply and some might even say you're better off without it; and maybe you can build one with junk parts; but this is a compact package, super high quality, with metering. Silly not to buy it.
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The fluke 407's show-up now & then on eBay but cvan be pricey. Heathkits can be reasonable if yoiu wait them out. I've got a PS-4: 400VDC but only 150mA max; plus bias voltage & 6.3VAC @ 4 amps.
For about $80 I also blundered into a gorgeous Warner-Chicago labs tube regulated HV supply: max 600VDC @ 120 mA. I plan to use it to power some vintage stereo tube preamps that have no internal PS's.
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That model looks pretty cool! (Fluke 407) I was unaware of it.
Now I keep seeing these electrophoresis power supplies good for (typically) 500 VDC *and* 250 ma but I cannot believe they are good for BOTH AT THE SAME TIME. :undecided:
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lambda TCR 600 - 1.5A (1RU) and 3A (2RU) versions.
http://cgi.ebay.com/EMI-EMHP-600V-50A-30kW-DC-SCR-Programmable-Power-Supply-/390220565499?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item5adaf54bfb
no PS sag here! :angel
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LOL. This is so you can weld while jammin'! :laugh:
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electrophoresis power supplies good for (typically) 500VDC *and* 250 ma but I cannot believe they are good for BOTH AT THE SAME TIME.
That sounds like a good HV PS supply to me at the right price. You'll still need bias and heater supplies though.
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I got a fluke 507 a while back. It needed new caps, still haven't done it yet! I figure it will be good for getting an amp in the ball park, however, once I am close, the proto board takes over.
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> BOTH AT THE SAME TIME
Maybe close. I found 600V 150mA, 150W output, with 117VAC input 3A fuse: 350 Watt input at fuse-blow is about right for 150W DC out.
I wondered if they were non-isolated, but there's a 0.5mA leakage rating.
The constant-power mode is sometimes useful in experimentation.
We may be witnessing a historic event. Electrophoresis may be going out of style. I don't find new electrophoresis gear at the usual bio-houses, and a lot of new gear that probably does similar work better. Meanwhile a lot of older electrophoresis gear is on the market at just above scrap value.
One gotcha: I'm not finding repair manuals. A bio-lab would not fix electrics, probably all factory depot repair, so the service info is not widely available. If it works, fine; if not, you may have a costly boat-anchor.
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I got a fluke 507 a while back. It needed new caps, still haven't done it yet! I figure it will be good for getting an amp in the ball park, however, once I am close, the proto board takes over.
Agreed, a regulated bench supply may be of only marginal use for diy guitar amps. Still, I was having a self-inflicted problem with a power amp. Using my bench supply to bypass the amp's PS helped isolate that problem.