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Old 11th January 2012, 01:22 PM   #401
Bonsai is offline Bonsai  Taiwan
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Originally Posted by bequerel View Post
James transformers are beautifully made, and very nice quality at an acceptable price, but probably not in the Hashimoto or Magnequest league.

(If you are on a very low budget, Daburu is usually even cheapter than James.)
Thanks for the feedback
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Old 11th January 2012, 01:24 PM   #402
massimo is offline massimo  Italy
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RTFM applies here, I believe.
RTFM applies always, I'm afraid!
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Old 11th January 2012, 01:33 PM   #403
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Ok, but how many (roughly)? 2? 4? 6? or....

P.S. If I'm not wrong Coleman's Regs work more or les on the same principle (CCS)
It can regulate down to around 2,5 V headroom but taking ripple in consideration I would say you need about 5 V headroom. Then your fine with just a big electrolyt before the regulator.

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Old 11th January 2012, 02:16 PM   #404
stajo is offline stajo  Sweden
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Needing 6,3 V regulated takes 6,3 plus up to 2V for rectifyer loss plus 5 for regulator. Divide that with 1.41 gives you around 9,5 on the loaded tranny. Salas choice of 10 was not a coincident.

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Old 11th January 2012, 02:18 PM   #405
Zen Mod is offline Zen Mod  Serbia
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Originally Posted by massimo View Post
Ok, but how many (roughly)? 2? 4? 6? or....

P.S. If I'm not wrong Coleman's Regs work more or les on the same principle (CCS)

say 4 as minimum

Rod's reg is made as filament (cathode!! for DH tube ) sandwiched between CCS and cap multiplier

it's waste using it for indirectly heated tubes ,with absolutely no benefit
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Old 11th January 2012, 10:29 PM   #406
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What would be the minimum recommended prefilter? I didn't realize this would cost as much as the rest of the amp. Mouser has hammond choke @$34 and Panasonic 500V 220uF caps at $10 each. JJ caps at parts connexion are $14 for 500uF. Also, If in a seperate enclosure, do i put all this in the psu and umbilical to main box or put prefilter in main box with regultor? I am assuming regulator needs to be in main box.
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Old 11th January 2012, 10:36 PM   #407
Salas is offline Salas  Greece
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220uF 220R 220uF I would say as minimum cheap CRC (with solid state bridge). When planning a reg it suffices. If you can make it CLC it tends to sound better. But the choke should be a man at >100mA constant current. 5-10H. If you will put the fiter in another box, use a 10uF MKP or MKT very near the reg's input to ground for decoupling.
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Old 11th January 2012, 11:43 PM   #408
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Hammond choke at mouser is 20H and 100mA. I looked at the Panasonic ED caps which are 450V 470uF. If this looks good, I will pull the trigger. I tried it all in Psud. Not a lot of difference using more or less capacitance on output, but i cant say i know what I am looking for. Its wierd, the filter with 200uF seems to reach regulated voltage faster than lower capacitance. This is just a result of greater charge time for larger cap, correct. Are you using seperate PSU and how is it arranged? tube rectifier recommendation or will any of the schematic list work equally? I think I read that 5U4G doesnt charge as quickly abd helps with v spikes, or is it current spikes?
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Old 12th January 2012, 12:05 AM   #409
Salas is offline Salas  Greece
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With tube rectifiers there is much smaller first cap max spec. Each one notes so in its datasheet. It doesn't work well beyond that max and it expires much sooner.
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Old 12th January 2012, 12:09 AM   #410
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I assumed a 4.7uF Obbligato Film in Oil in the first cap position since it is what i have, I also simmed the PSU with it. I was speaking of the second cap. I can get BHc aerovox on the Bay, but it will mean waiting. Will probably jst go ahead and get the PANa's.
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