September 26, 201015 yr Author comment_390939 the magic smoke results from the temporary caps shorting out the diode... Then apply power. And the other diodes in the bridge go flying. You would think that 15 amp peak diodes with a transformer that can only supply 250ma would win, but they don't. The cap across the primary doubles the spike noise it turns out. My equipment is evidently better than JC's. The sequerra method of a dual inductor (as in transformer but of only 10mh) with the main current thru the primary, and the secondary added out of phase with a tune cap also has no effect. (besides its way to big) The real life self inductance of the power caps makes any attempts at CRLCRLC pointless. When driven from a stack of mercury batteries (3 x 225v) and no load the circuit noise really is about 1.5 microvolt peak to peak. Report
September 26, 201015 yr comment_390940 cool, well perhaps you saw my version around here in a thread, but a shameless plug nonetheless here: I'm working on the PCB now. It's for much smaller currents and voltages of course. The large line cap needs MOVs to absorb large spikes and the CMC handles the smaller ones. Thermistors handle the interaction upon turn-on with the main caps. I tried the Sequerra method too. Didn't work as well as the two CMC. Anyways, congrats on the supply, looks like a winner. Report
September 28, 201015 yr comment_391343 Sorry if this has been asked before but would there be accommodations for single-ended inputs? EDIT: Eh, nevermind. Spritzer's post explained it a few pages back. Report
September 28, 201015 yr comment_391347 the magic smoke results from the temporary caps shorting out the diode... Then apply power. And the other diodes in the bridge go flying. You would think that 15 amp peak diodes with a transformer that can only supply 250ma would win, but they don't. The cap across the primary doubles the spike noise it turns out. My equipment is evidently better than JC's. The sequerra method of a dual inductor (as in transformer but of only 10mh) with the main current thru the primary, and the secondary added out of phase with a tune cap also has no effect. (besides its way to big) The real life self inductance of the power caps makes any attempts at CRLCRLC pointless. When driven from a stack of mercury batteries (3 x 225v) and no load the circuit noise really is about 1.5 microvolt peak to peak. Kevin, Have you ever tried John Swenson's snubber across the xfrmr secondaries? Tube DIY Asylum - Different type of snubber - John Swenson - March 26, 2010 at 15:08:48 Report
September 28, 201015 yr Author comment_391361 As far as i can tell, this is all for low voltage stuff. The secondary of the high voltage transformer is 1800mH. Can't find the original link. Report
September 28, 201015 yr comment_391362 As far as i can tell, this is all for low voltage stuff. The secondary of the high voltage transformer is 1800mH. Can't find the original link. http://www.hagtech.com/pdf/snubber.pdf Report
September 28, 201015 yr Author comment_391377 just tried that. It makes it worse by 2 microvolts. I don't think that kind of thing works for high voltages. Then again, very few nutcases are doing high voltage power supplies with microvolt range noise. Report
September 29, 201015 yr comment_391493 It has been asked before so read the damn thread... My sincerest apologies. It was a spur of the moment thing when I was enthralled by the SR404LE last night. Report
October 20, 201015 yr comment_396802 Hi all, n00b here. I really want to build this amp. Please include me in a future board set / toroid purchase. Thank you! Report
October 20, 201015 yr comment_396804 There will be no toroid group buy and any form of kits done by me aren't likely to happen. Report
October 20, 201015 yr comment_396806 Toroid should be a simple matter of calling up SumR and ordering the correct one, right? About the only thing that might be nice would be a case group buy, but even that's not a big deal since the size isn't excessive. Report
October 20, 201015 yr comment_396810 Hi all, n00b here. I really want to build this amp. Please include me in a future board set / toroid purchase. Thank you! I'd re-read your PM if I were you... Report
October 20, 201015 yr comment_396812 About the specs of the transformer, the original specs is rated at (2) 475-0-475 @ 39VA and (1) 15-0-15 @ 10VA, is this still correct? BTW, the silk screen reads 0 AC30 AC30... Report
October 20, 201015 yr comment_396824 If it said AC130 would it qualify as a RSA product? Military plane names and all.... Report
October 20, 201015 yr comment_396827 heh, I mean that the 0 AC30 AC30 should be 0 AC15 AC15. If its an RSA product, all the transistors would have their part number rubbed out. Report
October 20, 201015 yr comment_396830 Spritzer: is there anyway we could include the new TOTL Stax earspeaker in the kit as well? k thx bye. Report
October 20, 201015 yr comment_396831 For the record, please include me in the group buy. For the record, you should read the thread before posting: To manage things the group buy of boards will be a seperate thread. heh, I mean that the 0 AC30 AC30 should be 0 AC15 AC15. If its an RSA product, all the transistors would have their part number rubbed out. Ah yes....with the red nail polish upgrade as well, I take it? Spritzer: is there anyway we could include the new TOTL Stax earspeaker in the kit as well? k thx bye. For the record, I'm interested in this kit as well. kthxbye Report
October 20, 201015 yr comment_396838 Spritzer: is there anyway we could include the new TOTL Stax earspeaker in the kit as well? k thx bye. For you Marc, I'll send you a special modded version. I may look like a SR-507 which I'm asking 4K$ for but I assure you it is not... Report
October 20, 201015 yr comment_396842 Having a BOM and a fairly standard "Reference Build" would be very nice, especially for DIY newbies like me. So please, could somebody do that? Pretty please? Also, will this amp have enough voltage to drive my Westone UM2s? Report
October 21, 201015 yr comment_396934 There will be a BOM but I for one will probably never follow it. It's just not what I do... Report
October 21, 201015 yr comment_396952 Also, will this amp have enough voltage to drive my Westone UM2s? The problem is not voltage swing, it is synergy ! You should wait to read the reviews on hf. Report
October 21, 201015 yr comment_396971 New members reading this thread it has been said before by spritzer: don't use this thread to post that you want boards. Report
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