aussievintage Posted February 14, 2021 Share Posted February 14, 2021 9 minutes ago, itsparks said: My latest project, nelsonnpass aleph mini class a, my goal is to measure how clean it will or will not be using a smps vs the traditional toridial tx with crc psu. That will get quite a bit of interest I suspect 2 Link to comment Share on other sites More sharing options...
itsparks Posted February 14, 2021 Share Posted February 14, 2021 11 minutes ago, aussievintage said: That will get quite a bit of interest I suspect I just uploaded my video to youtube, i'll post the link tomorow. Link to comment Share on other sites More sharing options...
itsparks Posted February 14, 2021 Share Posted February 14, 2021 (edited) 16 hours ago, aussievintage said: That will get quite a bit of interest I suspect Video if interested ! I'm ordering the 48V smps's units this week for next stage of testing, then test with WA401 (3) Aleph Mini SMPS Test ! & QA401 Shoutout ! - YouTube Edited February 14, 2021 by itsparks 1 Link to comment Share on other sites More sharing options...
mwhouston Posted February 15, 2021 Share Posted February 15, 2021 I built a preamp with some 100year old tubes last year during a lockdown. The tubes are DHTs but the DIY PS I was using had the DC filament voltage negative and HT neg joined. With my ear inside the woofer at good listening level there was a 50hZ hum. Three or four tweaks got it extremely quiet, can’t hear it at 1M with my ear in line with the woofer. At my 5M listening distance, nothing. My new Radi0kit tube PS kits have regulated filament and smoothed HT with seperate earths. Today I removed the three pin power socket to the preamp and put in a four pin. Some rewiring and rebalancing of the voltages was required. Now still quieter but not perfect. No 50HZ hum but maybe 100 but very low in level. Tried bring the chassis to mains earth, same as PS metal enclosures, but that was audibly worse. Filaments have balancing 100ohm resistors across them. Happier though but did find the right channel a little noisier than the left but as I said unless you are flat on the ground with ear in woofer impossible to hear. I’ll checkout why. 90db sensitive speakers will always highly any noise. Fortunately I love the sound of this preamp and smile when I think the tubes are 100years old. Link to comment Share on other sites More sharing options...
aussievintage Posted February 15, 2021 Share Posted February 15, 2021 2 minutes ago, mwhouston said: Filaments have balancing 100ohm resistors across them. You need to fit a potentiometer to allow you to balance the filament w.r.t. the HT common/negative for minimum hum 1 Link to comment Share on other sites More sharing options...
mwhouston Posted February 15, 2021 Share Posted February 15, 2021 44 minutes ago, aussievintage said: You need to fit a potentiometer to allow you to balance the filament w.r.t. the HT common/negative for minimum hum Regulated 12V feeds a 5V regulator. The filament has 100ohm balance resistors which at the centre feed Rk with Ck across it. Link to comment Share on other sites More sharing options...
aussievintage Posted February 15, 2021 Share Posted February 15, 2021 (edited) 3 minutes ago, mwhouston said: Regulated 12V feeds a 5V regulator. The filament has 100ohm balance resistors which at the centre feed Rk with Ck across it. Yeah, but that's only a fixed point, depending on the 2 "100" ohm resistors. Also, the physical construction of the valve and filament is never perfect - so the balance needs to be adjustable. Feed Rk/Ck from the pot's wiper. Actually it is interesting, as you are using DC. I feed mine AC and just balance out the hum. Probably not as quiet as you want, but inaudible the way I use them. Edited February 15, 2021 by aussievintage 1 Link to comment Share on other sites More sharing options...
Ihearmusic Posted February 15, 2021 Share Posted February 15, 2021 I use rod coleman filament regulators in my build. http://www.lyrima.co.uk/dhtreg/dhtRegIntro.html No noise on my 99dB speakers. Currently got brand new MingDa MC 300 A here. It uses a simple dc supply and a balancing pot. No noise! Link to comment Share on other sites More sharing options...
aussievintage Posted February 15, 2021 Share Posted February 15, 2021 10 minutes ago, Ihearmusic said: I use rod coleman filament regulators in my build. http://www.lyrima.co.uk/dhtreg/dhtRegIntro.html No noise on my 99dB speakers. A nice idea, well implemented by the way it reads. 11 minutes ago, Ihearmusic said: Currently got brand new MingDa MC 300 A here. It uses a simple dc supply and a balancing pot. No noise! Yeah, that's what I was saying. You need a pot to set it for lowest noise pickup. The sweet spot on mine is very tight - you aren't going to get lucky with just fixed resistors. 1 Link to comment Share on other sites More sharing options...
Jone5y Posted February 15, 2021 Share Posted February 15, 2021 (edited) Some rear surrounds that will do some service upfront after an impromptu sale of my VAFs 19mm stringy bark flooring used for the cabinets, patched using auto body filler, couple of coats of high fill primer and gloss white on top and sides. Edited February 15, 2021 by Jone5y 8 Link to comment Share on other sites More sharing options...
Jone5y Posted February 16, 2021 Share Posted February 16, 2021 On 13/02/2021 at 6:55 PM, sfdoddsy said: Finished. 3 way passive open baffles. AST2560, Neo10, Satori WO24P. Corian baffle, sealed walnut bass enclosure. Colour me interested. Were these from a published design or did you design them yourself? Link to comment Share on other sites More sharing options...
itsparks Posted February 17, 2021 Share Posted February 17, 2021 New pcbs for a fee projects came in! Tube pre-amp and tube phono stage! Now to order some parts. 1 Link to comment Share on other sites More sharing options...
mwhouston Posted February 17, 2021 Share Posted February 17, 2021 15 minutes ago, itsparks said: New pcbs for a fee projects came in! Tube pre-amp and tube phono stage! Now to order some parts. Clone of any big brand? Link to comment Share on other sites More sharing options...
itsparks Posted February 17, 2021 Share Posted February 17, 2021 9 minutes ago, mwhouston said: Clone of any big brand? Both Phono & pre were bought from here ! ZinAmp | Pre & Power Amps 1 Link to comment Share on other sites More sharing options...
Ian McP Posted February 17, 2021 Share Posted February 17, 2021 On 09/02/2021 at 9:47 AM, mwhouston said: This came up on my retro-thermionic FB page. Too bad we don’t have the equivalent here. I suppose it just takes a few people to organise it and a lot to support it. “The NY Noise show brought together DIY hi-fi artisans who enjoy the glories of lower-powered vacuum tube gear. Their creativity shined through with incredible works of vacuum tube art! Blackie Pagano and JC Morrison organized this New York City extravaganza. This event was strictly by invitation only, and was so popular that it was standing room only!“ These two gurus were around at the start of Sound Practices and JoeNet now without Joe and known as Sound, it has been running continuously since the early 90's, yep, early days for the internet, all I had was text only on a monochrome CRT monitor via a university connection for it! Sound mailing list Sound@soundlist.org http://mailman.soundlist.org/mailman/listinfo/sound Blackie Pagano https://www.blackiepagano.com JC Morrison runs his impressive Labs JC site, what he doesn't know about tubes isn't worth knowing! Take a look! https://www.labjc.com/ his latest post is a fun read! https://www.labjc.com/?p=5734 1 Link to comment Share on other sites More sharing options...
mwhouston Posted February 17, 2021 Share Posted February 17, 2021 Not mine but what a nice looking amp. It’s a chip amp. That’s all I know. Link to comment Share on other sites More sharing options...
gainphile Posted February 17, 2021 Share Posted February 17, 2021 On 02/02/2021 at 4:08 AM, planet10 said: Thosephase plugs have a weak EnABL pattern. It will have next to no effect without the rest of the driver done. EnABL2 has placed the ringsets in more useful locations. [img] Unless those dots are drawn with heavy lead I don't see what's the effect. Even worse the plugs?? 1 Link to comment Share on other sites More sharing options...
itsparks Posted February 17, 2021 Share Posted February 17, 2021 16 hours ago, gainphile said: Unless those dots are drawn with heavy lead I don't see what's the effect. Even worse the plugs?? Its thin paint, he claims major improvements and they are noticeable with the human ear, and also noticeable income is benefited to his wallet too ! ( AKA crock of crap ) 1 Link to comment Share on other sites More sharing options...
gainphile Posted February 17, 2021 Share Posted February 17, 2021 29 minutes ago, itsparks said: Its thin paint, he claims major improvements and they are noticeable with the human ear, and also noticeable income is benefited to his wallet too ! ( AKA crock of crap ) Yeaahh nahhh ... 1 Link to comment Share on other sites More sharing options...
aussievintage Posted February 17, 2021 Share Posted February 17, 2021 So , DIY audio, are we allowed to scoff at things that might be taken seriously in other parts of stereonet? If so, yeah wow, really???? I have always wondered about these little dots and why people spend money on them. 1 Link to comment Share on other sites More sharing options...
planet10 Posted February 17, 2021 Share Posted February 17, 2021 That is fairly common across many forums on many subjects. dave 3 Link to comment Share on other sites More sharing options...
itsparks Posted February 17, 2021 Share Posted February 17, 2021 1 minute ago, planet10 said: That is fairly common across many forums on many subjects. dave Only on ones that are aimed to fool people out of their money. AKA painted dots on drivers, or cable lifters or speaker cables that cost more than a car, see where I am going with this ? Link to comment Share on other sites More sharing options...
Steffen Posted February 17, 2021 Share Posted February 17, 2021 It works best in fields were people who refuse to be fooled can be shamed for being ignorant, deaf, blind, poor, whatever. Wikipedia explains it thusly: Quote Two swindlers arrive at the capital city of an emperor who spends lavishly on clothing at the expense of state matters. Posing as weavers, they offer to supply him with magnificent clothes that are invisible to those who are stupid or incompetent. The emperor hires them, and they set up looms and go to work. A succession of officials, and then the emperor himself, visit them to check their progress. Each sees that the looms are empty but pretends otherwise to avoid being thought a fool. Finally, the weavers report that the emperor's suit is finished. They mime dressing him and he sets off in a procession before the whole city. The townsfolk uncomfortably go along with the pretense, not wanting to appear inept or stupid, until a child blurts out that the emperor is wearing nothing at all. The people then realize that everyone has been fooled. This fable goes back to the 14th century at least, so this must be a common and easy to exploit trait of human nature. As we all know, its exploitation is rife in audiophilia. Link to comment Share on other sites More sharing options...
mwhouston Posted February 18, 2021 Share Posted February 18, 2021 2 hours ago, itsparks said: Its thin paint, he claims major improvements and they are noticeable with the human ear, and also noticeable income is benefited to his wallet too ! ( AKA crock of crap ) I’m definitely not a measurements man but would love to see before and after tests; dots/no dots. I’m not sure even golden ears ( and I know one) could pick it. Subtle enough is not good enough. 1 hour ago, planet10 said: That is fairly common across many forums on many subjects. dave If there is anyone opinion I would respect it’s yours. Do you believe the dots make an improvement? 1 Link to comment Share on other sites More sharing options...
planet10 Posted February 18, 2021 Share Posted February 18, 2021 36 minutes ago, mwhouston said: Do you believe the dots make an improvement? Me? I certainly do. I posted earlier the few measurements that have been taken that show differences. How you interpret those is wide open. I can quickly pick out the EnABLed drivers in a double blind test (and it takes little time), there are certainly others that appreciate what it brings, there are many that cannot. I have had pairs of carefully matched boxes with and without, for people to take away and listen for themselves. I do not encourage anyone to buy them and its getting hard to, i’m not doing them any more. If you consider how many hours of manual labour go into drivers there is little or no money in it, it is not done to make money. dave 2 Link to comment Share on other sites More sharing options...
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