jleonne Posted October 25, 2020 Share Posted October 25, 2020 Hi, I'm looking for an Australian seller / distributor of a 12V switching power supply, something like the Mean Well RS-35-12: https://www.meanwell-web.com/content/files/pdfs/productPdfs/MW/Rs-35/RS-35-spec.pdf But then with a ripple & noise closer to 10mVp-p. More or less W & A is fine. Does anyone know of such a power supply? Link to comment Share on other sites More sharing options...
Snoopy8 Posted October 26, 2020 Share Posted October 26, 2020 A quick search using Google https://www.power-supplies-australia.com.au/MEAN-WELL-RS-35-12 Link to comment Share on other sites More sharing options...
jleonne Posted October 26, 2020 Author Share Posted October 26, 2020 1 minute ago, Snoopy8 said: A quick search using Google https://www.power-supplies-australia.com.au/MEAN-WELL-RS-35-12 The specification of that one mentions ripple&noise: 120mVp-p. I'm looking for a much lower value, closer to 10mVp-p. Link to comment Share on other sites More sharing options...
Snoopy8 Posted October 26, 2020 Share Posted October 26, 2020 Sorry, thought you were after an Australian distributor of the Meanwell product... Link to comment Share on other sites More sharing options...
Ian McP Posted October 26, 2020 Share Posted October 26, 2020 Jan Didden's Silent Switcher https://linearaudio.nl/silentswitcher https://diyaudiostore.com/products/linear-audio-silent-switcher Link to comment Share on other sites More sharing options...
jleonne Posted October 26, 2020 Author Share Posted October 26, 2020 1 hour ago, Ian McP said: Jan Didden's Silent Switcher That is rather impressive! I will keep that in mind for other projects. For this current project of mine, I should have been more clear. When I wrote "more or less W & A is fine.", I was hoping for the current range to be around the 0 ~ 3A mark like the mean well. 2A is minimum for me. This needs to power a eurorack system of about 300HP. Link to comment Share on other sites More sharing options...
gwurb Posted October 26, 2020 Share Posted October 26, 2020 10mVpp is really low. This has 50mVpp typical: https://au.mouser.com/datasheet/2/687/tpi30a_j_datasheet-1889920.pdf I would be curious what is commercially available at 2A+ . Maybe an LC filter at the output could be a consideration? Link to comment Share on other sites More sharing options...
andyr Posted October 27, 2020 Share Posted October 27, 2020 On 26/10/2020 at 11:06 AM, jleonne said: The specification of that one mentions ripple&noise: 120mVp-p. I'm looking for a much lower value, closer to 10mVp-p. So why don't you use a linear PS, instead of a SMPS? Andy 2 Link to comment Share on other sites More sharing options...
jleonne Posted October 27, 2020 Author Share Posted October 27, 2020 I'm sure this is controversial to say, but I see evidence that switching is better than linear when you want minimal ripple/noise/hum. Large linear power supplies cause excessive audible hum in eurorack modules. EM from linear tends to detune VCOs. Let's just say I want switching. Daitron claims to have switching supplies down to a mere 1mVp-p. It's very expensive though. They also have 10mVp-p versions, which are somewhat afforable, and I was wondering if there are any (cheaper) alternatives out there. Link to comment Share on other sites More sharing options...
andyr Posted October 29, 2020 Share Posted October 29, 2020 On 28/10/2020 at 10:56 AM, jleonne said: I'm sure this is controversial to say, but I see evidence that switching is better than linear when you want minimal ripple/noise/hum. That's not controversial - simply a tenet of belief by the 'how good are SMPSs! ' sect. My own experience is different. I make the AKSA 'Paris' head amp - ie. a gain circuit which allows a LOMC cartridge (say, 0.3mV output) to be used into a MM phono stage (which expects a 5mV input signal). It needs a 12v DC supply. The latest one I made was a custom order - and required a lot more internal wiring than normal. When I tested it out, after finishing the build, I was disappointed to hear an unacceptable level of HF hash coming from the spkrs. My first thought was that I hadn't done a good-enough job of shielding the internal wiring - then I realised that this was the first time I had tried powering a Paris with a 12v (SMPS) wall wart. Thinking that this must be the cause of the noise ... with a bit of reorganisation of my music system, I was able to use a 12v Sbooster LPS to power the Paris - in place of the 12v Meanwell SMPS. Result ... absolute quiet - no HF hash (which is how a Paris normally sounds)! Andy Link to comment Share on other sites More sharing options...
MLXXX Posted October 29, 2020 Share Posted October 29, 2020 2 hours ago, andyr said: I was disappointed to hear an unacceptable level of HF hash coming from the spkrs. Great to see a really specific, very concrete, audible report like that. (As opposed to the more common subjective reports seen such as, "this power supply provides a lowered noise floor", or "a blacker sound", which could leave one in doubt. ) It's understandable that with a very low output cartridge even a very small amount of interference can become noticeable. I guess the physical placement of power leads near the turntable could become critical - the further away the less likely to interfere. 1 Link to comment Share on other sites More sharing options...
andyr Posted October 29, 2020 Share Posted October 29, 2020 32 minutes ago, MLXXX said: It's understandable that with a very low output cartridge even a very small amount of interference can become noticeable. Naturally. 32 minutes ago, MLXXX said: I guess the physical placement of power leads near the turntable could become critical - the further away the less likely to interfere. There was no power cord "nearer the TT" when I used a 12v wall wart to power the Paris. The only thing that was causing the audible HF hash - with the SMPS vs. the LPS - was the SMPS itself. Andy Link to comment Share on other sites More sharing options...
Steffen Posted October 29, 2020 Share Posted October 29, 2020 16 hours ago, MLXXX said: It's understandable that with a very low output cartridge even a very small amount of interference can become noticeable. I guess the physical placement of power leads near the turntable could become critical - the further away the less likely to interfere. I found the same, in a vinyl-free setup. When dealing with the residual hash (ear against speaker drivers) I found that cable routing, plugging unused ports with shorts, using better shielded interconnnects, etc. made much more of a change than upgrading power supplies. FWIW, and vaguely circling back to on-topic, I used LPS models from this series in the past with good success, sourced from RS: https://docs.rs-online.com/20db/0900766b80a2ef74.pdf They have very low R&N, but wouldn’t be powerful enough for the OP. Link to comment Share on other sites More sharing options...
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