andyr Posted December 22, 2018 Share Posted December 22, 2018 8 hours ago, MLXXX said: MMn, I don't quite understand. Was the issue the stability of the TT rotational speed, or whether or not noise and hash etc was being injected into wiring near the TT? The 'issue' was ... I have long held the belief that the PSU is the key to the 'sound' of any hifi component - and I wanted to see whether this would still hold true with something as prosaic as a (non-signal carrying) TT motor speed controller. The speed controller itself provides a stable Hz and voltage to the AC motor. As to whether there was noise or hash on the (dedicated) mains circuit that the speed controller was plugged into - my view is that, yes, there always is noise and hash on a mains circuit. Hence an SLA supply was included in the test. There were 4 pairs of 'golden ears' listening, in addition to me - including: @Number 9, the designer of the TT speed controller, and the late, lamented Duc. We were all amazed that we could hear so much difference in the sound coming from the speakers, with the different PSUs driving the motor speed controller. The 'test record' was Vivaldi's "Gloria" (Argo ZRG 505), recorded in the Chapel of King's College, Cambridge - which has some lovely decays when the full choir stops singing. The difference in sound between PSU #1 and #5 was, basically, more of everything! Harmonics became more extended ... the room ambience was more clearly presented ... and the decays were extended. And this was simply with different PSUs powering the device that rotated the TT - not processed the signal! Andy 1 Link to comment Share on other sites More sharing options...
djb Posted December 22, 2018 Share Posted December 22, 2018 I attended this test the differences indicated were as if the proverbial ....veil had been lifted Link to comment Share on other sites More sharing options...
MLXXX Posted December 22, 2018 Share Posted December 22, 2018 1 hour ago, andyr said: The difference in sound between PSU #1 and #5 was, basically, more of everything! Harmonics became more extended ... the room ambience was more clearly presented ... and the decays were extended. And this was simply with different PSUs powering the device that rotated the TT - not processed the signal! I also would have been amazed. This is outside my understanding from an electronics 101 perspective. The turntable speed should have been reasonably smooth simply through inertia, I'd have thought, unless the motor was very aggressive in attempting to change the speed. As for mains hash etc, if such interference wasn't directly audible as hum or buzz but had the character of an insidious influence at a much higher frequency, it should have been filtered out by the cartridge preamp, I would have thought. [If attempting to diagnose the fault condition, I'd be inclined in the first instance to monitor the "stable Hz and voltage" sent to the motor. ] Link to comment Share on other sites More sharing options...
andyr Posted December 22, 2018 Share Posted December 22, 2018 8 minutes ago, MLXXX said: I also would have been amazed. This is outside my understanding from an electronics 101 perspective. The turntable speed should have been reasonably smooth simply through inertia, I'd have thought, unless the motor was very aggressive in attempting to change the speed. As for mains hash etc, if such interference wasn't directly audible as hum or buzz but had the character of an insidious influence at a much higher frequency, it should have been filtered out by the cartridge preamp, I would have thought. [If attempting to diagnose the fault condition, I'd be inclined in the first instance to monitor the "stable Hz and voltage" sent to the motor. ] I'm sure there are many things outside your understanding, from an "electronics 101" perspective, MLXXX. Me - I don't try and explain them ... I simply take on board what the experiments show me. But I fail to see what "the 'stable Hz and voltage' sent to the motor" has to do with anything? The same speed controller was used and we went back and forth between the various PSUs, several times - hearing the same results. Andy Link to comment Share on other sites More sharing options...
MLXXX Posted December 22, 2018 Share Posted December 22, 2018 8 minutes ago, andyr said: But I fail to see what "the 'stable Hz and voltage' sent to the motor" has to do with anything? Ah, simply to verify that it truly was stable with respect to frequency and wrt voltage. Link to comment Share on other sites More sharing options...
andyr Posted December 22, 2018 Share Posted December 22, 2018 22 minutes ago, MLXXX said: Ah, simply to verify that it truly was stable with respect to frequency and wrt voltage. I'll leave the designer to convince you of that, mate. I'm happy to believe it is - to me, there are much more logical reasons why we heard different things. Andy Link to comment Share on other sites More sharing options...
MLXXX Posted December 22, 2018 Share Posted December 22, 2018 3 minutes ago, andyr said: I'll leave the designer to convince you of that, mate. A CRO or other suitable measuring device would verify that the TT voltage was as intended by the designer. 5 minutes ago, andyr said: to me, there are much more logical reasons why we heard different things. Would you care to share any of those reasons with the forum? Link to comment Share on other sites More sharing options...
Addicted to music Posted December 22, 2018 Share Posted December 22, 2018 13 minutes ago, MLXXX said: Ah, simply to verify that it truly was stable with respect to frequency and wrt voltage. And this is while a belt driven TT is used, not a DD. There are some companies (not in the audio High Fidelity industry ) also recognises that having things operate correctly have ditched all components operating off the mains. They realised that 230/110/120 around the world isn’t consistent and can vary significantly, not in just voltage and hertz but distortion levels too, the mains is not a pure symmetrical sign wave. Hence the reason why the products I work on have all DC driven components, that’s supplied via a SMPSU that runs directly of 20 or 30A and usually have 2 of these to avoid going to 3 phase. You can imagine in high speed production reprographics where polygon mirrors spin at 15,000/30,000 rpm or slight veriation in supplied regulated DC to a VCEL laser will do to the overall product. Any variation here and the diagnostics shuts it down until the issue is resolved. Quality of DC rail isn’t just for audiophile nuts. Link to comment Share on other sites More sharing options...
Addicted to music Posted December 22, 2018 Share Posted December 22, 2018 If I were to get back into analog, @Number 9 would be the person to turn to. Link to comment Share on other sites More sharing options...
andyr Posted December 23, 2018 Share Posted December 23, 2018 34 minutes ago, MLXXX said: A CRO or other suitable measuring device would verify that the TT voltage was as intended by the designer. But it's Hz that controls the speed of an AC motor. 34 minutes ago, MLXXX said: Would you care to share any of those reasons with the forum? Not really ... as that would extend this - to me pointless, because we have totally different "world views" - discussion. Andy Link to comment Share on other sites More sharing options...
MLXXX Posted December 23, 2018 Share Posted December 23, 2018 (edited) 37 minutes ago, andyr said: But it's Hz that controls the speed of an AC motor. My reference to voltage was in the context of the use of a CRO. In that context not only would instantaneous peak to peak voltage be captured, but also waveshape, and frequency. Although a synchronous AC motor responds primarily to frequency, there will exist a small rotational phase offset under load. This small offset will vary in its size if the supply voltage or waveshape vary. Edited December 23, 2018 by MLXXX Link to comment Share on other sites More sharing options...
MLXXX Posted December 23, 2018 Share Posted December 23, 2018 57 minutes ago, Addicted to music said: Quality of DC rail isn’t just for audiophile nuts. Yes for any electrical device connected to the mains, the engineering design needs to ensure that the device will operate properly with expected variations in mains frequency, voltage, waveshape, DC offset, and hash level. Mission critical devices might need a standby power supply to kick in automatically if there is an interruption in the mains supply. As they say, horses for courses. In relation to the various upmarket DACs from MSB Engineering it appears that particular care is required in selecting a power supply, to obtain best performance. I don't understand why the particular DACs are so sensitive to which power supply is used, but @Ittaku has reported hearing a quite noticeable difference with at least one of the DACs. Link to comment Share on other sites More sharing options...
Volunteer sir sanders zingmore Posted December 23, 2018 Volunteer Share Posted December 23, 2018 Ahh we are talking about DACs after all. I thought for a moment that I’d stumbled into a turntable thread 1 Link to comment Share on other sites More sharing options...
bzr Posted December 23, 2018 Share Posted December 23, 2018 18 hours ago, MLXXX said: Did you get to hear "The Select DAC", which I see has a manufacturer's recommended retail price of US$84,500? Perhaps it would represent another non-subtle step up. I must say though I wonder how recording studios are able to compete. Do they spend this sort of money on their ADCs? No need to answer; more a rhetorical question. With so many bad recordings out there, I too would be rhetorical.... Maybe they should pay attention & go back to school... Link to comment Share on other sites More sharing options...
bzr Posted December 23, 2018 Share Posted December 23, 2018 5 hours ago, MLXXX said: Yes for any electrical device connected to the mains, the engineering design needs to ensure that the device will operate properly with expected variations in mains frequency, voltage, waveshape, DC offset, and hash level. Mission critical devices might need a standby power supply to kick in automatically if there is an interruption in the mains supply. As they say, horses for courses. In relation to the various upmarket DACs from MSB Engineering it appears that particular care is required in selecting a power supply, to obtain best performance. I don't understand why the particular DACs are so sensitive to which power supply is used, but @Ittaku has reported hearing a quite noticeable difference with at least one of the DACs. I've experienced everything the same, within the MSB range, as he has stated. What i haven't experienced, is a lot of intelligent opened mindedness from people that just won't simply accept that maybe..... just maybe....??? The guys at MSB are no slouches by a huge divide.... 3 Link to comment Share on other sites More sharing options...
davewantsmoore Posted December 23, 2018 Share Posted December 23, 2018 5 hours ago, MLXXX said: In relation to the various upmarket DACs from MSB Engineering it appears that particular care is required in selecting a power supply, to obtain best performance. I don't understand why the particular DACs are so sensitive to which power supply is used, but @Ittaku has reported hearing a quite noticeable difference with at least one of the DACs. There's more than a big difference between being sensitive the the 240v mains .... and a converter being sensitive to it's internal power supplies. Power supplies internal to a digital device a more than very important. Link to comment Share on other sites More sharing options...
Ittaku Posted December 23, 2018 Share Posted December 23, 2018 30 minutes ago, bzr said: With so many bad recordings out there, I too would be rhetorical.... Maybe they should pay attention & go back to school... Modern day classical recordings are worlds apart from rock and pop recordings, and recordings from the past. It's a veritable goldfield these days with most, but not necessarily all, classical releases sounding very good to exceptional. Even the big name labels these days rarely make a bad recording. Luckily, I listen almost exclusively to classical. Link to comment Share on other sites More sharing options...
MLXXX Posted December 23, 2018 Share Posted December 23, 2018 3 minutes ago, davewantsmoore said: There's more than a big difference between being sensitive the the 240v mains .... and a converter being sensitive to it's internal power supplies. Power supplies internal to a digital device a more than very important. Come again? Link to comment Share on other sites More sharing options...
davewantsmoore Posted December 23, 2018 Share Posted December 23, 2018 9 minutes ago, MLXXX said: Come again? 5 hours ago, MLXXX said: I don't understand why the particular DACs are so sensitive to which power supply is used I am saying that it isn't because it is sensitive to what is coming from the wall socket..... but because the device side power supplies are of varying 'quality'. DA converters and the like can be extremely sensitive to the local power supplies, and often quite lot of effort is needed. Link to comment Share on other sites More sharing options...
bzr Posted December 23, 2018 Share Posted December 23, 2018 34 minutes ago, Ittaku said: Modern day classical recordings are worlds apart from rock and pop recordings, and recordings from the past. It's a veritable goldfield these days with most, but not necessarily all, classical releases sounding very good to exceptional. Even the big name labels these days rarely make a bad recording. Luckily, I listen almost exclusively to classical. Sure, but I don't do classical.... so 95% of the rest of the recordings still apply within a percentage... Link to comment Share on other sites More sharing options...
Ittaku Posted December 23, 2018 Share Posted December 23, 2018 1 minute ago, bzr said: Sure, but I don't do classical.... so 95% of the rest of the recordings still apply within a percentage... You're right... And I'm sorry to hear that. Link to comment Share on other sites More sharing options...
MLXXX Posted December 23, 2018 Share Posted December 23, 2018 1 hour ago, davewantsmoore said: I am saying that it isn't because it is sensitive to what is coming from the wall socket..... but because the device side power supplies are of varying 'quality'. DA converters and the like can be extremely sensitive to the local power supplies, and often quite lot of effort is needed. Thanks for clarifying. I still find it bit surprising that the default power supply doesn't enable the DAC to operate at its full potential. 54 minutes ago, bzr said: Sure, but I don't do classical.... so 95% of the rest of the recordings still apply within a percentage... Pretty much all of what I listen to is classical. With a lot of other genres I find it difficult to assess quality. 1 Link to comment Share on other sites More sharing options...
bzr Posted December 23, 2018 Share Posted December 23, 2018 1 hour ago, Ittaku said: You're right... And I'm sorry to hear that. Don't be. I can appreciate it for what it is, I can recognise timing & delivery as such, but, to me, music is a story to be told ... hence,.. voice! Link to comment Share on other sites More sharing options...
AudioGeek Posted December 23, 2018 Share Posted December 23, 2018 2 hours ago, Ittaku said: Modern day classical recordings are worlds apart from rock and pop recordings, and recordings from the past. It's a veritable goldfield these days with most, but not necessarily all, classical releases sounding very good to exceptional. Even the big name labels these days rarely make a bad recording. Luckily, I listen almost exclusively to classical. Yeah, I agree. I find modern day classical is often a better way to quickly assess a component or system than listening to Pink Floyd or Diana Krall. Something like the Infernal Dance from the Firebird suite will promptly reveal if a system is up to it. Then if that is your preferred genre you will really get the most out of your gear most of the time. No point buying a Ferrari and all that... On the flip side, art is a subjective personal enjoyment. If someone is enjoying music on their system that's all that matters. 1 Link to comment Share on other sites More sharing options...
andyr Posted December 23, 2018 Share Posted December 23, 2018 2 hours ago, MLXXX said: I still find it bit surprising that the default power supply doesn't enable the DAC to operate at its full potential. I find that an extraordinarily naive statement. Why would you think that the power we are supplied with is 'perfect'? By which I mean: it is within the stated +/- voltage guide lines and it is a perfect sine wave with no hash - or DC. I believe that the suppliers may well be trying to do their best ... but with increased: renewable energy creating voltage variations, and next door's solar power inverters creating hash and DC on your supply ... they have a difficult task. (Thank you, greenies! ) Andy 1 Link to comment Share on other sites More sharing options...
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