Post by michaelw on Jul 21, 2019 15:39:57 GMT 12
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Post by Owen Y on Jul 22, 2019 21:36:34 GMT 12
All our usual audio electronics equipment is powered by DC voltage/current. Yet wll this stuff traditionally needs to have a 'rectifier' circuit up front, in order to convert our AC mains power to DC. So maybe with solar powered battery storage, without 'inverters', we can use the clean DC directly for audio electronics - using 'voltage multiplier' circuits to generate required higher voltages? The thing is, I'm not convinced that battery powered hi-fi components are generally that successful (not in my limited experience anyway). Has anyone had good experience with say battery-powered phono stages or such?
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Post by Owen Y on Jul 24, 2019 12:09:45 GMT 12
We moved this thread here, because Paul McGowan points out some interesting things abour power demands that audio equipment make on your domestic power supply & what it tends to do to a power supply, solar-powered DC-to-AC inverter systems, in particular: " When you start drawing current and voltage at different times, it can collapse the sinewave in ways that are not appreciated by stereo equipment & don't sound graet. " Most of us, of course, use mains AC electricity but often we do not appreciate the importance of a clean, low impedance (low resistance) power supply for our equipment.
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Post by michaelw on Jul 24, 2019 19:22:58 GMT 12
i remember hearing an early dnm preamp with battery power supply, it sounded much better than the owners big naim 32. it also had then innovative non-metal construction. later dnm switch from real batteries to a virtual battery setup. next heard a privately imported mission 776 preamp with battery power. a great match for the original 770 speakers, both sounded awful. jeff rowland also used battery power for some preamps. locally the plinius koru used a virtual battery supply. when i reviewed the koru, the factory also supplied a mint m14 phono. guess which sounded better ?
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Post by Owen Y on Jul 24, 2019 19:27:11 GMT 12
What's a 'virtual battery' PSU? Is that just a regular AC mains-to-rectified DC PSU, but with a huge capacitor bank representing a 'quasi-battery' DC 'reservoir'? My first DIY Diego Nardi linestage preamp was designed like that.
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Post by colinf on Jul 25, 2019 11:50:42 GMT 12
It depends.... Mains ac supplies have long wiring runs to the transmission lines outside that pick up interference and RF, and everyone else's switchmode laptop and phone power supplies etc. in the same street. The RF then travels into the audio circuit through the hifi component's mains transformer's capacitance between primary and secondary windings. Battery circuits have none of that and have, as you say, clean(er) power. But not all may be well in battery land. As the battery discharges its internal resistance increases which gives the audio circuit a varying impedance power supply. So it's still good to use regulation or capacitor filtering to lower the impedance from a battery. Also, most op-amp circuits require + and - supplies, necessitating the use of 2 or more batteries. To make a negative supply from a single positively-connected battery you need a voltage converter circuit which almost always consists of switching circuits that add noise from the switching transients. High voltage circuits for valves derived from batteries also have potentially noisy switching converter circuits. To charge the battery directly without an inverter you'd use solar panels or wind generators, both of which are cleaner than the mains but which have long wiring runs that pick up RF as well. So you'd disconnect the solar panels during a listening sesh. i fiddled extensively with batteries and their supplies in the 90s and thought that such a system can be good for solid state circuits that don't draw much current, unlike valve circuits. Opamp and discrete transistor circuits use negative feedback that continues to operate well into the Mhz frequencies and are very prone to RF on their power supplies and input and output. So a well RF-filtered opamp circuit running on batteries is ideal for a battery-based system setup.
AMR-iFi R&D
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Post by michaelw on Jul 25, 2019 13:31:55 GMT 12
What's a 'virtual battery' PSU? Is that just a regular AC mains-to-rectified DC PSU, but with a huge capacitor bank representing a 'quasi-battery' DC 'reservoir'? My first DIY Diego Nardi linestage preamp was designed like that.
that's how i understood the concept from the koru days - lots of capacitance and lots of regulation.
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Post by Owen Y on Jul 25, 2019 15:23:12 GMT 12
The best 'regulation' maybe, is simply a the lowest practical impedance PSU, so that when there is demand for power, the PSU does not sag, it maintains its voltage & current delivery. ie, without any active regulation.
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Pundit
Post by SL1210 on Jul 28, 2019 23:59:36 GMT 12
All our usual audio electronics equipment is powered by DC voltage/current. Yet wll this stuff traditionally needs to have a 'rectifier' circuit up front, in order to convert our AC mains power to DC. So maybe with solar powered battery storage, without 'inverters', we can use the clean DC directly for audio electronics - using 'voltage multiplier' circuits to generate required higher voltages? The thing is, I'm not convinced that battery powered hi-fi components are generally that successful (not in my limited experience anyway). Has anyone had good experience with say battery-powered phono stages or such? I have had experience with a phono stage that was charged with capacitors. So on startup there would be a compulsory wait while the capacitors charged. It was the Fosgate Signature. Nice to look at and it sounded just fine too. Downside: It was not silent. If you put your ear to the tweeters you could hear a slight hiss. The unit made use of half a dozen valves and I put the hiss down to that, rather than the power supply. But on the other hand I know as much about electronic circuits as you know about 15th Century Indian rope-dancing. Overall it was a good unit and I only sold it after I got an Ayon Eris, a preamp based on 6H30 small-signal valves.
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Post by Owen Y on Jul 29, 2019 9:49:42 GMT 12
My first separate Linestage preamp was a DIY build of a design by Diego Nardi, a tube design with high voltage DC PSU that had a large cap supplying each channel, acting like a 'quasi-battery' PSU:. Diago's explanation - " a 1800uF/400v electrolytic cap per channel with a 'time constant' of about 10 secs. These caps, during bench tests, display constant & low ESR up to about 50kHz and are in fact acting as batteries in the general economy of the preamp. "
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Post by michaelw on Jul 29, 2019 12:12:04 GMT 12
linsley hood and batteries rings a distant bell...
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Post by sub on Jul 30, 2019 10:49:09 GMT 12
Red Wine Audio amps were/are battery powered. Never heard one, but was tempted by one on TM a while ago.. I live completely off grid, relying on solar to charge my 48V AGM battery bank. I have a 5Kw petrol generator to charge the batteries as back up for when the sun doesn’t shine for extended periods. I looked at the Red Wine amp as it seemed an ideal compromise, as having its own battery it would not deplete the household one’s when used at night. But, when making enquires I found the amp and battery had to be left on 24/7. I have a 3000W pure sine wave inverter to deliver 240V to the house, and while I cannot make a comparison, I believe the clean power does make a difference to the performance of my system - Ortofon 2M Black. Ittock LV11 arm, LP12 with Valhalla, Pure Audio Vinyl, Plinius 8150, Kef Reference 104/2 (refurbished).
However, the original question can be taken two ways - does solar power deliver clean power? And, is solar power clean as in green and clean? I think the answer to the first is yes, but with caveats as to the quality of the off grid set up, but is it cleans and green? Yes, when supplying power, but no when the various components are being manufactured. Batteries in particular are “dirty” to manufacture, solar panels also, but to a lesser extent, while the path to producing copper cables, from mining through to manufacture is also not clean and green.
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Post by Owen Y on Jul 30, 2019 15:52:16 GMT 12
Solar (photo-voltaic) energy is a relatively 'green' strategy in NZ- only IF you have battery storage. If not, your reduction of power demand load on the 'grid' take place when general power demand on the grid is lowest & thus the low-demand to peak-demand difference is exacerbated. In NZ, whilst 80% of power generation is 'renewable' hydro-electric & geothermal , peak demand is topped up using non-renewable fossil fuel s.
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Post by michaelw on Jul 31, 2019 12:12:18 GMT 12
going off course here. the clean in the original post referred to the state of power going into a stereo system, not to the greenness of generation.
yes, the earth is bombarded with immense amounts of solar energy.
the task is to effectively harness it.
less environmental impact ? solar collection requires enormous physical resources and manufacturing activities that arguably has as much impact as traditional energy harvesting.
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