They were clearly marked "Made in China"
Ran at less than 50% of their rating.
One even blew out house circuit breaker.
Just because you got a couple of bad items that were made in China doesn't mean everything made in China is bad, Nigel. FFS!
BMW is even making their automotive glass there now instead of Pilkington because it's a superior product with less defects, and costs less to boot.
BMW is even making their automotive glass there now instead of Pilkington because it's a superior product with less defects, and costs less to boot.
No I don't think batteries are a green solution and I have seen spectacular failures so I keep them outside my home. I have measured many SMPS and they are noisy in general whereas linear power supplies don't exhibit that phenomenon.
Today I finished a 15V 3A LDO ultra low noise PSU and the results are stunning compared to the standard SMPS that was delivered with the device. In this specific case the manufacturer also offers a 300 Euro upgrade linear PSU for that device which goes to show 😀
Noise and RF do have an audible effect in audio. A device is a good as its power supply is. I am quite sure you will hear and measure it too when you would compare SMPS to well designed modern linear PSU's. In fact it is a no brainer in many cases when bog standard SMPS wall warts are delivered with an audio device.
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I prefer the simplicity of linear supplies and their reliability.
I used to run a mobile disco and would never consider SMPS where I needed something reliable.
I'd like to see an 850W 12V linear ATX power supply... Actually, no I wouldn't since it wouldn't fit in the bloody computer case. Seasonic sells a FANLESS 600W 80+ titanium supply that has a 12 year warranty running full out at 40c...
I'm not by any means trying to say that one technology is better than the other, but both have their usages. Even my microwave uses an inverter because it works better. Try and make a linear traction motor controller for a train that doesn't weigh a tonne and waste power... There is NO reason a linear upgrade should cost more than 300$! I don't spend 300$ on the entire linear And SMPS parts of my tube amp power supplies, let alone on a wimpy 6W DAC supply. Someone has gone FAR past the point of diminishing returns IMHO. I could be wrong.
The Chinese, like almost anybody, can make stuff as good or as BAD as they think the customer really wants.
When you are 8,000 miles away and buying on price, why should they care?
BMW probably has managers all over that glass factory, with authority to refuse goods (and stop payment) if there is *anything* they don't like. That seems to be true of all the good made-in-China products: as much on-the-spot oversight as they would have in their home factories. The chip and hard-drive companies have played this game for decades. Experienced in-factory oversight.
I had a 72 Watt linear PC supply out of a Diablo paper-terminal. It was half the size of an AT (not ATX) case, actually bigger (I ran it in a "coffee table"). It ran a 286 mobo OK, fan-less, but huge and hot.
Topic is a 12V 0.5A linear PSU for a Musical Fidelity DAC. To the OP: don't bother and buy or build yourself a decent (!!) ultra low noise linear PSU and hear the difference. Focus on recent regulators instead of the noisy old regs that keep sticking their head out for unknown reasons. You want ultra low noise and LDO for less heat etc.
A PSU with LT3045 would be the optimum as no better regs exist. First measure current draw of your DAC to make sure it consumes 500 mA maximum and let's say 300 mA average. This one drew my attention but as usual you will have to replace electrolytic caps and measure it before using it. Could be a choice when the V90 consumes less than 500 mA. I would combine it with a nice 20VA 12V R-core transformer. A metal case (with a few ventilation slots) and an IEC inlet with PE would make it a safe and complete device.
LT3045 Hifi Low Noise DC Regulator Linear Power Supply for DAC preamp | eBay
20VA Pure copper R-core transformer 6V / 9V /12V /15V/ 18V/ 24V/ 28V L16-2 | eBay
I never have tried both of these but I regularly try Chinese LDO boards. If you try these please let us know the results. Sometimes one has to be the first to try stuff 🙂
This one surely works and it delivers 1A with ease. It has a 1.5V drop because of the pass transistor. Please note that replacing electrolytic caps for known quality ones is advisable too. You can use the same 20VA 12V R-core transformer.
LT3042 Ultra Low Noise Linear Regulated Power Supply board for DAC L12-53 | eBay
A PSU with LT3045 would be the optimum as no better regs exist. First measure current draw of your DAC to make sure it consumes 500 mA maximum and let's say 300 mA average. This one drew my attention but as usual you will have to replace electrolytic caps and measure it before using it. Could be a choice when the V90 consumes less than 500 mA. I would combine it with a nice 20VA 12V R-core transformer. A metal case (with a few ventilation slots) and an IEC inlet with PE would make it a safe and complete device.
LT3045 Hifi Low Noise DC Regulator Linear Power Supply for DAC preamp | eBay
20VA Pure copper R-core transformer 6V / 9V /12V /15V/ 18V/ 24V/ 28V L16-2 | eBay
I never have tried both of these but I regularly try Chinese LDO boards. If you try these please let us know the results. Sometimes one has to be the first to try stuff 🙂
This one surely works and it delivers 1A with ease. It has a 1.5V drop because of the pass transistor. Please note that replacing electrolytic caps for known quality ones is advisable too. You can use the same 20VA 12V R-core transformer.
LT3042 Ultra Low Noise Linear Regulated Power Supply board for DAC L12-53 | eBay
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Thanks to all for the suggestions. I have decided to use the present switching power supply for now and continue my study of power supply design. I hope to build a linear design of my own sometime in the not-too-distant future.
If you have an old fashioned linear adjustable lab power supply you could connect a cable from it to your DAC and try for yourself if it brings something. It does 🙂 but it probably will give the motivation to do it. Even an LM317 based PSU can give an impression of the possible minimal improvement in performance. The definitive low noise LDO PSU will then likely only be better. That is how I test and decide to build or not.
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PSU for DAC
I built a DAC from ES9038Q2M board and mod another ready built unit. From an e-bay seller with good reputation. Using the SMPS from a S.M.S.L. class D power amplifier, I got about -84dB noise floor using SMPS. It is not bad, but can be readily improved. When I finished the LT1083CP based linear PS, the noise floor dropped to better than -103dB. I am not a golden ear type, but can easily hear the difference. The LT1083CP LDO is no magic, just a higher capacity LM317. I did not try the ultra low noise LDO as jean-paul suggested. The LT1083CP was a happy middle ground for me.
I have a few post in the ES9038Q2M Board thread about my modest effort. Most other posters on this thread were aiming at the -120dB using multiple ultra low noise PSU.
This is sound advice for everyone who builds or mod a DAC.
I built a DAC from ES9038Q2M board and mod another ready built unit. From an e-bay seller with good reputation. Using the SMPS from a S.M.S.L. class D power amplifier, I got about -84dB noise floor using SMPS. It is not bad, but can be readily improved. When I finished the LT1083CP based linear PS, the noise floor dropped to better than -103dB. I am not a golden ear type, but can easily hear the difference. The LT1083CP LDO is no magic, just a higher capacity LM317. I did not try the ultra low noise LDO as jean-paul suggested. The LT1083CP was a happy middle ground for me.
I have a few post in the ES9038Q2M Board thread about my modest effort. Most other posters on this thread were aiming at the -120dB using multiple ultra low noise PSU.
Assemble a 12 V Battery pack from NiCad ( only !) cells. These old tech batteries produce the cleanest power possible.
Evidenced as beyond the resolving power of the Lab test instruments.
Use that as your baseline comparison/ reference ?
To determine If there is audible difference with your silly Dac when powered by the Nicads Or the wall wart.
Evidenced as beyond the resolving power of the Lab test instruments.
Use that as your baseline comparison/ reference ?
To determine If there is audible difference with your silly Dac when powered by the Nicads Or the wall wart.
I'm waiting for someone to suggest that only the power from an electric eel is pure enough for a DAC...
It a 20dB or 40dB difference in noise is not audible to you, so be it. It is clearly audible to many.
ES9038Q2M Board
That depends... 20db over what? if it's already -180db what's another 20db? I probably can't hear down past -80 or so anymore unless were talking about levels not obtained through normal means (10000W sound system in my apartment?).Also, it was more a stab about the merits of different battery tech and which is the best.
Sorry but your comments are not constructive. A device is a good as its power supply whether you like that or not. If a well designed linear PSU does not cost an arm and a leg as I have showed why not try out and test?
It is so darn simple, a low cost SMPS simply looses from a linear low noise PSU in many if not most cases. We are talking 12V at 0.5A here. No need for an SMPS at all. SMPS was not meant or designed for audio but for lower cost and higher efficiency, lower weight etc. Quality is not a key design parameter with low cost SMPS. The use of ready made OEM wall wart SMPS also moves the certification jungle to the responsibility of the OEM that produces these devices.
It is so darn simple, a low cost SMPS simply looses from a linear low noise PSU in many if not most cases. We are talking 12V at 0.5A here. No need for an SMPS at all. SMPS was not meant or designed for audio but for lower cost and higher efficiency, lower weight etc. Quality is not a key design parameter with low cost SMPS. The use of ready made OEM wall wart SMPS also moves the certification jungle to the responsibility of the OEM that produces these devices.
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That DAC will operate at 96k via usb inputs, for something like that I usually just use a transformer wall-wart, snubber on the diodes, an lm7812 followed by a 100uf capacitor and call it good.
Or not bother changing anything🙂
Or not bother changing anything🙂
Good is not good enough in audio. At least not when one can get ones hands on way higher quality PSU's for comparable costs. After many years or modding and DIYing I learnt that I better build excellent stuff . One looses time anyway so why not go for really good? The 78xx/79xx have no place in audio anymore. These should be made obsolete.
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With reference to my earlier post #33.
I built a DAC from ES9038Q2M board and mod another ready built unit. From an e-bay seller with good reputation. Using the SMPS from a S.M.S.L. class D power amplifier, I got about -84dB noise floor using SMPS. It is not bad, but can be readily improved. When I finished the LT1083CP based linear PS, the noise floor dropped to better than -103dB. I am not a golden ear type, but can easily hear the difference. The LT1083CP LDO is no magic, just a higher capacity LM317. I did not try the ultra low noise LDO as jean-paul suggested. The LT1083CP was a happy middle ground for me.
I have a few post in the ES9038Q2M Board thread about my modest effort. Most other posters on this thread were aiming at the -120dB using multiple ultra low noise PSU.