I have a Feickert turntable that utilizes a 24v Meanwell brick power supply. I would like to build a linear power supply for it. I'm searching for a kit, which I assume would be a scaled-down version of the Pass amplifer power supply, for those amp kits. A complete kit with the PC board and components would be optimal, but if I can get a PC board with a component list, I can certainly handle that after building an F5, F5T, Amp Camp, Korg Pre and a couple of other great components offered on this site. I don't see anything in the DIY Store that seems to fit this application. I would like to go a level above using the Meanwell with the filter kit in the DIY store. But may settle for that.
Any guidance or links to kits would be greatly appreciated!
Any guidance or links to kits would be greatly appreciated!
Do you mean this?!
http://www.feickert.org/index.php?id=26&L=1
the only things that matter are ( other that being regulated)
http://www.feickert.org/index.php?id=26&L=1
the only things that matter are ( other that being regulated)
- 24 V / 500 mA DC sec.
- current limitation sec. at 1000 mA
I do realize Feickert has a $900 linear power supply it offers. It does not come with the turntable. There is a Meanwell brick that comes as a standard.
Somehow I feel I'm going to get a lot of flack over thinking a LPS will help when feeding a motor on a belt driven TT, And I can't say I don't think the same way but, this just seemed like a fun project. And linear power supplies just seem cooler than switching ones. Toroidal Xfmr, bridge rectifier, some decent caps and some type of voltage regulator. How hard can it be?
And no, the TT is not malfunctioning with the Meanwell that was provided. I was just hoping for some sonic improvement but don't want to spend $900 to see if there is.
Somehow I feel I'm going to get a lot of flack over thinking a LPS will help when feeding a motor on a belt driven TT, And I can't say I don't think the same way but, this just seemed like a fun project. And linear power supplies just seem cooler than switching ones. Toroidal Xfmr, bridge rectifier, some decent caps and some type of voltage regulator. How hard can it be?
And no, the TT is not malfunctioning with the Meanwell that was provided. I was just hoping for some sonic improvement but don't want to spend $900 to see if there is.
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Read this thread; your questions will be answered:
https://www.diyaudio.com/community/threads/post-you-smps-noise-spectrum-measurements.394518/
SMPS will spit the noise back into the mains supply where the rest of your equipment is connected - good enough reason to never use them ( like never, ever... ever) in an audio system.
In addition to the above, you will realise (after reading the thread I provided the link to) that the noise present on the low voltage DC side is very hard to filter because... the SMPS simply (by design and by the requirements of isolation between the mains side and the low voltage side) do not have a low impedance ground path to couple that noise.
If still doubtful, connect two RC battery packs in series and see if you can tell the difference vs. MeanWell brick. You'll notice exactly what the manufacturer has stated under the benefits:
"Sonically
you will immediately recognize a darker background. Not only is there more quietness but more inner fine-dynamics in the sound. More details are revealed, and a virtual curtain is removed. A more precise focus with better imaging of the actors gives you a far better experience of your records..."...and then build a low noise linear power supply with good load regulation (and choke filter - CLC)... you'll never use another SMPS in your audio system again.
I KNEW there was a rabbit hole to be found on this subject. 
I haven't read all 10 pages of that post yet but the hypothesis is that the noise will even bleed back through the AC side to other stuff. Does that mean you need to eliminate all the SMPS power supplies in the house since they would all be adding noise to the power system?
And will all the LPS in the system filter this noise to their associated components?
@Extreme_Boky do you have a PS kit or design you would recommend for this application?
I haven't read all 10 pages of that post yet but the hypothesis is that the noise will even bleed back through the AC side to other stuff. Does that mean you need to eliminate all the SMPS power supplies in the house since they would all be adding noise to the power system?
And will all the LPS in the system filter this noise to their associated components?
@Extreme_Boky do you have a PS kit or design you would recommend for this application?
I do not have/sell the PS kit.
The post #43 provides a few hints... have a read:
https://www.diyaudio.com/community/threads/post-you-smps-noise-spectrum-measurements.394518/
The inductor (CLC) will remove all (very) HF rubbish, and a series regulator will provide low-impedance rail for the full required spectrum (suitable for analog and digital equipment... even for the sample rates into MHz, i.e 1.53MHz PCM with capable DACs). I used 2 high power series pass transistors for 6A constant current draw (burning around 10V there, so a large heatsink will be required), with another 4-5 transistors for the rock solid and reliable power supply start-up, great load regulation and very low noise almost independent of the current draw.
The above should be enough to get you started. There are similar designs available on the net that are not too bad.
The post #43 provides a few hints... have a read:
https://www.diyaudio.com/community/threads/post-you-smps-noise-spectrum-measurements.394518/
The inductor (CLC) will remove all (very) HF rubbish, and a series regulator will provide low-impedance rail for the full required spectrum (suitable for analog and digital equipment... even for the sample rates into MHz, i.e 1.53MHz PCM with capable DACs). I used 2 high power series pass transistors for 6A constant current draw (burning around 10V there, so a large heatsink will be required), with another 4-5 transistors for the rock solid and reliable power supply start-up, great load regulation and very low noise almost independent of the current draw.
The above should be enough to get you started. There are similar designs available on the net that are not too bad.
If you descend into a bunny hole, be sure to take some Mpingo disks with you.I KNEW there was a rabbit hole to be found on this subject.
I haven't read all 10 pages of that post yet but the hypothesis is that the noise will even bleed back through the AC side to other stuff. Does that mean you need to eliminate all the SMPS power supplies in the house since they would all be adding noise to the power system?
And will all the LPS in the system filter this noise to their associated components?
@Extreme_Boky do you have a PS kit or design you would recommend for this application?
The Meanwell bricks are quite robust. However, when consider the vast knowledge on this site there are definitely options. And don't forget that half the fun of DIY is building something and comparing it to what you might currently have.
The DIYaudio store has the Universal Power Supply (+/- 25V) and the Super Regulator (3.3 to 18V) so not quite what you're looking for. The VRDN would be a nice regulator for you but is 11V to 20V. I would think the part you might want would be the Salas SSLV1.3 Shunt Regulator. It can do 5V to 40V.
https://www.diyaudio.com/community/threads/salas-sslv1-3-ultrabib-shunt-regulator.322411/
You'll need the rest of the parts of course, so transformer, IEC, chassis, etc. I haven't read complete through that thread but it could be the right one for your project. There seem to be regular group buys for the boards as well.
Good luck!
The DIYaudio store has the Universal Power Supply (+/- 25V) and the Super Regulator (3.3 to 18V) so not quite what you're looking for. The VRDN would be a nice regulator for you but is 11V to 20V. I would think the part you might want would be the Salas SSLV1.3 Shunt Regulator. It can do 5V to 40V.
https://www.diyaudio.com/community/threads/salas-sslv1-3-ultrabib-shunt-regulator.322411/
You'll need the rest of the parts of course, so transformer, IEC, chassis, etc. I haven't read complete through that thread but it could be the right one for your project. There seem to be regular group buys for the boards as well.
Good luck!
Might it make sense to design a filter to isolate the noise, if it’s really a problem?
There is a highly regarded phono stage designed by an Analog Devices fellow using a Meanwell switching supply. A simple filter was added to it’s output and there was no sign of switching noise entering the phono stage. Using an IEC power entry filter was up to the discretion of the DIYers.
There is a highly regarded phono stage designed by an Analog Devices fellow using a Meanwell switching supply. A simple filter was added to it’s output and there was no sign of switching noise entering the phono stage. Using an IEC power entry filter was up to the discretion of the DIYers.
The understanding that I am gaining from this discussion is, since this is a power supply for only the motor, and not anything carrying a signal, that most, but not all the contributors feel there is really no need to go with a linear PS. I lean toward accepting that conclusion.
BUT, there are suggestions that a switching PS adds noise in the supply power that could infiltrate the signal path in other components. Something I never considered.
Accepting that hypothesis I have a ton of switching PS in my home. Phone chargers, wall warts, almost everything we plug in has a switching power supply either internally or externally. I certainly can't eliminate all of those.
Then I question the overall "grid" feeding my system power supplies. I have a dedicated 20amp circuit for my system from my main breaker panel. I'm considering making sure there are no switching supplies on that circuit. But yet, it ties in with all the others in my load center. So does that really matter? Won't noise feed through that panel? And even then, I have an A/V amplifier in the room that I use for surround for movies. I have DVD players, CD players, and other audio video components that are quite likely utilizing switching supplies.
So what to do if I accept the idea that the switching PS add noise though the AC system. I see no solution to eliminate that problem in a normal home unless you add a filter to each component, or at least to the signal carrying components that have linear power supplies.
What am I missing here?
BUT, there are suggestions that a switching PS adds noise in the supply power that could infiltrate the signal path in other components. Something I never considered.
Accepting that hypothesis I have a ton of switching PS in my home. Phone chargers, wall warts, almost everything we plug in has a switching power supply either internally or externally. I certainly can't eliminate all of those.
Then I question the overall "grid" feeding my system power supplies. I have a dedicated 20amp circuit for my system from my main breaker panel. I'm considering making sure there are no switching supplies on that circuit. But yet, it ties in with all the others in my load center. So does that really matter? Won't noise feed through that panel? And even then, I have an A/V amplifier in the room that I use for surround for movies. I have DVD players, CD players, and other audio video components that are quite likely utilizing switching supplies.
So what to do if I accept the idea that the switching PS add noise though the AC system. I see no solution to eliminate that problem in a normal home unless you add a filter to each component, or at least to the signal carrying components that have linear power supplies.
What am I missing here?
You’ve touched on an interesting topic - most of our electrical appliances and devices use switching supplies.
Most modern audio equipment also uses switching supplies and they seem to have some degree of immunity to perturbations and line noise (if there is any) from other switching devices.
For devices that are noisy or susceptible, would it not make more sense to filter that noise where it’s coming from and other devices where it may enter?
I guess it comes down to the cost basis, but also, have we measured and determined the noise actually exists and that is affects the output of the audio chain?
Most modern audio equipment also uses switching supplies and they seem to have some degree of immunity to perturbations and line noise (if there is any) from other switching devices.
For devices that are noisy or susceptible, would it not make more sense to filter that noise where it’s coming from and other devices where it may enter?
I guess it comes down to the cost basis, but also, have we measured and determined the noise actually exists and that is affects the output of the audio chain?
I have not determined that noise actually exists in the chain. I am the OP and was originally curious about benefits of adding a LPS vs a switcher to supply power to my turntable motor. A poster then offered the information about switching power supplies adding noise to the AC network and other components. So the reason to go to the LPS would be to lower the noise in my other components, not my turntable. That clear as mud?
Understand. My opinion is, if there really is noise injected by others things in my house there is no way to eliminate all SPS sources. I'm not sure I'm buying the theory to start with. But I have no way to confirm or refute it. But I may try to at least get anything with a SPS off my dedicated circuit just to make myself feel better. I'm sure I can convince myself it sounds better too. And perception is really all that counts. Right? 😁
Yeah, I haven’t seen a lot of empirical evidence.
Older audio designs with inadequate noise rejection could end up with other noises on their output if the line noise was high enough, so there is a use case, but I have yet to read of a ‘phile blaming their TV or laptop charger for the stereo sounding unusual. I suspect city power grids would be a higher source of noise.
A bit tangential, but a balanced line transformer should isolate the system from noise on the line. Antek makes several ready-to-go balanced line transformers up to 1000VA with a filter on the input. The bonus is reduced vibration and hum from transformers, if applicable.
If everything else in the audio system on it’s dedicated circuit uses linear and non-regulated power supplies, then a LPS on the turntable motor drive module may be fine.
There are several ways to go about it for sure.
Simple: better power supply = better sound, if your system (or your ears) have a high enough resolution to let you hear it.
Proof: quite a few people, including Linn (not an endorsement) make a living out of selling PS for turntables. I use the Zeus described in this very forum.
From a practical standpoint, I'd buy a "24v linear power supply audio" (search terms on Aliexpress). At USD 50-100 a piece shipped, the ready built items are probably cheaper than buying the parts. I've bought a couple of 5V versions to power my COSMOS stack, they're alright.
Proof: quite a few people, including Linn (not an endorsement) make a living out of selling PS for turntables. I use the Zeus described in this very forum.
From a practical standpoint, I'd buy a "24v linear power supply audio" (search terms on Aliexpress). At USD 50-100 a piece shipped, the ready built items are probably cheaper than buying the parts. I've bought a couple of 5V versions to power my COSMOS stack, they're alright.