Looking for the smallest linear power supply ?

For one of my projects, I have just little space to built my components in.
As I have to power an Up2Stream Mini v3, I need a 5 Volt, 1 Amp AC-to-DC power supply.

I have tried several AC/DC 230 to 5v converters. All af them were switching power supplies. But in audio applications, they all cause ripple noise.

Therefor I want to try a linear power supply, but it has to be very small. Preferably close to the size of a USB power wall plug, like the iPhone power supply, or the one delivered with the Arylic S10. Example see picture.

Anyone who knows where to find that?

I think iPower X and iPower 2 from iFi is the smallest Linear PSU’s of the market.

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Ernst @KolfMAKER

Welcome to the murky world of power conditioning and power supplies :roll_eyes:

It’s a difficult market to fathom cost vs quality vs actual improvement. I know some HiFi enthusiasts who spend serious amount of money on power conditioning e.g. for the extreme:-

https://www.psaudio.com/products/directstream-power-plant-20/

However should we spend more money on a Power Supply than the Hardware we are buying ? :slight_smile:

I certainly don’t have any better suggestions than @Pepelitsa which I am sure are good ones. There are other factors involved too like The Mains Supply, House Wiring, Line Interference from your equipment, your neighbours equipment, wireless signals etc. etc.

Maybe buy something that suits your price range and return it to Amazon/eBay if it doesn’t do the job :slight_smile:

As we say in English you have “opened a can of worms” :joy:

Regards, Kevin

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@Pepelitsa - Thanks Samaras. I didn’t know these PSU’s yet. So I will definitely have a look into them.

@NWT.Stuff - You are right Kevin, like in your saying “you open a can of worms”. It can be very difficult to get everything right. Nevertheless, from my projects I have learned that shielding is important. Since I have changed the cables I use, I got rid of a lot of issues.

Actually the only issue I have left, is a ripple. I am almost sure that this is caused by the ripple in the power supply I use for the Up2Stream Mini v3 (as a result from a lot of testing). As said, this is currently the iPhone USB charger (see picture in this thread), because from all of this kind of plugs, the iPhone one causes the least ripple.

Though, there is still some ripple and it is too much. Therefor I am looking at:

  • Exchange the PSU to a linear one, but also very small.
  • Test some kind of shielding

Still open to any ideas.

Hi,I don’t know how ripple sounds are, but from my experience with linkplay a31 boards i have like pulsation sound made from wifi and Bluetooth wire antenna,if i move the wire in diferent direction noise disappear.

@Viktor1212 - Thanks Victor!
I think your description is quite clear. Ripple is a kind of pulsation, or as a I call it a repeating sound.
I have recorded the sound. If you let me know your email, I will send you the recording.

I find it interesting what you say about moving the wire in a different direction, and that the ripple/pulsation disappears.

Questions

  • In this case, I guess you mean that you move the wire of the Arylic WiFi antenna?
  • So you more or less turn the wire while it is connected to the Arylic PCB?
  • Did you find that a certain direction of the antenna, works best in most cases to prevent ripple/pulsation?

Exactly,just rotate the wire that is connect to player with you hand and you will heard that that pulsation sound will increase in some position and will be quieter in diferent position,in some position will be death quiet. My mail is viktor1212us@gmail.com but i don’t know if you can send me file bigger than 25mb.

Also you can try with different usb cable if you try couple of power supply with same cable,some usb cable are with just two wire inside 5v and ground and some is with 4 wire for data,if you have some cable in hand you can try it.

@Viktor1212 I understand the different USB cables but in your experience are you saying it is better to have 2 wire cable, 5VDC Power Only ?

After all USB is a connector designed to allow 2 wire serial communication. It seems that for example the MINI Board has an option to power 5V on screw terminals. I am thinking maybe if we separate the philosophy of a connector with 5VDC Power and Serial Comms and Terminals for Device Power then maybe the 5VDC to terminals could produce better results :thinking:

Ernst,

I think I read somewhere else of the forum that you have 6 MINIS providing 3 Stereo Outputs ?

There are quite a few people on the forum that have posted a “central control unit” with multiple Amplifiers. Some of the design and wiring is amazing and exceptionally well done.

I am just thinking aloud to provoke discussion, but let’s say I am willing to spend 25% of the Arylic Hardware on on a Power Supply. If I have a MINI that means $15 for power supply. However if I have 6 MINIS and I distribute the 5VDC my budget is now $90.

So my unconventional thinking is better performance will be achieved by distributing a good clean DC Voltage around the the house (be it 24VDC, 12VDC, 5VDC). Of course there is a huge consideration of the distribution of cables in a house an whether this would affect the living space in a negative way.

However it seems pointless to have so many AC/DC convertors plugged into wall sockets and it can’t be efficient :thinking:

Food for thought, Kevin :slight_smile:

@Pepelitsa thanks for the suggestion. It seems that the products you suggested have amazing quoted Noise Levels and also great reviews. Do you have personal experience with them ?

Regards, Kevin

@NWT.Stuff - Hi Kevin, my answer is yet, but …

Yes, I do have 6 Mini’s providing 3 stereo outputs, but actually these are:

  • 3x 2 speakers with built-in amplifiers, in which I have added the Mini.
  • These stereo sets (so 3 sets) are each in a different place/house. I have 3 ‘customers’, and to each of them I delivered a stereo set.

Concerning the linear power supply: I need a mall one for reasons of limited space to built-in. And I prefer linear, because a switching one will always be a source of (potential) trouble)

I my other thread (https://bit.ly/3ahZvvN) about the volume control issues that I have with Mini + FW 4.6.328252.28) I used this situation description to show that I have the volume control issue with three different sets, in three different locations.

I do understand your ‘provoking discussion’ ( :slightly_smiling_face:), but in my case the speaker is a HiFi speaker, so all components have to be a certain level, also the PSU.

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Ernst,

I guess something like this could be a solution for you https://www.ebay.co.uk/itm/121962363423

Regards, Kevin

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@NWT.Stuff - Thnx Kevin, so happy with your suggestions.

Your suggestion could definitely be something. I also like that it is a PCB-PSU, instead of a power plug or so.

The unfortunate thing however, is that the size is too big to get it built into the space I have.
I do realise that linear PSU have more volume than switching PSU’s. But if I can find smaller, it would be better for my project.

Ernst,

OK I am guessing that the “Stereo Sets” are Powered/Active Speakers ?

What Make & Model ?

Do they have some some DC available to “hook into” ? e.g. if 12VDC is available in the speakers you could step this down to 5VDC with a simple Voltage Divider arrangement :thinking:

Regards, Kevin

Exactly Kevin, this is also what I am thinking about.

I would then need a good ‘audio-grade’ DC to DC converter.
I will have to look into the schematics of the speakers amp, to see where I can pick up a good voltage.

Will let you know later.

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Ernst,

Two audio grade resistors should do the trick :wink:

After all it’s a DC Voltage and a Load :thinking:

Seriously, Will be interested if you can find the right place to tap in, what you choose to do, and of course the “end” result :slight_smile:

Good Luck, Kevin

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@NWT.Stuff - Thanks Kevin!

Audio grade resistors - Please help me a bit Kevin (I have no electronics back ground, learning by the day/doing). Which audio grade (incl. value) resistors would I need? And how/where should I place them?

DC-to-DC converter: I found a DC-to-DC converter for audio applications. It is based on the Texas Instruments TPS7A4701 / TPS7A3301 for Ultra-Low Ripple: https://bit.ly/3Dnatg4
If I am right, I only need to find a DC source on my active speaker of between 3v and 36v. And with the board I should be able to adjust it to 5v. What do you think about this?

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Ernst,

Sorry for my very bad English Jokes but “Audio Grade Resistors” was just that a very poor joke :joy:

However a simple DC Voltage Divider might work :thinking:
voltage-divider-main-circuit

I think a TI chip would probably be better :slight_smile:

I’ll have a look at the convertor and see if you can find a suitable place to tap in. I am happy to look at the schematics if you want to send me them. I also have a friend whose job is repairing hifi so I can also consult him.

Kind Regards, Kevin

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No problem @NWT.Stuff, keep making jokes! :wink:

Concerning the DC-to-DC module I mentioned …
I am looking into tapping power from the amplifier in my active speaker. I am not sure what point is best to choose and with what voltage I can work as input.
May I ask you to have a look with me at the schematics? Probably with your experience you have an advise which point and voltage to use. If you are willing, let me know your email address. Then I will send the schematics.

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