Do you need a toroidal transformer for power supply?

I’ve seen most projects with a toroidal transformer in them, is this necessary?

I bought a 5v 5a power supply that you attach your wires to, will this suffice?


In general a Regulated Linear Power Supply, has less distortion than a switched power supply.

  • A switched power supply is smaller and automatically detects the line voltage, it can be connected to both 110V or 220V, without turning any switch. However this can generate high frequency spikes, which can influence the sound. There are some vendors who did reduce this noise like the iFi iPower2.

Basically if your PSU sounds OK too your findings, there is no need to change it.

Thank you for your response.

Not sure why battery packs are being pulled into this conservation, but IMO, these battery packs will not improve audio, as there are electronic circuits in place to come to the output voltage. As the measurements are pretty identical.

This topic is regarding toroidal (LPS) vs stock PSU.

It all depends on your equipment. If you connect your Volumio system to a low end amp, it is not going to matter a lot.
If you can’t hear the difference between mp3, flac or SACD, dsf, don’t worry about your power supply.
If you don’t worry about sound stage, instrument separation, 3D representation, … take the cheapest solution.

If you have high end and equipment, you will hear the difference between a regulated power and a switched power supply. Adding super capacitors in the equation, medical grade toroidal transformer and medical grade power inlet, adds even more to the listening experience. Batteries are phased out in favor of the supercaps.

It all depends on what music means to you. Is it just background, or do you listen eyes closed focused on only the music. And to what you are willing to pay for your equipment.

from 19’07" where Gabster measures the noise coming from these switched power supplies.

Worthwhile watching is his video of the World’s second Best DIY Dac and Streamer Detailed Build

My Volumio system is built with the sigma 11 power supply (, medical grade toroidal transformer and power inlet, Raspberry PI 4 and DAC (AUDIOPHONICS DAC I-Sabre ES9038Q2M Raspberry Pi / I2S & SPDIF / PCM DSD USB-C Power Supply - Audiophonics ).
GATO Audio AMP 150 and GR-Research X-MTM speakers.
The first time I listened to it, Pink Floyd, Great Gig in the Sky, I was very emotional. Never heard the music coming to life that way. Except for a real concert.

The next build is planned completely based on Ian Canada’s components like Gabsters DAC.
Why, because my Lotoo PAW 6000 with the ZMF Verité Closed LTD edition sounds better that my current setup.
This thread has been my guide:

I am using an add on DAC (HAT) a “HiFiBerry DAC Plus” to my Raspberry Pi setup, it has a link you can remove to enable a separate DC power feed to the DAC, rather than getting it’s power from the Pi’s header.
Doing so, from a 7805 linear reg gave a great improvement.
The background digital crud (common mode noise?) dropped quite a bit, however the music improvement seemed way above that noise drop.
I’ll have to re-visit it and see if changing the 'Pi from a mini-USB power feed to being fed from the header side will help - as in make the header end the power earth reference point rather that the USB power in socket the reference point. (Kind of the default)

There are two main types of power supply used for audio equipment.
Switched mode supplies, which are common consumer items, and rectified transformer based power supplies (ideally using a toroidal transformer) which were once the only viable option but which are now mostly used for customised systems.

Because they work differently, there are arguments to be had over which is better or worse in a particular application.

However, when taking the differences into account it’s useful to remember that most devices work fine with both types of supply (an electron is an electron) and many devices are designed specifically to work with switched mode. Many devices, where necessary, also contain power conditioning circuits to clean up noisy supplies and modern amplifiers also contain large capacitors to ensure that a cheaper switched mode supply is functionally indistinguishable from a posh rectified toroidal transformer supply.

So it is certainly a brag to have everything powered by a custom toroid, but it is not at all ‘necessary’, which was your question. The difference is indistinguishable, probably unmeasurable in most systems. And the killer feature of switched mode supplies is that they are widely available, relatively cheap and you don’t have to worry about power design considerations because all modern switched mode supplies will just shut themselves down for a bit if they experience any weirdness.

Provided that your desired voltage doesn’t droop and your current needs are met (5V 5A is more than enough for a RPI4 + DAC), I would go for switched mode every time if I’m paying the bills. Much better to concentrate on removing noisy ground loops where possible than getting into the arcana of power supply designs.

spot on, one remark though.

Normally Hifi devices, using a switch power supply, have a well designed power circuit, to filter out all rubbish. This is not the case for the rPi. So it is possible that the rPi is much more sensitive to this.

Yes, the Pi4 is very noisy, two things to say about that wrt music quality.

  1. Use digital transport out of the Pi, not analogue if it can be avoided.
  2. ideally break the ground loop between Pi and DAC. If you connect via USB, use a USB isolator (¬10-20 USD) between, many DACs take care of this for you but most dongle DACs need isolation.
  3. (3rd of 2) If you’re really serious about noise transmission, use balanced (3 wire rather than 2) transport to the amp.

I join this interesting discussion by reporting my experiences and above all the test solutions that I am comparing before arriving at my “Definitive Streamer”.

The concept I intend to adopt is a single well engineered and compartmentalized case where inside, in the open air, there is space for the PI4/mini pc/NUC, an internal 1TB SSD storage, a low noise linear toroidal power supply, a touch display, a quality DAC like my smsl DO300.
Individually or in pairs I have already tested some solutions and the results speak for themselves.

At the moment I have come to the conclusion that the best solution is to develop everything around a mini pc. The PI 4B has obvious digital audio management problems, to make it suitable you need to invest as much as a good external DAC of a completely different price range. The PI4B’s standard power supply is really a disgrace and is completely underpowered if you want to add a display and internal memory. Furthermore, while acknowledging many merits to the Raspberry System, I must admit that an X86 system remains much more versatile with rapidly updated HW-SW solutions.
I have two audio grade linear power supplies; one 12V 120W and the other 5v 52W. Both the mini pc (12V) and the PI4 (5V) record an appreciable improvement in my audio chain, which has been amplified with the introduction of the DAC s.m.s.l. DO300 (balanced outputs)

I also tried lithium battery packs and power banks, which I find just a complication without any appreciable benefit in terms of appreciable audio quality, not only at an instrumental level.

The main problem, in my opinion, in my project remains the heat to be disposed of in fanless systems, which while continuing to operate, their performance level is reduced due to the automatic reduction of the CPU clock frequency. Furthermore, the wifi/BT modules are the first that tend to suffer real blocks due to the increase in heat. Another problem remains the return current of the Touch, through the USB connection which is at 5V, while the mini PC works at 12V.
A hi-fi format factor case/cabinet is a critical point in my design. In fact I will be including the DAC in the streamer cabinet, I can’t stand a “box” lying around like the DAC!
The quality DAC, plugged into the USB port, already has a treatment/filter on that port. My DAC sounds better on the USB port than the Optical one, small but perceptible differences.

In the next few days I will test a Noctua 200mm 12v fan whose speed I will try to reduce below the minimum value of 350rpm. The noise from the LNA for this fan is only 10dB, but what is of concern is the electrical hum from the electrical contacts of the motor rotor brushes.

The truth that many hide is that as our streamers grow in configuration, performance already decreases with just the increase in file storage, and can only be compensated for with more performing CPUs that unfortunately require active cooling. There are also extreme solutions in dielectric oil bath.

What are your opinions and suggests?