 Should I replace the external power supply of my audio device for an audiophile model and in so which one? Most audio devices have their power supply built in, but there are devices that use wall wart or power brick power supply. The reason for this is simple. Power supplies have to comply to local regulations and in general that means being locally or regionally certified. Before the European Union became effective, a power supply had to be certified for each and every country in Europe. Those days are gone luckily, now only one certificate for the whole of Europe survives. But that leaves many other countries or regions that need certification, which is a lot of work. So if the manufacturer of an audio device packs an already certified universal power supply with his product, he doesn't need further certification. This product is seen as a low DC voltage device that doesn't need certification and the power supply is certified. As with everything in tech, the quality of the power supplies vary as do their prices. Surprisingly, the cheaper ones in general are lower in quality while the expensive ones are the best. At least when used for audio. There are two types of power supplies commonly used for audio, linear power supplies and switch mode power supplies. Linear power supplies use a transformer to convert a 115 or 230 volts DC grid voltage to a lower voltage. Such transformer has two coils close to each other that differ in number of windings. If for instance the grid voltage is 115 volts AC and 11.5 volts AC is needed on the secondary side there is a 10 to 1 ratio in windings. That AC current needs to be converted to clean direct current, DC for short, by a rectifier and capacitors. A voltage regulator then makes sure the specified DC voltage is maintained. Linear power supplies are made for a given grid voltage or can be set to the local grid voltage by a voltage selector. Switch mode power supplies work very differently. The incoming AC is first converted to DC by a rectifier, followed up by a filter and sent to a small transformer. A transistor switches on and off at a very high frequency, normally a few hundred kilohertz, as told by an integrated circuit. On the secondary side of the small transformer there are some components like a diode and a capacitor in simple designs. The transformer can be that small since there never are large currents flowing through. The voltage is already switched off before a large current starts to flow because of the high switching frequency. It might be clear that this is not a very clean DC and will influence the electronics it powers. The good switch mode power supplies therefore do serious filtering of the output voltage. There are also other measures that get the noise low and the voltage stable. Switch mode power supplies normally lose about 5% of the energy put in, while linear power supplies will lose in general around 35% of the energy in the conversion. Switch mode power supplies can work over a large range of grid voltages so you never have to worry about that. Many linear power supplies only work on one grid voltage, for instance 230 or 115 volts. Some can be switched between these voltages while I have seen automatically switching linear power supplies for the first time in Denafrips DAX. In general, good switch mode power supplies are less expensive than good linear power supplies. But top-of-the-line switch mode power supplies might cost about the same as top-of-the-line linear power supplies. It's my experience that quality switch mode power supplies lead to better sound quality on all digital equipment, like switches and network bridges, since they are capable of delivering current faster than linear power supplies. A good example of a high quality switch mode power supply is the SOTM SPS500. The i5i power is an affordable alternative. Only when using a linear power supply that is capable of delivering loads of currents as fast as switch mode power supplies, the sound quality might be equally good. A good example is a Syntax power supply. Analog audio equipment usually sounds better when using quality linear power supplies. In general, I use the SBooster power supplies and for devices that have a modest power consumption I also use the Optone Audio LPS 1.2 that uses supercapacitors. Supercapacitors are somewhere in between electrolytic capacitors and batteries. They have larger capacity than capacitors, they can handle charge and discharge much faster than batteries. That makes them fit for digital devices. But supercapacitor-based power supplies are linear power supplies. They are also very well suited for analog devices like streamers, DACs, preamps and the like. The Optone Audio LPS 1.2 I use is capable of delivering 1.1 amps. The supercapacitors are charged by a medical grade switch mode power supply. Still it can be considered a linear power supply since the supercapacitors and not a switch mode power supply power the connected audio device. Some believe batteries to be a good alternative. They are cheap, do only direct current and thus cannot generate nasty frequencies. Well, there are batteries and batteries and some are more equal than others but even the better ones have relatively high internal impedance and thus are slow in delivering current. Furthermore the chemical process causes noise so they are not the most silent power supplies either. But then again, if your budget only allows for a cheap switch mode power supply and you have the batteries lying around, you better use the batteries until you can buy an audio grade power supply. As with all equipment, the quality of the components used in power supplies have a great effect on the quality of the DC power it outputs. Ghido Tent of Grim Audio gave a presentation at a local AES meeting over a year ago demonstrating that the same type of voltage regulator from different makes produce different noise levels. So the quality of a power supply is impossible to judge from the components used. You can only judge the finished product from a source that guarantees a constant quality. It is important to realize that all audio devices are in fact devices that modulate the input power so when you feed an audio device with a dirty power, you get a dirty audio. Like a beer tap can only provide the beer that is in the keg. Which brings us to the end of this video. It is one of the Q&A videos I have made over time. Go to the Q&A playlist for answers and more questions. I also post new videos every Friday at 5pm central European time. If you don't want to miss that, subscribe to this channel or follow me on the social media so you will be informed when new videos are out. You can help me reach even more people by clicking the thumbs up icon and mentioning my work on the social media. Many thanks to those viewers that support this channel financially. It keeps me independent and thus trustworthy. If that makes you feel like supporting my work too, the links are in the comments below this video on YouTube. I am Hans Beekhuyzen, thank you for watching and see you in the next show or on theHBproject.com. And whatever you do, enjoy the music.