The quality of DC from phone chargers varies greatly, according to someone on the Internet who tested a bunch. I try to stick with genuine name brand things from thrift stores and yard sales. For powering audio gear, I'd look for a wall wart or power brick that delivers a couple volts more than the desired final voltage, and use a 5V linear regulator. There used to be a 78H05, a 5 amp version of the classic 3-terminal regulator; I used one to power my Apple ][+ clone. Now the closest thing might be the LT1084CT-5, which is still available. If the DAC really draws several amps, you'll need a big heat sink; aim for enough heat sink that the regulator only gets comfortably hot.
Fanatical linear PSU builder here. It is indeed a very well audible difference when one uses a well designed linear PSU. SMPS are out of the question for me because of their pollution of the mains voltage reaching other devices. SMPS in original form (exceptions like the iFi confirm the rule) have way higher ripple and noise than even mediocre linear PSU's. This can easily be measured and is no myth. SMPS in the wall wart form also never seem to reach the longevity of a transformer. I repaired a lot of them and never allow them to be plugged in under voltage when I am not at home.
They are not worth the trouble but they are cheap and standard so many use them. Since they have become standard many assume they are the best in technology but they aren't certainly not for low power applications like under 50VA. There are solutions to polish the output voltage of SMPS here on diyaudio but it still is polishing a turd in many cases.
A good transformer with twice the VA rating, a metal casing connected to PE, a mains filter, an ultra low noise regulator, a handful of the parts combined with a careful design and some elbow sweat is all that is needed. The choice of a good silent transformer and also of a good LDO regulator is so many times discussed here that I won't repeat it but make sure it is a low noise type with sufficient power. With uLDO regs and LT4320 based rectifiers one can manage to have 5V output with a 6 or 7V transformer and thus have low heat/low loss.
All this is in the philosophy when one does something one better does it the best way possible. Therefor I wouldn't let a phone charger even come in the vicinity of my audio devices. Doing things cheap is a whole other and apparently popular area but doing things cheap twice or thrice makes that a more expensive affair. Quality has a price. If one sees building quality equipment as an art then it is very rewarding to build these PSU's. Ready made ones of excellent quality are even more expensive so DIY is a good choice in this area.
They are not worth the trouble but they are cheap and standard so many use them. Since they have become standard many assume they are the best in technology but they aren't certainly not for low power applications like under 50VA. There are solutions to polish the output voltage of SMPS here on diyaudio but it still is polishing a turd in many cases.
A good transformer with twice the VA rating, a metal casing connected to PE, a mains filter, an ultra low noise regulator, a handful of the parts combined with a careful design and some elbow sweat is all that is needed. The choice of a good silent transformer and also of a good LDO regulator is so many times discussed here that I won't repeat it but make sure it is a low noise type with sufficient power. With uLDO regs and LT4320 based rectifiers one can manage to have 5V output with a 6 or 7V transformer and thus have low heat/low loss.
All this is in the philosophy when one does something one better does it the best way possible. Therefor I wouldn't let a phone charger even come in the vicinity of my audio devices. Doing things cheap is a whole other and apparently popular area but doing things cheap twice or thrice makes that a more expensive affair. Quality has a price. If one sees building quality equipment as an art then it is very rewarding to build these PSU's. Ready made ones of excellent quality are even more expensive so DIY is a good choice in this area.
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SMPS is a cheap way to do it.
A transformer, bridge and caps is the expensive way.
An SMPS will be self contained too.
I use a +/- 15VDC 1 amp supply o na class A with no problems.
Its also over current protected.
A transformer, bridge and caps is the expensive way.
An SMPS will be self contained too.
I use a +/- 15VDC 1 amp supply o na class A with no problems.
Its also over current protected.
No problems is how it should be 🙂 Overcurrent protection is standard in regulators.
And cheap , well... the world is full of cheap stuff and so is the landfill. There was time that reaching the highest quality in audio was a goal itself. "A device is a good as its power supply"... I recycle older instruments in combination with high quality designs and they last. They alway find a second use when I build a new one. Till now all the SMPS I tested did not reach the level of the linear PSU's but I admit that the linear ones are way more expensive (by far) and I do this for decades and see a challenge in making them as good as possible. Since I have seen too many incidents with stuff that is always powered on with DIY there is a possibility to use real mains switches and stuff is really switched off.
Postive experiences with a JLH class A amplifier on 24V 5A SMPS per channel. No excess ripple like normally occurs with class A. For low power no SMPS for me. In audio (again, low power applications) they create quality problems for which their price doesn't make up.
And cheap , well... the world is full of cheap stuff and so is the landfill. There was time that reaching the highest quality in audio was a goal itself. "A device is a good as its power supply"... I recycle older instruments in combination with high quality designs and they last. They alway find a second use when I build a new one. Till now all the SMPS I tested did not reach the level of the linear PSU's but I admit that the linear ones are way more expensive (by far) and I do this for decades and see a challenge in making them as good as possible. Since I have seen too many incidents with stuff that is always powered on with DIY there is a possibility to use real mains switches and stuff is really switched off.
Postive experiences with a JLH class A amplifier on 24V 5A SMPS per channel. No excess ripple like normally occurs with class A. For low power no SMPS for me. In audio (again, low power applications) they create quality problems for which their price doesn't make up.
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