Well, I think that at least SONY Walkman owners in this thread who are at least a bit capable of logical thinking should be able to derive from the posts by
@Sonywalkmanuser the logical chain of causes and consequences that leads to the clear conclusion - the more the walkman is optimised for music reproduction only (i.e. cutting all unnecessary apps off), the less the SoC is utilised. Then the less energy is consumed, the less noise is there.
I cannot exclude the rare chance that there are some SONY Walkman users who do not get it anyway. Well, nobody can understand everything.
In such a case I must only wonder what it needs for such a person to persist on his opinion stubbornly despite the official statements by SONY engineers who have had a lot in common with Walkman development. Does such a person think that he has better know-how than SONY in this respect?
@Sonywalkmanuser : You should not better feed the trolls anymore.
If you read through what has been said by Sony engineers with regards to development of better sound quality, they would often mention having a clean power supply and addressing and preventing noises/interference that affects the audio circuitry. It is not just Sony alone, these points of having clean power, reducing noises/interference has also been mentioned by other DAP and audio equipment manufacturers as well.
https://www.sony.com.sg/electronics/dmp-z1-interview
The D.A. hybrid amplifier built in to the TA-ZH1ES headphone amplifier achieves a high output, producing a high-quality sound even from high-impedance headphones. However, it relies on a large (AC) mains power supply.
The drawback of this is that mains power often carries considerable noise. There are also many different factors
you need to pay attention to if you want to provide the best audio, such as the quality of the USB cable you use to connect; or when the PC is being used as the audio source, its power supply, the playback app it uses and its USB port.
However,
our flagship Walkman® NW-WM1Z runs on clean battery power, meaning the audio quality is very high.
With this Walkman®, all the components in everything from the playback device to the amplifier are internal and there are absolutely no external elements that will be affected by the power source. As long as it's charged up, you can take it anywhere and enjoy the high audio quality that we've strived to provide. However, the device is limited by its size and can't ensure the large output required for high-impedance headphones.
So, we thought that if we could take a stationary device like the TA-ZH1ES and make it run on clean battery power with no external elements, like the Walkman®, we could create a product that would allow our customers to easily get the full potential out of their headphones.
How does the built-in battery lead to higher audio quality?
Hiroaki Sato, Sound Quality Designer:
When you get right down to it, the power source is at the root of the sound played back by an audio device. If the power source is impure, you won't get a beautiful sound, no matter how good the audio circuits are. Like if you don't have clean water, you can't make delicious tea.
Sony Video & Sound Products Inc.
V&S Business Division DMP-Z1 Leader for Sound Quality Design
Hiroaki Sato
Tanaka:
In the world of pure audio, there are people who install electrical outlets specially designed for audio, buy large power units and even go so far as to install their own electricity poles in order to cut noise from the power supply. But if you just use battery power (a DC power source) then there's no need for all this effort and investment, and you can
eliminate any concerns related to the power supply. Unlike a speaker amp, which requires a large output of tens of watts to drive a speaker, the DMP-Z1 is a device made for headphones, so it can provide high audio quality through battery power. It doesn't need a huge power supply block to convert variable-quality AC into clean DC power. The
equipped batteries are separated into three independent blocks, preventing any drop in audio quality caused by interference or conversion circuits.
Hiro (S):
We've designed new power circuits with totally unique specifications. When the amplifier is in operation, there's a high current due to positive- and negative-output batteries with large-capacity that are connected in series.
It was hard to achieve this without using a DC/DC converter, which brings with it the possibility of slight noise from the negative power source. In particular, the battery designers went to great pains to create a design that uses transistors to cut off from the negative battery and switch to charging when necessary.
Don't those problems occur when the device is running on battery power?
Matsuzaki:
No, they don't. The power circuit structure for running on battery power at normal gain is very simple, so there's nothing in the power supply that can become a source of noise. However, in high-gain mode, which is used with high-impedance headphones, the voltage is increased.
This means that even when the device is in battery power mode and isn't being powered by the AC adaptor, the power supply can still be a source of noise to a lesser extent. But to counter that we use high-grade switching controllers—the kind that are used in measuring instruments—so that the effects are minimal.