iFi iPower2 vs Allo Nirvana?

Audio Gear Everything else
21

Video vs Audio is not an equal comparison. If due to latency a frame (Video) is dropped, you’ll not notice, only when more frames are dropped. This behavior you don’t want with Audio.
The reason to upgrade the PSU for the DAC is to improve the analog output, not for the digital domain. There are checksums build for the digital communication between rPi and DAC. If the checksum fails, the digital data will be resend. As long as the buffer is filled, you’ll not notice this.
Until you get to the point that he buffer is empty and the checksum fails again. Them the audio will start stuttering as there is no data to be played and the DAC is waiting for Audio data.

Stating that the details are being reduced, is simply not correct.

22

Ah, thank you very much, you explained it well.
You never stop learning!

23

Hello Wheaten
I understood about the data flow between the computer and the DAC, the connection seems to be solid.
One more question for my understanding. You may be able to assure me of this:

  • Are errors in the DAC chip itself not possible, e.g. due to noise in the power supply?

  • Or is it not also possible that the clock (44.1 & 48 Khz) does not work optimally precisely if the power supply contains noise?

1 Like
24

Things that can occur, is related to timing. Hence the expensive clocks you can buy. Due to jitter or really bad clock in the DAC a bit pattern, can be read differently. As it is all about high and low level voltages. Even a weird spike in the line voltage can be interpreted as a high instead of low. If this happens at the lsb (most right bits), you might not even notice, however on the most left side you do.
It is possible a bit pattern is interpreted different.

Just a simple example with RGB colors, to make it visible (very basic example to demonstrate)
starting with 127,100, 231 (01111111, 01100100, 11100111)
image

Changing the most right bits, like 127,100,232, (01111111, 01100100, 11101000) wont reveal much difference is color
image

Or even 2 bits, 127, 100, 233 (01111111, 01100100, 11101001)
image

You can even change the bits in every color group and you will not notice:
128, 101, 232 (10000000, 01100101, 11101000)
image

The same on the left: 127, 100, 131. (01111111, 01100100, 10000011) This you will notice
image

Please have a look at: Understanding Jitter in Digital Audio: Measurements and Listening Tests | Audio Science Review (ASR) Forum Movie in the first topic. I think Amirm did a pretty good job explaining this.

25

I got the nirvana, haven’t used it yet. I normally plug everything into a Furman power conditioner/surge protector thing.

Should the nirvana be plugged into that, or better straight into the ‘wall’? Or doesn’t matter…

26

There’s a reason why many Dac’s and amps come with or offer outboard power supplyies. Burson is one.

27

Yes it will sound better - it’s not just the USB that creates noisy power.

1 Like