Difference between a streamer and a dac?

A streamer is a DAC that connects to your network via ethernet and/or wireless, and receives music data over the network using network protocols for data transfer.

A straight DAC usually just has s/pdif inputs and connects to things with s/pdif outputs; cd players/transports, dvd players, mixing desks, set top boxes.

It is perfectly possible to have a DAC with both network-streaming and s/pdif inputs - the Linn Majik DS-I is such a thing, the Logitech Transporter and Perfectwave DAC others.

And don't forget the Naim Uniti.

Many people belive that a streamer is superior because ethernet gurantees the integrity of the digital music signal, while an s/pdif connection is subject to more uncertainty. In practice it is possible to acheive great sound either way.

From a user standpoint, the stremer also acts more like a cd player, you can usually control playback from the face of the streamer, while a DAC only a passive receiver of the signal received from another player, whether it is a software player on a computer og a disc spinner.

Some streamers have no front panel controls at all - the Linn DS range, Logitech Squeezebox Duet. They are controlled from other things on the network - laptop or pc or PDA or wireless remote or iPhone - whatever is convenient.

Another streamer: a clean power iPhone

An iPhone can be directly connected to the Naim DAC.
An iPhone with the PlugPlayer software can stream music from UPnP/DLNA media servers to the Naim DAC.

UPnP media server with WAV files >> Wi-Fi >> iPhone as UPnP media renderer / player using PlugPlayer software >> bit-perfect audio streams >> Naim DAC

The battery-powered iPhone should offer less jitter and cleaner sound.

"With PlugPlayer, you can use your iPhone to remotely control another copy of PlugPlayer."
http://www.plugplayer.com/

Power supply of the server really shouldn't matter when streaming, the protocol is insensitive to such small disturbances. One proof for that assertion is that we are sitting here enjoying the internet in bit perfect glory. Random flipping of bits simly doesn't happen, because it's caught by the built in error correction.

The same technology drives audio streamers.

quote:

Originally posted by Bach_Man:
Power supply of the server really shouldn't matter when streaming, the protocol is insensitive to such small disturbances. One proof for that assertion is that we are sitting here enjoying the internet in bit perfect glory. Random flipping of bits simly doesn't happen, because it's caught by the built in error correction.

The same technology drives audio streamers.

As always: Listen and hear the difference, it really exists. So do the difference between CAT 6 cables.

/Erik

quote:

Originally posted by Bach_Man:
Power supply of the server really shouldn't matter when streaming, the protocol is insensitive to such small disturbances. One proof for that assertion is that we are sitting here enjoying the internet in bit perfect glory. Random flipping of bits simly doesn't happen, because it's caught by the built in error correction.

The same technology drives audio streamers.

The media server is isolated by a Wi-Fi network from the media client, iPhone as media player + Naim DAC.
Thus usually there is no impact of the power supply of the server. Nevertheless the power noise from a cheap switch-mode power supply of the server can feedback into the AC means and affects the power supply of the Naim DAC.

Also there is no jitter impacted by a media server, because there is no timing information of the audio stream before the WAV file playback time.

The iPhone as a UPnP media player usually receives error-free WAV files, but the resulting PCM audio streams should have error free data information, and more or less drift timing information (i.e. jitter).

A dirt power supply of a media player can affect the clocks, and the power noise can affect the analog part of the DAC.

The battery-powered iPhone should offer less jitter and cleaner sound.

Jitter is simply not a construct that can be applied to data transferred via ethernet protocols. It is a measurement of the stability of a timing signal embedded in an s/pdif data stream. It just does not apply to ethernet, any more than wow and flutter does. This is one reason reason that streamers like the Linn DS have advantages.

Thank you for your responses.

Hans

quote:

Originally posted by Bach_Man:

Random flipping of bits simly doesn't happen,

Except this one time where the internet left out a "p".

quote:

Originally posted by winkyincanada:

quote:

Originally posted by Bach_Man:

Random flipping of bits simly doesn't happen,

Except this one time where the internet left out a "p".

Luckily there is sufficient redundancy in written English for you to know what the mistake was, and correct it, just as there is sufficient redundancy in an ethernet packet or cd block for nearly all errors to be detected and corrected

quote:

Originally posted by Erik:
As always: Listen and hear the difference, it really exists. So do the difference between CAT 6 cables.

/Erik

It's a funny thing: My ears are usually deaf to all those differences that people claim in non blind tests (aka listen with your wallet). I can hear the difference between 5-series and reference, and beetween different loudspeakers. But between ethernet cables? Nope.

quote:

Originally posted by Bach_Man:
Power supply of the server really shouldn't matter when streaming, the protocol is insensitive to such small disturbances. One proof for that assertion is that we are sitting here enjoying the internet in bit perfect glory. Random flipping of bits simly doesn't happen, because it's caught by the built in error correction.

The same technology drives audio streamers.

Your analogy is not "bit perfect" The requirements for text and audio are not the same. Audio is very time sensitive where data such as text is not.

Bob

[QUOTE]Originally posted by DanBa:

Thus usually there is no impact of the power supply of the server.

There is always an impact, which is why Naim are so fixated with power supplies and grounding.

Bob

quote:

Originally posted by BobF:
Your analogy is not "bit perfect" The requirements for text and audio are not the same. Audio is very time sensitive where data such as text is not.

Bob

No, you get it completely wrong. The music is just a collection of sequential data. The ethernet connection doesn't handle any timing information, just as a cd doesn't. In fact timing is wildly inaccurate, but it doesn't matter because the clock is provided by the player. Everything is buffered and clocked once the streamer receives the data. The analogy is about the actual data being received exactly as it was read from source.

quote:

There is always an impact, which is why Naim are so fixated with power supplies and grounding.

Bob

This is apples and oranges. Anything that is in contact with the analog or PCM, yes. But TCP/IP is far more robust. You can readily access a server in a closet on the other side of the world and read bit perfect data. That's how good it is.

If network cabling and mains-leads and so forth affect sound quality of digital music data then the NAIM download store is a waste of time. Think of the computers, servers, microwave links, fibre-optic cables, telephone exchanges, hubs and network technology that the download goes through - without a single Powerline in sight. If these things corrupt the music, then it will be utterly destroyed by the time it gets to your pc. If, on the other hand, completely uncorrupted data gets to your pc through all that unimaginable network complexity, how is it not possible to transmit it over another few feet of ethernet cable to a DAC without messing it up?

I hear Naim has a powerline and 555PS on their server to ensure that downloads have the proper PRaT.

That's good to know Bach_Man. I haven't yet replaced the telephone cable coming into my property, or got my local telephone exchange running off a dedicated spur, so the benefit is possibly lost by the time a download gets to me.

This is interesting discussion. I am also wondering how can a streamer or transport add audio value. On paper it seems all streamers and transports should sound same. But I also read that people have heard considerable difference between different products. So, I plan to listern for myself.

ASenna04