Chord bluetooth - puzzled after Bristol show

[AlmaataKZ]

Just back from the show. (Fantstic show by the way, lots of impressions and useful conversations with the people with first hand knowledge of the products).

One thing puzzled me. A chap at Chord room talking about their dacs with bluetooth receivers insisted that i can stream lossless audio from ipod touch via bluetooth to chordette gem and it will get bit-perfect uncompressed stream. Alternatively, according to him, i could plug in an inexpensive senheiser bluetooth dongle into ipod classic and get a bit-perfect uncompresses stream on the bluetooth input of a Chord dac. I argued that afaik bluetooth compresses but he was adamant - lossless and bit perfect. Really?

I have a Gem and bluetooth input sounds significantly worse compared to usb in, although i have not tried lossless over bluetooth because i thought there was no point.

what do you make of this?

 

[Craig M.]

having just done a quick google, it would seem that audio can be sent losslessly via a2dp bluetooth. i'll check later to see if i can hear a difference between optical and bluetooth, i'll also check if it will stream 24/96 over bluetooth.

 

[AlmaataKZ]

Woould appreciate, CraigM.

 

[Anonymous]

I too saw the Chord dacs - the point of the Chord dacs is that data is sent in whatever native format it can regardless of connection method. ie a Apple TV optical out has a limit of 16bit 96khz, but the Chord DAC will use this limit to transfer at this "bandwidth" until it makes up 24 bit 196khz if that was the original source.

lossless or not - it gets data in its original format- thats what's great about it

 

[AlmaataKZ]

woollyjoe, I don't understand you post. ok. let's say original format is apple lossless file on ipod touch. according to the guy form Chord I can stream it via ipod touch's 2nd gen built-in bluetooth to chordette gem and the gem will get apple lossless. I was not sure about it and he would not explain but he insited it was true. I was sure from reading various sources that bluetooth compresses stereo audio with losses for transmission.

 

[Alec]

"...he would not explain"...?

 

[Anonymous]

I think these DACs take advantage of the Apt-X codec (http://www.aptx.com/Home.aspx) over an AD2P bluetooth connection. As mentioned Sennheiser have started using this technology in their latest Bluetooth headsets like the Sennheiser PX210BT

 

[AlmaataKZ]

he would not. I asked the question in two or three diferent ways looking for any details of "how", a comparison of how it works in the gem and in more expensive dacs, but all I heard in reply was along the lines of "yes it will work". I was not expecting him to disclose any trade secretes etc but some sensible words could point me in the right direction, maybe furhter reading, but no. So, this left me a bit puzzled (se post title).

 

[Anonymous]

The limit of the transfer method is irrelevant for a Chord DAC.

Think of the data being sent as data, rather than music data. Or a bit like broadband connection. lets say you need to stream a CD from internet to your DAC in real time but your broadband only has bandwidth to do this as an MP3 or compressed audio - the sound you normally get is compressed. But with a Chord DAC, it will send the CD as data (packets) over your limited connection and wait until it has a whole song before playing rather than playing what it gets.

So Chord treat music transfer in speed or Mbits / sec rather than the mp3 or lossless. It then waits until it has all the bits before rebuilding it into its native format.

 

[The_Lhc]

Does that explain why it sounded so awful? I can't remember what the speakers were but they were apparently £3k and it was far and away the WORST sound of the day.

 

[AlmaataKZ]

Sorry, still don't get it. Waiting for bits to arrive would mean either a delay before a track starts to play or droputs as it plays, if you are near the limit of the bandwidth.

 

[Alec]

Thanks for the clarification AlmaataKZ.

 

[Anonymous]

It is hard to get your head round, but there is a lag as the buffer builds with data before it plays but no drop outs.

If there is a drop out - the connection will have been compromised. For example Chord won't use wifi because it has a variable connection strength which affects the volume of data which can be sent and thus you may be connected but get drop outs. With Bluetooth, it is all or nothing and is a better connection as long as you are within range.

Music data has a structure which limits its use in transferring between devices if you keep this structure. Chord bypass this industry standard and treat it as raw computer data thus allowing it transfer as normal.

It makes sense if you have ever burned a Music CD - you can burn an album as a data CD or as a Music CD - Chord choose to transfer the music as raw data as it sits on the hard drive rather than using an architecture such as 24bit192khz. This means its quicker. It also means an Apple TV which can output music via optical at a max 16bit / 96khz to a DAC, will infact send the raw data via optical to the Chord at which point the Chord will rebuild it as 24bit 196khz or native format.

This effectively means it does not matter what transport you use - it is absolutely irrelevant. All other dacs ask the transport to send the music in a music format, which makes the transport vital.

 

[Anonymous]

To add - storing the music as data on a mobile phone or PC is then irrelevant - you should get the best quality the DAC can manage.

I know this to be how the QBD64 works - I'm assured that the transfer method is the same for Chordette - the dacs are just different (and connections obviously).

PS - I didn't know apple products had appropriate bluetooth? Chord have a list of devices which support the best version of bluetooth.

 

[Anonymous]

@OP - Presume you are either satisfied with responses or given up?

 

[AlmaataKZ]

woollyjoe:

Chord have a list of devices which support the best version of bluetooth.

I coudl not find this info. Do you have a link?

 

[AlmaataKZ]

Craig M.:having just done a quick google, it would seem that audio can be sent losslessly via a2dp bluetooth. i'll check later to see if i can hear a difference between optical and bluetooth, i'll also check if it will stream 24/96 over bluetooth.

Also very much interested in CraigMs findings if he ever tries it.

 

[Anonymous]

The chord will stream 24/96 over bluetooth as long as its via a2dp bluetooth. It sends it as data - not data music so the connection doesn't matter. With regards, using apple products - I don't think Apple is supported - the bluetooth is not good enough

 

[Craig M.]

my macbook will only output bluetooth at 16 bit and 44.1 or 48khz.

afaik, a2dp works fine on macs with leopard onwards.

 

[Craig M.]

woollyjoe:
It is hard to get your head round,

It makes sense if you have ever burned a Music CD - you can burn an album as a data CD or as a Music CD - Chord choose to transfer the music as raw data as it sits on the hard drive rather than using an architecture such as 24bit192khz. This means its quicker. It also means an Apple TV which can output music via optical at a max 16bit / 96khz to a DAC, will infact send the raw data via optical to the Chord at which point the Chord will rebuild it as 24bit 196khz or native format.

This effectively means it does not matter what transport you use - it is absolutely irrelevant. All other dacs ask the transport to send the music in a music format, which makes the transport vital.

you're not kidding it's hard to get your head round. i don't understand how the dac connected by optical can have any bearing on the bit depth or sampling frequency that the source is sending, the source will not know what kind of device is connected via optical. it's a one way street. if i send 24/96 via optical, that is what the dac receives as this is what itunes sends it. how can it access the "raw data" off the hdd? it can't.

i'm not sure how the bluetooth connection can access the data from the hdd either, as it gets what it's given by itunes? i also thought that a2dp was a one way street data transmission as well? the apt-x bluetooth codec states 16/44.1 as the limit: http://www.aptx.com/Technology-Portfolio/apt-X-Bluetooth.aspx

 

[Diamond Joe]

the_lhc:Does that explain why it sounded so awful? I can't remember what the speakers were but they were apparently £3k and it was far and away the WORST sound of the day.They were Dynaudio Focal 220s, I'm surprised you thought they were that bad, I thought they were superb, each to their own I guess.

 

[Anonymous]

@craig m... I agree with sentiments, but Chord led me to believe that they get the original data regardless of what the bandwidth limits are. I'm not a techie, but the engineer and computer guy at the show were absolute - it does not matter what connection you make with a Chord DAC (talking specifically about QBD) or the source, as long as the music is of high quality, the chord transfers differently to every other product..

 

[PJPro]

I found the Chord people to be arrogant and aggressive at the London Show as year or so back. For that reason, I would never buy a Chord product, no matter how good.

 

[Anonymous]

PJPro:I found the Chord people to be arrogant and aggressive at the London Show as year or so back. For that reason, I would never buy a Chord product, no matter how good.

Hello PJ,

You are not alone there. My experience with Chord is nearly the same,,,,,very good on the phone....... but at Bristol they were wierd, almost surly when I needed to ask them a question about a product made by them that I already owned. I say owned because I have since sold the product and replaced it with the Caiman..........I felt like I was a bit of a nusiance(spelling) to them.

Which leads me to thank you for your help on my headphone question

D

 

[Anonymous]

2 guys there this year were nice. One is the chief engineer I think and the other is more computers.

They struck me as super intelligent people who may have a lacked a little social sophistication, but I didn't find them arrogant - just passionate about their products. Maybe misunderstood genius'

The guy from Naim however, wanted to lecture me on rubbish pop culture music and how he didn't listen to that rubbish - however I do (am talking stuff like Adele BTW) and he was meant to be running a demo for me. In the end I ended up having to listen to "the X". That is arrogance.