Arcam rDAC details

[roob]

http://www.arcam.co.uk/products,solo,dacs,rDac.htm
Looks cute.

[DSJR]

£300 is just about the tops it could sell for, but it's still double the price of the V-DAC and little black boxes tucked away is all many people need. It's even dearer than a Caiman, but I admit there's dealer margins in the £300 whereas Stan sells directly.

[aquapiranha]

I get the distinct impression that is designed to sit under a Mac-mini! mabe not though.

Looks nice and neat

[purite audio]

It's async USB too, it could be good.
Keith.

[Labarum]

It's async USB too, it could be good.
Keith.

I had heard that, but I don't see it in the specs.

Async is supposed to yield advantage, but I must say when playing CDs ripped to FLAC through my Caiman I can't here the difference between the S/PDIF and USB inputs.

Does the rDac go higher than 16/48 using USB?

[Nak]

£300 is just about the tops it could sell for, but it's still double the price of the V-DAC and little black boxes tucked away is all many people need. It's even dearer than a Caiman, but I admit there's dealer margins in the £300 whereas Stan sells directly.

I'm thinking about saving my pennies that were going to go on the vdac or music streamer for one of these. It checks all the boxes for me. no headphone amp, bought in the UK, async usb, looks cute. I'll have no doubt changed my mind by the time it comes to press the button.

[roob]

I had heard that, but I don't see it in the specs.
To achieve this Arcam have teamed up with dCS (Data Conversion Systems), licensing their Asynchronous USB Technology*. This unique system is usually reserved for ultra high-end HiFi and professional audio applications. Arcam and dCS have had a long and fruitful relationship that goes back to the highly innovative Alpha 9 & CD23 versions of dCS’s Ring DAC

The dCS technology allows a precision clock to drastically reduce the level of jitter from USB music sources and delivers a massive improvement in sound quality over the standard USB ‘adaptive’ system.

[Nak]

I get the distinct impression that is designed to sit under a Mac-mini! mabe not though.

Looks nice and neat

I was thinking the same thing myself, at first I thought it was white.

[roob]

Technology Licencing
DAC
Wolfson 8741 24-bit multilevel Delta-Sigma DAC
Frequency response
10Hz — 20kHz, +0 -0.2dB
Total Harmonic Distortion + Noise
0.002%
Signal-to-noise ratio (A–Weighted)
112dB
Maximum output level
2.2V RMS
Supported sample rates
USB
32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz
Optical
44.1kHz, 48kHz
Coaxial
44.1kHz, 48kHz, 88.2kHz, 96kHz, 176kHz, 192kHz

[FuriousD]

Can i ask a dumb question, and please do shoot me down in flames but why is the USB input the same as that of a printer? Why not a standard USB input, it has been a long while since i bought a usb cable so sorry if i am being stupid.
D

[StanleyB]

If asynch is supposed to be a massive improvement over adaptive, does that mean it should be possible to hear this improvement?
On the same subject: if asynch relies on resending any missing bits, how does it know bits are missing and does the audio output gets put on hold until the missing bits have been resent and the audio waveform corrected? If so, wouldn't we hear a start/stop delay in the music?

[purite audio]

I had heard that, but I don't see it in the specs.

Async is supposed to yield advantage, but I must say when playing CDs ripped to FLAC through my Caiman I can't here the difference between the S/PDIF and USB inputs.

Does the rDac go higher than 16/48 using USB?

S/pdif and adaptive USB both have an embedded timing signal alongside the data, I wouldn't expect either to be better than the other, async USB I would expect to make a positive difference.
Keith.

[purite audio]

Asynch doesn't rely on resending data, it just allows the dacs clock to be in total control of the flow of data.
Keith.

[StanleyB]

async USB I would expect to make a positive difference.
How exactly?

[purite audio]

See above, there has been a long and heated discussion of 'Async' on the CA forum, technically Ethernet async USB and Async firewire are the best methods of transferring timed data.
Keith.

[StanleyB]

Asynch doesn't rely on resending data, it just allows the dacs clock to be in total control of the flow of data.
The timing clock for the whole DAC is controlled by the receiver like the CS8416. That's already in control of the flow of data, and derives its control from the mark/space ratio from the audio data. That's how it also works out when the data is AAC/DTS instead of PCM.

[StanleyB]

See above, there has been a long and heated discussion of 'Async' on the CA forum, technically Ethernet async USB and Async firewire are the best methods of transferring timed data.
Keith.
Well, time for AoS to put asynch under the microscope on a professional level :). We are after facts, not wild claims. So far the facts don't add up in favour of the claims attributed to asynch by a select few.

[purite audio]

Perhaps you can license M2 Tech's async USB technology or ask Daniel to implement an async firewire protocol for you?
Then you can compare it for yourself.
Keith.

[StanleyB]

Why would I want to license a technology that is questionable when applied to DACs? Asynch implies that the clock is derived from the data. That's exactly how the receiver chip in a DAC circuit works, but no DAC company makes bold clams about their DAC being asynchronous. Suddenly however some are beating their chest about async USB when every DAC receiver already use asynch. Is this PRat and upsampling doing a snake oil on us for sales purposes?

[Krisbee]

How come the rDAC USB sample rates are limted to 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz? Is it just using a Tenor TE7022L chip?

Anyway, I'm not interested unless it works with Linux, has a headamp and can be used as a preamp. Incidently M2Tech has still to produce Linux drivers for their products. If, and when my knackered old ears can hear one of these gizmos I might be able to decide what all the fuss is about.

[StanleyB]

The Tenor chip is isynchronous.

[Themis]

Can i ask a dumb question, and please do shoot me down in flames but why is the USB input the same as that of a printer? Why not a standard USB input, it has been a long while since i bought a usb cable so sorry if i am being stupid.
D
Well, in fact, USB inputs and outputs have different connectors : Type A and type B
http://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Types-usb_new.svg/220px-Types-usb_new.svg.png

One type is used for hosts (A) and the other for devices (B). They are different, because you can't plug together two hosts or two devices.
Some devices can become hosts, that's why they made the AB type...

[FuriousD]

Thanks Dimitri,
D

[trailer]

The Naim DAC has two type A inputs. I think these were specifically used so you could play from USB sticks / iPods without an adaptor.

I was going to compare the USB to the Beresford USB but I couldn't find an A to A cable in the box of wires :donk:

[Ali Tait]

I tried to find an A to A and couldn't.

[lurcher]

Why would I want to license a technology that is questionable when applied to DACs? Asynch implies that the clock is derived from the data. That's exactly how the receiver chip in a DAC circuit works, but no DAC company makes bold clams about their DAC being asynchronous. Suddenly however some are beating their chest about async USB when every DAC receiver already use asynch. Is this PRat and upsampling doing a snake oil on us for sales purposes?

I haven't posted for some time, but without wanting to argue about it, thats not true Stan. Normal audio is transferred using the Isochronous (=equal time) mode. In that mode data is sent in packets synchronized to a 1ms (1kHz) clock tick Full Speed or 8 times that rate for high speed. The receiver has to synchronize with the frame rate, and synthesize a audio data rate from that. There is no flow control and no error recovery, so the clock in th e receiver has to either attempt to lock to the sending rate, or implement a indefinably large buffer to allow it to run at its own rate. That means like spdif, the receiver has to create its data rate from within the sent data.

Asynchronous operation is a mode of the standard iso transfer, in that data is still sent in packets per frame, but now there is a additional channel of communication from the receiver to the sender that allows the receiver to control the rate of data. It still arrives in 1ms blocks, but the receiver can control hos many bytes arrive each frame. So the receiver can be clocked by a high quality local clock, and the transmitter can be locked to that clock. The use of a accurate local clock is something that AFAIK only USB can do in the transfer of audio using conventional methods of transfer. Some others allow the sender to include a accurate clock but thats not the case for the consumer formats.

I have spent the last 7 months looking into USB and there are many problems in the way of getting it all playing, especially if (like I have) you decide not to use the TI chipset (mainly in my case because thats already been done, so whats the point).

If I could find the time money and inclination I would look harder at the problem, I have a chipset in mind that will do the job, but other things have consumed my playing budget. In some ways the best solution would be to use a standard IP core and implement it all in a FPGA, but I am only doing this in my free time, so thats a bit too far left field. The XMOS solution is a good one, and their USB reference board will do exactly what we are talking about, provide a async USB device that runs up to 192/24 and output toslink. Its about £100 for the board, but its far from a finished device. Though they have just release a final set of firmware that I should download to the thing and try.

[lurcher]

How come the rDAC USB sample rates are limted to 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz? Is it just using a Tenor TE7022L chip?

Anyway, I'm not interested unless it works with Linux, has a headamp and can be used as a preamp. Incidently M2Tech has still to produce Linux drivers for their products. If, and when my knackered old ears can hear one of these gizmos I might be able to decide what all the fuss is about.

The Full speed USB data rate is one frame per 1ms or a 1000 frames a second. In Iso mode the max data that can be carried in one frame is 1023 bytes, adding that up, the highest data rate that can be carried is 170k 24bit stereo. So 96k is the highest standard rate that fits. High speed (USB2) can transfer 1024 bytes in three packets per microframe so thats 1024 * 3 * 8 * 1000 per second or 24 Mb/Sec, pleanty of room for audio.

However (at this point) only Apple implements the USB 2.0 audio drivers as standard, so its extra cost and/or hassle to get USB 2 on other platforms, hence the 96k limit. Up to that speed any OS with USB support should work just fine.

[Themis]

I tried to find an A to A and couldn't.
It exists only with male-female plugs, afaik.

[trailer]

There's plenty on eBay

Do a search for A to A USB.

[Gazjam]

Same Wolfsen Dac chip as the Akurate....hmnn?
Always curious as to how much difference (all things being equal of course) this would actually make?

[DSJR]

Same Wolfsen Dac chip as the Akurate....hmnn?
Always curious as to how much difference (all things being equal of course) this would actually make?

AVI use the same one I understand. It's not expensive and apparently performs very well indeed I'm told.

[Ali Tait]

There's plenty on eBay

Do a search for A to A USB.

I did.There aren't any,not,as Dimitri says,without using adaptors.

[lurcher]

It exists only with male-female plugs, afaik.

Yes, as a extender like this

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=472-5264

There is no situation where one would need a cable with a A plug on both ends.

[Ali Tait]

I wanted to try connecting the Drobo both to the Touch and a laptop using a y-type arrangement to see if it would allow me to download new music to the Drobo without always having to disconnect and reconnect Nick.There is only one USB on the Drobo.Firewire also,but the laptop doesn't have one.Not sure if it would work though.

[Stratmangler]

I wanted to try connecting the Drobo both to the Touch and a laptop using a y-type arrangement to see if it would allow me to download new music to the Drobo without always having to disconnect and reconnect Nick.There is only one USB on the Drobo.Firewire also,but the laptop doesn't have one.Not sure if it would work though.

Have you tried a USB hub Ali ?
http://www.microdirect.co.uk/Home/Product/14970/Trust-EasyConnect-4-Port-USB-2-Powered-Hub

[lurcher]

I wanted to try connecting the Drobo both to the Touch and a laptop using a y-type arrangement to see if it would allow me to download new music to the Drobo without always having to disconnect and reconnect Nick.There is only one USB on the Drobo.Firewire also,but the laptop doesn't have one.Not sure if it would work though.

USB doesn't work like that Ali, its not a network, its a point to point serial link, The only way to do what you want is to add a USB hub into the system. Hubs are not passive devices, they get involved and are seen by the single host.

[Ali Tait]

I didn't think of that! Told you I was a computer numpty.Would that work for what I need?

[Stratmangler]

They're not particularly expensive - try one, suck it and see.

[Ali Tait]

USB doesn't work like that Ali, its not a network, its a point to point serial link, The only way to do what you want is to add a USB hub into the system. Hubs are not passive devices, they get involved and are seen by the single host.

Cheers Nick.The idea is to not have to have a pc running all the time I'm listening to music.I just thought if I could connect laptop,Touch and Drobo together,I could either turn off the Touch and download to the Drobo,or turn it on and play music with laptop off.I think I'm going to have to go down the dedicated pc route sooner or later though,as TinySC will only cope with a certain size of database,at least at the moment.Not what I wanted really,hence waiting for the Touch to come out.

[trailer]

I did.There aren't any,not,as Dimitri says,without using adaptors.

http://cgi.ebay.co.uk/USB-2-1-8METRE-BLACK-A-MALE-A-MALE-CABLE-LEAD-/360276470261?cmd=ViewItem&pt=LH_DefaultDomain_3&hash=item53e226a9f5

[Ali Tait]

I'll get a hub for now though.Thanks for the suggestion chaps.

[Ali Tait]

Am I better getting a powered one or is that not necessary for my use?

[Stratmangler]

Powered I'd say.

[Ali Tait]

So using a hub should enable me to do what I've described?

[Stratmangler]

Maybe - suck it and see time.

[Ali Tait]

OK ta.

[StanleyB]

The idea is to not have to have a pc running all the time I'm listening to music.I just thought if I could connect laptop,Touch and Drobo together,I could either turn off the Touch and download to the Drobo,or turn it on and play music with laptop off.
It's possible already. I have been using an INOI multi media drive for that. It connects via USB to my laptop, and via a CVBS video lead to a small monitor. When the PC is off I can use the monitor screen to select music tracks off the INOI for playback. I also have a Freecom wireless multi media HD that does the same. This allows me to upload music to the Freecom wireless from the laptop situated in a different part of my home, whilst leaving the Freecom optical output connected to my DAC.

[Ali Tait]

Hi Stan,
I can already play stuff with the Drobo connected directly to the Touch,which is why I waited for the Touch to come out before going down this route as I don't like having a pc on while listening as I find it distracting.I can also control the Touch with an app on my Android phone.The problem I have is that for some reason my old laptop won't see the Drobo as part of the network,but only when it's directly connected to the laptop,so every time I want to download new music to the Drobo,I have to disconnect the USB going to the Touch from the Drobo and connect this directly into the laptop so it will see the Drobo and allow me to download new stuff.I then have to disconnect and reconnect this lead back into the Touch to play music again.It's this problem I'm trying to get around.

[technobear]

The problem I have is that for some reason my old laptop won't see the Drobo as part of the network,but only when it's directly connected to the laptop,so every time I want to download new music to the Drobo,I have to disconnect the USB going to the Touch from the Drobo and connect this directly into the laptop so it will see the Drobo and allow me to download new stuff.I then have to disconnect and reconnect this lead back into the Touch to play music again.It's this problem I'm trying to get around.

A USB hub will not help you. The Drobo is a USB client device. You can only connect it to one USB host at a time - either to the Touch or to the Laptop.

However, if Samba is enabled on the Touch then it will share the Drobo over the network as a network drive so you can then access this from your laptop(assuming you have a network).

[Ali Tait]

Samba? What's that,and how do I enable it?

[Peter Galbavy]

Did anyone notice the "Wireless" LED and the antenna connector on the back ?

Also, I have a USB A-to-A cable and there are uses for them. My Thecus Nano disk enclosure can function either as a host or a mass storage device, depending on a switch setting... so there :ner:

[technobear]

Samba? What's that,and how do I enable it?

Found on the Slim Devices forum:


Network share access to logs, and the hard drive

Enable network sharing under:
Settings > Advanced > USB & SD Storage > Sharing > Enable Sharing


For network share access the (default) username is 'Squeezebox' and the password is '1234'.


Access the logs and hard drive through Windows Explorer (not Internet Explorer or another web browser). You'll find the Touch under the workgroup named 'Workgroup'. Below that you should see the 'logs' share and some convoluted share name for the hard disk and/or SD card.

http://forums.slimdevices.com/forumdisplay.php?f=34

[Ali Tait]

Yes had already done that but thanks anyway Chris,I thought it was something else I wasn't aware of.I've sorted it though! For some reason the laptop now sees the Touch,so I have now pointed EAC to the Drobo via the Touch.Only problem now is it's taking about half an hour to rip a cd with EAC and going to the Drobo via the Touch,whereas before with the Drobo connected directly to the laptop it was taking 5 mins or less. :scratch:

[technobear]

Yes had already done that but thanks anyway Chris,I thought it was something else I wasn't aware of.I've sorted it though! For some reason the laptop now sees the Touch,so I have now pointed EAC to the Drobo via the Touch.Only problem now is it's taking about half an hour to rip a cd with EAC and going to the Drobo via the Touch,whereas before with the Drobo connected directly to the laptop it was taking 5 mins or less. :scratch:

That is to be expected. The Touch is a very low powered computer.

[Ali Tait]

That was my thought,just wanted to check I hadn't done something else silly.Thanks for the help Chris.Guess I'm going to have to bite the bullet and put together a little server for the Drobo and Touch.Didn't want to do that,s'why I waited for the Touch in the first place.Can you recommend something small and silent,not a netbook,that I could use? Something just to run squeezecenter and maybe sleep till I want to play music?

[Stratmangler]

Sheeva plug, maybe ?

Have a natter with Tony Moore - he's got one running Squeezebox server, although I'm not sure of the version (you'd need to run the latest for the Touch).

Also I'm not sure if there is sufficient processing power to perform some of the more processor intensive server functions, such as SOX conversion.

[trailer]

Did anyone notice the "Wireless" LED and the antenna connector on the back ?

I've got a feeling this is going to use Arcams proprietary wireless system:

From the Arcam site:

"A wireless version of the rDac, ready to be connected to a wireless USB dongle, will be released later in 2010. This helpful feature enables music to be sent wirelessly to your audio system from a laptop via the rDac. The wireless transmitter also features dCS technology and offers music lovers with large stored collections a level of performance that was previously only available from expensive audiophile systems.

Inputs

* 1x Optical SPDIF (Toslink socket)
* 1x Coaxial SPDIF (Gold plated socket)
* 1x USB
* 1x Wireless (optional, requires dongle)"

[Ali Tait]

Sheeva plug, maybe ?

Have a natter with Tony Moore - he's got one running Squeezebox server, although I'm not sure of the version (you'd need to run the latest for the Touch).

Also I'm not sure if there is sufficient processing power to perform some of the more processor intensive server functions, such as SOX conversion.

That looks interesting Chris,I'll have a word with Tony.Ta.

[technobear]

That was my thought,just wanted to check I hadn't done something else silly.Thanks for the help Chris.Guess I'm going to have to bite the bullet and put together a little server for the Drobo and Touch.Didn't want to do that,s'why I waited for the Touch in the first place.Can you recommend something small and silent,not a netbook,that I could use? Something just to run squeezecenter and maybe sleep till I want to play music?

One answer is to rip music onto your PC's hard disk and then use SyncToy later to copy it to the Drobo while you go off and do something else.

As for small silent PCs, have a look at Tranquil PC. I've been using a pair of T7 Atoms for nearly 2 years now and they perform well and are quiet. They do need ventilation though. They are not too happy in a cupboard in mid-summer but in the open they are fine.

[Ali Tait]

Thanks Chris,I'll have a look at those too.

[Ali Tait]

Had a look around and found there is a successor to the Sheevaplug called the Guruplug,more flexible so have bought one.Only problem is the 4 week waiting list.See here-

http://www.globalscaletechnologies.com/p-32-guruplug-server-plus.aspx

[Stratmangler]

Looks to be a good way to go Ali - they've upped the spec from the Sheevaplug.
You should be able to get it to boot from SD, and also put SBS 7.5.1 onto the same SD card.

Looks like a long phone call to Lurcher might be in order:eyebrows:

[Ali Tait]

Aye! :lolsign:

[Ali Tait]

There is something on slimforums about installing sbs on a sheeva,I'll give it a try myself first.

[Stratmangler]

Learn Linux in the school of many kicks in the nuts ?:lolsign:

[Ali Tait]

Well I've got a month to learn!

[Stratmangler]

From what I can find out the Sheeva/Guru plug is powerful enough to cope with everything that SBS 7.5.1 can throw at it except for SOX resampling - apparently it can do the resampling, but it's not fast enough to perform the task in real time.

Essentially this means that it can transcode 24/192 files to 24/96 (the fastest the Touch can handle natively), but the tracks will play back at half speed.

Other than that it handles the task of running SBS superbly well.

[Ali Tait]

Not a problem then,since I don't have any 24/192.