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Pure i-20 iPod dock

I bought my uncle a new 16GB Nano a while back and recorded a bunch of Lossless Classic Jazz for him to enjoy. It held a few dozen albums. He was blown away and now he can enjoy Jazz without upsetting his wife (she thinks its the devil's work).

Anyway, last time he was over we played it on the i-20 connected with digital coax to a Music Hall DAC 25.3 and it sounded great! Amazing such sound can come out of something so small!
 
This evening I had the first opportunity to set down for some serious listening with this setup. Chalk it up to psycho acoustics, wishful thinking or whatever you want to but right now I seriously think this is the best this system has ever sounded. I'm using the on board DAC and listening to strictly apple loss less files tonight. As typical when the mastering of the track is shoddy it sounds shoddy but when the mastering is good this cheap little Dock produces digital audio like i've never heard in my house before. It is that good and i've got my entire CD collection at my beckon call.

I've gained a new found respect for well mastered CDs thanks to Pure. i've also grown a bit more annoyed at the loudness fanatics. What were these guys thinking? Now to find an external DAC to see if things are improved a bit.

Oh... I did notice the volume control is a bit flaky would be better to just use the volume control on a preamp.

Steve
 
targeteye said:
The analog output of the base as a variable output.

Steve
Click to expand...

I'm sorry, maybe I'm just thick-headed today. Are you saying that there's a level control on the base of the I-20? Or, that the iPod volume control controls the line-out level?

Either one would be a disappointment to me. Mine arrives tomorrow.

I assumed that since the iPod output was digital, and the I-20 has an internal DAC, that the iPod volume control was out of the circuit and that you'd simply get a correct line-level output to plug into a pre-amp, or integrated amp.
 
jviss said:
I'm sorry, maybe I'm just thick-headed today. Are you saying that there's a level control on the base of the I-20? Or, that the iPod volume control controls the line-out level?

Either one would be a disappointment to me. Mine arrives tomorrow.

I assumed that since the iPod output was digital, and the I-20 has an internal DAC, that the iPod volume control was out of the circuit and that you'd simply get a correct line-level output to plug into a pre-amp, or integrated amp.
Click to expand...

let me see if I can clear things up.

1. The volume control of the IPOD itself is disabled while plugged into the base because the linkage between the ipod and the base is purely digital.
2. The base itself has a choice of digital out bypassing the DAC that is in the base or analog out that makes use of the DAC that is in the I-20.
3. When you use the analog out of the base (and thus the DAC that is in the base) the base itself can be adjusted in volume output via the remote control. This would be similar to a CD player that has a variable ouput.

The ipod volume control is out of the circuit. I'm not sure why this would be a disappointment to you as you don't have to use it if you do not want to.

Steve
 
Thanks, Steve. I guess I just didn't imagine that it would be a good idea to vary the line-out level to adjust volume. I wonder what the nominal line out level is (when volume is at max)? Does the dock remember the volume level through power cycles?
 
jviss said:
Thanks, Steve. I guess I just didn't imagine that it would be a good idea to vary the line-out level to adjust volume. I wonder what the nominal line out level is (when volume is at max)? Does the dock remember the volume level through power cycles?
Click to expand...

Good question... i'll have to check later. I guess if you leave the volume on the doc down low and turn your amp up louder then the S/N ratio could be impacted. I just leave my amp volume where it is at a decent level with the i-20 all the way up then adjust with the dock. Unfortunately I don't have a remote control preamp at this point. Soon to be corrected I hope.

Steve
 
So that is interesting. I connected the S/PDIF out of the I-20 to the input on my Phillips CDR. What I discovered is that the Volume control on the DOC work regardless if you are using the digital or analog ouput. Which means there is some digital signal processing going in in the DOC. Perhaps this is obvious now since we know its using a 24bit 192kbs DAC

The volume stays the same when going from on to standby and back to on.

Steve
 
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Got my I-20 and it failed in 10 minutes!

I was thrilled to receive my I-20 today. I connected it to my Marantz 1060 driving AR 4x speakers, dropped in my iPod Classic, and started listening. Sounded pretty good, but admittedly not great (Apple lossless from a ripped CD).

The remote worked, and the volume controls on both the remote and the iPod clickwheel worked to adjust volume, which I found odd. Maybe the doc was passing through the headphone out on the dock connector?

Anyway, 1/2 way into the second song, silence. It just quit. The remote did nothing.

I then tried my iPhone 3G, and my iPhone 4, and these work fine!

Contacted Pure support. Kind of a funky support interface. We'll see what happens.

Regarding the iPod, the product lit says the sixth generation iPod Classic is supported. However, nowhere from Apple can one find a generation designation applied to iPod Classics. I have a 120GB slim aluminum case model A1238, purchased new December 2008; so, I assume gen. 6.

Oh well! Any input on this is appreciated.

jv
 
Update on this I-20 failure

It's working now.

Here's what happened. During the first listening, when the system went quiet, I had blown two speaker fuses. I had been playing with the volume on the iPod, and I guess I stressed something.

Apparently something glitched the iPod. I did a "restore" in iTunes, reloaded all my stuff, and now it works.

I have also verified that the volume control on both the iPod and the remote is a digital volume control. I did this by running an optical cable from the dock into my MacBook Pro, and watching the level using Audacity. So it's somehow altering the data to reduce volume. I don't know if it's happening in the iPod or the dock, most likely, I think, in the iPod. I don't like this, since I'd prefer the original bits to be submitted to the DAC. Am I correct in assuming I should leave the iPod volume all the way up, and turn off iPod volume limiting?
 
Pure I-20 DAC resolution v. iPod output capability

What's the point of the Pure I-20 "High-performance 24-bit 192 KHz DAC (-105 dB signal to noise ratio, -93 dB THD+N and 2V RMS)" if the iPod can only put out 44,100 by 16?
 
jviss said:
What's the point of the Pure I-20 "High-performance 24-bit 192 KHz DAC (-105 dB signal to noise ratio, -93 dB THD+N and 2V RMS)" if the iPod can only put out 44,100 by 16?
Click to expand...

Perhaps anticipating future iPod capabilities?
 
Better, ...

I asked the same question of Pure technical support and received a very prompt, very informative reply. Apparently the iPod currently supports 48kHz by 24. I assume the support to 192k is simply a characteristic of the DAC that Pure selected for this unit, and of course, it would support future devices at those rates.

I would buy Pure products solely on the quality of the support!

jv
 
jviss said:
What's the point of the Pure I-20 "High-performance 24-bit 192 KHz DAC (-105 dB signal to noise ratio, -93 dB THD+N and 2V RMS)" if the iPod can only put out 44,100 by 16?
Click to expand...

Answer from Pure:
Dear John,

Many thanks for your recent e-mail.

The Apple iPod is capable of 24bit 48 KHz playback and although in many cases the original material you may have will have come from compact disc and hence be encoded at 16bit 44.1 KHz there are definite and clearly measurable benefits to implementing a higher specification digital to analogue convertor in the presence of lower bit-rate or sample-rate source material, not least in the available dynamic range and noise performance commanded by high-specification digital to analogue converters.

The converter within the i20 dock was selected after measurement and audition of a number of candidate devices. It was chosen by the design team because of its excellent linearity, channel separation and high signal-to-noise ratio.

I trust this is sufficient for your enquiry.

Regards,

David Wilson

------------------------------------------------------------------------------------
David Wilson, Technical Support Engineer
PURE, Home Park Estate,
Kings Langley, Herts, WD4 8LZ, UK
PURE is a division of Imagination Technologies Ltd.
Click to expand...
 
uofmtiger said:
I have not had this issue with the Touch 1G, iPad 1, or my iPhone 3GS that I have tested it with. If you do not have this problem with other docks (in other words, if you are sure the Pure has the issue), you may want to see if you can exchange it.
Click to expand...

How stable is this thing with your iPad docked in it? I have a new iPad 2 that I want to stream Pandora to my stereo with, and this seems like a good choice for that as well as our iPods. I have a cheap cable that uses the iPod dock connection to Stereo RCA now, but it didn't work with the iPad. The Pure site lists the iPad as a compatible device, but doesn't specify which version. I assume the iPad 2 will work?
 
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