[cat6man]

it would be interesting to know if there are jitter issues on the digital output, as some dac are more
sensitive to input quality (pulse shape, jitter) than others.  if the ipure doesn't sound as good as the
other digital docks, it could be one of many things, including noise on power.
 
has anyone tried modding this puppy?
 
btw, i have one and it sounded fine to me, but i wasn't critically comparing it to anything else.
 
 

 

[renpar61]

Hi everyone. First post here.
 
I stumbled across this thread, as owner of the Pure i-20, I found it very informative.
 
I would like to go back to the volume control issue with a few questions: all discussion about digital manipulation through the iPod volume set aside, it seems like the recommendation is to turn the iPod volume to max (first question: with i-20 remote or iPod wheel? no difference?) to get the best from the digital source.
In my case, the output is so loud I can barely move up the knob on my small 40W integrated amp. Therefore is very difficult to control the overall volume. Is there something wrong with my setup?
latest iPod Classic 160G --> Pure i-20 --> MF V-DAC --> NAD integrated --> DefTech 8020
(the V-DAC was added recently, same issue before going straight from i-20 to amp)
 
Would I be better off with just a power amp? Any amp in particular in the 100/150 wpc range hat works well with the i-20?
 
Thanks!
 
 

 

[166848]

i finally starting having problems with my i-20. when im listing to it all of a sudden it doesnt recognize the ipod and stops playing music, then it will start back for a while then the same thing all over again. any ideas. thanks

 

[qruizer]

Hi, I'm a newbie and a car audio freak.
I've got an iPod classic 160gb 1st gen and an iPhone 4, playing mostly Apple Lossless files.
 
I can't seem to find any iPod DACs designed for car use, so I'm considering buying an i20 and make a custom mount for it on the dashboard.
 
Do you think the dock is steady enough to for the iPod/iPhone not to fall off when hitting bumps with my old Mk2 VW Golf?
 
If not, I'm no stranger to modifying it using some some parts from a car iPhone holder
 
And do you think the i20  will handle the varying temperatures and climate, from a cold startup in freezing winter, to hot summer days?
 
 
The i20 takes 7,5volt DC power, so I'm thinking of using something like this as a power supply:

 

 

[estreeter]

Just when I think I've heard it all, a post like this comes along. 'Pimp My Ride' and 'Monster Garage' have a lot to answer for.

 

[qusp]

Quote:

Hi there,
I just want to say something about this pure thing.
 
been using it for couple moths now, but I don't use analog out because it is not as good as my cd player (analog out).
 
so I try as a transport to compare with Wadia and Onkyo, well the pure sounds not as good as wadia nor Onkyo in general.
 
I wonder if anyone has done "mod" this pure ?????? and how is it sounds ?
 
the reason I bought this is because this can be use a transport of Ipod which I though it must be good.
but I'm dissapointed, because I have Wadia and I thought it should not make a big difference. but it is.
 
looking forward how to modify this thing ? with better X'tal ? 
cal

i think like most of these type of devices that the clock will be derived from the DSP, which is connected to its own clock, but its not a digital audio clock so to speak. i could be wrong, but thats how the clas and fostex work afaik. so while upgrading the clock may produce an improvement, its not the same thing as when you would upgrade the clock on a regular dac.

 

[Mochan]

 
 


Quote:

it would be interesting to know if there are jitter issues on the digital output, as some dac are more
sensitive to input quality (pulse shape, jitter) than others.  if the ipure doesn't sound as good as the
other digital docks, it could be one of many things, including noise on power.
 
has anyone tried modding this puppy?
 
btw, i have one and it sounded fine to me, but i wasn't critically comparing it to anything else.
 
 

I've found that the i20 has jitter issues if I turn on the crossfade feature of my Nano 6G.

 

[Sylverant]

Quote:

And at half the price of hte ND-S1, this also has a digital pass-through. So I can skip switching on the PC and just dock the iPod to use the same DAC and amp. Now I can't decide whether I'll get this for my 5g or the X3 when it comes out.

 
I thought the ipod 5g/5.5g couldn't send its signal out to dacs, only amps?

 

[cooperpwc]

Quote:

i think like most of these type of devices that the clock will be derived from the DSP, which is connected to its own clock, but its not a digital audio clock so to speak. i could be wrong, but thats how the clas and fostex work afaik. so while upgrading the clock may produce an improvement, its not the same thing as when you would upgrade the clock on a regular dac.

Jeremy, the literature suggests that the CLAS reclocks and the Fostex does not. I don't claim to understand these things as you do but I am surprised that you describe them as using the same clock system.

 

[Br777]

i may have mentioned this in another thread, but i was surprised to find that when i use an optical cable out of the stock built in sound card in my computer, vs the optical out of my pure i20, feeding into a schiit bifrost -  rsa sr71b and balanced out to LCD-2 r.2 - fed from an ipod touch 4th gen with lossless files, the computer actually sounds better than the pure.
 
i wondered if it had something to do with my computer using the foobar2000 wasapi function?
definitely makes me wonder if i'd be better off upgrading to the onkio or wadia dock.. unfortunately i know little to nothing about how all this stuff works.
 
 
 

 

[qusp]

Quote:

Jeremy, the literature suggests that the CLAS reclocks and the Fostex does not. I don't claim to understand these things as you do but I am surprised that you describe them as using the same clock system.

hmm, well that doesnt make a lot of sense, since the ipod does not have the ability to act as the usb master. are you sure you arent mixing up reclocking with resampling? it does not have to be asynchronous, i specifically didnt mention that as i dont know the details of the fostex there, but the fostex MUST supply the clock, it may do this by literally synchronously controlling the ipods clock as master (unlikely), or by reclocking asynchronously. i do not think the ipod can supply mclk, i could be wrong, but i dont think so, that would be a really strange way to do it if planning to supply an upgrade as it would then keep the ipod jitter and add its own from the data conversion, as well as its own inherent jitter.
 
pretty sure you arent understanding what i'm saying either, the DSP to allow this whole idevice digital out to happen must generate its own clock, it either does this by actually having a separate audio clock or clocks (with speeds at multiples of the 22.1x and 24x audio frequencies) and a USB/DSP clock, or simply by using the DSP clock and some math to divide the the one clockspeed to generate an audio clock at the desired frequency as well as what it needs for the DSP and MCU. using the clock in the ipod to control the clock of the fostex would be an idiot move that fostex just wouldnt make; if it were even possible (and i dont think it is, the ipod was never designed to do this)

 

[cooperpwc]

Jeremy, you lost me at hello. 
 
(I am very surprised if reclocking for jitter reduction is performed by the Fostex HP-P1 since they don't declare it. I have the Fostex manual and they are not shy about declaring features. However this really is beyond my technical skills.)

 

[qusp]

hehe yeah it seems i did, because you completely missed what i said =) i'll try and use a bit less lingo here and try again
 
they pretty much HAVE to (and you can pretty much disregard the words pretty much), one of the devices has to act as master and supply the master clock for the dac; which is designated mclk, following basic engineering principles this clock source/crystal should be as close to the dac chip as possible and since the ipod cannot act as USB master to control the data flow, not only would it be incredibly stupid to have the ipod at the end of another non-standard cable and at least 2 unsuitable connectors away supplying the audio clock when just a few cm of circuit trace causes jitter, but i doubt its even possible.
 
i think you are confusing resampling with reclocking and tbh mate, i dont think that using the fact something that isnt made a big deal of by the marketing department, as a reason why it mustnt have it, is that valid. Perhaps the technical team didnt make a big deal about it because there is no other choice but to do it and thus hardly a technical marvel.
 
the other choice, as i mentioned is to sidestep that process by controlling the data-stream synchronously, which means that the fostex would control the rate the data is clocked out from the ipod, which would actually be superior. in both cases the clock is supplied by the fostex and it either has a dedicated crystal for doing this, or it uses the previously mentioned math to divide its DSP clock frequency to produce a suitable audio clock frequency
 
bare in mind there are 2 clocks at play here, one for the usb and another for the local audio clocking, but they can be one and the same if a clock recovery, or clock division process is used

 

[deniall83]

Looks like i'll be getting one of these to pair with a DACMini. 

 

[Duncical]

Hey when I put my iPod on the i20 the volume goes down to 3 bars. Is this normal?