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iDSD micro Black Label. Tour details (page 147). Release info (page 153). - Page 44

Poll Results: What % of your listening is Desktop vs Portable? (click on ONE answer please)

Poll expired: Apr 22, 2014  
  • 22% (30)
    Desktop (100%)
  • 36% (49)
    Desktop (75%) & Portable (25%)
  • 18% (25)
    Desktop (50%) & Portable (50%)
  • 17% (24)
    Desktop (25%) & Portable (75%)
  • 5% (7)
    Portable (100%)
135 Total Votes  
post #646 of 2380
Quote:

 

How this benefits the listener

In practice one might connect the SPDIF connector as input from an external SPDIF source (in this case to power the iDSD, no USB source is needed, a 5V Charger will do). The source may be a streamer, DVD Player or some such component.

 

One may even connect USB and SPDIF together, just remember that playing USB overrides SPDIF.

 

 

 

So let me see if I got it correct:

I can connect my sat receiver via analog audio (using an optical cable I think) to iDSD and the computer via USB; then RCA connectors to stereo amplifier or just plug a headphone on the front panel.

When I turn on my sat receiver, I will get the sound through my ampli or headphone and iDSD will run on battery. When the battery is running short, I can just turn on the computer, but then SPDIF will work as out (or just stop working as input since I have an optical cable plugged in) and it will recharge my battery. In this case USB will be the input, even if the computer is not playing any audio file, I guess.

I can't continue listening to sat until I turn off the computer or until I unplug the USB cable and plug it into a 5v charger (but this will be very difficult since all cable are nicely hidden!).

Is that right or is there a way to continue listening to SPDIF input with USB cable connected to computer and computer on (so as power source only)?

Does the USB port delivers power (and then recharges the iDSD internal battery) even when the pc is off?

Thanks!


Edited by guglia72 - 6/4/14 at 4:46am
post #647 of 2380
Actually, I got a little bit complicated there @.@
post #648 of 2380
Quote:
Originally Posted by BillsonChang007 View Post

Actually, I got a little bit complicated there @.@

It did indeed. But if it actually works that way that you can have both SPDIF in and Computer USB connected at the same time and the micro iDSD picks up what is the active signal and charges the battery at the same time then we have a winner.

post #649 of 2380
Quote:
Originally Posted by roamling View Post

It did indeed. But if it actually works that way that you can have both SPDIF in and Computer USB connected at the same time and the micro iDSD picks up what is the active signal and charges the battery at the same time then we have a winner.

And it actually solved some of the problems we mentioned earlier (switching between SPDIF and USB). Great work!
post #650 of 2380
Quote:
Originally Posted by BillsonChang007 View Post


And it actually solved some of the problems we mentioned earlier (switching between SPDIF and USB). Great work!

 Of course we have to wait and see if IFI can confirm if this is the way the DAC is working or not, until then I am cautious with joy :wink: 

post #651 of 2380
Thread Starter 
Quote:
Originally Posted by guglia72 View Post
 

 

So let me see if I got it correct:

I can connect my sat receiver via analog audio (using an optical cable I think) to iDSD and the computer via USB; then RCA connectors to stereo amplifier or just plug a headphone on the front panel.

When I turn on my sat receiver, I will get the sound through my ampli or headphone and iDSD will run on battery. When the battery is running short, I can just turn on the computer, but then SPDIF will work as out (or just stop working as input since I have an optical cable plugged in) and it will recharge my battery. In this case USB will be the input, even if the computer is not playing any audio file, I guess.

I can't continue listening to sat until I turn off the computer or until I unplug the USB cable and plug it into a 5v charger (but this will be very difficult since all cable are nicely hidden!).

Is that right or is there a way to continue listening to SPDIF input with USB cable connected to computer and computer on (so as power source only)?

Does the USB port delivers power (and then recharges the iDSD internal battery) even when the pc is off?

Thanks!

 

Hi,

 

If you run the iDSD using SPDIF input and you run it on battery, once it gets low, your PC (if switched on) can recharge the battery. BUT only if you play USB audio in (ie: start play in JRMC), the SPDIF will revert back to output. 

 

But if you leave the PC switch on and not play audio, it will only recharge the iDSD.

 

Alternatively, with the same above SPDIF signal input, if the micro iDSD is not placed near a PC (to supply USB power) then you can use a 5v type charger to recharge the iDSD instead.

 

If the PC is off, there is no power being supplied via USB so the iDSD will not be re-charged!

 

With PCs, sleep mode usually retains charging (you close the lid on your PC, leave your iPhone connected via USB and it still charges) so you can use the sleep mode to keep the iDSD charged.

 

Hope this helps.

post #652 of 2380
Thread Starter 
Quote:
Originally Posted by BillsonChang007 View Post


And it actually solved some of the problems we mentioned earlier (switching between SPDIF and USB). Great work!

Yes Bilson and yes Roamling.

 

You guys got it!

 

Damm - we should have thought of this as a puzzle. :blink:

post #653 of 2380
Quote:
Originally Posted by iFi audio View Post
 

Yes Bilson and yes Roamling.

 

You guys got it!

 

Damm - we should have thought of this as a puzzle. :blink:

 

we don't mind any retrospective price awards... :ksc75smile:

post #654 of 2380
Thread Starter 
Quote:
Originally Posted by roamling View Post
 

 

we don't mind any retrospective price awards... :ksc75smile:

 

Okay....now you are teasing us back! I guess we are due some.

post #655 of 2380

Reading the dialogue and OP comments, I like the way the micro iDSD is progressing. It has a good hope of delivering on what has been is promised.

 

Peking Duck has noted what the company and the Japanese reviewers noted, of the low-end grunt of the micro iDSD.

 

I hope it doesn’t disappoint as it seems almost too good.

 

 

Anyone have good recommendation for a UK retailer for this?


Edited by Mr Creosote - 6/4/14 at 10:15am
post #656 of 2380
How does the headphone out on the micro iDSD compare to the iCan? If there still s ned for a iCan still?
post #657 of 2380
Thread Starter 

Super Duper Features 1.4

 

Femto Clocks – Picky about Phase Noise

 

 

Background

All Femto clocks are good, very good in fact. They exhibit jitter levels lower than most clock crystals which leads to better sonics. An oft quoted benchmark for accuracy is Femtoseconds (Fs) / parts per million.

 

Back in 2008, before the word “Femto Clock” became all the rage, AMR developed a special type of clock in DP-777 as part of the “Global Master Timing” (GMT) and “Jitter less” technologies (why special? See below, because not all Femto clocks are the same).

 

We called it the GMT Clock platform (which is comprised of specialised hardware+software) as it is not just buying a “clock in a can” and job done.

 

Having worked with all sorts of clocks, including discrete, Rubidium, Superclocks and not the least Femto clocks over the years, we know them quite well.

 

All Femto Clocks exhibit excellent low phase-noise (measured jitter within the clock). However, as their origins lay in being part of SONET (http://en.wikipedia.org/wiki/Synchronous_optical_networking), the popular SONET targeted “Femto-clock” is less desirable as its best phase-noise performance is concentrated in the > 12KHz region (read: at the very top and way above the audible band, so benefits audio less).

 

As an example, this link highlights the use of Femtoclock technology in the telecommunications sector where they are spec'd for:

http://www.thinksmallcell.com/System/clock-frequency-accuracy-within-femtocells-for-timing-and-location.html

 

 

The ubiquitous Femto (SONET) Clock

This is an Optical Comm system (aka SONET - which is a Subset). We added the blue line to highlight the -70dBr region so that when referenced to the AP2 chart in the next section of the micro iDSD, it is more of an “apple to apple” comparison.

 

The spike at 50KHz is the "signal" As you can see, for quite a few KHz around this region, phase noise is low, this is what matters in this application.

 

However, the area around the green arrow is the most crucial human audible range of 20Hz > 20kHz where phase noise performance is less impressive in the region of -100dB to -70dB. 

 

 

Explanation

Therefore, the key for AMR was to design a new system, the “GMT” clock platform which not only exhibits the lowest phase-noise in the crucial audible band, but offers precision (< 0.004ppm tolerance) adjustability with literally millions of possible frequencies  (as per the DP-777 "GMT" Technical Paper).

 

The GMT Clock system designed into the micro iDSD measures <280 Fs, comparable to many Femto-Clocks (because it was designed to give low jitter).

 

From the AP2 graph of the micro iDSD below, you can see that jitter in 9kHz > 15 kHz is very good, the micro iDSD noise floor goes all the way down to -150dB which is virtually across the board.with no spikes.

 

AMR/iFi GMT Clock Platform

 

 

How this benefits the user

Consistent, across the board negligible jitter means timing is supreme, with just the right amount of attack/decay and of course, tonal accuracy. We are really pleased with the very low jitter performance of the micro iDSD in the most crucial audible range – in fact, we would not mind if customers pit it against significantly more expensive DACs.

 

We hope you found this interesting as it sheds some light on the particular attention we have paid to parts performance and custom design in the micro iDSD (actually, we took it from the DP-777!).

 

 

 

 

 

 

 

Addendum: What about Rubidium Clocks?

Below is a chart of several types of rubidium clocks. What they all exhibit is many sharp spikes in phase noise. Even though they measure well, some down to -150dB, when they spike, noise levels jump up to -70dB to -90dB.

This is far from ideal which is why we have not used such clocks, neither in iFi nor AMR products. It all boils down to paying close attention to the specific clock/s used and its performance in the audible range.

 

post #658 of 2380

so in other words, this thing sounds good. ;)

post #659 of 2380
Thread Starter 
Quote:
Originally Posted by kugino View Post
 

so in other words, this thing sounds good. ;)

 

Fingers crossed - but we also hope readers like to know a little about the history to the different clocks out there. As they didn't stem from audio applications, they shouldn't be expected to be a match made in heaven for audio applications.

post #660 of 2380
Quote:
Originally Posted by Mr Creosote View Post

Anyone have good recommendation for a UK retailer for this?

http://ifi-audio.com/sales/#unitedkingdom

Darren at Audio Elevation is a good chap. He'll sort you out.
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