[iFi audio]

I've read that AMR paper before but thanks for bringing it up again.

I hadn't realised that John Westlake was stretching the truth a little until I read this review in Hi-fi World:

http://www.hi-fiworld.co.uk/index.php/cd-dvd-blu-ray/62-cd-reviews/642-audiolab-q-dac-filters-.html

You are correct that ringing is not eliminated, only reduced. The effect is still quite audible though.

Hi,
 
You may wish to look at this:
https://www.dropbox.com/sh/hztjbez6hj916i4/IwX-ECxFi7/1%20-%20Stereophile%20equivalent#lh:null-03%20-%20iDSD%20nano%20Impulse%20response%2044.1KHz%20minimum%20Filter.jpg
 
This is the Minimum Phase filter of the nano iDSD (the micro iDSD will come):

As you can see, the nano iDSD has a distinct lack of ringing.
 
So as not to clog up this thread, for further graphs/measurements.
https://www.dropbox.com/sh/hztjbez6hj916i4/li9iSIXOac
 
Just to reference our measurements of the nano iDSD, a customer this morning pointed us to this review by Triode Dick aka Dick van de Merwe - who really knows what he is talking about and also supplies accurate measurement data in the review - using his own and not inexpensive Audio Precision gear.
 
http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=da&ie=UTF-8&u=http%3A%2F%2Fwww.audio-creative.nl%2Fhifi%2Fifi-nano-idsd%2F
 
Just for Technobear - the Metrum Hex is Euro2,850. 

 
We hope you like this very thorough review and analysis of the nano iDSD.

 

[technobear]

All very interesting. Thank you.

I would like to add one more wish for the micro iDSD:

i) the audio signal will not pass through a volume pot on its way to the RCA outputs.

Preferably the RCA outputs should be fixed at 2V but if they must be variable then please use a stepped attenuator chip. I believe you already do this in the iTUBE. What is the implementation in the iCAN?

 

[iFi audio]

All very interesting. Thank you.

I would like to add one more wish for the micro iDSD:

i) the audio signal will not pass through a volume pot on its way to the RCA outputs.

Preferably the RCA outputs should be fixed at 2V but if they must be variable then please use a stepped attenuator chip. I believe you already do this in the iTUBE. What is the implementation in the iCAN?

Hi,
 
The iCAN micro and iCAN nano and and iTUBE micro (and iDAC micro) all use an analogue volume control made for us by a factory founded by former Noble (resistors/potentiometers) engineers.
 
The specifications are very tight and exceed those for Alps Blue Velvet volume controls.
 
The iDSD uses a 64-position stepped attenuator Chip, controlled via the MCU which senses the Volume control position via an ADC. This is actually integrated with the Headphone/Line-Out Amplifier, allowing us to make the iDSD nano as small as we did.
 
The exact design of the iDSD micro's line outputs is still under debate, as some seem to be asking for a fixed output while others demand a variable output. So give it some thought guys!
 
thanks

 

[roamling]

... The exact design of the iDSD micro's line outputs is still under debate, as some seem to be asking for a fixed output while others demand a variable output. So give it some thought guys!
 
thanks

 
I would prefer a fixed output (2V). The main function of this device is to work as a standalone DAC/Headphone amp in my opinion. If there is a gain switch (which I think ther will be) there should be no issues adjusting the volume for low impedance headphones. The RCA out, in my opinion, is mainly to connect the micro iDSD to a an integrated amplifier or another headphone amp (for example to drive high impedance headphone or low efficiency headphones). I don't see any need to have an variable output and personally I haven't used a variable output in over 20 years of my HiFi existence. I would focus on implementing other functionality that already has been mentioned in this thread so far, and there is plenty!  

 

[iFi audio]

   
I would prefer a fixed output (2V). The main function of this device is to work as a standalone DAC/Headphone amp in my opinion. If there is a gain switch (which I think ther will be) there should be no issues adjusting the volume for low impedance headphones. The RCA out, in my opinion, is mainly to connect the micro iDSD to a an integrated amplifier or another headphone amp (for example to drive high impedance headphone or low efficiency headphones). I don't see any need to have an variable output and personally I haven't used a variable output in over 20 years of my HiFi existence. I would focus on implementing other functionality that already has been mentioned in this thread so far, and there is plenty!  

 
Hi,
 
Understood.
 
We will try - opinions are evenly-matched on this one. Because the desktop speaker market is growing and people would like to directly feed powered speakers.
 
Keep it coming....really appreciated design inputs from you all.

 

[ostewart]

Another addition i would like to see is Optical in, as it's small and just adds a little more versatility, say with a TV setup to a receiver it would be awesome.

 

[iFi audio]

New Schedule – all systems go!
Well, across the board, the volume of informative design inputs from you has left us with little opportunity to sit around and sip Starbucks.
 
We are jamming on a 7-day week (in between exhibiting at the Brighton AudioWorld Show this weekend just gone which was great as there were one or two head-fi customers there). Part 1 here: https://www.facebook.com/media/set/?set=a.675882262447519.1073741875.460963790606035&type=1
 
What we can do is update you with the following schedule:
 
Design ideas:                                                                     close 11^th April
 
Feature specs:                                                                  18^th April
 
In iFi stockists:                                                                  early July
 
The close date has been brought forward slightly as the emails and FaceBook messages and the Head-Fi comments have all given us a very strong idea of what is going to make the micro iDSD an absolutely storming product.
 
Some of you even prepared a pdf with photoshopped gfx! Super cool and groovy.
 
As you can see from the new schedule above, the close of all inputs in 11^th April and in the run up, we will publish features that are going to make it.
 
Around 18^th April, we will outline the salient features and in early July, the micro iDSD is expected to be in stores.
 
The launch of the micro iDSD is expected in early July as the inputs you gave us means it will take us a little longer to implement but it should be worth the extra few weeks’ wait.
 
Can I Pre-Order? Yes, but no Pre-Pay
Some have you asked if you can reserve the micro iDSD – our answer is for you to contact your iFi stockist.
 
Some of you have also asked about a discount for pre-ordering. For iFi, we do not ask you to pay 1 penny upfront so there is no discounted price.
 
The idea of using our customers to fund us is not something we like nor do. So just leave your details with your stockist and only pay once it is ready to be posted out to you in July.
 
We like to be transparent, fair and thank you for your design inputs so far.

 

[kugino]

Great news! Now get to work in the mini iDSD!!

 

[iFi audio]

Great news! Now get to work in the mini iDSD!!

Thanks - through these design inputs some of which are more applicable to the mini means good news for the mini too.
 
One stone, two birds and all that.

 

[iFi audio]

  Another addition i would like to see is Optical in, as it's small and just adds a little more versatility, say with a TV setup to a receiver it would be awesome.

 
Optical has popped up but not so much.
 
Something else is coming down the skunkworks which is has optical in. 

 

[ostewart]

Ah ok thats cool looking forward to it.
 
It was because a few people use Optical and it makes it very versatile.
 
I just got a DDS DAC-01 which has every input under the sun with a tube output and solid state amp output, but it is the size of the Mini series you guys will bring out.

 

[technobear]

Ah ok thats cool looking forward to it.

It was because a few people use Optical and it makes it very versatile.

I just got a DDS DAC-01 which has every input under the sun with a tube output and solid state amp output, but it is the size of the Mini series you guys will bring out.

For optical from your TV to your receiver, I recommend you look out for a used Beresford Caiman. Fit and forget.

 

[iFi audio]

Bring in the world-wide iFi community
Having been up and running for a few years, iFi is available across the globe and we always try to bring our customers into the one, same iFi community.
 
We have received emails from our distributors from different non-English speaking countries. Their customers were confused as to whether or not they could post on HF.
 
So, we checked with HF and admin confirmed that foreign languages can be posted, but Google translated version must be posted along with the original foreign language.
 
Hence, over the next few days, we shall look to see new posts from people around the globe. These are new members to head-Fi and please understand that English is not their mother tongue so their explanation of the features they would like to may not be crystal clear.
 
We shall try to ask our distributors and their customers to post from countries ranging from Japan > Finland.
 
These are the comments collated so far and as the close of design inputs is 11^th April, we thought it would be nice to share their comments with you.
 
Thank you for your understanding and we look forward to an even bigger and better Crowd-Design project.

 

[darkub]

Hi,

Understood.

We will try - opinions are evenly-matched on this one. Because the desktop speaker market is growing and people would like to directly feed powered speakers.

Keep it coming....really appreciated design inputs from you all.

hi
But there is i tube to control volume.so I prefer fixed oitput

 

[darkub]

I would like to have optical input(most of receivers have optic output),LEDs on front panel,no headphone output(iCan is there to serve!)