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iDSD micro Crowd-Designed! And the new Firmware 'flavours' are here (page 138)

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 #1 of 2090
Thread Starter 

Micro iDSD: Urban Ultra-Fidelity



The next iFi advanced skunkworks product is the micro iDSD. It is the bigger brother of the nano iDSD, a top-selling portable DAC in Japan and with a loyal Head-Fi following around the globe.

The micro iDSD saw its global launch on 28 July.


For your local retailer, please click on this link:



We are all ears (no pun intended)

Thanks to you, the customer, we now have a super accomplished range that spans 10 products and continues to grow. Along the way, your suggestions have really had an impact - such as the 2013 update of the Head-Fi #1 micro iCAN with gain selection.

Table of Contents: for Noobs start herebiggrin.gif

Tech Talk with Thorsten - part 1 - iDSD core specs, take one


Tech Talk with Thorsten - part 2 - why Burr-Brown


Tech Talk with Thorsten - part 3 - why not balanced


Which USB Asynch does ifi use? AMR's of course!


Designer's Diary - 1 - early mechanical design


Designer's Diary - 2 - power supply gremlins, back to the drawing board


Designer's Diary - 3 - three prototypes


Software Design Team's Notes - 1 - the XMOS solution


Software Design Team's Notes - 2 - star clocking


The Final Countdown


Super-Duper Features 1.1 - the dual-core Burr-Brown DACs


Super-Duper Features 1.2 - filters, ringing


Software Design Team's Notes - 3 - ARM microprocessor, automated extras


Super-Duper Features 1.3 - the intelligent SPDIF port


Super-Duper Features 1.4 - why not femto clocks?


Measurements Matter (Not!) Part I of III – Hearing a fly fart at 20 feet - Signal to Noise Ratio


Technical Notes - 3 - cherry picking the chipset


Super-Duper Features 1.5 - direct/pre-amp output, ALPS micro switches, volume pot


Super-Duper Features 1.6 - 3D holographic for headphones and speakers


Outta This World 3 and Super-Duper Features 1.7 - SmartPower and turbo mode


Addendum: Super Duper 1.7 SmartPower: charging details


Power Supply Special - 1


Power Supply Special - 2


Super-Duper Features 1.8 - the 3.5mm analogue input


Software Design Team's Notes - 4 - DSD, no ordinary DSD


Why not "more modern and/or better spec chips"?


Super-Duper Features 1.9 - signal polarity +/-


Outta This World 2 - turbo/normal/eco and IEMatch


Super-Duper Features 2.1 - the CCK/OTG USB port


Software Design Team's Notes - 5 - digital and analogue filters


Outta This World 1 - octa-DSD


The 'Octa-Adopter' 512 units and what is iClub?


Super-Duper Features 2.2 - built-in iPurifier


Addendum on the CCK/OTG Port and what accessories are included in the box


Jitter Measurements


Smart Power (part I)


What speakers do you use for development?



How, why and what the Battery recharging function does.


SmartPower (partII)


Measurments of the nano iDSD: just for a bit of fun

"Pop" goes DSD - why does this happen?


 SmartPower - Please feed the Meaty Monster (part 1)


Orico USB Higher-Power USA Charger - one sure way to feed the meaty monster (Part2)


3 Steps: DSD "DoP pop fix" firmware update


iCLUB video announcement!


AKH K-1000: elephunked, on-the-go


Thanks to Bilson and Technobear for this suggestion!


From the staff and directors of team iFi.

Edited by iFi audio - 4/1/15 at 10:04am
post #2 of 2090

1) async USB, SPDIF, TOSlink, coax inputs


2) balanced outs


3) RCA outs


4) headphone jack


5) both battery-powered and 


6) AC powered


7) phase invert toggle


8) LED bitrate/resolution readout


9) Leatherman fold-out multitool (ok, maybe this could wait)

post #3 of 2090

1.) TRRS balanced 1/8" output. XLR takes up too much space. (But include an adaptor please).

2.) PROPER USB-B none of this micro/mini crap.

3.) I2S input, may be for a future iFi transport.

4.) A choice of digital filters.

5.) Defeat-able analogue volume control

6.) A USB interface that doesn't take any of the 5V from the USB cable.

7.) S/Pdif input (RCA is okay, but BNC would be nice).

8.) This is asking a lot, but may be an FPGA implementation, like that of Chord and more recently PS Audio in place of a mass produced DAC chip.

9.) This last one is a bit personal, but I'd love to have feet I don't have to stick on myself. Never sure if I have them in the 'right' places.

post #4 of 2090

1. LEDs showing sample rate on top of the unit, something like the 3 LEDs on top left of the micro iCan


2. keep the front clean:

   a. Headphone Out

   b. flick switch (on/off) for upsampling option for PCM files (to PCM/384kHz)

   c. flick switch for digital filter (like on iDSD nano, maybe add extra filter so there are three switch positions)


3. on the back:

   a. USB 3.0 in (like on iDSD nano, so that iPurifier and the USB Gemini cable can be used)

   b. RCA out


hope that makes sense

Edited by roamling - 3/22/14 at 6:12am
post #5 of 2090

Parts of this post are a (slightly edited and expanded) re-post I sent to someone within the iFi network, but here are my thoughts:


This is quite cool for what it is. If I needed just a decent desktop set-up this would a fine choice, but I went for the mighty CEntrance HiFi-8 for a very powerful desktop/portable DAC/amp device.


Looking at some of the suggestions already, I concur with many of them, but here are my suggestions of really good implementations, if possible:

  • Long battery power,
  • Native PCM conversion, from Redbook all the way up to DSD/DXD (for those crowds who are fans). Truth is I know that this is a feature that's baked in already (from my insider friend), but I'm not sure if many of the Head-Fi crowd knew that, so yay, I guess!!?
  • True balanced in/out feature (differential perhaps?),
  • FPGA DAC chips,
  • Both full USB and S/PDIF inputs (I say optical for the current PMP devices, but maybe have various versions of the Micro iDSD for different crowds aka HiFi-M8 style?),
  • iFi integrated USB noise/power filters (ie. integrate the iFi iPurifier inside the Micro iDSD).
  • LED indicator's of current sample/frequency rate of music playing.


These would make this device my new desktop purchase, over that of the Chord Hugo.

Even so, my CEntrance HiFi-M8 is hard to beat, especially on the power/portability/features, but I can neither afford an advanced DAC beyond the HiF-M8 for my desktop. Cost is not the biggest issue, as I can save for good devices, but it's the value of that device for the long-run.


To be honest, right now DSD has no interest to me as I have no music in DSD, nor are my favorite artists/albums available in DSD quality. I still believe that 24 bit/192kHz (and 96/kHz) to be ultra-fi quality.

I respect that DSD can be sumit-fi, but at this moment about 98% of my music is redbook CD lossless.

However, your Micro iDSD will compete strongly against other DSD implementations, just as the Nano iDSD did against Shiit Audio's Loki.

I'll keep my eyes and ears open to your (iFi) implementation of DSD tech.



post #6 of 2090
  • iFi integrated USB noise/power filters (ie. integrate the iFi iPurifier inside the Micro iDSD).


I second that!

post #7 of 2090

redesign the layout, top led is useless if we stack them , move it to the front, have more led for better understanding


bring the filter switch to the front


bring the RCA output to the rear


Make the RCA output as dual function, selection by a switch between digital and analog, once digital option is selected, the RCA output becomes a Digital output and a Digital Input. 


Keep the Battery and increase capacity by 10%, technically good and still portable


beef up the headphone output to 250mW


Better Windows Driver, especially for the DSD part


1/4 inch headphone jack


incorporate  the iPurifier internally, lesser connectors

PCM to DSD mastering :)


post #8 of 2090

Ok, here is my design :-)


I still think the LEDs for the Sampling Frequency should be on top. Even when stacking items the micro iDSD can be on top.

I used a large headphone out in my design but of course it could also be a 3.5mm out instead






post #9 of 2090

Ok I wont go technical.


Only things I would change are put a 6.3mm socket as it's easier to use a 6.3mm to 3.5mm adapter than the other way round.


Also RCA output on the back.


I think that simple is best, so have the USB in and RCA out on the back along with the upsample toggle.


On the front have the headphone out, the volume pot and maybe the filter toggle.


I think Coax and optical is not needed and is over complicated, keep it simple for PC use as there will be another product for all your optical and coax needs.


Also the headphone out could be a little more powerful, if the space allows, lets say 200mw-300mw or close to those values.


iFi are great guys, and it's great to involve the customers! good luck

post #10 of 2090

I currently own the nano iDSD and like how it sounded for the price I'm paying.


I also own the exaSound e28 which is based on ESS Sabre Ref DAC chip, and of course the iDSD is no match to it in terms of sound quality.


I must say the Burr Brown DSD1793 chip on the nano iDSD is not very good (especially on low frequencies where it sounds fat and boomy).


If the new micro iDSD is consider a higher class of nano iDSD, then I would think it make sense to go for ESS DAC chip for improve sonic quality.


Also, I think the gain output of the headphone jack and the RCA should be separated. Current, the RCA output level is way too low as line level (I only measured 1.65V @  max. with 1kHz @ FS) , but this is consider too high when driving high sensitivity IEM. Perhaps a gain output sensitivity control will be good to take care of this issue rather than the expensive approach of using 2 different op-amp circuits (although it would be good to have :D).


Better in-build USB noise isolation is a must as the current nano iDSD is extremely poor in filtering computer noises.


DXD and DSD playback capabilities should stay as this is the main reason why I purchased nano iDSD. For those not interested in these formats, iFi already has the iDAC which is pretty good (and happens to be based on ESS DAC chip).

If all this are make available on the micro iDSD, I would not be hesitate to buy it and retire my current iDSD :beerchug: 

Edited by kktan - 3/23/14 at 11:11pm
post #11 of 2090

I was thinking about an alternative design which does not include any headphone amp section. Lets call it more DAC focused design

Without an external power supply the headphone amp will always be limited by the power available, so why not complete remove the headphone amp section and built a killer desktop DAC!


That means removing the volume knob and headphone out from the front, there will only be the 2 flick switches for the Filter and Up-sampling option and if you wish, the LEDs for the Sampling Frequency at the front (same labeling of LED's like my on top design but 2 rows of 3 LED's next to each other instead)


Then go nuts inside the DAC, I don't have to much technical knowledge but things that come to mind is a dual DAC design and the already mentioned iPurifier implementation.


In combination with the iCan (or any other desktop headphone amp) this DAC only design would be a great desktop combo for all available High Res Audio formats.

For mobile use the nano iDSD will be a viable alternative with a different user group in mind.


Another feature I would like to add is a USB upgradable firmware option for the DAC section.

post #12 of 2090
Thread Starter 

Wowzers, this is a stonking start.


A few answers to questions received already:


1. The micro iDSD is a pure DSD/PCM/DXD dac. So it plays all 3 main formats in their purest form (ie: without conversion to one of the other formats). More on this in the coming weeks. It does not ONLY play DSD! It is pretty darn powerful, just like its baby brother the nano iDSD!


2. The micro chassis size is very much a "cigar box" type size. Approximately 158(l)x68(w)x28(h)mm. Its aims is desktop whilst being portable. A few very good suggestions have already come our way on this so watch this space!


thanks and keep em coming!

post #13 of 2090

yes ampless DAC only

RCA at rear

differential signal pairs on circuit board to reduce noise.

transformer coupled outputs

on top display indicators

rubberized coating if going to be portable.

DSD analog LPF

post #14 of 2090
Originally Posted by iFi audio View Post


1. The micro iDSD is a pure DSD/PCM/DXD dac. So it plays all 3 main formats in their purest form (ie: without conversion to one of the other formats).


Just to clarify on that - that means no PCM only up-sampling either? For example 16bit/44khz PCM recordings upsampled to 32bit/384khz PCM (that was my suggestion) 

Chord Audio even claims the sound quality limit for sampling lies in the MHz region but they seem to build their DAC strategy mainly on implementing these filter algorithms.


I had an AQVOX DAC in the past which had a load of options for oversampling, filters and a phase invert option. Out of the three I found the Phase Invert setting useful sometimes. 

So maybe that could be an option as well at the front of the suggested design (instead of an up-sampling option)

I am not sure how many of the old master tapes that are released in DSD or High Res PCM might be affected by an inverted phase but I assume that could be an issue. 


Looking forward to hear your thoughts on that. 

Edited by roamling - 3/24/14 at 5:40am
post #15 of 2090
Features from a mobile practitioner and not too technical product requirements, focus on usability and pairing with mobile phones:

1) NFC chipset for NFC to Bluetooth handover upon tapping of NFC handset to amp for automatic pairing via android streaming via Bluetooth a2dp
2) tap again to disconnect
3) dsD support
4) enough power output to drive full sized headphones adequately at a volume that is reasonably good
5) chassis cool enough with heat dissipation
6) noise reduction from plugins including USB
7) color options of the shell
8) rubberized corners that protect chassis from scraping against desk
9) toggle for lower volume selector out of the box, seems to be a requirement in uk if I'm not mistaken to comply to so that there is always a low volume trigger to protect ears
10) muses 01 and muses 02. Perhaps?

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