Head-Fi.org › Forums › Sponsor Announcements and Deals › iDSD micro Crowd-Designed! Phase 3: iPhone 6 Plus & Micro iDSD. Ultimate transport/dac/amp? (page 129)
New Posts  All Forums:Forum Nav:

iDSD micro Crowd-Designed! Phase 3: iPhone 6 Plus & Micro iDSD. Ultimate transport/dac/amp? (page...

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 1926
Thread Starter 

Micro iDSD: Urban Ultra-Fidelity













 




Introduction

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:

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








 

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/30#post_10399550

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/60#post_10404689

Tech Talk with Thorsten - part 3 - why not balanced

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/135#post_10422306

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/375#post_10482095

Designer's Diary - 1 - early mechanical design

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/315#post_10467562

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/405#post_10496728

Designer's Diary - 3 - three prototypes

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/450#post_10518630

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/510#post_10545817

Software Design Team's Notes - 2 - star clocking

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/525#post_10569555

The Final Countdown

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/555#post_10583107

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/585#post_10585670

Super-Duper Features 1.2 - filters, ringing

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/615#post_10591026

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/630#post_10599164

Super-Duper Features 1.3 - the intelligent SPDIF port

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/630#post_10602951

Super-Duper Features 1.4 - why not femto clocks?

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/645#post_10606215

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/660#post_10611007

Technical Notes - 3 - cherry picking the chipset

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/690#post_10617050

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/720#post_10623177

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/720#post_10625021

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/735#post_10627797

Addendum: Super Duper 1.7 SmartPower: charging details

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/735#post_10628199

Power Supply Special - 1

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/765#post_10631317

Power Supply Special - 2

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/765#post_10633478

Super-Duper Features 1.8 - the 3.5mm analogue input

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/795#post_10635371

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/825#post_10641278

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/840#post_10641478

Super-Duper Features 1.9 - signal polarity +/-

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/855#post_10643380

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/885#post_10646012

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/990#post_10658655

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/1050#post_10662147

Outta This World 1 - octa-DSD

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/1050#post_10664154

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/1080#post_10667244

Super-Duper Features 2.2 - built-in iPurifier

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/1125#post_10671925

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/1140#post_10674374

Jitter Measurements

http://www.head-fi.org/t/711217/idsd-micro-crowd-design-the-meaty-monsters-are-flying-out-page-95/1200#post_10676898

Smart Power (part I)

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-smartpower-how-why-and-what-it-does-page-98/1455#post_10729764







 

What speakers do you use for development?

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-smartpower-how-why-and-what-it-does-page-98/1500#post_10733382






 

How, why and what the Battery recharging function does.








 

SmartPower (partII)

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-smartpower-part-ii-just-recharge-until-light-goes-out-page-102/1515#post_10735399








 

Measurments of the nano iDSD: just for a bit of fun
http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-a-teeny-weeny-update-page-104/1770#post_10776053






 


"Pop" goes DSD - why does this happen?

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-when-and-where-do-you-listen-to-the-meaty-monster-page-121/1815#post_10808320


 SmartPower - Please feed the Meaty Monster (part 1)

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-smartpower-please-feed-the-meaty-monster-page-124/1845#post_10817967







 

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

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-smartpower-please-feed-the-meaty-monster-page-124/1845#post_10818222





 







 

3 Steps: DSD "DoP pop fix" firmware update

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-smartpower-please-feed-the-meaty-monster-page-124/1890#post_10905962






 

iCLUB video announcement!



 

http://www.head-fi.org/t/711217/idsd-micro-crowd-designed-phase-2-dsd-dop-pop-fix-page-127/1890#post_10918815







 

Thanks to Bilson and Technobear for this suggestion!








 

From the staff and directors of team iFi.


Edited by iFi audio - Today at 3:54 am
post #2 of 1926

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 1926

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 1926

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 1926

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.

 

:k701smile: 

post #6 of 1926
Quote:
 
  • iFi integrated USB noise/power filters (ie. integrate the iFi iPurifier inside the Micro iDSD).

 

I second that!

post #7 of 1926

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 1926

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 1926

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 1926

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 1926

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 1926
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 1926

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 1926
Quote:
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 1926
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?

Manualvin
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Sponsor Announcements and Deals
Head-Fi.org › Forums › Sponsor Announcements and Deals › iDSD micro Crowd-Designed! Phase 3: iPhone 6 Plus & Micro iDSD. Ultimate transport/dac/amp? (page 129)