iDAC 2 - Quad DSD256 / PCM 384Khz / USB DAC & headphone amp

[buonassi]

A little late to the game, but does the iDAC2 support Audirvana+ "Direct Mode"?  

[buonassi]

On 12/29/2017 at 3:20 PM, AMR/iFi audio said:

 

This is USB Audio Class 2.0 compliant deivce and as such it should work. But this software related matter than anything else, hence if you want to be in 100% sure, please ask Audirvana about this.

@Jud was able to confirm that his iFi unit works just fine.  You and he just had to be so helpful and responsive, didn't you?  Now I'm going to be forced to break the promise I made to my dad about "not buying audio gear" with the money he gave me for Christmas.  Well, last night I took the plunge and ordered iDAC2+ micro iUSB3.0 which will feed my Arcam rHead phone amp.  The allure of DSD was just too tempting.  Let's see what this burr brown can do with its own filters as well as with upsampling in Audirvana+.  @AMR/iFi audio I'll be sure and post impressions (if not full reviews) here and on headfi of these iFi units after some time with them.  

 

ps, really like the vendor interaction from iFi thus far.  You guys are really involved in the community!

[buonassi]

On 12/31/2017 at 9:07 PM, Les Habitants said:

 

I own this combo and use it in my bedroom system, you won't regret this purchase, it punches WELL above it's weight class.

thx, good to get some reassurance.  Do you think upgrading USB audio cables between both computer/iUSB and iUSB/iDac, will add any sonic difference?  The cables that come with the iFi units look to be good quality, are USB 3.0, and are very short.  My hope is that these cables will not pose an issue given such short length, especially with the reclocker in the mix.  And the USB 3.0 spec - no idea if that is superior to asynchronous transmission integrity.  My gut feeling tells me I'll be fine with the stock cables, but gremlins always seem to punch me in the gut when it comes to my audio fidelity quest.  

 

I read somewhere, can't remember where, that appliances like the schiit eitr or the iUSB3.0 have much more "apparent" effect on SQ than USB cables, and cables would only be the "cherry on top" if you will.  

[buonassi]

Been listening to the iDAC2 for a few nights now.  Not ready to share thoughts at this point, other than to say, so far so good.  I am not having buyer's remorse, let's put it that way.  I still have to allow my brain to adjust to it before I can make comparisons or really speak to its strengths/weaknesses.  

[buonassi]

12 hours ago, Em2016 said:

 

Can you remind me what your chain is, feeding the iDAC2? Only if you don't mind of course.

 

I found that the better quality the USB bus power (cleaner), the better the iDAC2 performed.

 

I got my old man (my dad) the iDAC2 and it's being fed by a Sonore ultraRendu & Uptone LPS-1 combination that I got him also, with all music being up-sampled by Roon to DSD256. It sounds incredible.

 

You don't NEED all that for it to sound great. The above is just to take an already great DAC another level up, sonically (to my ears anyway).

 

 

 

 

MacMini late 2014 , 8 gigs ram, I5 2.6ghz processor, SSD.  Audirvana plus 3.2.4 with a couple top shelf AU plugins (fab filter proQ2 and Goodhertz can opener studio).  USB cable to power supply/reclocker, then another USB cable to the DAC.

 

I opted for the nano iUSB3.0 power supply/cleaner and USB regenerator.  I haven't done any real A/B with and without it in place, but I hear the DAC as being devoid of any noise while using it.  I'm not sure how noisy Mac minis are in the first place, but figured it was an appliance that wouldn't hurt to have, being as serious about computer audio as I am.  That said, I certainly didn't pick up on any USB noise using my Schiit modi multibit when plugged straight into the Mac. 

[buonassi]

or jitter for that matter.  Actually, while I can hear the effects of transient smearing based on digital filters used, I can't say I've actually heard "jitter".  Not sure what to listen for.  Ditto USB noise.  Not sure if that's something that's readily apparent if there's a problem, or if all computers have it, and I just can't pick up on it.  

 

More testing on my end to come - with and without the regenerator on both of my dacs.  

[buonassi]

2 hours ago, Em2016 said:

 

The nano iUSB will provide clean bus power to the iDAC2 - no worries there.

 

Don’t worry yourself too much about hearing for jitter with the asynchronous USB connection there.

 

I think you’ll find the effects of with/without the nano iUSB more obvious. Maybe, maybe not.

 

Also try sox up-sampling to DSD256 or PCM384kHz - this bypasses the iDAC’s internal filtering.

 

Nice setup. Don’t forget to enjoy the music too ! 

 

oh I'm more than familiar with upsampling, but you are so correct - having control over the filter can really help you get the sound YOU want for the type of music you enjoy most.  For me, I have to have a min phase filter, because I value attack and timing of transients over separation (just me).  I have liked the new SOX with both 176.4 and DSD128, but love the very granular control over iZotope SRC in A+.  Unfortunately, my computer won't hang with 256.  DSD is a whole other animal sonically speaking.  Something is definitely going on there, and I'm impressed initially.  More time needed with it. 

 

I'll be updating with some more impressions on the iDAC2 in a couple weeks.  Thanks for the votes of confidence from you and @Les Habitants.  I am happy with this purchase.  

[buonassi]

On 12/11/2017 at 1:39 PM, AMR/iFi audio said:

 

Minimum/Listen Filter selected: 

• 44.1kHz .. .48kHz -> No ASRC, synchronous oversampling to 352.8/384kHz using ultra short FIR (minimum ringing Bezier) digital filter 

 

Specifically for iDAC2 - When you say "minimum/listen" are you referring to minimum ringing or minimum phase?  I think the former is what is meant by these descriptions and also after reading the article on the nano idsd:

https://ifi-audio.com/audio_blog/does-the-nano-idsd-measure-good-bad-or-ugly/

 

Is the "minimum/listen" setting still technically a linear phase filter but with reduced delay of the input signal (less pre and post ringing)?  The impulse response appears to be symmetrical, like a traditional linear phase sharp rolloff filter, but with visibly less ringing before and after the transient (see pic).  At least this is how it is shown in the idsd article.

 

When I think of minimum phase, I think of the filter in the dragonfly red (see other pic), which shows all the ringing post transient.   I'm still learning and may not understand the difference between minimum ringing and minimum phase so please forgive my ignorance. 

 

So is the iDAC2 impulse response symmetrical like the iDSD nano or does it dump all ringing after the transient spike like the minimum phase filter in dragonfly red?  Is it right to call this, technically speaking, a minimum phase filter?

 

[buonassi]

On 12/11/2017 at 1:39 PM, AMR/iFi audio said:

Bitperfect filter selected (all micro products only):

• 44.1kHz ... 384/768kHz -> No ASRC, no upsampling, no digital filter
• DSD64 ... DSD256/512 -> No ASRC, no upsampling, no digital filter

 

so there is an analogue filter i'm assuming.  It seems that the analogue filter imposed by the "bitperfect" setting is static.  Meaning that it starts to rolloff well below 20khz regardless of sample rate being played (except 352.8 and 384khz)  

 

I've tried this with 2x and 4x PCM 44.1 content and I can hear the rolloff when in bit-perfect position.  Yet when I play 8x PCM (352.8khz) content, it sounds like it is extending the high frequencies further, without this noticeable rolloff.  

 

Am I hearing this correctly?  Is this what is happening?  The analogue filter is defeated (bypassed) when sending 8x44.1 or 8X44.8?