The iFi Micro iDSD Signature can do DSD256 DoP with firmware 5.2. I have one and it sounds better than my RME ADI-2 DAC.
On Firmware 5.3 DSD is reduced to DSD128 DoP because they shuffled around some code in the XMOS USB chip to enable MQA rendering.
Unfortunately the way MQA and the code works it puts an overhead on the USB chip that limits it to DSD256 Native or DSD128 DoP when using this firmware (whether decoding MQA or not). But you still have the option of the 5.2 firmware that does DSD512 native (Windows/Linux) and DSD256 DoP. (PC and MAC/Linux)
The ifi Signature DAC AMP works perfectly on Windows 10 JRiver MC with either firmware above and all sample rates upto DSD512 native with ASIO driver and PCM @ 768kHz on firmware 5.2. (DSD256 native and PCM 384kHz + MQA renderer on firmware 5.3 and 5.3c)
On a MAC you would get DSD128 DoP on firmware 5.3 & 5.3c and DSD256 DoP on firmware 5.2 (DSD512 only available with Native DSD playback on Windows and Linux)
On Firmware 5.2 and 5.3 it has a choice of 3 x PCM digital filters - Minimum phase, Standard and No Oversampling (NOS) and 3 x analogue DSD filters
- Extreme, Extended and Standard.
On Firmware 5.3c it only has a Gibbs Transient Optimised (GTO) filter for PCM (plus MQA and limited to DSD128 DoP or DSD256 Native.)
This DAC/AMP even works on an iPhone with another player that support bit perfect playback. Also on Android with another different player app. (not JRiver)
How does it sound? Really really good.
I can't believe how much more I like this over my RME ADI-2 DAC.
It's way more powerful (upto 4000mW per channel on turbo gain).
It's detailed but slightly smoother and very slightly warmer.
It also has ie match built in for high sensitivity IEMs like my Campfire Audio Andromeda's - that sound fantastic on the iFi.
Optical SPDIF in that I've used with Chromecast audio to stream upto 96k 24bit files no problem.
2 channel RCA out.
6.3mm headphone out.
4.4mm balanced headphone out.
3 headphone gain settings (Eco, Normal, Turbo)
3 ie match settings (off, high sens, ultra high sens)
xbass switch - dont use this (about +6db @ 20hz +4db @ 30hz +2db 60hz +1db 100hz +.05db 150hz and flat @ 500hz)
3D+ - dont use this unless it's a recording with hard panned intruments or vocals (headphone crossfeed type thing and it has a different effect on line out)
2 x dual core 1793 Burr-Brown DACS (dual mono with effectively 2 DAC per channel for better SNR and THD)
Native DSD decode DAC - doesnt do any internal resampling like a lot of the non-Native DSD DACS that do internal resampling on DSD
Native PCM decode to 768kHz 32bit
Hybrid Multibit / Delta-sigma architecture DAC
Unlike most delta-sigma architectures that convert everything to a 1-bit stream first before filtering, the iDSD preserves the high order 6-bits of a PCM data stream and only converts the rest of the low order bits via its internal 256fs (DSD256) modulator. iFi claims that this allows the iDSD to keep some of that Burr-Brown signature warmth while still retaining all the smoothness delta-sigma modulators are so famous for. Obviously for pure DSD input, those Burr-Brown's handle it natively using that same DSD256 modulator to convert to analog.
The different digital filters have more of an effect than the filters on the RME. Standard sounds a little congested to me, minimum phase opens the sound up a bit and NOS also opens things up but can sound a bit bright on some tracks. The differences are very very small and I would be happy with any of them except for maybe NOS. The GTO filter similarly opens the sound up a bit and is very smooth and full sounding, it's probably my favourite.
I've listened extensively now with my Fostex TH610's and they sound way better on the iFi than on the RME. They need the power and the filters and musical warmth of the ifi compared to the clinical sounding RME.
My HD600s sound really really good, the best I've ever heard from them. Some older Sony MDR1A's sound pretty good too though they are a bit muddy and boomy compared to the HD600 and TH610s.
Oh and when playing on my main system in 2 channel or 2.1 it sounds great! Better than the DAC in my receiver for sure and slightly better than the RME. SMooooother.
20210310_212152 by
Hilton, on Flickr
iFi iDSD Signature - iPhone SE - Perfect! by
Hilton, on Flickr
DSD256 by
Hilton, on Flickr
384khz by
Hilton, on Flickr
Connected to my DX220 DAP via USB
iFi iDSD DX220 MQA DSD256 by
Hilton, on Flickr
JRiver MC playing MQA file over DLNA to USB Audio Player pro doing first unfold and DAC doing final full MQA render (MQA renderer is just a MQA filter). (ifi iDSD Signature DAC connected to Samsung Galaxy note 20ultra)
JRiver UAPP DSD MQA by
Hilton, on Flickr
JRiver MC playing DSD128 over DLNA to USB Audio Player pro (ifi iDSD Signature DAC connected to Samsung Galaxy note 20ultra)
JRiver UAPP DSD MQA by
Hilton, on Flickr
JRiver MC playing DSD256 over DLNA to USB Audio Player Pro (ifi iDSD Signature DAC connected to Samsung Galaxy note 20ultra)
JRiver UAPP DSD MQA by
Hilton, on Flickr
JRiver MC playing 352.8kHz DXD over DLNA to USB Audio Player Pro (ifi iDSD Signature DAC connected to Samsung Galaxy note 20ultra)
JRiver UAPP DSD MQA by
Hilton, on Flickr