GTO has 'so far' not been supported via the SP/Dif input. (and if it was no one at iFi would care to let us know, even if we were asking their back office directly)
The webpage for the product lists, via an asterisk, that the iFi Diablo is 'more unique' than some other iFi products in that the XMOS also handles the SP/DIF input.. (I literally just read this five minutes ago when doing the typical 'does iFi care to update the firmware pages with relevant info (spoiler: they DO NOT))
Whilst I believed for the longest time that my reasons with DSD issues via SP/DIF and a lack of GTO via SP/DIF was to do with the XMOS not being 'in line' to process.. reading the iFi Diablo product pages just now, and seeing a very special line of text that goes to effort to explain that the iFi Diablo does handle the 'other digital input(s)' via the same XMOS was a nice thing to see.
But, erm, yes.. GTO is USB only (but who knows.. the 'universal' firmwares they roll out can easily get upgraded on another product, and that works for the Diablo, but 'no one at team iFi, even asked point blank, will give an accurate answer...
If I sound annoyed with iFi support it is simply due to so much time wastage with them that I have politely glossed over or NEVER mentioned on the internet, with the end result them telling me to stop asking for a feature that was advertised (prior to purchase) on their homepage, and then found out, after a rep rudely repremanded me publicly 'for
mentioning I'd like to see USB DAC support with the gaming consoles', that the feature was not coming and to stop being angry or 'caring' for the product...
I then bought a FiiO BTA30 to do the task..
and then found out that a working firmware that gave the feature had been available in the public space for a month or more... (and I could have downloaded from the iFi webpage, and the official method to do that is to lie to the firmware check tool as to which product I am using so I can get a 'new' firmware that gives the feature.
As someone who has given a LOT of backoffice support (and won awards internationally for outstanding commitment to companty mission statement/service standard delivery etc); having been lambasted publicly, lied to, and even wasted many many hours 'back and forth'ing' with iFi directly (ie NOT via HEADFI).. I simply moved on.
The last iFi product I bought I gave away unopened.
Having moved to an entry level chinese DAC more than a decade old to simply remove the Diablo from my chain (bad taste), i have little reason to watch this thread.
Glad that we have active lip service from iFi reps, but sadly, having watched this stance for years now.. words without actions grow tiring and waste time.. (and time is the one resource we all have too little of)
GTO lights up yellow, and will apply to USB input. When running GTO firmware the top of the tree sample rates get downgraded, and given MAC already run DSD at half rate only, this might prove troublesome to 'some'.
I still stand by the GTO filter being a reason to consider an iFi part,,.. as it takes CD/redbook (44khz 16bit) and makes it near equiv to 'true High resolution formats' in playback, for our brains...
Taking console gaming systems and getting 'nice sound' from a half decent 'budget' Delta Sigma DAC is great.
For many people, they will NEVER roll a GTO firmware,.. and so we have
iFi reliability (nope)
and
iFi service (nope)
given I was flagged 'anti iFi' when all I have done was try to sell and support their products.. I suppose all that is left for me here is to try and share the facts that the internet tells me (subjective?).
the newly learned fact for me, this hour, is that the pathway for digital on the iFi Diablo might actually ALLOW for GTO over my prefered input methods.
whether I care to roll unofficial firmwares for my product on an out of warranty part... hmmmm (No!)
iFi have a lot chops, but won't pay the piper to get over the line...
whether that be to recommision a circuit designer to update a product so that it can technically do the things it is advertised as doing, or whether they care to have a maintained webportal for 'current products' is on them.
They don't - so I don't care.
having seen a lot of reps on these boards do the due dilligence.. I find it easy to sort the wheat from the chaff...
My Diablo is presently being fed into a Grace m903 (uses the same DAC chips even).. the resultant sound is great.
When I take my IEMs and feed them from the Diablo directly, the sound quality drops significantly.. (the Grace IS a beautiful part)..
but the Diablo, as a DAC, still has chops and something to offer.
For me?; I bought it for console gaming, and by the time it could do that task, the FiiO BTA30 was inline and I could use it to convert USB to sp/dif and enjoy the consoles through proper home DACs..
GTO is great, and is an excellent reason to stick with iFI..
if rolling firmwares to play with esoteric filters is your thing.. then iFi have your entertainment bases covered.. (just so long as you feel comfortable trusting random people on head-fi to direct you to unofficial firmwares for your product that you can only get access to by tricking iFi webpage into thinking you have 'another product')
Having worked for businesses that WILL NOT perform firmware updates for customers (high risk perception), this situation of having to be a cowboy and fight in the wild west/frontier land for a product update that MAY exist and give advertised features that were not ready at product launch..
to iFis credit.. at least they are not auto firmware updates that we have no control over.... (that would be WAY worse)
edited to add screenshotz (yes, would have been 'nice' if I closed a few parenthesis too, but, you get what you pay for..)