@Brooko I'm using this as my dac amp to compensate SQ at home laptop and at work, possible as dac amp stack with smartphone also, so it's all very good.
 
However the lineout issue you mentioned kinda confused me. Good guy from Q1 impression thread suggest using line out to connect to earphone. Although its kinda cumbersome because I can't control the sound manually in Q1, the depth and timbre it render really capture me. Perhaps it just sounded EQed on the lower end but I'm not sure if it really is. The bass didn't have much warmth to it and it need some time to adjust but after I adjust to the new sound it's no turning back for me! TBH the bass is still there when certain track call it and it did dig deep on my E80. 
 
TQ for the solid review

Cool review as always!
@Sp12er3  it's a compliment.

Great review as always Paul. When you say that when used as a dac only, "we" would not be able to hear the treble roll-off, you meant "we" old guys, right? Sorry, couldn't resist. Are you planning to ever review the k553s? Or have you done so and i missed it? Old guy, remember? Cheers, mate.

@fairx - thanks.  See if you can volume match between line-out and headphone-out and then compare.  My comment on line-out was based on using the Q1 as DAC, then line-out to another amp (in my case iDSD and also E17K) - both just for testing.  I wasn't wowed - so I put them through the measurements.  I actually picked up higher noise floor via line-out.  But again - could be my gear.  If you like the line-out - use it.  It's not what I think, but what you think is all that matters
 
@garcsa - thanks.  i got it.
 
@senorx12562 - yep definitely we old guys  Haven't done the K553 yet - too many others in the queue at the moment to actually review my own gear yet.  Don't worry - it is still on my list.

Solid review Brooko. I'm planning to buy this soon. Just wondering how it pairs up with the audio technica im02. They are quite a picky pair. Please advise if you can throw some light on this. Thanks in advance.

Unfortunately I haven't heard the AT IM02 - but if you check with Alex (Twister6), he might eb able to shed some light on the pairing.

Thanks for the prompt reply. Will reach out to Alex.

@AzureSerenity IS it so? great then... still gonna see how long mine will hold out for now though
@garcsa Sorry if I offend you... just interpret it differently back then...

Yep it died this morning... With a grand total of 20 hours battery life... Still a good result, but fall short of Fiio's stats.

Was it full charged, what were you driving, what was the gain setting and how high was the volume? Both my actual tests from fully charged battery were between 29 and 31 hours.

Was fully charged (green light when I switch charge off) running on Low Gain with the pot stays mostly around 3-4. I don't have any gear that's really demanding you see, the hardest to drive is M40x that's already very comfortable at 4.
Hrm... It mine faulty then? It's been like this since the beginning.

Yep - I'd be talking to Fiio.  Could be just a battery that's not quite holding the full charge.

Did you make sure the charging circuit had its "100%" level properly calibrated first? Could save you the trouble of sending it back and waiting for another one etc. Discharge it completely and then recharge to full without interruption, maybe leave it on another half hour or so after the LED indicates it's full.

Hello Brooko - Thanks for the very thorough and insightful review. Any idea if that "test cable" you showed with the iPhone is available yet? Would be neat if Fiio (or someone else) would made a short IC cable with a lightning to 3.5 MM.

I don't think its ready for official release yet - but as soon as it has been approved, I'll definitely spread the word on how and where to get one.

Thank you for your impressions on iPhone vs iPhone Line out to Q1 vs iPhone Digital out to Q1! I've been searching for that for so long and not expecting half the details you delivered!
Any news on the "test cable"? I'm seeing mentions of FiiO L19 and Penon Audio L19 circulating ebay but it doesn't seem official.
 
I've read your other reviews too and I think you should do well as a YouTube reviewer. Cheers!

Here's the link - http://penonaudio.com/L19-Lightning-to-Micro-USB
FiiO never officially listed it - but it definitely works.
 
And thanks for the kind words. I don't think I'd have the patience for youtube reviews - mine take long enough to set up now  I rather suspect my days reviewing may be drawing to a close eventually as my spare time diminishes with work commitments sadly.

Great review! I got the Q1 to use as an outboard DAC/AMP combo on my iPhone 6s+ & have been happy using it during the last few months. It can drive my HE500, HD600, Mad Dogs but am interested in finding a less "bulky" cable setup (am using CCK w/the supplied USB cable). Am interested in the L19 "test" cable. The CCK doesn't allow me to use the original Fiio e17 even when I turn off charging. I get the generic message on the 6s+. Will the L19 work with the e17 (versus the e17k). I don't want to buy another dac/amp combo (I already have too many at home). What would you suggest?

Unfortunately I can't tell you as the E17 original is one of the few FiiO's I don't actually have.  Probably still worth trying the L19 though due to low cost, and the lightning connector will at least be handy for later dac/amps you try (and of course the Q1 too).

Total newbie question here again... I own the FiiO X3ii, and use it with my ATH M50s (original), and it seems to work well. I notice that you plug the Q1 into the X3ii and your headphones into the Q1. Can you tell me what difference this makes to the sound, as opposed to plugging headphones directly into the X3ii? Or do you do this because the headphones you use require more power to drive them?
 
Another question - if the music coming into the Q1 is at a higher bit rate that 24/96, (say it is 24/192), will the Q1 just downsample before output? Or will music at a higher bit rate just not play?
 
Thanks (sorry for the newbie questions).