Nice review! Have you or anyone been able to get it to work on an iPhone? It says it’s compatible with iOS but no luck yet on either of my iPhones…

Mate, you've confused gain with output impedance. Colorfly CDA M1 doesn't have a gain switching mode. Those two buttons, if pressed together, switch between high and low output impedance. This doesn't change the gain. What it does is adapting to high and low impedance headphones. The only audible difference might be in microdynamics, making transients a little bit softer in the high impedance mode, if you use the same headphones.

@-rowan- Thanks, unfortunately I don't have any iPhones to test. But with the right adapter I believe CDA M1 will work fine on iOS

woah, amazing review

Do you think it will pair nicely with Timeless?

Compared to the M12, which one is brighter?

@Aradea M1 will appear slightly brighter and M12 is in fact mildly more organic natural in comparison

After much thought got mine. So far it's becoming my favorite dongle. It has this magic for planars and the sound signature it's totally my field. Only thing as you mentioned... The 2 button gain change its a fiasco. Do we have a way to contact the manufacturer? A firmware update might be the solution

@AlexCBSN It's not a fiasco. You and the author of this review completely misunderstood the purpose of this two button function. It's not a gain switch. Never was and never will be. It's an impedance switch, similar to what Singxer SA-1 does. It adjusts to the impedance of your headphones, either high or low. You will never hear any gain change with it as it's not supposed to do it by design. The only audible change might be smoothing the transients on high impedance, if you listen with the same headphone. It's in the manual btw.