Totl anon here, got baited into buying the Questyle CMA15 last weekend. Just wanted to vent about this metal box:
>Pros
- Physical switch to toggle between amp and dac-only, this should make A/B-ing future amps easier.
- Built like a shit brickhouse
- Class A operation doesn’t get too hot (approx. 50°C~)
- No audible noise-floor for IEMs. I’ve seen some reviews mention “power supply hum”, well I don’t hear it.
- Current-driven amplification. Way more powerful than its specs (2W@32ohms) would suggest.

>Cons
- Too powerful, keeping the volume potentiometer on low naturally results in channel imbalance, but I can’t turn the volume up lest I blow my ears out. This issue is isolated to my Jomo Nautilus, so I’ve learnt to live with it.
- NOT powerful enough for the Duality/Modhouse Tungsten/Susvara. Bass on the Duality still sounds mildly pillowy. Long-term I’m getting a better amp and relegating the Questyle to DAC duty.
- Gain switch: Why did Questyle put that shit at the bottom? Also, you can’t change the gain while the unit is switched on. If changing gain was easier I wouldn’t be seething over the first con.
- IIR filter: there’s only 1 filter and you can’t change it. Because of this HQPlayer has a very minimal effect.
- No XLR input, only RCA.

>Measurements
https://www.l7audiolab.com/f/questyle-cma-fifteen/

>Sound quality
Largely uncolored. Though the leading edge in the treble is a tad harsh – I’m getting mild sibilance when I didn’t used to. Fortunately, separation is way better than on the DX340 – some busy tracks sounded less congested on the Questyle. At least timbre isn’t dry and harsh like the Topping or I might actually kms from having bought this.

Looking to buy the Mass-kobo 485 or Zahl H1 next so I don't have to cope with the amp stage of the CMA15. Fuck actually I want a proper R2R DAC too.