I've had the Mytek Liberty THX AAA for over a week now and also own a Benchmark HPA4. Two key observations:
- Mytek achieves much more powerful sub-bass than Benchmark. Still linear, perfect tonal balance, no distortion, but it underscores the power limitation of the Benchmark. The Mytek is more like listening to big speakers.
- Mytek sounds filtered (but not quite veiled) with noticeable treble roll-off compared to Benchmark. It's so significant that I have resorted to setting my DAC filter to Slow or even NOS, and it still doesn't fully compensate for the missing spaciousness.
I would say the soundstage is taller with Mytek due to the excellent sub-bass extension, but much narrower due to the lack of air. So people who are used to fully balanced amps might find the soundstage uncomfortably narrow (I still do). I found the same conclusions when comparing the Mytek to SMSL SP400. The SP400 was surprisingly more airy than Mytek, but SP400 has even less power headroom than Benchmark so quickly becomes insufficient for insensitive headphones.
Other brief (and rough) comparisons done so far, adding Violectric V280 and V281 into the mix:
- Sub-bass under load: Mytek > V280 > Benchmark >= V281 > SP400
- Tonal balance / linearity under load: Mytek > Benchmark > V280 > SP400 >= V281
- Air / spaciousness: Benchmark > V281 > SP400 > V280 > Mytek
- Midrange power: V281 > V280 > Mytek > Benchmark > SP400
"under load" means testing with Hifiman Susvara. The Mytek is the only desktop amp I have found that can adequately drive sub-bass on Susvaras and give a realistic bass decay. Lesser-powered amps seem to have all attack (blip/pop sounds) and no decay when given a heavy load. And somehow Mytek has the smallest chassis of the lot and never gets above luke warm. Impressive.
The lack of air in the Mytek isn't all bad either. Its imaging and depth still exceeds that of the Violectric amps even if I consider them more spacious in soundstage width. Thanks THX.
Mytek's build quality is stunning, really solid while also beautiful. But you could almost say the same about Benchmark and Violectric. Only SMSL misses the grade there, but for the price that's totally understandable.
The purchasing experience was slow, but that's not unheard of with small manufacturers of high-end equipment. I ordered in October, payment was accepted immediately, then got no response to any of my emails for the next month. Finally after finding the private email address of a Mytek employee I got a response from the founder Michal who said it would be sent the next day. Actually it took another 10 days to get a tracking number and then another 14 days to arrive (the final part is because I'm in Australia). Overall two months from order to delivery. And now I find my bonus Sundaras are faulty so hopefully can get that rectified after the holidays.
Overall Mytek seems to have achieved something unique - unmatched power in a THX AAA headphone amp. I only wish there was more space in this concert hall... Maybe a fully balanced (4 amplifier) design in the next model please Michal?
I hope some people found my first post useful. Obviously I've been collecting gear for a while already.