Zähl HM1 - Reference Headphone Amplifier - Official Thread

Have you shared these measurements anywhere? I’m simply curious from an academic perspective.


Nor do I have any plans to.

They were something I did for my own amusement while taking other measurements for another project.


Two weeks and change with the HM1 …

Well, since I received it anyway, there’s been some travel/time away from it since it arrived. But, I’ve spent every moment available listening to it.

I’m just as delighted and thrilled by its delivery as I was on the first day.

It’s magical with the ZMF Atrium and Audeze LCD-5, as well as Focal’s Utopia.

Any lack of commentary on my part, here, is due to being tied up with other things. A proper, subjective, comparison to other amps is something I plan to do … but I won’t get to write that up until after a trip to Europe (mostly the UK and Sweden).

But … still … amazing stuff.


Oh, yes …

… there may have been an HM1-fueled ABBA marathon involved, here, at some point in the last day or so … or today … and … it’s still going on … right now … (damn stores playing good/fun music … and setting this stuff off).

There’s a pitch-bend in one of these tracks that I’d never heard prior to the HM1 (I’m sure it’s there elsewhere … and will check … but still, this is the first time I’ve heard it).

Have you had a chance to listen to any Nils Frahm, Aphex Twin or Chemical Brothers with the HM1?

There’s a nice continuity to it given as they produce with Zaehl gear.


After the ABBA marathon go for the VANGELIS. :slight_smile:
He recorded his music fairly well.
Albums like DIRECT (1988) CHINA (1984) and BLADERUNNER (1982) are terrific places to start a marathon.

Enjoy my friend. A new amp can be a real game changer. Happy for you. Merry Christmas as well. :slight_smile:


Of course!

Anything less just wouldn’t be cricket!

(Fellow Brit, even if I live in the US now …).

I did it the other way around, but yes; the ABBA inspiration came from a little boutique store - great taste in music, iffy otherwise!


I’ll be officially joining the HM1 gang in 2023! Looking forward to more impressions shared and listening to it myself in Canjam NYC.

The dual inputs will likely be used for DAC and turntable so not much use of the mixing feature. It’s going to be my main headphones amp and also preamp the Genelec monitors on my desk (good for the tone and stereo base adjustment), and probably also taking part in preamp duties for my 2ch system considering the sources will already be connected to it.

I hope they get the remote released in time for shipping as that’ll be nice to have in some of my use cases.


Nice :-). The remote though will only be a remote source A/B switcher attached via cable. Probably most useful in a studio environment to give people away from the desk the ability to switch sources. If that’s all you need everything is fine. I just wouldn’t expect anything wireless with the ability to control volume etc.

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Oh then no that’s not useful.
I’d like volume control (even if wired that’s fine). No use for source switching in my case.
I can use my DACs remote for volume if that’s my only option and that is only for the 2ch use case anyway so I’m covered in any case.

I have my HM-1 up and running now for 2 days. Currently still recovering from a cold so I wasn’t able to get definite impressions yet. But what I’m hearing for now is nothing short of amazing. I’m gonna post some more impressions once I’m fully recovered. The cold didn’t stop me from taking a few pictures though :slight_smile:


Wow!! Incredible! Good job man. :blush:


If you haven’t seen it yet, I’ve posted a written review and comprehensive measurements of the HM1 here: https://headphones.com/blogs/reviews/zahl-hm1-review-measurements
A video review is on the way!


A “proper” week back at home, and I’ve spent most of my listening time therein going through all of my dynamic and planar headphones with the HM1.

It absolutely elevates every one of them …

Pre-departure, I’d indulged in a little, purely coincidental, ABBA marathon.

While in Sweden we hit a number of clubs, and the result of that may have been some subsequent extended (and untypical for me) use of the HM1’s bass lift. Which has proven quite addictive with certain musical genres (right now, I’m running Above & Beyond’s “Ajunabeats Vol. 15”).

Almost makes me want to try and find a demo of the DCA Expanse …


6 months wait, multiple delays and issues but my HM1 is finally here, number 47/50 :saluting_face:


Absolutely incredible. Congratulations. The amp worth killing for. Lol.

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@DJJEZ you are in for a treat. Happy listening

For me the more relevant question is “Is it worth starving for?”

No it is not. Nothing in audio is.


A lot of these audio products these days are worth planning and saving for. Having higher quality of sound improves your mood and way of life. At least for me. :slight_smile:
Worth the financial pain. Lol.

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