[Netforce]

The +15db mode on the HM1 at canjam was distorting and required either switching to 0db and/or lowering the output of the Weiss 502 DAC. That led to the Susvara needing a lot more juice from the HM1, for me at least. Volume knob was around 2ish I think. That might explain some of the impressions of that pairing.
After sorting the distortion out though, it sounded great to my ears.
I can also confirm excellent synergy with the Final. The Limited Edition is my main headphones these days, more than the Sus which is a first with any headphones I ever owned parallel to it.

Can confirm that the Weiss was set little too hot at CanJam Day 1, I didn't realize until day 2 and when I was troubleshooting a buddy of mine remarked that I should change the output gain of the Weiss which fixed it. Little bit of oversight on my end and makes me feel little bad about overlooking this day 1 considering how busy we were. Will definitely remember to double check and set correctly for future events.

 

[IanB52]

Again, if the Weiss has a maximum output of 6.8v, why on earth would anybody turn on the +15db switch? It will clip for sure. You would have to be down in the millivolt range for that switch to make sense. And why would anyone then turn down the DAC rather than turn off a +15db boost? It makes zero sense. Nobody should be using that boost with anything other than DAPs or extremely low output DACs.

My own DAC is about 7v balanced and I have zero difficulty of driving the Susvara. In fact, the HM1 loved my 10.5v Mytek with not a single clip or hint of distortion.

It really seems like someone incorrectly thinks that +15db is "Susvara mode" when it is actually only for extremely weak sources.

 

[Netforce]

Mostly an oversight on my end, completely forgot about the 2V limit and the 6.8V output on the Weiss until day 2 when it was pointed out to me. Was juggling a lot of setups on the headphones.com table and it got really busy really fast. CanJam SoCal we had our HM1 paired with the HiFi Rose RS150B and encountered the same issue thinking back, so it has been a recurring issue that will be corrected at future events.

Sorry about those who had heard that issue at both those CanJams so far. I will probably include a note in the box to remind us to check in future events. For USA, it probably will be the next SoCal we will have the HM1 available for demo. But if there are other events that I can try to make, I ask the team if I can borrow our demo unit for it.

 

[IanB52]

Mostly an oversight on my end, completely forgot about the 2V limit and the 6.8V output on the Weiss until day 2 when it was pointed out to me. Was juggling a lot of setups on the headphones.com table and it got really busy really fast. CanJam SoCal we had our HM1 paired with the HiFi Rose RS150B and encountered the same issue thinking back, so it has been a recurring issue that will be corrected at future events.

Sorry about those who had heard that issue at both those CanJams so far. I will probably include a note in the box to remind us to check in future events. For USA, it probably will be the next SoCal we will have the HM1 available for demo. But if there are other events that I can try to make, I ask the team if I can borrow our demo unit for it.

Sorry, if I came down a bit harsh. It sounds like you guys are having to gain stage the whole setup so it works with your DAC and whatever DAP source attendees might want to plug in?

 

[Netforce]

Sorry, if I came down a bit harsh. It sounds like you guys are having to gain stage the whole setup so it works with your DAC and whatever DAP source attendees might want to plug in?

Oh no, its fine. I work enough CanJam's and other audio events to realize my mistakes and try to correct it on my end! Or at least try to remember to correct it in the future.

I kinda played it by ear at this CanJam since this was probably the busiest CanJam I have worked at so far. Mostly we stuck to our our DAC and iPad source, let some folks plug in their DAP or DAP source if it wasn't too busy. Didn't allow too complex of recabling for example on Saturday morning/afternoon when the HM1 had a constant line. But late Saturday and mid day Sunday I allowed folks to plug in if it wasn't too disruptive to the entire chain.

Most folks were rather understanding and were cool with that.

 

[Spawn300Z]

Has anyone compared this to the Wells Audio Headtrip II or the new Headtrip III?

 

[chinyue]

Is there any difference between using XLR input or RCA input to HM1? Some amps emphasize their fully balanced design and recommend using XLR input. Is HM1 one of them? HM1 owners do you have preference using one over the other?

 

[Hiyono]

Is there any difference between using XLR input or RCA input to HM1? Some amps emphasize their fully balanced design and recommend using XLR input. Is HM1 one of them? HM1 owners do you have preference using one over the other?

I think I read that hm1 is single ended with separate grounds.

 

[Hiyono]

Dual Mono vs. Balanced amplifier design​

With its dual mono design, the HM1 features the same advantages as a balanced output stage but avoids the drawbacks.

The drawbacks of a balanced output stage are the significantly increased number of electronic components - a balanced output contains two output stages per channel which work in reverse phase. Two output stages result in doubling the output impedance. More components result in an increased risk of non-linearities.

https://headphones.com/products/zah...adphone-amplifier?_pos=1&_sid=620d64997&_ss=r

 

[IanB52]

YMMV, I'm finding that the HM1 sounds better at 110v in my system than 120v. The higher voltage might be a little more detailed and precise, but the bass suffers, background is not as dark, images not as rich and big, treble sounds a bit harder.

I think most are going to 120v as default, but in some (or many) systems, the lower voltage might sound significantly more musical and rich.

I also found that aftermarket fuses do improve the sound to a degree, but not as much as with other amps. I would guess this is because the power is still AC when it leaves the PSU/transformer box that houses the fuses. It's still worthwhile IMO, esp if you want more richness or warmth.

 

[orrman]

YMMV, I'm finding that the HM1 sounds better at 110v in my system than 120v. The higher voltage might be a little more detailed and precise, but the bass suffers, background is not as dark, images not as rich and big, treble sounds a bit harder.

I think most are going to 120v as default, but in some (or many) systems, the lower voltage might sound significantly more musical and rich.

I also found that aftermarket fuses do improve the sound to a degree, but not as much as with other amps. I would guess this is because the power is still AC when it leaves the PSU/transformer box that houses the fuses. It's still worthwhile IMO, esp if you want more richness or warmth.

Did you test your wall AC?

 

[IanB52]

Did you test your wall AC?

No. My multimeter is hiding out there somewhere...but basically just going trial and error. My assumption is we get around 115v.

 

[Roybenz]

Does anyone know the power output in volt and watt @60 ohm for the Zahl?

 

[kwilkins]

Has anyone who previously placed an order for March 2022 ship date received their HM1?

 

[orrman]

Has anyone who previously placed an order for March 2022 ship date received their HM1?

I don't think I've heard anywhere of a commitment to March 2023. Latest I've heard we were looking at April-May in the US but that might've changed (I'm preparing myself for June).