Metrum Acoustics Aurix

[zilch0md]

^ You're not working the Aurix too very hard, then. Thanks for this report. I've never had any HiFiMan headphones, by the way, but keep telling myself to give them a try.

 

[astrostar59]

Just wanted to say I only have about 25 hours on my Aurix so far and love what I am hearing. Who knew there was so much space between your ears.
My setup for this trial was rather simple as I am currently between homes, it consisted of a Dell XPS 17 laptop running Windows 10 and JRivers 23. This was connected to the Menuet with the supplied USB cord, the Menuet is connected to the Aurix with a Kimber KS-1026 interconnect and the Aurix powering Grado GS-1000i's.
The set up impressed me so much that I went in search of a 600 ohm load to give this Aurix its due justice as recommended above.
With that said I located a pair of Byerdynamic T1's (1st gen) that I was willing to purchase, unfortunately they will not arrive in enough time as I will be departing for an overseas rotation over the next several months.
The good news is I should be in my new home by the time I return and with have my full setup available for auditioning and with it being the height of the winter months listening sessions shouldn't be hard to come by.

Looking forward to seeing how this new setup will compare to my old and how well it will compare to my McCormack Platinum modded Integrated Headphone Drive (MPHD)

If it sounds as good as I hope the MPHD will become an amp to drive a pair of desktop speakers.
The thought of all this is going to make the next 70+ days just drag slower.
Very excited about future finds and will keep you posted.

I must agree with your impressions. I have had my Aurix for 5 months now, and since I bought it move from the LCD2-C to the LCD4s (still use the LCD2-C in my second system which also uses the Aurix. My previous DAC was an Audio Note DAC 5 (30K new, I bought it used) which had 2v SE output and the LCD4s sounded great. I had the gain on high setting and the pot at 2 o'clock for loud listening. I then moved to a new Aries Cerat Kassandra DAC (18K) which has 10v SE output. WOW is all I can say, this little amps kicks arse big time!

Fantastic transparency, huge soundstage, totally smooth vocals and treble details, just fantastic sound, better than 60K+ speakers can do IMO. This is on the LCD4 and I set the Aurix to No Gain, i.e. unity, so a pas through and impedance fixer only. IMO this may be the trump card to this little amp, no fancy gain stages or masses of parts in the way. You don't need the gain with most cans just an impedance fixer. And you DON'T want to put a complex amp in the chain to muddy the details and mess up the imaging, add noise and other attracts, or generally colour the sound. In other words, if you have a good DAC with a good gain stage, you 'just' need the Aurix IMO and you are done - wire with gain (or no gain in this case).

So pity Metrum have stopped making this amp, I might have bought almost the last one as it went off their website 2 weeks after I bought one. IMO Metrum to bring it out again, but in a better chassis, to befit it's performance, and appeal to non Metrum owners. It is a bit bland looking, and too home styled to Metrum. I get why they did that though. But IMO it is a cracking little amp that slipped through the net....

I modded mine with new heavy duty feet and a baseplate glued to the bottom of the chassis to beaf up the weight and reduce any vibrations (if there was any). I like modding stuff, but it isn't necessary to get great sound from it.

 

[astrostar59]

Hi Guys (Aurix owners)
I have had the Aurx for a while now, and have been thinking about this little amp and how it performs. I am coming to realise on the low impedance setting it is actually unity, so no gain. This makes the amp a true buffered passive pre with a volume control, using the Lunhai transformers to achieve it.

Basically 'fixing' the output impedance on line out of a DAC for HP use - by bringing it down to 2 ohms to then send the signal on to your HPs. Remember you can't just drive a HP from your line out of a DAC even though it could have 2v output, as in most (almost all) cases the output impedance is way too high. You need to be on the 10 times rule, so for a HP at 100 ohms you need 10 ohms output impedance or less, ideally 3 ohms for example. Typically a line out can be 300 ohms or much higher especially if a tube gain stage. Without careful impedance matching frequency shift and phase shift can occur leading to a chaotic sound basically.

I find the sound quality on low impedance setting on the Aurix to be just wire, i.e. straight through. But on high impedance setting it engages the fets and I can detect some loss of micro detail, blurring and lower contrasts. It isn't bad, but does take it lower down in sound Qqality IMO. However to run it on low setting, you need a fairly efficient HP PLUS a DAC with a decent line stage and plenty of current, preferably more than 2v out. Many opp amp stages on DACs are not up to the task without the help of another powerful amp in the chain.

I am using the Aurix on low setting right now with my LCD2-C and it sounds great. This is with my Audio Note DAC 4.1 which has about 2.5v tube stage line out. And I have the pot on 2 o'clock for loud listing, and it has plenty of dynamics, no compression, lots of headroom. Massive bass power and enough treble extension. Metrum did say this amp will reflect the source, a bit of a chameleon in fact, so this makes sense to me. i.e. to work well it needs enough juice to feed it.

In my main system my Kassandra DAC is much better than the Audio Note DAC, the dynamics are off the scale better on 2 channel speakers. Also this DAC has an unusually high 10v line out at a lowish 55 ohms output impedance. So lots more current, and 6dB more gain. The LCD4 I use with this DAC is roughly 6db less efficient, at 200 ohms and 97dB, not 70 ohms and 102dB like the LCD2-C. Thus again I have the pot at 2 o'clock from my Kassandra DAC feeding the LCD4s via the Aurix on low gain setting. It just seems to work so well.

So what is all this verbiage?
It is my view, that if you have a decent gain stage in your DAC, and have efficient enough HPs, you maybe don't need a fancy powerful amp to feed them. I also believe having more parts and components in the signal path can and will loose information and blur imaging. You can't generate something from nothing, but you can loose something from something. What I think any HP amp is doing is fixing the output impedance down to very low levels, then providing enough current to the particular HP with gain. In many cases you don't need that gain.

It could be a quirk of the Aurix as it has the ability to act as a buffered passive, not sure f that is the case with most HP amps that are on the market.

This is all relevant if you want straight wire, not after some colouring of the sound or to 'tame' a DAC to suit a brighter HP for example.

I was hovering over the GSX MK2 for the LCD4s, but on speaking to headlamp, and after telling them about my main DACs high output, they told me I would end up running that on it's lowest setting for loud listening (unity). This made we wonder why buy it? True, it can be run balanced out, but at 3K I decided to not move on it.

Anyway, my view on the Aurix. Might be bull, but I have come to believe I don't need a bigger badder HP amp, as my main DAC is on steroids already. Hope this helps somebody. I guess the best way it test your own DAC with the Aurix v another amp in the same demo, and your particular HP.

 

[beyerdude]

Okay Aurix owners, I have an issue which I'm trying to get resolution on - I was an original Aurix buyer some years back so know the product quite well. I've recently purchased another second hand - sold as new (and looks it) - I'm away from my main set up so am testing it with a MacBook pro - with my DT880 600ohm it sounds as it should (possibly a think bit of distortion at the low end but hard to tell) - with my t90 it sounds appalling - it's breaking up, distorting even at low levels, sounds scratchy - has anyone come across something similar? - is this a faulty unit? - I can't see why it would be the source - i've tried it with a MacBook pro and also a teac tape deck and it does exactly the same from both - any ideas?

 

[astrostar59]

Okay Aurix owners, I have an issue which I'm trying to get resolution on - I was an original Aurix buyer some years back so know the product quite well. I've recently purchased another second hand - sold as new (and looks it) - I'm away from my main set up so am testing it with a MacBook pro - with my DT880 600ohm it sounds as it should (possibly a think bit of distortion at the low end but hard to tell) - with my t90 it sounds appalling - it's breaking up, distorting even at low levels, sounds scratchy - has anyone come across something similar? - is this a faulty unit? - I can't see why it would be the source - i've tried it with a MacBook pro and also a teac tape deck and it does exactly the same from both - any ideas?

Could be the output from your Macbook. I assume you are using the headphone out socket? Thus is not the right impedance, or have enough current to drive the amp init IMO.

Only other thoughts, have you checked the 2 Lundhai transformers are seated well, not worked loose?

 

[beyerdude]

I'm hoping you are right about the impedance not being correct - but saying that it does the same from the line (RCA) out from a TEAC tape deck which surely should be the right impedance? - Haven't checked the transformers but it does the same with 0db gain so had ruled it out?

 

[beyerdude]

Could be the output from your Macbook. I assume you are using the headphone out socket? Thus is not the right impedance, or have enough current to drive the amp init IMO.

Only other thoughts, have you checked the 2 Lundhai transformers are seated well, not worked loose?

I've contacted Metrum support, it's weird as it doesn't seem to do it (or the distortion is so low ) with the DT880 600ohm - just nervous as this is an ebay purchase and don't want to end up with a lemon.....if I wasn't away on business I would have a lot more sources/headphones to check it with - as it is I just have the two......

 

[George Hincapie]

I've contacted Metrum support, it's weird as it doesn't seem to do it (or the distortion is so low ) with the DT880 600ohm - just nervous as this is an ebay purchase and don't want to end up with a lemon.....if I wasn't away on business I would have a lot more sources/headphones to check it with - as it is I just have the two......

What was the outcome. Metrum are an amazing bunch; I have every confidence they will have resolved any hardware issue for you if it was in fact the Aurix.

 

[George Hincapie]

What are you guys using in the chain before your Aurix?

For me it is: Roon > VortexBox Prestige MX2 > Auralic Aries Mini (WiFi) > SPDIF Coax > Metrum Acoustics Musette (with upgraded DAC Two Transient Modules) > Metrum Acoustics Aurix > Audioquest Carbon NightHawks

I am generally pretty happy with that chain, but will be making a few changes shortly. I am hoping to replace the Aries Mini with the vastly superior Metrum Acoustics Ambre (I have one in my main system already) and also upgrade my official Audioquest headphone cable with a Moon Audio Silver Dragon one that is longer and should hopefully get a little more detail out of the NHs.

After that I will be looking to upgrade both the Musette and the Aurix with a new Reference class Metrum product

 

[borrego]

Yesterday I took my Metrum Aurix out from storage and hooked up to the M7S. The Metrum Aurix is virtually a simple current buffer design and it would only sound as good as the output buffer circuit of the feeding source. With the Aurix I can immediately tell the M7S's Class A single ended output buffer circuit is superior to the Class A push-pull buffer circuit design of my Reference 5.32. The Aurix sounds quit a bit less grainy when being fed from the M7S comparing from the Reference 5.32. I am not sure if the OPA2140 DC servo opamp I put in the M7S also has something to do with the smoother sound. Having said that, the Reference 5.32 sound output was completely without any grain when connecting to all my other headphone amps except with the Aurix.

 

[George Hincapie]

I'm still using my Aurix, but am thinking about changing. No particular reason other than wanting to upgrade all of my headphone station equipment. Have any of you Aurix owners moved on to another HPA? If so, what did you move to? I've been reading about the HeadAmp GSX2, and that looks interesting.

 

[Venture Guy]

Does anybody have an Aurix that is gathering dust and needs a new home? PM if you do

 

[Rebel Chris]

Hi Guys,

I came across a 2hand metrum Aurix. Is it still a great buy in 2021?

Kind regards, Chris

 

[Pjotr27]

If the price is right, it is worth a listen. I used a Aurix for about three years and it is still a great sounding unit.