Because I have a feel that was not Amir's conclusion style based on previous reviews. I mean based on measurements and measurements/price ratio.
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CHORD Alto Headphone/Power Amp Review
- Thread starter amirm
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As has been explained multiple times, this is not the first time Amir has had a "controversial" final recommendation where he found a product amenable despite what appeared to be questionable measurements or vice versa. Ultimately the recommendation is his personal opinion. In this case, he quite clearly stated the recommendation was based on this device ability to output power to drive not just one but multiple low-sensitivity/high-impedance headphones simultaneously. And despite the less than stellar noise/distortion, audibly it was clean.
If you ask Amir directly whether most people should purchase this, I'm quite certain you'll get a resounding no since most people don't need that much power and can get objectively better headphone amps for much cheaper.
FFS...
Interesting.. I would like to see Amir's reviews where he recommended power without numbers (measurments)....
Thank you in advance
OP
- Thread Starter
- #164
What does this mean?
It is mean that you were
This means that you were particularly critical of very expensive devices that did not meet the highest measurement standards. But not in this case. But anyway, I've already said that I have the utmost respect for your mission here in general. All best
OP
- Thread Starter
- #166
I still can't figure out what you mean. As has been repeatedly explained, this amplifier produces a ton of power to drive headphones. I have said many times in reviews that amount of power is one of the most important measurements in my review of headphone amplifiers. And this amp aces that. So it is not at all a case of it failing measurements. Examples:
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You want me to keep going???
VientoB
Addicted to Fun and Learning
I have heard Blaine at Headphones.com state that you really don't need a powerful amplifier like this for headphones. What volume are you expecting people to listen at?
Granted this one has 4 headphones outputs so for that purpose it covers that but how many people are going to use that feature with 4 headphones used at once. Seems quite a niche thing. I suppose if you need that then it would be easy to recommend this amplifier but for most people I remained puzzled as to why they would go for this with so many better value options.
Granted this one has 4 headphones outputs so for that purpose it covers that but how many people are going to use that feature with 4 headphones used at once. Seems quite a niche thing. I suppose if you need that then it would be easy to recommend this amplifier but for most people I remained puzzled as to why they would go for this with so many better value options.
solderdude
Grand Contributor
The issue here is that a music signal consists of an entire spectrum of signals that are all added (summed).
This means that at specific short moments in time the phase of signals comes together and a peak SPL is formed.
That, however, can consist of bass notes, voices, instruments etc that when they would be reproduced individually would be very loud but all summed reach -0.1dB peak level.
Now... if we consider most of the energy is in the bass and less for all the other sounds and, due to Equal loudness contours, and even rolled-off transducers would even mean an increased output level then it is not very hard to see where this is going.
To go loud, have high dynamics and impressive bass all the combined signals will have to be reproduced without the chance of clipping the amplifier.
So... when we have a momentary peak in recordings hitting 0dB SPL and that recording has, say, a DR of 15 and we like to play it loud with 'Harman' bass from say ... a hifiman HE6 or LCD-2 then the amp must be able to let a headphone reach 115dB SPL peak.
Now... most people confuse this with the 'exposure charts' and look at 115dBA exposure of noise levels (not music) and say ... wow what an idiot that thinks he needs an amp that can make the headphone reach 115dB. That, however, is a peak level and there might well be a +5dB low bass boost (for Harman compliance lovers at around 80dB average).
This means that when reaching 115dB peak levels the average level is around 95dB.
Sure this is loud but visit any pop live event and realize much higher levels are blasted at you for 1 or more hours.
The thing is... when someone occasionally likes to play a song 'at impressive high levels' reaching 95dB average (for which safety guidelines say 1 hour exposure time = safe) then the amp needs to be able to provide enough voltage/power (and have a few dB headroom to ensure no clipping at these levels) then enough power should be available to reach 118dB SPL (3dB headroom, 5dB Harman bass correction for the below mentioned planar headphones).
Then going of sensitivity numbers for HE-6, Susvara, LCD-2 for instance the amp needs to provide respectively 25V, 20V and 13V.
This amp provides 18V max (and then it is already clipping) and 14V on the cusp of clipping.
Even the HD600 would need 6V to reach that level.
So... sure most headphones will likely hardly ever see 1V on its input so this kind of amps is not needed for that and agree with Blaine that these amps are not needed to enjoy music with sensible listening levels.
However, people that fork out for say Susvara, HE6 (not even that expensive) or LCD-2 and want to occasionally like to enjoy music a bit loud they will need something like this amp or some other amp that can reach 12V or 15V.
For those folks, that may also own a DAVE and all kinds of other gear this amp could well be 'a ticket' that can bring them there.
But yes ... agreed... most people won't need a powerhouse like this nor ever fork out that kind of money but that is not what ASR is about.
And obviously Amir (as well as me) recognizes that for some headphones powerhouses like this (or Emotiva or Topping etc) are fine.
Would be great if it were $ 400,- but it isn't ... get a Topping for that and that will even perform better.
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The only problem I see with the prior comments saying this level of headphone amplification can only be generated with high noise and distortion is that it’s not true. I revisited the measurements of the A90 Discrete and found that it makes the same 6W at 32ohm. Also it has a max of 49Vpp (17.32 Vrms). This power is provided with far cleaner levels of noise and distortion. Also, the A90 Discrete is far cheaper.
Unless you are talking about the power amplifier output being used to drive headphones, nothing in the headphone output makes it special going by the measurements provided.
Unless you are talking about the power amplifier output being used to drive headphones, nothing in the headphone output makes it special going by the measurements provided.
OP
- Thread Starter
- #170
As @solderdude explained, he is mostly wrong. I have heard this claim so many times that I produced a video on it:
solderdude
Grand Contributor
Sure... A90 is objectively (technically) much better performing.
But... to reach the same wattage you would need to use it balanced, the Chord (being a 'speaker amp') does this in SE as well as balanced connectors and can drive 4 insensitive headphones at the same time (assuming they have the same efficiency and all have different connectors). The A90 in SE 'only' reaches 1.5W in 32ohm
My choice, if I HAD to choose between the A90 and the Chord, would be the A90 and have funds left to boot but would be missing out on the colored illuminated balls (which I don't like so no harm done).
b.t.w. I just assume the distortion 'crap' below 5uW is measurement error.
caocaolatre199x
Member
In 2025, with such a bad measurement result, I was really surprised when you recommend it. This doesn't seem like your style.
Since some were wondering I just wanted to explain how this might be useful in a studio.
As well as main monitors many studios have additional speakers - usually NS10s or Auratones or both. These are often driven by old Quads or similar, but it’s sometimes hard to think of a suitable lower power amp.
So I think the aim here is to make a studio headphone amp - which can also drive those secondary monitors.
As well as main monitors many studios have additional speakers - usually NS10s or Auratones or both. These are often driven by old Quads or similar, but it’s sometimes hard to think of a suitable lower power amp.
So I think the aim here is to make a studio headphone amp - which can also drive those secondary monitors.
Paperdragons
Member
2
Seems like a POS. I wouldn't pay 400$ for this thing let alone 4k. How'd this get a recommendation? I used to not worry about outside payments affecting reviews here, but not I'm not so sure.This is a review, listening test and detailed measurements of the CHORD Alto "Professional" hybrid power (speaker) and headphone amplifier. It was sent to me for testing by Bloom Audio and costs US $4,320.
View attachment 434572
CHORD's iconic design elements work quite well in this package, giving it an elegant while strong feeling. The volume control feels great especially with that dent in there for your finger. Four headphone outputs are provided but the balanced ones are just connectors and don't provide more power (see measurements below).
Then we get to the lightshow buttons which are as always, a step back from ease of use. It is so bad that the company provides a cheat sheet for you to use to decode which light means what. Fortunately they left light is dedicated to input and right one, to output so that part you don't have to guess. The center globe rotates and again thankfully, that doesn't do anything. You just push it in to power cycle the amplifier.
Sequential cycling worries me for a professional product. Imagine cycling to speaker output at high volume when you wanted headphone with the client present.
Back side shows the standard connections but with inclusion of recessed banana jacks for speaker output:
View attachment 434574
The speaker outputs had a tape over them and said to read the manual before using. I read the super brief manual but found no warnings about using them so don't know what that was about.
As you see, the power supply is a very high current 12 volt unit. It comes with super stiff AC cable and cable that connects to the amplifier. Fortunately the amp is heavy enough to not be tugged by it but still, it adds annoyance to having an external power supply to begin with.
Since this is a professional device, I limited my testing to using XLR input.
If you are not familiar with my amplifier measurements, please watch this tutorial:
[And subscribe to the channel]
CHORD Alto Headphone Amplifier Measurements
As usual we start with our "unity gain" amplifier test where input and output voltages are the same:
View attachment 434575
I was disappointed by the spray of distortion products which likely indicates low amount of feedback. The spec is better than what I show but lacks detail to know if it is a comparable test. As is, performance is very much on the low side when it comes to noise+distortion:
View attachment 434576
View attachment 434579
As noted, I tested 4.4mm pentacon output as well and it is the same. Here is the noise performance:
View attachment 434577
Good with unity gain but residual noise is too high for any sensitive headphone or IEM:
View attachment 434578
Frequency response is nice and flat:
View attachment 434580
Now we get to good part: this HP amplifier produces a ton of power!
View attachment 434581
View attachment 434582
I have probably only tested one or two amplifiers with this level of output. Noise and distortion are compromised to get there but we get something useful for that.
Channel balance is excellent for an analog control:
View attachment 434586
CHORD Alto Power Amplifier Measurements
I set the output to speakers and volume to maximum:
View attachment 434587
We again get the spray of distortion. SINAD of 73 is some 7 dB worse than the average for all amplifiers tested.
Noise performance is excellent for a power amplifier (needed for the HP output to be any good):
View attachment 434588
Frequency response is load independent as one would expect:
View attachment 434589
Crosstalk is disappointedly high for class:
View attachment 434590
Distortion rises with frequency:
View attachment 434591
I think this is the worst 19+20 kHz intermodulation distortion results I have seen, since I started running this test:
View attachment 434592
Power output is modest but more or less matches the spec:
View attachment 434593
View attachment 434594
Once again noise and distortion are very high for the class.
At this point, I went into measuring power at 1% THD. For this test, I have to let the analyzer push the amplifier into clipping so it can then back down and find the 1% THD level. I typed in 4 volts for output. This immediately cause the ALTO to shutdown which is not unusual for some amplifiers. Alas, the amplifier would no longer output anything. Its front panel was working but no matter what I did, there was no output. I went back and tested the headphone output and it too was dead. I disconnected the power and cycled it a couple of times but it would still not work. I let it sit overnight and this afternoon, it started to work again:
View attachment 434595
View attachment 434596
I was too afraid to run reactive and regulated ("FTC like") tests as I wanted to listen to the unit. But did run the frequency power sweeps:
View attachment 434597
The increase in distortion is almost linear with frequency which indicates little to no feedback.
Soft power on/off produces strong pulses which are likely audible on speakers:
View attachment 434598
CHORD Alto Headphone Listening Tests
I connected my RME ADI-2 Pro interface's balanced output to the Alto and plugged in my everyday Dan Clark E3 headphone into it. The Alto drove the E3 harder than any amp I have used with it b before. Well before max volume, the loudness become intolerable while the sound remained clean without any distortion. Dynamics as you can imagine were superb with nothing to complain about.
I watched a video where it was said that the Alto was designed to drive multiple headphones. So while I had the E3 still plugged in, I also added the Audeze LCD-XC to another socket. The Alto drove both of them with ease and once again producing a level of power that was both pleasing and dangerous!
Conclusions
There have been amplifiers where company also recommends their use for headphones. But the Alto is the first one I have tested that claims that capability from start. Benefit of this approach is that there is the potential for tons more power which the Alto deliver son in spades. Both objectively and subjectively, you basically have unlimited amount of power to drive not one, but two or more headphones simultaneously. While you don't have independent control over each volume, I can imagine this being useful in a studio where the same headphone is used for multiple people to listen at once.
The compromises are kept low with distortion that is too high for my liking. Noise is good enough for most headphones but not IEMs.
I am not sure of the usefulness of driving speakers with it given the modest power output and potential issue with protection circuit. But I guess it comes for "free."
The cost is of course way up there. So you would have to value the looks, the brand, support, etc. and decide if it justifies its cost.
I am going to recommend the Chord Alto on the basis of its copious amount of power. Nothing ruins the performance of an amplifier more than when it runs out of juice.
My appreciation also goes to Bloom Audio for providing this sample for test.
EDIT: Video review posted:
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Curupira
Addicted to Fun and Learning
VientoB
Addicted to Fun and Learning
Yeah how is it "warm"? Need to watch that when I get home.
VientoB
Addicted to Fun and Learning
Interesting video. He seems to think it's distortion characteristics are responsible for the warm sound? Quite a subjective review, though, with a smattering of measurements.
jaibautista
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I was able to try a unit using different headphones (Focal Utopia, Sennheiser HD800 S, Hifiman HE1000 Stealth, ZMF Caldera) and I was disappointed with what i saw and heard. First off, the 4.4mm and 3.5mm jacks appeared to be defective (any 4.4mm plug I inserted in the 4.4mm jack won't properly lock, hence the sound kept cutting randomly; in the times I was able to hear music, there seemed to be channel imbalance, even at higher volumes; although the 3.5mm jack was able to accept plugs, the channel imbalance issue was also present). Second, there appeared to be a difference between the left and right 6.3mm jacks (with the right one sounding off). Third, there was audible scratching whenever the volume knob was turned up (maybe dust got inside? perhaps corrosion? I don't know), which I wasn't expecting from a headphone amp this expensive.
In terms of headphone pairing, I thought the Focal Utopia (through the left 6.3mm jack) sounded wonderful but the rest (especially the planars, H1000 and Caldera) sounded really, really bad: treble was sibilant, upper mids were quite hard (it's as if a hammer is being pounded to your ears), and the bass was quite woolly (relative to what I thought was engaging and hard-hitting bass with the Utopia). Honestly, I had a much, much, much better listening experience with my USD275 Topping L70.
I owned Chord products before (the original Mojo and Hugo) so getting such awful listening experience with the Alto was really unexpected. I am unsure if it's bad design, engineering or craftsmanship with the unit I demoed but if I were in the market for a high-end headphone amp, I will definitely steer clear away from the Alto.
In terms of headphone pairing, I thought the Focal Utopia (through the left 6.3mm jack) sounded wonderful but the rest (especially the planars, H1000 and Caldera) sounded really, really bad: treble was sibilant, upper mids were quite hard (it's as if a hammer is being pounded to your ears), and the bass was quite woolly (relative to what I thought was engaging and hard-hitting bass with the Utopia). Honestly, I had a much, much, much better listening experience with my USD275 Topping L70.
I owned Chord products before (the original Mojo and Hugo) so getting such awful listening experience with the Alto was really unexpected. I am unsure if it's bad design, engineering or craftsmanship with the unit I demoed but if I were in the market for a high-end headphone amp, I will definitely steer clear away from the Alto.
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