Originally Posted by xnor
I haven't seen Stax amp measurements. Audeze doesn't seem to have their own amps, they just sell ALO tube stuff (just the PanAm afaik).
edit: Oh you meant headphones. Well, yeah, some headphones are quite good actually, others are just abysmal (Ultrasone Ed10 for example).
edit2: SanjiWatsuki summarized it pretty well.
Apparently I didn't include those in my list..
Should I continue with my list?
ALO PanAm specs the frequency response starting at 40 Hz (hopefully only -3 dB!), and 1% THD+N (with no mention under what circumstances, so could be a lot higher in real world usage). As it uses tubes, this is no surprise. No mention of output power.
The International (ALO) has a phase wrap at 1 kHz.
Grace M903, at least Tyll's model, had a noise problem (noise floor at -8x dB unweighted).
The Firestone models Tyll tested (Fireye, Fubar HD) measured badly: low output power or high noise, harmonic and intermodulation distortion.
The Headamp Pico is ok, the Slim and BitHead less so (limited output power, IMD).
Isn't PanAm a tube amp? (I said "SS Amps" as I never understand tube amps) I don't care much for the above products anyway.
I'd love to see Audio-GD measurements.
The Auralic Taurus (€ 1800) is comparable to an O2: a bit higher output voltage (+1 dB into 600 ohm, +4 dB into 32 ohm), but also higher output impedance (2.2 ohm). Sure, it measures a lot better than previous examples, but is it really worth € 1800? Specs also say input sensitivity is 4Vrms, so you might actually get lower output than from an O2 with tuned gain and a standard 2Vrms source. I don't know how high the noise floor is.
Bryston BHA-1 (€ 1600) is similar to the Taurus, with 87 dB SNR, ~6 ohm output impedance, but 3 dB higher output voltage.
If you really need that amount of power why not get a nice NAD power amp for a fraction of that cost (€ 350)?
Leaves us with Violectric. I only have measurements of the V181 here (€ 850) from audio/stereoplay.de. With 4.7 V output into 600 ohm, 1.3 ohm measured output impedance an O2 beats this hands down.
Orz I don't want to start on O2...
For most I can only comment based on information I managed to find on their websites and online, at least those brands I listed seem like serious business to me. Nitpicking on already low enough output impedance values doesn't seem very meaningful to me... There are other important metrics like FR, channel balance etc. And at least for BHA-1 your data is very different from mine. I have one and it came with an individual measurement cert, unweighted SNR is about -107~109db for both channels, and THD+N is about 0.001~0.003%. Output impedance is listed as 2ohm per opamp, which means 2ohm for single-ended output and 4ohm for balance output.
Indeed, some high fidelity devices do in fact come with cheap transistors and some supposedly high-end DIY devices that are crap come with most expensive op-amps or whatever.
That's when the DIY designers follow the "expensive parts must be good" myth blindly without measuring actual performance. Even if the parts themselves are good doesn't guarantee that the overall implementation makes any use of the part's superb performance.
I follow a much more pragmatic approach. I don't care what op-amps or transistors or caps or .. are inside of a device just like I don't care about the number of transistors or shader units or ... in a graphics card. What I care about is the actual overall performance.
Apparently people can have different concerns... you have yours, I have mine. At least to me there are other aspects to consider beside measured performance and I am willing to pay for that.
Comparing apples with oranges here.
A look at hardware measurements takes as much concentration and time as a look at audio devices or headphone measurements.
I'd also argue, that in depth graphics card benchmarks with lots of different games, configurations, benchmarks ... take more time than let's say headphone amp measurements.
I said, LISTENING TEST demands full concentration (Did you ever try? I know I did.), not graph starring... Hardware Benchmarking may take long time, but the actual effort required from human operator is very low and simple. And this whole apples with oranges thing is brought up by yourself...
Blind testing is very uncommon with computer hardware since people there don't insist on invisible magical properties but rely on measurements. Doing a blind test between different graphics cards would not be less time consuming than between two headphone amps or DACs or even headphones.
Well actually I don't know what blind tests to do with graphic cards...
Audio is somewhat different that its more analog based, each number/graph measurement tells you different aspects of the performance but not everything. Similar case in computer hardware is perhaps display monitor, where one needs to actually take photos to compare certain performance metrics.
Why, did NuForce fix the defect in the last ~3 years?
I leave the sugarcoating to others.
If the audio industry were anything like the computer hardware industry we'd see better and cheaper components each year. Instead we see more expensive devices with sometimes a large step backwards in performance.
Computer hardware market is filled with fancy expensive rubbish too, so as most if not all commercial markets. Actually I don't quite understand why you are so negative on audio equipments... I don't see less problem in computer hardware industry anyway