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Burn-in Review: HeadAmp AE-2 #24 vs #103

post #1 of 16
Thread Starter 
Intro

Not too long ago, I ordered up another AE-2, on top of the one I'd previously ordered in February this year, for two reasons: (1) I didn't entirely like the first one's gold volume knob, and (2) I didn't like the red LEDs that much either. So when I ordered up the second one, I asked for it in entirely black, and if the LED color could be customized. Well as the picture below shows, the color of the LEDs can indeed be customized. I went with green because I thought it would be cool to have an AE-2 that resembles the AE-1 of yore!

And since this gave me the opportunity to own two AE-2s simultaneously, I thought I would write up a comparison between the two that addresses the ever controversial issue of burn-in!

Serial numbers of the two AE-2s: #24 (ordered Feb '07), #103 (ordered June '07). #24 had over 300 hours applied to it before it left me for Loaner #6 (link in signature), and thus 400+ hours when it came back to me on 8/24/07. #103 arrived on 8/25/07 with zero hours and started from there.

All CD tracks were played on #24 first, and then on #103 immediately afterwards.

Equipment Used

Source: Arcam FMJ CD33
Power cord: Signal Cable Silver Res Reference
Interconnects: Signal Cable Silver Res Analog w/ Eichmann silver bullets
Headphones: AKG K701 w/ Equinox, Audio-Technica ATH-AD2000 w/ APureSound

Pic



Comparisons

- Alison Krauss - Lonely Runs Both Ways - "Goodbye Is All We Have" (with K701)

This track has quickly become one of my references for soundstage and layer presentation. Immediate impressions of #103 were that it had a less fluid sound with soundstage placement completely different than #24 - not as in front, too much to the side. There was more air expansion, and less body to the sound.

- Eva Cassidy - Songbird - "Over the Rainbow" (with K701)

Less power and presence to Cassidy's voice on #103. Not presented as forward & intimate as on #24. Left/right dimension of soundstage also a bit smaller - less dimensionality. Also less crispness on the guitar notes throughout.

- Howard Shore - Lord of the Rings: Return of the King [OST] - "Ash and Smoke" (with K701)

Soundstage very oriented towards the left and right sides on #103, whereas #24 is integrated with the center. Again, not much dimensionality on #103. Less violin/strings presence on #103 as well.

- KT Tunstall - Eye to the Telescope - "Other Side of the World" (with AD2000)

Noticeably slow attack on some of the guitar runs on #103 - mashes, not clear and crisp. Very little difference otherwise, only noticeable part was a reduction in some ambience.

- Massive Attack - Mezzanine - "Black Milk" (with AD2000)

No doubt about it, #103 misses that last bit of bass extension on the rhythmic pulse of this track. Not as weighted either, as it exudes less power.

- Neotropic - Mr. Brubaker's Strawberry Alarm Clock - "Gutted" (with K701)

This track is one of my references for its overload of high-frequency layers simultaneous with undercurrent bass and spontaneous noises throughout. #103 wasn't as quick to recover from the spontaneity of the digital effects that pervade the track and instead came across as sluggish. Bass didn't reach as viscerally low either for that undercurrent feel. #103 didn't retrieve quite as much high-frequency detail either - a tiny part of it lost due to some recession. Also a lack of ease in letting the effects pass from one channel to the other.

- Porcupine Tree - In Absentia - "3" (with K701)

Less dynamics to the music on #103, not as hard-hitting. Impacts not as swift & hard either, and it has the sense of fatigue rather than energy. A more metallic sound to the guitars as well, and also less fleshed out with body and fullness.

Conclusion

Well there you go. #103 turned out to be several steps behind #24. I wasn't surprised by the results, though I do admit I was expecting more of a difference considering my burn-in progress reports on the previous AE-2 thread that I updated. So burn-in may not be such a huge factor on the AE-2 at all. YMMV.
post #2 of 16
Quote:
Originally Posted by Asr View Post
#103 arrived on 8/25/07 with zero hours and started from there.
did you ask Justin how long he listened and tested your new AE-2 before he shipped it to you?


Quote:
Originally Posted by Asr View Post
... I was expecting more of a difference considering my burn-in progress reports on the previous AE-2 thread that I updated. So burn-in may not be such a huge factor on the AE-2 at all. YMMV.
can't forget your mind and ear already had been fully acclimated to the AE-2s' sound signature. granted minor sonic changes might occur during the first few hundred hours as somewhat similarly changes occur each and every time the amp and source finally reach it's peak operating temperture, but the "difference" is probably more analogous to the mind adjusting to a new optical prescription, which usually takes time and, of course, individual specific. though most ears are exceedingly slow at grasping new sonic pictures.

Very cool you bought another and shared your impressions--thanks.
post #3 of 16
I would recommend using a headphone switchbox for doing such a subtle A/B comparison. It's difficult enough as it is to compare different headphone amps well, let alone with two same amps of different build times and generation.

The differences you hear might not be as big as you thought. I find that most differences I thought I heard between headphone amps was simply because I was listening to one amp louder than the other one.

-Ed
post #4 of 16
I think it's good good data and well written (very concise). Not many are in the position to do this type of comparison. Thanks Ars!
post #5 of 16
Great review Asr! BTW I like the new color combination much better.
post #6 of 16
Quote:
I would recommend using a headphone switchbox for doing such a subtle A/B comparison.
Yes, and make sure that the wires and jacks on both sides of the switch box are equally burned in.
post #7 of 16
Thanks ASR...
My fave portable amp and one of my fave cans.

I'm meeting up with a couple other San Jose members next week, PM me if you wanted to do a DBT kind of thing.

Thanks... Nice choice on the color combo too.

Justin rocks!!
post #8 of 16
Oh, Asr's burn-in reviews. So refreshing.

Quote:
Originally Posted by Edwood View Post
It's difficult enough as it is to compare different headphone amps well, let alone with two same amps of different build times and generation.
Fair point. If Asr did a follow-up comparison with both amps at 400 hours and they wound up sounding essentially the same would you be impressed? I imagine not.
post #9 of 16
Quote:
Originally Posted by mrarroyo View Post
Great review Asr! BTW I like the new color combination much better.
...but silver is so classy

I like the green LED better than red. I actually would prefer blue even though that color has been worn out-how about green for charge and blue for pilot

My AE-2 has well over 1,000 hours...and it is good
post #10 of 16
Thread Starter 
Quote:
Originally Posted by 909 View Post
did you ask Justin how long he listened and tested your new AE-2 before he shipped it to you?
No, but I don't see why that would be relevant - any testing that Justin does should be equivalent across all AE-2s, and I wasn't comparing two zero-hour AE-2s.

Quote:
Originally Posted by 909 View Post
can't forget your mind and ear already had been fully acclimated to the AE-2s' sound signature. granted minor sonic changes might occur during the first few hundred hours as somewhat similarly changes occur each and every time the amp and source finally reach it's peak operating temperture, but the "difference" is probably more analogous to the mind adjusting to a new optical prescription, which usually takes time and, of course, individual specific. though most ears are exceedingly slow at grasping new sonic pictures.
Actually I spent very little time listening to #24 before moving to #103. My goal was simply to find out if these two units differed, and if so, by how much, not to do an extensive comparison, because an extensive comparison would put a number of hours on #103, which I don't want to do yet.

Quote:
Originally Posted by Edwood View Post
I would recommend using a headphone switchbox for doing such a subtle A/B comparison. It's difficult enough as it is to compare different headphone amps well, let alone with two same amps of different build times and generation.

The differences you hear might not be as big as you thought. I find that most differences I thought I heard between headphone amps was simply because I was listening to one amp louder than the other one.
Well with the AE-2's notched volume knob it's actually feasible to calibrate them to the same volume - maybe not truly identical without an SPL meter, but should be close enough I'd imagine. And I don't think HeadAmp builds "generations" of amps, not sure what you're saying there.
post #11 of 16
Quote:
Originally Posted by Asr View Post
No, but I don't see why that would be relevant - any testing that Justin does should be equivalent across all AE-2s, and I wasn't comparing two zero-hour AE-2s.
if Justin spent nearly the same amount of time testing and listening to each AE-2 before shipment obviously it wouldn't be so relevant, yet actually knowing in this specific instance would be important.

people assume far too much and too often -- the "average" doesn't take into account the times he spends more than the norm.

Quote:
Originally Posted by Asr View Post
Actually I spent very little time listening to #24 before moving to #103. My goal was simply to find out if these two units differed, and if so, by how much, not to do an extensive comparison, because an extensive comparison would put a number of hours on #103, which I don't want to do yet.
my point, you had already spent a substantial amount of time listening to #24 in the process of posting your impressions prior to receiving #103 and as a result your mind and ears had been fully acclimated to the AE-2 sound signature. in the op you indicated you were expecting more of a difference considering your burn-in progress reports, but i suggest you weren't acclimated to the AE-2 previously or put another way it took 200+ hours for the AE-2s sonic picture to come into focus for you.

i agree with your conclusion that burn-in may not be such a huge factor on the AE-2 and add amps in general, but most people often tend to overlook another plausible explanation--it's their perceptive that's evolved.
post #12 of 16
Thread Starter 
Quote:
Originally Posted by 909 View Post
my point, you had already spent a substantial amount of time listening to #24 in the process of posting your impressions prior to receiving #103 and as a result your mind and ears had been fully acclimated to the AE-2 sound signature. in the op you indicated you were expecting more of a difference considering your burn-in progress reports, but i suggest you weren't acclimated to the AE-2 previously or put another way it took 200+ hours for the AE-2s sonic picture to come into focus for you.

i agree with your conclusion that burn-in may not be such a huge factor on the AE-2 and add amps in general, but most people often tend to overlook another plausible explanation--it's their perceptive that's evolved.
Oh I see what you're getting at, but actually I did forget what the AE-2/#24 sounds like, as I didn't have it for quite a while, and I spent no time listening to it between the time I got it back and when I started listening for this quick review. I literally dropped both amps into my system with no memory of the AE-2's sound, listening to them as-is.

I do acknowledge that psychoacoustics often comes into play with these things but I always try to reduce that variable by not listening to what I'm burning in as much as possible. I might listen to something for an hour or two, then put it on unattended burn-in while I'm at work or out (a day at a time, more than a day in some instances), then come back to it a few days later - that's my methodology when it comes to burn-in, which is what I did on AE-2 #24. #103 I took out of its box and started listening right away.

Basically what I did for this review was drop two amps into my system for a quick comparison - I essentially disregarded the fact they were two AE-2s and merely viewed them as two of the same amp, where one just happens to have a lot more hours than the other.
post #13 of 16
i believe we never fully forget on a subconscious level even audio impressions especially those engraved over many hours and more so over 100+ hours. Granted you may have forgotten, but i suspect you remembered things fairly quickly whether realized or not. once acclimated you can't un-ring the bell.
post #14 of 16
Quote:
Originally Posted by Asr View Post
I do acknowledge that psychoacoustics often comes into play with these things but I always try to reduce that variable by not listening to what I'm burning in as much as possible.
i believe this has little to do with not listening to something as it "burns-in" but how long it takes the listeners' mind to understand and appreciate that new thing they're hearing and generally for most that takes 100s of hours.
post #15 of 16
Thread Starter 
Quote:
Originally Posted by 909 View Post
i believe we never fully forget on a subconscious level even audio impressions especially those engraved over many hours and more so over 100+ hours. Granted you may have forgotten, but i suspect you remembered things fairly quickly whether realized or not. once acclimated you can't un-ring the bell.
That may be the case, but for all intents and purposes, I effectively forgot the sound of the amp and didn't bother to get re-acquainted with it. If I had taken the time to get re-acquainted with #24, I bet that would've skewed the results in favor of finding more differences.

Quote:
Originally Posted by 909 View Post
i believe this has little to do with not listening to something as it "burns-in" but how long it takes the listeners' mind to understand and appreciate that new thing they're hearing and generally for most that takes 100s of hours.
True, it can take a long time to really understand the sonic signature of any audio electronics, but that also depends on how critically you listen and how well-trained your ears are to discern differences and subtleties.
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