[Xenophon]

  Also, Tyll measured his HE-500 to be less efficient than spec btw. Anyway, THD isn't just THD. The sound of distortion can and will be different at the same THD with different amps, and there's also other kinds of distortion anyway. You kinda don't get the hole picture just looking at THD. Distortion can sound good after all... and bad.
 
Anyway, I don't really disagree with you on the ability of the o2 to drive the HE-500's, but personally I'd get an amp with more headroom as it isn't impossible to encounter distortion that wouldn't be there if the o2 could push some more juice. Never tried the amp, actually.

 
Agree with the first statement but let's not visit the second 

 or we'll end up in a taliban-like quasi religious argument (as I said, I'm not a tube guy but I respect that there are different schools of thought and after all, everyone's entitled to his personal taste/opinion).  If you have the occasion, give the O2 an audition.  Price/quality wise it's simply incredible.  My Fiio E17/E09K combo is gathering dust since I purchased it, there's simply no comparison.  Of course it's a different story compared to my Violectric dac/amp setup, but given that that one cost me about 2.5k USD there'd better be some difference.  Considering the price, however, the O2 is the clear winner. 

 

[ethan7000]

  If it were just the comparison between different speaker amps and how they drive the HE-500 then ok, I could live with that and it's much appreciated.  But I'm having a REALLY hard time believing the bold assertion that any reasonably powerful headphone amp such as the (small though it is) O2 couldn't drive the HE-500 well.
 
The cans are rated with a sensitivity of 89 dB by the manufacturer.  Compare with the HE-6's 83.5 which makes a huge difference, the scale being logarithmic.  Tyll's measurements specify 0.310 Vrms to reach a 90 dB SPL.  The O2 outputs 0.630 mW into 33 Ohm (HE-500 is 38 Ohm), that works out to about 4.5 V (limited to avoid damaging low impedance cans) or about 1.5 Vrms.  Don't have time to go into detail but look at the specs and do the math...it'll drive 'em with room to spare.  I'm confidently asserting this not only because I trust Tyll, the designer of the O2 and calculations but also because I happen to own the epiphany acoustics O2 dac/amp combo, have an HE-500 on loan and actually own a HE-6 (for which the O2 indeed lacks power).  
 
The HE-500 are driven just fine, even without extra gain.  Volume rarely goes past 11 'o clock and I listen to classical which has a huge dynamic range.  Some of the pieces I listen to I've heard multiple times live so I have a pretty good idea of how they should sound and I do recognize clipping and failing bass.  The epiphany acoustics O2/DAC is my setup at the office, at home I drive the cans with a Violectric V800 DAC, coupled balanced to a V200 amp and that setup outputs 2000 mW at 7Vrms into a 32 Ohm load.  Also sounds fine of course, matter of fact I use this to drive the HE-6.  But  just to say that this is a comparison point and I can confidently say that even just going by ear, the O2 also drives the HE-500 well.  Also, as someone else remarked, Woo audio showcase the HE-500 with one of their amps.  I'm not into tubes but I credit the guys at Woo audio with not being cretins....

 
I think this is really interesting from the 500 thread:
 

  I think it is a different interpretation of "the He500 at its best" that is driving this debate
Bass response from the amplifier end is largely driven by capacitors, speaker amps have large capacitor banks designed to drive large drivers to high spl.
I doubt these budget speaker amps have the finesse in there design to control all that power at the very low levels required by the He500.
 So what you get is a boosted bass response much like a loudness switch or FM radio.
To many this sounds great and I can see why many would see this as the He500 at its best.

I'm starting to think it's not so much about power or distortion but the kind of sound speaker amps output because of components designed to move larger drivers.

 

[bhazard]

   
I think this is really interesting from the 500 thread:
 
I'm starting to think it's not so much about power or distortion but the kind of sound speaker amps output because of components designed to move larger drivers.

It's all theoretical until you actually try it and see for yourself. Remember, 613mW is max output. You want your amp to have some headroom.
 
I can tell you from experience, that the Magni did not sound very good compared to the Lepai, despite being able to get loud before 11 o' clock, and the Magni is more powerful than the O2. Magni sounded great with every other headphone of mine however.

 

[VTV]

The emo is not balanced

My fault. It says fully discrete.

 

[Sonido]

Edited post #18 and added a new graph and some impressions for WA7+Emotiva combination with the WA7 acting as a preamp.

 

[nehcrow]

Wow What!? A $20 Lepai amp can actually drive the HE-500, that's crazy!
Wonder how it stacks up against a Magni...

 

[ab111]

Hi everyone,

I have a HE-4 and I've been curious about using a speaker amp with it. I am currently using a schiit lyr which has a ton of power but I hear these headphones love more.

I wanted to try the emotiva but it's almost twice the price shipped to Canada so I've settled on getting the lepai to try speaker taps.

For the cabling I just want to be sure I'm doing it correctly. I can simply cut off the end of the ttrs cable, figure out what is each channel positive and negative and connect those directly into the back of the amp? Nothing else is needed?

Thanks,
Ab111

 

[bhazard]

  Wow What!? A $20 Lepai amp can actually drive the HE-500, that's crazy!
Wonder how it stacks up against a Magni...

It's better than the Magni. I wanted to know the same so I tried them both.

 

[Sonido]

Hi everyone,

I have a HE-4 and I've been curious about using a speaker amp with it. I am currently using a schiit lyr which has a ton of power but I hear these headphones love more.

I wanted to try the emotiva but it's almost twice the price shipped to Canada so I've settled on getting the lepai to try speaker taps.

For the cabling I just want to be sure I'm doing it correctly. I can simply cut off the end of the ttrs cable, figure out what is each channel positive and negative and connect those directly into the back of the amp? Nothing else is needed?

Thanks,
Ab111

Yup

 

[ab111]

Thanks everyone, and especially Sonido.

I cut off the connector to my trrs cable and ended up with 4 wires that appeared to be bare copper wires. It was insulated with some invisible material that I googled and used a lighter to burn it off. Used a multimeter to figure out the connections and terminated in banana plugs. Unfortunately my banana plus don't fit the lepai so bare wires for now.

Works great and I'm impressed vs my Schiit lyr. After 2 days of say lyr is better than the lepai in direct mode but I can make the headphone 'fun' using the tone controls. I think I have the bite to get a nicer amp with time controls. Any suggestions under 400? O have a music Hall DAC fully nodded that I would describe as neutral and extremely detailed.

Thanks,
Ab111

 

[Sonido]

Emotiva a-100 MiniX @ $169 with current sale price. It's very neutral and you can pair it with a tube preamp, or even an OTL headphone amp like I'm currently doing with the Bottlehead Crack, and you'll get the the tube signature of your amp with the power of the speaker amp. The preamp can do all the controlling like a speaker setup. Stay tuned for how well the Bottlehead Quickie will work with the Emotiva. It's a $99 tube preamp that's supposed to sound better than the Crack as a preamp according to their website.

 

[ab111]

Thanks sonido but as I said I want tone controls on the amp I get. I also mentioned that the emotiva price is double to get it to Canada. I understand that it is still within my price range but I feel like I should be able to get something nicer at the same cost since the majority is going to be shipping duties etc. Not the actual amp. But if the emotiva is the best amp with tone controls at a 400 price point then maybe I'm wrong about speaker amps driving my HE-4s.

 

[mnarwold]

I got the the Lepai recently to drive some bookshelf speakers, but thought I'd try it out on my HE-500 just for kicks. I made a new cable for the lepai and got to listening. There is definite noise in the lepai, but I don't really notice it when the music is playing. Between tracks however there is a slight hiss, almost like listening to a tape. The sound was good overall.
 
I tried to compare to my O2 and ran into the problem that I couldn't switch the headphone cable out very fast for ABing. I got pretty good at changing the cable, but it still probably took 15-30 seconds to switch, which is way too long for proper testing. So, take these comments with a grain of salt. I could notice a slight increase in bass in the lepai compared to the 02, maybe 1 or 2 db, so not a big difference. I could also hear that something was a little different in the treble, but after several attempts I couldn't figure out what was actually different. Overall I thought the lepai did well, except for the noise, which annoys me since I can use the dead silent O2. I preferred the sound of the O2, but I couldn't test very well and it could all be in my mind. My tests were sighted.
 
If anyone has any ideas of how to A/B faster let me know. I would love to test this without changing the headphone cables. I would even try some blind testing if I could figure out a good test rig.

 

[kothganesh]

Sonido,
 
thanks for the review. Like you, I ended up buying the Emotiva at $169. Got the cables from Brian at BTG with the speaker taps adapter for both the Hifiman and the Audez'e cans that I have. The HE 4 in particular loves the power that the Emotiva throws at it. In fact, I bought an old pair of Stax SR-5 and connected it to the Emotiva. The sound is very very good. I think I am now looking at speaker amps as a general way to go.
 
Edit: I ended up buying one more Emotiva at the same price. Need one in the office to replace the Lyr 

 

[mnarwold]

OK, so I did some more testing between the O2 and the Lepai and this time I used an SPL Meter to level match the two amps to within .1db (actually took a lot of fiddling to get the volume exact). Still not a double blind test, but in this case the O2 won hands down. With the amps level matched I didn't notice any increase in bass with the lepai, but there was a slight decrease in the treble, especially when it came to clarity. Now, I'm not calling the Lepai muddy at all, the difference between it and the O2 wasn't night and day, but was there, and it can best be described as a lower level of clarity. For instance, on Take Five by Dave Brubeck Quartet, the sax had a lifelike texture to it with the o2 that just wasn't there on the lepai. After a bit of listening I realized there was a very slight treble buzz that gave it the life-like texture, which was only present on the O2. Anyway, this is all IMO and YMMV. I wouldn't recommend anyone use the Lepai to drive their HE-500s.