[DJ The Rocket]

AE-5 and I'd definitely give the detail advantage to

What do you mean by this? Details (or lack thereof) don't have anything to do with the amplifier, provided the amp meets certain minimum thresholds for noise, distortion, or less likely, slew rate, etc. One amp is going to have precisely the same detail as the next.

Often, certain kinds of treble distortion can be perceived as being "more detailed," but that's not true detail. Again, there's nothing wrong with enjoying this kind of distortion more than transparency. I personally consider anything that decreases transparency a flaw.

Also if you wonder about my hearing, I can hear grasshoppers just fine - even when there's other noises around.

Okay. That's neat? This is a really, really strange thing to say. From the context I think I know what you're trying to prove, and I'm trying really hard not to sound condescending here and I don't think I'm going to succeed, but the fact that you think this example means anything demonstrates that you don't understand how hearing perception works. Maybe someone else with better tact can break down exactly why?

 

[MrMateoHead]

Here's are some measurements just to see if my ears work correctly. I wanted to know if these reflect what I actually hear. The DAC on AE-5 is ESS ES9016K2M SABRE32 Ultra.

Full specs of test system:
Intel Core i7-3770K & Thermalright True Spirit | ASUS P8Z77-V | Corsair AX760 | Define R4 | 4x4GB G.SKILL RipjawsX 1600MHz | EVGA GeForce GTX 1070 GAMING ACX 3.0 | Creative Sound BlasterX AE-5 | Samsung 830 128GB & 3x HDD = 5TB | Windows 10 Pro x64

Method:
ASIO playback and record. Main volume was set to 94% to avoid clipping (about 1dB headroom). Line out was 100%. Direct HP mode was used for AE-5 while Direct mode was used for Objective 2.

Things to note: SoundCore3D chip's ADC is the limiting factor for AE-5 and it's pretty safe to assume that AE-5 has even larger advantage in dynamic range and noise level. Not for Objective 2 amp though. Noise level, dynamic range and stereo crosstalk do not fit within the error margin and the AE-5 advantage is rather large. Those basically explain the difference in soundstage and everything really.

What is direct HP mode? What is "directo Mode"? What was the source for the O2 measurements? The amp should be showing approximately 115 dBA for the noise level. The creator claimed upwards of 130 dBA at full output. With an ODAC hooked up my guess is it would drop to about 103 dbA with up to 115 dB dynamic range limited by the ODAC, not the amp. Worst case crosstalk is about 65 dBA and best case is about 95 dBA impedance / signal depending. Did you build the O2 yourself? Something looks off with these values.

 

[Arkady Duntov]

Did you build the O2 yourself? Something looks off with these values.

One thing I didn't recall while responding is that the OP said his O2 was from Massdrop and questioned whether they had "cut corners." That could be an important point.

 

[DJ The Rocket]

One thing I didn't recall while responding is that the OP said his O2 was from Massdrop and questioned whether they had "cut corners." That could be an important point.

Far, far more likely than "cut corners" is an innocent mistake, like ESD killing a FET or a manufacturing defect in a component, or something like that. It's uncommon but it does happen. It would be unspeakably stupid to intentionally do something like that on what's possibly the most well documented headphone amp that's ever been designed.

Technically the problem would be with whoever Massdrop contracted anyway, not massdrop themselves, though they're who you would deal with. It's not like MD manufactures anything in-house. I also have to think Massdrop would take this very seriously if it was the case. They should take any defective product seriously, regardless of fault

 

[Oscar-HiFi]

Far, far more likely than "cut corners" is an innocent mistake, like ESD killing a FET or a manufacturing defect in a component, or something like that. It's uncommon but it does happen. It would be unspeakably stupid to intentionally do something like that on what's possibly the most well documented headphone amp that's ever been designed.

Technically the problem would be with whoever Massdrop contracted anyway, not massdrop themselves, though they're who you would deal with. It's not like MD manufactures anything in-house. I also have to think Massdrop would take this very seriously if it was the case. They should take any defective product seriously, regardless of fault

I do recall a picture of a power supply that came with the massdrop units, it was 12v...

 

[Anarion]

I do recall a picture of a power supply that came with the massdrop units, it was 12v...

I'm not using that. I use the G.E.Z. 15V AC adapter (same as this). Highly doubt that it's the problem. The thing that came with Massdrop is definitely junk.

The one that Massdrop bundled is on the left (ignore the right one).

It's entirely possible that this is the so called "Monday unit". It's also possible that O2 just isn't quite one par with AE-5. At the very least I don't think there's any reason to believe that O2 should spank AE-5 (or the other way around). In any case though, the measurements line up with how it actually sounds (for what ever reason).

What is direct HP mode? What is "directo Mode"? What was the source for the O2 measurements? The amp should be showing approximately 115 dBA for the noise level. The creator claimed upwards of 130 dBA at full output. With an ODAC hooked up my guess is it would drop to about 103 dbA with up to 115 dB dynamic range limited by the ODAC, not the amp. Worst case crosstalk is about 65 dBA and best case is about 95 dBA impedance / signal depending. Did you build the O2 yourself? Something looks off with these values.

This is the Massdrop pre-built Objective 2 amp. Source for Objective 2 was Creative Sound BlasterX AE-5 (line out). Direct mode means that the Sound Core3D chips was bypassed and the audio went straight to the DAC. On paper ODAC is worse than the line out on AE-5 so it shouldn't make a difference for the better.

What do you mean by this? Details (or lack thereof) don't have anything to do with the amplifier, provided the amp meets certain minimum thresholds for noise, distortion, or less likely, slew rate, etc. One amp is going to have precisely the same detail as the next.

Often, certain kinds of treble distortion can be perceived as being "more detailed," but that's not true detail. Again, there's nothing wrong with enjoying this kind of distortion more than transparency. I personally consider anything that decreases transparency a flaw.

"More detailed" is a combination of things. Dynamic range and crosstalk all play a role. I consider more accurate soundstage and better dynamic range as "detail". Dynamic range difference may play even larger role once you start lowering the volume (to something that you actually use for listening).

Okay. That's neat? This is a really, really strange thing to say

In case you though that I have a hearing problem. Considering the way you started writing... You started out rather hostile and condescending. How do you think people will respond?

 

[MrMateoHead]

Basically, my hunch is that you should seek another O2 before subjectively OR objectively concluding that the Soundblaster AE-5 is superior - and that its superiority is plainly audible.

To prove that, I would seek out a neutral 3rd party, and A/B the amp+DAC for them. It won't conclude WHY the AE-5 is better (could be the amp, the dac, or some combo of the two), but if it is the users preference the majority of the time, it is probably a winner, period.

I tried this exercise with some really good speakers separated by $400 in price (full retail), and coax vs. "regular" drivers / alignment. Set up and volume matched to 1 dB (for a listening level of about 65-70 dB+ peaks at about 6 feet). Source was Laptop using an ODAC and FLAC recordings. Trust me, 70 dB or so average SPL is basically plenty loud for music listening - any louder would start to be uncomfortable and glare (a little about myself, I think most concerts sound like s*** because they are just too loud, my ears can't take it). I did sighted listening while the "blind" person did the A/B listening.

After three days, I hate to admit it, the more expensive speaker won. Apart from its advantages NOT in play (superior horizontal and vertical response), I suspect the slightly better bass extension and weight (it measured noticeably better around 45-65 hz) contributed to it sounding "bigger" and more powerful. Personally, I felt that the added depth (e.g. transparency) of the more expensive speaker, when it was apparent on some recordings, was just undeniable. Then again, I must say the cheap, $100 speakers were demonstrably awesome. They lacked for nothing in the room, and were in some cases almost preferable - almost. I've never heard them sound that good and I suspect the "liveliness" of the room helped the high frequency response a tad.

No I didn't test Maximum SPL or push volume to concert levels to see which speaker fell apart first - that just isn't my "90%" rule - how does it sound, when 90% of the time you aren't cranking it to death?

Anyway the bottom line was you do sometimes get what you pay for (when both products are from companies that obviously care about real performance). BUT given that the "winner" cost, technically, several times more, I wouldn't recommend them to someone that didn't have money to burn, because the gains just weren't THAT great. Absent an A/B test, you wouldn't feel you were missing out at all. After averaging the response of each speaker from several positions, I discovered the measured extremely similarly - that is, great speakers DO probably measure somewhat alike. With tonal balance almost the same, this was a great way to see if lower distortion, larger cabinets etc. make a difference.

 

[Anarion]

It would be nice to test another O2 but that's not possible. I also tried different 3,5mm to RCA cable just to rule that out - no improvement. This particular unit that I have here definitely doesn't perform that well. It would be nice if someone with O2 and AE-5 could test.

My O2 is the 1x & 3,3x gain version. I've used the low gain option. AE-5 has three gain settings and I used the low gain one which also seems to be 1x gain (since both produced the same volume, give or take 0,5 dB).

It's annoying that often the sound in movie theatres is often so loud that you actually hear things more clearly once you plug your fingers in your ears. I bet that would apply to concerts too. I can't handle loud sound very well at all and I use rather low volume levels myself. No one ever complains about leakage when I use open cans. HD 595's are rather pain in the backside because they are so sensitive. With O2 I have to turn the volume knob around 33% (in low gain) while PC's master volume is at 10%... If I'd plug them directly in the card I'd have to use something around 2-4%.

 

[MrMateoHead]

The reality is that most headphones require, at most, just a few mWs of power to CRANK. when 1 mW can yield 90-100 dB, frankly, the power requirement is too low to justify a dedicated amp. That is why, frankly, most of my midrange cans sound just fine on a modern smartphone. Its the higher impedance stuff that gets tricky.

The only headphone which definitely needed the O2 was the HE-400s I own, which I playback at close to noon-1 pm when I am really feeling crazy. My Old 595s benefited from the amp a bit but still sounded about the same.

Here's what I would like to have. A volume knob that steps up the power in fractions of a mW for about half the travel. Then one that scales from that mW to hundreds of mWs over the next 6-9 hours for the insensitive cans. I'm sure it would be bizarre, but at least it might add some flexibility.

To use my O2 with my PSBs, I raise the knob until I am just clear of the L/R channel imbalance area, about 9 O'clock, and then use windows volume control from about 20-50. Luckily I detect no loss of fidelity even if it is there. Thats it. Then just strap in the best source I have available.

 

[DJ The Rocket]

"More detailed" is a combination of things. Dynamic range and crosstalk all play a role. I consider more accurate soundstage and better dynamic range as "detail". Dynamic range difference may play even larger role once you start lowering the volume (to something that you actually use for listening).

Ah, so we're using different definitions for the word "detail." How lovely that audio doesn't have any sort of standardization about what words mean. No wonder this hobby is such a mess, we can't even communicate without defining terms at the beginning of every post.

I always thought that every 101-level college course was mostly just to teach the basic vocabulary of the field, otherwise the more advanced courses wouldn't make any sense to anyone. Somebody--anybody--should put together a standardized glossary of terms for describing audio, and then we'd need a critical mass of people to follow it and people with more tact than me to nudge everyone else to get them on board too. It doesn't matter if we use your conception of detail or mine or anyone else's, everyone will adjust eventually.

 

[DJ The Rocket]

I do recall a picture of a power supply that came with the massdrop units, it was 12v...

I wonder what it actually measures at. I use a reterminated "16V" linear supply from Schiit, and it measured 19.5V, just barely within o2 spec.

 

[Arkady Duntov]

Far, far more likely than "cut corners" is an innocent mistake, like ESD killing a FET or a manufacturing defect in a component, or something like that. It's uncommon but it does happen. It would be unspeakably stupid to intentionally do something like that on what's possibly the most well documented headphone amp that's ever been designed.

Technically the problem would be with whoever Massdrop contracted anyway, not massdrop themselves, though they're who you would deal with. It's not like MD manufactures anything in-house. I also have to think Massdrop would take this very seriously if it was the case. They should take any defective product seriously, regardless of fault

Your conclusions are some I failed to make and I agree with you.

Another mistake I made was to attribute the differences encountered by the OP to problems in the AE-5; while it's possible I was correct, that isn't the only reasonable deduction.

 

[Anarion]

I wonder what it actually measures at. I use a reterminated "16V" linear supply from Schiit, and it measured 19.5V, just barely within o2 spec.

It's an 12VAC unregulated power adapter. Someone measured it at and it seems to drop below 14V while other tested that it's just above 14V. Somewhat questionable decision from Massdrop to bundle that adapter with it. There are likely cases where it's not in within spec for O2.

The reality is that most headphones require, at most, just a few mWs of power to CRANK. when 1 mW can yield 90-100 dB, frankly, the power requirement is too low to justify a dedicated amp. That is why, frankly, most of my midrange cans sound just fine on a modern smartphone. Its the higher impedance stuff that gets tricky.

The only headphone which definitely needed the O2 was the HE-400s I own, which I playback at close to noon-1 pm when I am really feeling crazy. My Old 595s benefited from the amp a bit but still sounded about the same.

Here's what I would like to have. A volume knob that steps up the power in fractions of a mW for about half the travel. Then one that scales from that mW to hundreds of mWs over the next 6-9 hours for the insensitive cans. I'm sure it would be bizarre, but at least it might add some flexibility.

To use my O2 with my PSBs, I raise the knob until I am just clear of the L/R channel imbalance area, about 9 O'clock, and then use windows volume control from about 20-50. Luckily I detect no loss of fidelity even if it is there. Thats it. Then just strap in the best source I have available.

The irony is that, HD 595 for example, doesn't need amplification (gain) at all quite the opposite. Why they sound better with amp (assuming that the amp has low output impedance) is the fact that they work better with low output impedance. HD 595 sound a bit boomy and sloppy when plugged to line out directly for that reason.

Some amps have pretty significant gain even in the low gain mode and might be a really bad thing for sensitive headphones because they would be just too loud. Degain options would be perfect for some headphones.

 

[DJ The Rocket]

I've noticed that the O2 sounds amazing with dynamic drivers, it will lift a dynamic to it's theoretical maximum capability (/exaggeration but not really). It plays great with any dynamic from 16 to 600 ohms. But the o2 doesn't do very well at all with planar magnetic drivers. It seems particularly ill-suited for my 45ohm Alpha Primes, which sound terribly ordinary on it. I realize that the o2 is pretty marginal power-wise, but it's no better at low volumes.

Has anyone else with planar magnetics thought the same? Can anyone explain why this would be? I didn't think their power requirements were really that different. Am I wrong and they are different, or is this some compromise in the o2 design, making it optimized for one and not the other?

 

[Nitreb]

I've noticed that the O2 sounds amazing with dynamic drivers, it will lift a dynamic to it's theoretical maximum capability (/exaggeration but not really). It plays great with any dynamic from 16 to 600 ohms. But the o2 doesn't do very well at all with planar magnetic drivers. It seems particularly ill-suited for my 45ohm Alpha Primes, which sound terribly ordinary on it. I realize that the o2 is pretty marginal power-wise, but it's no better at low volumes.

Has anyone else with planar magnetics thought the same? Can anyone explain why this would be? I didn't think their power requirements were really that different. Am I wrong and they are different, or is this some compromise in the o2 design, making it optimized for one and not the other?

My LCD-XC (2014 version) sounds very fine with the O2.