[Noobzilla]

I was checking for shipping and tax costs then I found out I'm only 15 minutes away from OPPO. I'll drop by their store later. I'm still torn between Explorer 2, Dacport 1 Ohm mod, and the HA-2. But who knows, I might buy it on the spot if they have it in stock. 

 

[money4me247]

 
Well, I'm not a believer in high rez as I certainly can't hear any difference. So before sinking tons of money into high rez files do yourself a favour and go to the sound science forum here and ask about blind listening testing. In a nutshell there appears to be no valid reason that above 16bits you can hear differences, I think often high rez versions are mastered louder as louder sounds better, or they may be from different masterings sometimes. Anyway go to the sound science forum and ask for some thoughts/advice on amplification and high resolution files. If you play your amp for long periods of time I would at least take it out from the bag once in a while. I'm not sure how much if any impact there might be on the amp, but some ventilation at times is always a good idea.

bit rate does make an audible difference to many listeners in a blind test (eg. moving from 192kbps to 320kbps). sampling rate above the current normal of 16/44.1 or 16/48 will not lead to an audible difference in a blind test as the current normal bit depth & sampling rate already achieves bit-perfect reproduction from the source.
 
the only reason that different bit depth or sampling rates may sound better is because there was a difference in mastering for the specific song (aka not the same source) or that your dac may be optimized for a specific bit depth/sampling rate.
 
I have more links on the topic in my profile if interested in learning more about the topic.

 

[Happytalk]

Hi!

I've been using the PM-3's and the HA-2 for about two weeks now. 
Last week I attended a conference in New Orleans, and thought it would be an ideal way to test the new gear on the road, in planes, etc.

First thoughts are that the combination of the HA-2 and PM-3s are a dream combo. The PM-3 had almost no sound leakage, and I asked my fellow passengers to listen for leakage and they said they couldn't hear anything, even when I cranked the volume, and the ambient noise cancellation was very good. As for comfort, they were just wonderful. 

Using the HA-2 took a different turn. I don't really have much music stored on my Samsung S5, or my older iPad Retina. So, I brought along a Seagate Wireless Plus drive with a built-in hotspot. Using the older 40 pin iPad cable to the HA-2 worked great, and I streamed high-res audio FLACs to the iPad, and then played them using Capriccio to the HA-2. Worked fine. 

I also tried with the HA-2 rubber banded to my S5, used the small mini to mini USB connector between the phone and HA-2, and played a few files on my phone (Rolling Stones - Official Bootlegs, Brussels, and Los Angeles concerts) and they sounded great. Then I used the browser on the phone to connect to the Seagate Wireless Plus and once again the files played just fine. 

I had a bit of worry that I damaged the phone cable for the PM-3, as I couldn't get both channels playing, but it was a "Doh!" moment. I had inserted the wrong end of the cable into the PM-3s, so once I figured it out and plugged the proper side of the cable into the headphones all was fine! My bad!

By the end of the flights, I found myself tossing the Seagate Wireless Plus drive into my backpack, and the phone/HA-2 rubber banded combo into my jacket pocket and all was well, high-quality music on the road, with TB's of tracks to choose from.

As for hiss, I simply had none. Even in a dead quiet hotel room, using the PM-3's, I had the phones on my head, the HA-2 cranked up, but the battery had run out on the Seagate unit, I kept checking to see if the green LED was still lit on the HA-2, as it was so quiet with the phones on and no source audio. I've not tried the HA-2 with IEM's, and I have quite a few to choose from, so will see if I can hear any hiss with them. But for headphone use the HA-2 seems dead quiet. I did try them with Oppo PM-1 and PM-2, and several Audio-Technica headphones, and same results, no hiss. 

The unit does run a bit warm, but this is expected for an amplifier of this design. Everyone who saw the combo asked to listen to them, and once they did wrote down the Oppo website in their phones. 

I have the white models, which are quite cool looking, but I think I preferred the black design a bit more. Why the white models? My wife and son said "Get the white ones, you have so many black headphones already" so.. white model it was!

Forgive me for dwelling on an off topic, but quick question. Is there a large capacity storage device that you can travel with, sync to your iphone, and play high resolution files ultimately through a DAC that sound as good as if they came from a DAP? Seagate 5?

 

[Harris]

Forgive me for dwelling on an off topic, but quick question. Is there a large capacity storage device that you can travel with, sync to your iphone, and play high resolution files ultimately through a DAC that sound as good as if they came from a DAP? Seagate 5?

 
Hi, not off-topic at all. You have to feed the DAC!
 
The short answer is yes. The Seagate Wireless Plus is one example (In its third revision) of a large HD (1TB in my case) with a built-in wifi hotspot. You can sync any device with wifi to it, and stream whatever files are on it, so it just acts as a remote storage device.
 
They have dedicated apps to make this easier, but you can also just use a web browser. As for quality, there isn't any loss, since you are merely accessing the files on the device, not having the device play them. Other folks make them, Kingston has a nifty SSD unit, not as much capacity but smaller and long battery device, WD makes one, so does Hitachi. 
 
So, playing an audio file from a wireless storage device to your phone or tablet, which is then plugged into you external DAC is totally doable. One advantage of this approach with any of the iPads is that Apple doesn't provide a SD card slot, or USB port, so difficult to add to storage. The WiFi enabled storage units work around this issue. You can use the camera adapter, but it's a bit of a kludge.
 
Let me know if this helps.

 

[Sonic Defender]

  bit rate does make an audible difference to many listeners in a blind test (eg. moving from 192kbps to 320kbps). sampling rate above the current normal of 16/44.1 or 16/48 will not lead to an audible difference in a blind test as the current normal bit depth & sampling rate already achieves bit-perfect reproduction from the source.
 
the only reason that different bit depth or sampling rates may sound better is because there was a difference in mastering for the specific song (aka not the same source) or that your dac may be optimized for a specific bit depth/sampling rate.
 
I have more links on the topic in my profile if interested in learning more about the topic.

That was what I said, it is most likely the mastering that counts for any perceived difference. I wasn't talking about differences between lossy files. However, I do think that it would be very, very difficult to tell a 320mp3 from a CD version of the same track.

 

[miceblue]

 
Just received the HA-2 today.  After using it as DAC+ Iphone6 for 2 hours, the device felt warm.  Any comments from fellow head-fiers with this issue.
Cheers

It is a Class A amplifiei design (at least partially) so it should get warm during operation. The circuits produce a great deal of heat.

It's class AB, which is nearly as efficient as class B, but produces a waveform nearly as accurately as a class A. The heat most likely isn't because of the amp but rather the battery itself getting warm from current draw.

 

[Sonic Defender]

It's class AB, which is nearly as efficient as class B, but produces a waveform nearly as accurately as a class A. The heat most likely isn't because of the amp but rather the battery itself getting warm from current draw.

Isn't it Class A for a certain output then Class A/B after that? Maybe I need to read the specs more carefully.

 

[miceblue]

Isn't it Class A for a certain output then Class A/B after that? Maybe I need to read the specs more carefully.

Class A is what audiophiles prefer because it uses a single, always-biased transistor to amplify the entire input signal. Because of it's always-biased nature, it's very energy inefficient and the circuit tends to run very warm/hot similar to the LH Labs Geek Out for example.

Class B uses 2 transistors in a push-pull configuration (or two half-wave amplifiers) to create half of the input signal and are added back together. Class B is more efficient than A because its transistors are never biased until there's a signal. Because of this on/off biasing nature though, distortion tends to be higher since the circuit needs some time to activate.

Class AB is a hybrid between the two. It uses a push-pull configuration like class B but it uses biasing diodes in place of resistors before the amplifying transistors to always have the amplifying transistors minimally biased similar to class A but not nearly as inefficient and doesn't have the on/off distortion problem like class B.

The HA-2 uses a class AB amplifying section.

 

[Sonic Defender]

Class A is what audiophiles prefer because it uses a single, always-biased transistor to amplify the entire input signal. Because of it's always-biased nature, it's very energy inefficient and the circuit tends to run very warm/hot similar to the LH Labs Geek Out for example.

Class B uses 2 transistors in a push-pull configuration (or two half-wave amplifiers) to create half of the input signal and are added back together. Class B is more efficient than A because its transistors are never biased until there's a signal. Because of this on/off biasing nature though, distortion tends to be higher since the circuit needs some time to activate.

Class AB is a hybrid between the two. It uses a push-pull configuration like class B but it uses biasing diodes in place of resistors before the amplifying transistors to always have the amplifying transistors minimally biased similar to class A but not nearly as inefficient and doesn't have the on/off distortion problem like class B.

The HA-2 uses a class AB amplifying section.

Thanks, yes I  went and read the specs relising that it is a hybrid A?B amp with no true class A portion. Thanks for the clarification.

 

[steffi]

Why would the HA-2 dac and amp be better than a dx90? Is their firmware far superior in the HA-2?

 

[Noobzilla]

Hello all,
 
I just got back from the OPPO store in Mountain View, CA to test out the HA-2. The store is not your usual store -- it's more of a small office + small warehouse with a cubicle for product testing. Nonetheless, they have their products out and a wide variety of headphones. 
 
Just a fair heads up that I'm absolutely new to this audiophile stuff and no way I would call myself as one. Though if you ever wondered what a total noob would think of listening to audiophile grade headphones for the first time, here it is. 
 
 
 
 
The HA-2 is smaller than my Galaxy Note 4 and I would say it's about the size of an iPhone6 or Galaxy S4. The build quality is top notch and felt nice to my hands. The HA-2 has a lot going on around. Besides the usual power button, volume control, and audio out, there's a Low or High Gain switch for low or high impedance headphones. There's also a Bass switch for more bass, though some details got drowned by it so I spent most of my time with it off. Three inputs for regular USB (A), and micro USB (B), audio jack (C) and a slider for selecting A B or C. Using the regular USB to pair with my phone just made the HA-2 an external battery charger, so I had to use the micro USB for music. 
 
The HA-2 was able to run all the headphones in order of difficulty: PM-1, HD 650, DT990, HE-6. I had to turn the volume down when switching from DT990 to HD 650, so I'm assuming it's the Premium 600 Ohm version. Then quite high up on both my phone and the HA-2 to run the HE-6 at a decent volume (~80%+ on both).
 
I don't really have any other experience with amps/dac other than my gaming Astro Mixamp, so I can't really give a good review about HA-2's sound quality. But if there's anything I'm certain about, the quality coming out of my phone and the HA-2 is outright noticeable. I don't know the proper words to describe it, but everything sounded a lot cleaner and smoother. My favorite part is the more I listened, the more sounds I discovered. "I did not hear that before" moments happened quite a bit. It was very fun listening. 
 
Would it be worth $300 for me? Not quite sure yet. I didn't get much of a wow factor compared to upgrading to a 120hz monitor or playing with my Sennheiser PC360 for the first time coming from cheap laptop speakers. It certainly is an ear opener though. 
 
 
--- Off topic headphones impression --- 
 
I brought my PC360 and Klipsch X10 with no expectations other than to test the HA-2, but seeing the familiar HD 650 and DT990 made me smile as I have never tested those before. The other two are Hifiman HE-6 and OPPO PM-1. They have a lot of other headphones like Audeze, but I didn't want to test too many things at once. I mostly listened to Linkin Park since I'm most familiar with it.
 
In terms of headphones quality, I like the sound of HE-6 the most but it is also the most painful to wear -- very very heavy. As much as I like the overall sound, the discomfort was not worth it for me. The HD650 sounded nice too with less bass than the HE-6, but I probably have the wrong gear and kind of music to make the most out of it. The clamp is a bit tight and I'm surprised to find my PC360 to be more comfortable. PM-1 ran easily and provided the best comfort. I didn't have a lot of time to test it, but it's a fun headphones and it's something I can see myself taking on a nice beach vacation. The DT990 was disappointing for me. Although 2nd best in comfort, something just didn't sound right. It sounded a bit metallic/sharper/not as smooth as the HD650 or HE-6. Or maybe I was just getting too hungry...
 
Once I get my Denon D600 I'll definitely drop by to do more testing. I'll also bring other genre of music now that my ears got a bit of training. And of course, eat lunch and set aside more time for listening. Overall, very very fun experience! 

 

[Sonic Defender]

Nice little test lineup there! I can't possibly imagine how the He-6 could be even remotely driven by that amp as it is universally accepting as being one of the hardest to drive headphones. It must have been quiet or you listen at really quiet volumes (which I've never understood as music sounds so thin at quiet playback levels).

 

[SptTablo]

Can anyone compare this one with ifi nano dsd?
 
I am considering purchasing either of those.
 
I might use them with their line out function as I want to use my Cayin C5 amp. (Comment on this if this will lower the SQ..)
 
Thanks in advance.

 

[Noobzilla]

  Nice little test lineup there! I can't possibly imagine how the He-6 could be even remotely driven by that amp as it is universally accepting as being one of the hardest to drive headphones. It must have been quiet or you listen at really quiet volumes (which I've never understood as music sounds so thin at quiet playback levels).

 
There's some phone calls and a few people working, though it was overall quiet. Not sure what would be considered "really quiet," but I'd say I'm probably in the low volume listener category. The max I would listen with my PC360 on my phone is 10 or 11/15 with no amp. The HE-6 was set at either 12 or 13 and above 4 on the amp (max 5), which I would say would be the equivalent level of PC360 at 9. When I visit the store again next week I'll pay more attention to the volume levels and see how much louder I can run HE-6.

 

[money4me247]

There's some phone calls and a few people working, though it was overall quiet. Not sure what would be considered "really quiet," but I'd say I'm probably in the low volume listener category. The max I would listen with my PC360 on my phone is 10 or 11/15 with no amp. The HE-6 was set at either 12 or 13 and above 4 on the amp (max 5), which I would say would be the equivalent level of PC360 at 9. When I visit the store again next week I'll pay more attention to the volume levels and see how much louder I can run HE-6.

if its the samsung s5, that is normal listening volumes. i use that volume range as well