Oppo HA-1 Impressions Thread
Aug 13, 2014 at 6:59 PM Post #1,441 of 5,414
Another positive review:  http://www.cnet.com/news/the-oppo-ha-1-headphone-amplifier-definitely-a-slam-dunk-for-audiophiles/#ftag=rss.audiophiliac.ftag
 
Aug 13, 2014 at 7:05 PM Post #1,442 of 5,414
I am sure this has been discussed before but for the life of me I can not find an answer.

Everything I play through the HA1 shows as one step above. 16bit shows as 24bit and 24bit shows as 32bit. Any ideas?? I am feeding the HA1 via USB from a ZEN Music player..

Thanks guys in advance.
 
Aug 14, 2014 at 1:18 AM Post #1,444 of 5,414
  This is a question for OPPO / HasturTheYellow : What is the impedance of the single-ended and balanced outputs on the back of the HA-1 unit. I am considering using a passive pre-amp for volume control in between the OPPO and a power amplifier and would like to take the HA-1's output impedance values into account.

 
I don't have any specific impedance measurements, but as I recall the BDP-95 had an output impedance of 300 ohm. I would expect something similar from the HA-1.
 
I'll try to get numbers for you tomorrow, but I will make no guarantees, as last timed I had asked for discrete numbers I was not provided any. We usually just tell customers that they should use the BDP9x/10x and HA-1 products with devices that have an input impedance between 10K and 40K, but the player will work all the way down to 1K input impedance.
 
Aug 14, 2014 at 1:20 AM Post #1,445 of 5,414
  Hi, guys. I have some problems with my setup. I have my Retina MacBook Pro hooked to the HA-1 via USB cable (5 meters), the headphones are HD800s. There's something wrong with the sound on Mac OS X. First, I thought that the USB cable is the problem, but it's not. The problems are gone when I boot into Windows 8.1 via BootCamp. On Mac OS X there are "pops" and "cracks" in the sound. Are my settings wrong?

 
5m may be too long, even if it works properly in Window 8.1. We do not recommend cables which are longer than 12' in length.
 
Have you tried a shorter cable, like a 6' USB cable that came with a USB printer?
 
Aug 14, 2014 at 3:42 AM Post #1,446 of 5,414
My question is, where do you get a converter from the 4-pin XLR balanced headphone output to two 3-pin XLR balanced outputs that could feed a power amp? Also, how would this even work? You need a total of six connections for a balanced stereo power amp:  
Left: V+ / Gnd / V-
Right: V+ / Gnd / V-
 
The 4-pin XLR balanced headphone out only offers:
 
Left: V+ / V-
Right: V+ / V-
 
So how would a converter cable even work (i.e., where is the Gnd connection coming from)? I've heard of 5-pin XLR which carries a ground pin and can be split into two 3-pin XLRs via a Y cable. But how in the world do you go from 4-pin XLR into two 3-pin XLR, there just aren't enough pins?
 

 
The whole point of balanced signals is that they are not referenced to ground.
Each signal is carried by a pair of + and - voltages to cancel out common mode noise.
The earth is only required for a screen shield and should connected at the one correct end only (to avoid hum loops).
So, you should be able to construct a minimal stereo balanced adapter with 4 wires.
 
Aug 14, 2014 at 7:46 AM Post #1,447 of 5,414
   
5m may be too long, even if it works properly in Window 8.1. We do not recommend cables which are longer than 12' in length.
 
Have you tried a shorter cable, like a 6' USB cable that came with a USB printer?

 
This seems to be the problem, after all. I tried to change my graphics card settings from my Retina MacBook Pro but this didn't solve the popping and crackling of the sound. Unfortunately I don't have a shorter USB A-B cable atm so I can't test that.
 
I'd rather not buy a shorter USB cable, anyway, because it would make things too complicated with my setup. My HA-1 is not close enough my MacBook and computer desk + my TV set is right next to the HA-1 (and my PlayStation 4 hooked via 1.5 meter optical cable). With a shorter USB cable, I'd have to change the whole setup and buy a longer optical cable, too.
 
So, would an active USB hub solve this audio problem? Could it remove the popping and crackling of the sound with the 5 meter USB cable? JML, what kind of a USB hub do you have?
 
Sorry about the off-topic conversation.
 
Aug 14, 2014 at 8:09 AM Post #1,448 of 5,414
Can you temporarily set up the HA-1 close to your computer, and just buy a shorter cable to test it out?  If that works, then at least you know it's the cable or the cable length.  Reading the USB spec explanation, the length limitation is due to the delay in the signals carried by the cable, and that may be the cause and not the AC power that a hub would augment.  A good inexpensive USB cable would be the Belkin Gold Series, which is only available in two sizes, 6 and 10 feet.
 
Aug 14, 2014 at 10:06 AM Post #1,451 of 5,414
Hi Mike, I only have the Zen as a USB source.
 
I unplugged Zen + iUSB etc.. and checked/unchecked the ''play DSD over PCM'' and everything seems to be back to normal (for now). Strange.... I think it may be a glitch within the Logitech settings.
 
Aug 14, 2014 at 12:17 PM Post #1,452 of 5,414
   
I don't have any specific impedance measurements, but as I recall the BDP-95 had an output impedance of 300 ohm. I would expect something similar from the HA-1.
 
I'll try to get numbers for you tomorrow, but I will make no guarantees, as last timed I had asked for discrete numbers I was not provided any. We usually just tell customers that they should use the BDP9x/10x and HA-1 products with devices that have an input impedance between 10K and 40K, but the player will work all the way down to 1K input impedance.

 
The lower the output impedance, the better. If the HA-1 truly has a 300 ohm output impedance on its rear XLR balanced outputs, that would be awesome!
 
Aug 14, 2014 at 5:11 PM Post #1,455 of 5,414
I was considering to buy it in the next months, but price in Europe seems to rise from $1200 to €1500. That is a whopping $2000 , or a 66% price increase, so I will be interested in your opinion if it is still worthy or I will be better with other options.
 

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