[ekrauss]

I will pass along the above posts. If I need more information, I'll let you know. Thanks. Eric

 

[ekrauss]

Read the last few posts I made in this thread. It's described in extreme detail several times - and I have had 10s of people contact me directly with the exact same issue. All have gotten useless replies (if any) from Oppo. The problem is without ANY doubt caused by the HA-2 having bad shielding and "rebooting" because of EMI - not the phone, cable or iOS's fault (not unless you consider increasing the power to the antenna a fault in iOS).

It happens with every cable (zeskit, stock, unbranded, apple etc.), every (offline) music app, every iPhone from 5S and up (I don't have older models). It's easy to replicate - just stack them together in a faraday cage and within a minute or two the HA-2(SE) will "reboot" and loose connection 9 out of 10 times (if you are using high sensitivity iems you can actually hear the RFI noise increase as the phone slowly turns up the antenna gain - up until the point where the HA2 gives up). If you keep them 10-20 cm apart with a long cable it won't happen. You cannot replicate it if you are in an area with good coverage as it usually comes when the phone is either roaming or on really low power 2g/edge network - so you cannot replicate it with airplane mode like people have tried - as it won't adjust the antenna gain if the first signal it sees is strong.
Personally I travel by train each day (130km x 2) and I experience the dropouts (both HA2 and HA2SE with several models of iPhone) about 10-20 times during the trip (which goes through several tunnels). 

As I said before - the GSM noise leaking into the amplifier is probably somewhat acceptable (it happens both the the Mojo and Dacamp), but the HA2 rebooting is a big mess (it pauses the music, requiring a pressing of play - and hoping that the HA2 has reconnected or the music will blast out of your phones speakers - not smart when you are in the public and listening to weird stuff).

As for the other "old" issue of the HA-2 that keeps popping up in the thread about it going into sleep mode and disconnecting after a minute or so (was it 33 seconds?) - I still believe this should also be fixed by Oppo (other MFI dacamps don't have this issue - at least not the ones I have tried).

Anyways - I did really like the HA-2(SE) and the features - and if you live in a city with good cell coverage you will probably never experience the issue (i didn't before my job required me to travel a lot). 

Also I know that some people have not been able to replicate it. I believe it might be because there is a wide range of mobile frequencies that are used for 2g, 3g and 4g/lte (and they are quite different from country to country). Maybe only some frequencies causes it to reboot - it happens however on the 3 different carriers I've tried here in Denmark.

What do you mean, "stack them together in a faraday cage"? You mean like putting them inside an RFID wallet or something similar? If you do not put them in a faraday cage, does this issue still occur?

 

[apaar123]

Can it be used only as amp.?

 

[mitsu763]

Yes. You will use the 3.5mm input on the front of the unit for that.

 

[apaar123]

Should I buy ha2 if I already have a good dap?

 

[arthurl]

I had the exact noise issues as dennistdk mentioned. Will not recommend pairing the HA-2 with phones (especially iPhones) unless you can turn the data off while listening.

 

[mitsu763]

Should I buy ha2 if I already have a good dap?

It's probably not necessary. If your phones are hard to drive you'd be better off with a more powerful amp.

I have and love my HA-2 SE.

 

[dennistdk]

What do you mean, "stack them together in a faraday cage"? You mean like putting them inside an RFID wallet or something similar? If you do not put them in a faraday cage, does this issue still occur?

To replicate the loss of signal and to provoke it in a "controlled environment" you can put it in a faraday cage - a metal construction that blocks electromagnetic signals - causing the phone to increase power which "reboots" the HA2 (like it would if you where in a place with little to no coverage).

 

[anticute]

I never said I didn't get a reply from Oppo. I did. First they blamed the cable, and when I insisted on this not being the problem (having tried four different cables, including their own) and told them, again, to read the thread, with direct links to a few relevant posts, they said that they were going to forward it. After that I haven't heard anything.
 
I guess that's par for the course when it comes to contacting tech support of any kind, but based on the praise some are giving Oppo support I wasn't expecting to have to argue with them to take a problem that has already been reported to them various times by various people seriously. 
 
But yeah, I can sort of live with the RFI noise which (sadly) occurs sometimes, even if I expected an aluminium DAC/AMP specially designed to be stacked with a phone (MFI certified ***..) to be completely rid of problems like that. However, the reboot issue is really annoying.
 
As I said - the HA2 is absolutely brilliant if you think of it as a sort of small desktop amp. When it comes to the engineering put into making it portable and cell phone friendly, I'm less than impressed for the price.
 
Anyway, the jury's out on Oppo and their support. Who knows, maybe tomorrow I'll receive an email saying that they'll send me a new unit that meets the expectations I had on it when I bought it (i.e. zero RFI noise, and definitely no reboots). Let's just say that I'm skeptical..

 

[ekrauss]

Passed all these on to Oppo. Funny how the story about Oppo "ignoring" complaints has changed, but that's the internet for you. FWIW, I don't think this issue has anything to do with RFI or EFI. My guess is that it is iOS related. We shall see.

 

[dennistdk]

Passed all these on to Oppo. Funny how the story about Oppo "ignoring" complaints has changed, but that's the internet for you. FWIW, I don't think this issue has anything to do with RFI or EFI. My guess is that it is iOS related. We shall see.

 
Thanks for doing that, but...
 
First... Tell me how it is not interference related? "Reboot/disconnects" happens when they are stacked together. Move them apart by a few centimeters (with the same cable) cable and it doesn't happen.
 
Second.. Oppo hasn't given any solutions for the problem to the people asking - and some people are still waiting for feedback/update. I would pretty much call that "ignoring" your customers.

 

[Jimmy101]

Plus 1 on it being interference related. Airplane mode is still using IOS and when not stacked it's still using IOS but no reboot

 

[halo9]

@halo9 Nice job nailing down the timing and describing the behavior clearly. This particular behavior has been discussed in the past and it's not a bug. The behavior occurring on input "A" is a battery saving "feature."

 
Thanks Timelord. In any case I have still reported it to apple and Oppo as a bug (it should be a feature) as from what I have read it does not seem to occur on other DACs, or the iPhone is able to "wake" these other devices. Could be an issue at either end which is why I have reported to both. Not a major fault, but annoying none the less.
 

 
 
As for the other "old" issue of the HA-2 that keeps popping up in the thread about it going into sleep mode and disconnecting after a minute or so (was it 33 seconds?) - I still believe this should also be fixed by Oppo (other MFI dacamps don't have this issue - at least not the ones I have tried).
 
Also I know that some people have not been able to replicate it. I believe it might be because there is a wide range of mobile frequencies that are used for 2g, 3g and 4g/lte (and they are quite different from country to country). Maybe only some frequencies causes it to reboot - it happens however on the 3 different carriers I've tried here in Denmark.

 
Sorry guys, I did try reading a lot of the posts and searching , but over 4200 posts is a lot to check through 

  Also I was hoping to describe it clearly and in a way that anybody (including apple and oppo) can replicate. Only a drama if you pause and walk away for over 3 minutes, otherwise not an issue.
 
@dennistdk I think you have hit it on the head about the range of frequencies and was thinking this same thing. I still have to go on my long drive through many drop out zones so am hoping this does the trick to replicate the issues. A quick search reveals that Denmark uses UMTS bands B1 (2100) and B8 (900 GSM), though in Australia we use those 2 and also B5 (850). On the carrier I use I am sure I am on the B5 band. I haven't been able to replicate it so far following your methods, a coincidence with the frequency difference? Maybe... or maybe it means nothing, who knows. I will report back after the trip but if it cannot be replicated here, then I must be inclined to think this issue does not affect everyone in every market, so unless oppo is making different devices for different markets (like apple), then maybe the root cause could possibly lie elsewhere also (apple), as there doesn't seem to be any reports from Android users (that I have noticed). It must be considered. Also thanks for the explanation on the faraday cage idea, good stuff.

 

[alpovs]

I've been following this with curiosity. I have no problem using my HA-2SE with my Android phone Nexus 5X connected by a short cable. They are stacked together touching each other. Bluetooth is on. Works on WiFi and on LTE. Never a problem. iPhones operate on the same networks, so I would think they should emit similar spectra of radio waves. I guess OPPO is perplexed.

 

[DrunkSaru]

  I've been following this with curiosity. I have no problem using my HA-2SE with my Android phone Nexus 5X connected by a short cable. They are stacked together touching each other. Bluetooth is on. Works on WiFi and on LTE. Never a problem. iPhones operate on the same networks, so I would think they should emit similar spectra of radio waves. I guess OPPO is perplexed.

I second this. Also N5X (Fi) but with HA-2. Had mine for a year and a half, maybe a bit longer. no issues. I also use it with my S7 using frequency:

1900 g, 850, 2500 (Sprint)​

. I did have a reboot issue with a Note 4 (T-Mobile) once when trying to connect to my friend's phone but he was saying he was having multiple issues with the phone already so I didn't bother to replicate the problem. I'm waiting for him to get a replacement.