Dangerous fault using app

I have NDX Supernait connected with system automation & app on iPad.   I've not encountered this problem & don't recall it mentioned on the forum.  You don't say what smartphone (iPhone or Android). So without other clues it might be "fat finger" problems. 

Mike,

Phone Samsung s6, tablet samsung a7. 

It's like the '+' key is getting stuck thus sending volume + to the NDX.

Also, I have an iPad. Might give that a go and see what happens. I use it for nserve duties anyway.

To avoid this issue happening I lower the Max Volume setting to 60% in the Audio setting in the app. 

I think that works on streamers for e.g. my muso. But not on amplifiers. 

This doesn't sound like a problem with the Naim app itself otherwise a lot of people would have mentioned it.

Given the the 'phones and tablets use an electronic touch screen (capacitative in the case of the Samsungs) there's noting to get 'stuck' as such, however contamination on the surface of the screen can theoretically cause problems, so try cleaning the screen (cloth very lightly dampened with screen cleaner, rather than using the liquid directly!).

The most probable cause however is interaction with another app running in the background of the device; the problem here is that it'll be near impossible for anyone to identify which app you have that's causing the malfunction.  The only thing to say is that it's probably not a mainstream app.

ray sheldon posted:

Phone Samsung s6, tablet samsung a7.   It's like the '+' key is getting stuck thus sending volume + to the NDX.

In addition to my normally used iPad I also have the Android app on my Samsung phone,   I don't use it much but still not had the volume problem.         I'm tempted to go along with Huge on having two devices active,  my iOS & Android apps get very confused if they are both on. 

Changed to IOS just over a month ago but did have the volume problem as noted on both my Unitilite and NDX into a 252 using system automation worrying as it catches you by surprise.

A couple of years ago, a firmware update to my Superuniti caused it to reset to factory settings. This included removing my volume cap of 60, and setting it to 100. It also set the volume to max, and turned on iRadio. Fortunately, I was still next to the unit, and was able to dive for the volume control before any damage was done to speakers or ears. Thankfully, this was a one-off. 

About a year ago I, too, had the identical problem with my NDX and Nac282 which was driven by a Android tablet. Just managed in time to hit the mute button before my hearing and speakers were permanently damaged. As mentioned above, manually turning down the  volume control just meant that it would start again to increase the volume. In the end I disconnected the lead at the back. I now have an iPad and all is well.

GEEPEE,

So presumably you now use the naim remote for volume?

In the app, I configured the max volume setting for my DAC/Streamer ( 272/250DR ) to 42/100. Like this way, even if I hit the slider to the right by accident in the app, it will only hit 42 (on a scale of 100), even at this level, it's still safe for my ears, my speaker, and my neighbours too. I never listen louder than 42-45. 

Same here with NDX and SN2. It happened only once using Vodafone Smart Ultra 6 (Android).

I managed to get to the mute button in time but I disconnected the lead and haven't reconnected since, made me a little.nervous in case it happened and I wasn't around. I'm quite happy using the app for selections/inputs and the remote for volume now though. If I one day get an iPad then I would reconnect the system automation cable, but from a convenience perspective I'm OK with it using my phone and the remote control. Its my feeling that it is Android related and not necessarily the fault of the app, but I don't know for sure!

Ray Sheldon.

In the end, I bought an iPad which not only solved the wayward volume control but was more stable and user friendly than the Android tablet. Having said that I never had a problem using the Naim app with my Android phone. As ChrisH has suggested, it maybe some particular combination(s) of app and tablet that causes the problem.

geepee posted:

Ray Sheldon.

In the end, I bought an iPad which not only solved the wayward volume control but was more stable and user friendly than the Android tablet. Having said that I never had a problem using the Naim app with my Android phone. As ChrisH has suggested, it maybe some particular combination(s) of app and tablet that causes the problem.

GEEPEE, Ray I changed to a IOS device mainly due to an interaction problem when using my Core the dealer advised to try an IOS device and that has alleviated  the problem. I must admit the IOS device is much better particularly in the case of the Core with the editing facilities. 

ray sheldon posted:

Anybody experienced this using the app on NDX...

A few months ago the volume on the SN2 was turning clockwise by itself when using the app on my smartphone to control the NDX when streaming from US. This happened a couple of times and fortunately I was close by to act before I ruined the speakers. 

Obviously I've got the SN2 and NDX linked with the remote cable. And I'm using the volume control on the app.

It hadn't happened for a while until last weekend when me and the girlfriend were listening to some tunes, this time using the app on a tablet. I had to jump out of my seat and wrestle with the volume knob whilst it was being forced clockwise.

Clearly I won't be using the app in another room in future leaving sprinting distance from upstairs for e.g. 

What is causing this I wonder?

Best,

Ray.

Would the speakers really get damaged? My speakers have a max watt rating >> my SN2 output. Could they get damaged at max volume?

This once happened to me. Not due the app but because my daughter sat down on the physical remote. Scared the crap outta us.

Kevin Richardson posted:

Would the speakers really get damaged? My speakers have a max watt rating >> my SN2 output. Could they get damaged at max volume?

Yes, the amp will go into hard clipping and put far too much energy into the tweeters.

Kelvin, 

Most likely yes.  Your as much(if not more) likely to ruin a pair of speakers were the amp is much less capable than the speakers than the other way round. Distortion etc is usually caused by the amp running out if steam which then sends a crap signal to the speaker.  You could very easy end up with voice coil burn out. I.e. end of drive units.  Perhaps this woukd occur before the amp over heated and cut out.  I'm going to remove the remote cable when I get home. 

When an amp goes into clipping, it doesn't overheat as the heat dissipation in the output transistors falls to a very low value.

Huge posted:

Kevin Richardson posted:

Would the speakers really get damaged? My speakers have a max watt rating >> my SN2 output. Could they get damaged at max volume?

Yes, the amp will go into hard clipping and put far too much energy into the tweeters.

So amps go to "11" when they are set to max volume. I know nothing about EE or hifi design but why does the volume control go all the way to max if it is not usable? Seems like my SN2 could have some kind of software based protection mechanism...

Kevin Richardson posted:

Huge posted:

Kevin Richardson posted:

Would the speakers really get damaged? My speakers have a max watt rating >> my SN2 output. Could they get damaged at max volume?

Yes, the amp will go into hard clipping and put far too much energy into the tweeters.

So amps go to "11" when they are set to max volume. I know nothing about EE or hifi design but why does the volume control go all the way to max if it is not usable? Seems like my SN2 could have some kind of software based protection mechanism...

Because not all recordings are made at the same level and not all source components output the same volume.

I guess it's similar to say a car with a top speed of 130mph. You wouldn't want to have to achieve that doing 7000rpm. So I suppose there's extra room to be able to cruise rather than burn out. 

ray sheldon posted:

I guess it's similar to say a car with a top speed of 130mph. You wouldn't want to have to achieve that doing 7000rpm. So I suppose there's extra room to be able to cruise rather than burn out. 

Sorry, that analogy doesn't hold at all.

From personal experience, I can assure you that an amplifier rated at 15 watts per channel can easily blow a tweeter in speakers rated at 80 watts. I had inadvertently plugged a CD player (output approx 1 volt) into an input of the amp which was expecting 100mV. When I turned the volume up, the amp went into clipping and the ultrasonic harmonics took out a tweeter. Well, that's my theory.

Well that's a shame HUGE, I agree with what you said though and have material were the volume goes 3/4 round and other stuff were peak power us probably around 10-11 o'clock.  I guess my point is that a dial will always go past the intended level.  The speedometer on my A4 says it will do 160, although I doubt it will.  Perhaps ill have a go down hill and write my next post from a cell !  ;-)

Doesn't the SOA cirtuit in Naim amps protect the speakers in these circumstances??????????