IR Receivers for Amplifiers, other Audio Components, via 3.5mm plugs

[GoodDIYjob]

I'm having a bit of brain fade here. A long, long time ago I used to set up some remote switching using full xantech kits, receiver, emitters, power module etc. However, my needs are not that extensive.

All I really want is to control an old Rotel amplifier volume which is inside a cabinet (it has a remote and has IR in plug) and also I have a MJ acoustics Ref 150mkII subwoofer, which I have the remote for but have lost the IR eye (which is also 3.5mm plug). It is handy to change the subwoofer presets.

Can I purchase an item that work with these devices? I tried purchasing a cheap generic IR eye off ebay and it doesn't work with either item!

Thanks

 

[Lucid]

First thing to check is whether you bought IR receivers or IR emitters. I suspect you got it right, but it is worth checking: Receivers will have a single IR block attached to a cable ending in a 3-pole 3.5mm jack plug. Single block IR emitters will terminate with a 2-pole jack plug.

Next, if the standard wiring doesn't work then check with each manufacturer how their sockets are wired.

 

[GoodDIYjob]

Yes, I bought a receiver with 3 pole jack. It was cheap as chips like £4 so not sure if it is worth persisting with that. Would something like this be more likely to be successful?

https://cpc.farnell.com/pro-signal/psg03520/ir-receiver/dp/AV20243

I take your point about wiring, not sure MJ Acoustics will tell me, when I phoned them they wanted £50 for the receiver or £100 for the receiver and remote!!!! Can I damage it if I trial and error the pin configuration or can I test with a multimeter? I guess I can for the Subwoofer as it should have a DC supply on one of the pins?

Thanks for the help.

 

[Lucid]

All simple IR receivers should have power connections (0V ground and +5V). Then there'll be the signal connection.

IIRC, ARCAM had/have an odd way of wiring up tip, ring, sleeve. Maybe MJ do too?
https://learn.adafruit.com/ir-sensor/testing-an-ir-sensor
https://learn.adafruit.com/ir-sensor/testing-an-ir-sensor

 

[GoodDIYjob]

Ok, thanks. I will try to test the MJ Acoustics 3.5mm 3 pole plug for starters to determine where power is..

Are most of the external IR repeat kits 12V?

 

[Lucid]

The main box may be 12V, but that's because it's the hub device. The IR receiver and IR flashers still run at 5V though because that's the common spec for the semiconductor and (I guess) diodes. They drop the voltage for the power rails for the receiver and emitters.

 

[GoodDIYjob]

Ok, update - I am still trying to get my two requirements solved...

For the subwoofer IR eye:

1. I tested the 3.5mm 3 pole socket on the subwoofer IR receiver socket, and the ring (middle section) provides +5V. Pairing with this appears to be ground (sleeve) and I guess, by elimination, signal on the tip. (strangley, when testing the socket on the subwoofer, there is still 4.3v shown on signal input i.e. between tip and gnd. Would that be expected?

On the pro signal IR receiver I have, which has a plug wiring diagram, which I would need to alter to align to subwoofer, it indicates it is +12V 30ma. It doesn't work out of the box - not surprising given the connection plug diagram suggests the wiring poles are not right for the tested subwoofer connections, but if it says it requires 12V so it probably won't work anyway, if it steps down voltage? Where would I get a IR receiver that accepts 5V?

2. The rotel amp is 15 years old. The manual says xantech type IR receivers work. So this Pro signal one should probably work - the wiring layout on the Pro signal receiver looks same as xantech (sleeve +12v, ring ground, tip signal). However, to get power I would have to splice in a 12v supply to 12v and ground. Or maybe use the 12v trigger from the amp? I don't have connecting blocks or hubs to use but my soldering is ok and have heat shrink....

thanks,

 

[GoodDIYjob]

Ok did some more testing / configuration and have got to two new roadblocks now.

1. On the sub woofer ext IR receiver use. I tried the cheapie IR receiver based on assuming std xantech wiring colour coding for the IR receiver end, to tested pole locations on the subwoofer socket e.g. +5V to Black and Gnd to Red (I can't prove what the three pins are on the IR receiver itself). But it didn't work. But I now suspect the remote is also US. So conclusion unknown.

2. On the amp, I used this pro signal dual band IR receiver, Spliced in a 5v and then switched it to 12V supply to the sleeve and GND. The blue led light flashes when using an IR remote, I thought great job done, but it does not trigger any functions. I double checked my joints for the signal wire.

Interestingly, the Subwoofer remote failed to light the led, all other IR remotes I had to hand did. So I suspecst the subwoofer remote is also faulty. It would be not worth paying £50 for the remote, I suppose try a Harmony universal which says MJ Acoustics subs are supported, still a bit unsure where I would source a decent quality 5V Ir Receiver that is likely to work. Maybe this chinese non name receiver would work, if I had a remote that provided a signal.....

There is still the option of just paying the £40 or £50 for the IR kit and emitters, but the amp should work with just a receiver and power - right?

Thanks for anything I have missed.

 

[Lucid]

There's not much info about the MJ Acoustics IR receiver, its wiring or the codebase. I know that the codes exist for the MJ 200 sub, but I'm not sure if they're applicable to the other subs in the range. TBH, without being able to sit down with a sub and do some playing around then it's hard to give you any further direct help.

What I can say is that you'll need either the original MJ remote, or at the very least a programmable remote which you know for sure 100% is programmed with the correct codes for your sub. It would help if you had the MJ receiver as well. That way you could verify any 3rd party remote before introducing the IR relay kit.

As a simple test, most phone cams except those on later Apples or those fitted with an IR filter will pick up he flashing of the infra red emitter on a remote control.

 

[GoodDIYjob]

Yes, thanks, it is a bit of a roadblock unless i can find a way round.

I wouldn't have thought the MJ acoustics IR codes would vary much. Maybe some have a few more functions or presets but I would be surprised if the code base differs. I guess I will have to take a punt on a Harmony Programmable remote which suggests it covers some MJ acoustic models..

After I test the IR output from the original remote with a camera - tks for suggestion.

I don't really understand why the remote receiver won't work on the rotel amp, given it has power and it responds by led flickering when it "sees" a remote signal. But I'm losing the momentum so may just have to go with a 2nd hand IR dist kit here. It wouldn't be used for the MJ acoustics as the sub is outside the Audio cupboard. And I don't believe there is an integrated IR receiver on the sub to use with an emitter. That is why it was supplied with a plug in IR receiver.

So I am still stuck finding a solution for that or otherwise, setting and forget but the preset settings are handy for Movies v music and also you can switch between high and low level inputs (and thereby have it usable for two different amp sources)..

cheers.