MRA Amps with no MRA switcher

I have been looking for a solution for a multiroom audio system for a long time. Nothing has come close to the "features" of the MRA system with digital audio distribution, amps that are rated for in ceiling use etc. and control over the amp.

I want to start with just some remote amps first without the switcher. Is there any issue with using them without the MRA switcher?

All I need to be able to do is use the local input, turn power on and off and change the volume (and switch inputs as per below)

For a second input I believe I can use a remote distribution unit to convert a second input into a digital audio signal and feed that to an individual amp.

Are there any perceived issues with this approach.

Mick

 

Hi znelbok,

I agree fully, i believe the cbus audio setup is a great offer..

I have a 3 zone setup with no matrix switcher in my place, works a treat.. I have the 2 sources in each zone, one is a global source (audio distribution unit) which runs to all 3 amps via rj45 splitters, which is connected to a combo am/fm tuner, cd player, audio stream device, and then the local source, which in each zone is connected to the tv local to that area..

Just remember you need a powersupply for each amp, and that if you wish to run out to an external audio device, ie powered subwoofer, etc, then you will need to go the 25w amps..

 

Thanks for the feedback.

I was going to PM you but thought it may be better for anyone else who is interested in this.

What are you using for an RJ45 splitter?

The concept you outlined is what I was hoping could be done.

Mick

 

Good thinking.. I believe the matrix unit is great, however the price really blows the audio system price out..

I am using the below as they were easy to come by locally, however the official clipsal part number for the same thing is 5600TEE and is in the TPG, page 381..

http://www.jaycar.com.au/productView.asp?ID=YT6082

Also if you havent already, have a quick read of this before going ahead with it..

http://www2.clipsal.com/cis/__data/page/428/10319801_F1914_560011_MRA_DistributionUnit_press.pdf


Ps a clipsal rep mentioned to me that they were able to do the audio distribution unit and 10w amp mounting clips along with a few other odd cbus bits quite a bit cheaper before the end of the year due to wanting to clear out some excess stock.. Contact me asap if you would like me to enquire further..

 

Finally got around to a temporary PS for the amp and got nothing out.

The help indicates there is a ON/Off but there is no area to designate a group address to an on/off function.

Can I assume that a volume of 0 is also an off? Or is there something I am missing

Thanks

Mick

 

Hey Mick,

Yep Volume controls on/off, also make sure you have a source cbus group address assigned, and then set the group to the input you are using, ie digital or local.. I find it easier to use absolute control as it allows setting the amp to a specific input based on group address level, opposed to just cycling between sources in sequence..

Cheers..

 

Of course, I forgot about the source select - thanks for the info.

Mick

 

Found my problem(s)

1 - I had the polarity reversed on the power supply - plays havoc with the C-bus network.

2 - Forgot to set the input (I had the local as default on startup but it lost all its settings)

Some info

Power usage on standby:- 36mA @24VDC
Power usage when on:- 230-300mA @24VDC

This is with no Digital input connected and hence no power required for the Audio Dist Hub. I dont have oine yet to measure the power usage when that is connected

That,s a lot of spare headroom 5.7A on a 6A supply as recommended by Clipsal.

 

Glad you got to the bottom of the no going!

6A supply? The low power amps use a 1.25A supply and the bigger amps use a 3.75A supply if i remember correctly..

Being an amplifier, obviously power use will fluctuate with volume/bass/treble levels, impedance of speakers connected, etc.. However i would be supprised to see it fluctuate above 900ma for the 10w amp and above 2.1A for the 25w amp..

 

oops - bad memory not 6A.

Typing too quick and not checking details.

Either way its not getting anywhere over 1A even when cranking the volume and everything else. Just though I would post it for future refence.

 

Mykel,
You said you got the power polarity around the wrong way. Can you post the pin layout on the 8pin mini Din plug used?

 

Its on the bottom of the amp. Problem was that I was not sure if the diagram was for the plug or the socket. As per usual, when faced with a 50/50 guess I got the wrong way.

The amp lit up fine, but the C-Bus network went down pretty quickly.

Its a 4 pin mini din plug (just to be pedantic about details) - same as that used for S-Video.

When I get a chance I will pull the power from the amp and bell out the wires to check for you.

 

I have the earlier 4 pin mini din supply socket. My C-bus retailer says the power supplies are a month off and the hi temp one is 6 months off. and they are the 8pin din plugs.
My case sticker shows as
pins 5,8
3,6 RTN.
So does that mean 5 and 8 are DC inputs and 3,6 are an output (return)? and which one(5 or 8) is the +ve and which -ve?

Any one have a unrequired supply they want to sell?

 

I too have a set-up almost identical, has worked flawlessly for 5-6years except for the power supply.

I have had a 2nd power supply die just before Christmas. Part no 5600P24/3750AU. It is mounted in a cupboard in a fully ventilated position. I can't understand why I've had two fail now. It gets little & gentle use.

 

Hi, can anyone please provide the pin outs for the 4 pin mini din plug.

 

If you have an amp they are printed on the amp sticker.

two pins on left commoned up, two pins on right commoned up.

Cant remember which is + and -, but it wont hurt the amp if you get it wrong. You will know straight away because your C-Bus network will go down.

Learned this the hard way as I got it wrong the first time.

Mick

 

Here you go:

 

Can anyone test there power supply with a multimeter and advise which pins are + and which are - ?

I called cbus tech support and they didn't know for sure though believed that pins 8,6 are - and 5,3 are +. But from what znelbok posted 5,8 and 6,3 are pairs

 

The picture above is correct looking directly at the socket on the back of the amp (or looking at the back of the plug). I just checked it with a meter. Pins 5 and 8 +ve, 3 and 6 -ve. Pins 5&8 are joined internally as are pins 3&6. I assume this is just to increase the current capacity. Pretty crummy choice of power plugs really.

According to the specs you can use a 21Vac supply so there must be and internal bridge rectifier. That's why Mick didn't blow his up when he got the polarity wrong. Not sure why the wrong DC polarity would take out the bus though.

 

I'm only guessing, but the second pair of terminals may be for voltage sense wires.

These can be used by the power supply to make sure he voltage at the device is correct and nulls out any losses in the cables and connectors with changes in current.

I'm only guessing though, based on other power supplies I've seen.

Cheers

Rohan