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Anthem MRX720 pre-out help

MikeF

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Hello, I recently purchased a MRX720 to use in my home. I have a question regarding the preamp outputs I am hoping someone can help with. I am upgrading from an MRX700. I have a 7.1 system and am using all external amplification (pre-outs only). I hooked up the 720 in the same way. I read in the manual for the 720 that the rear back channel amp can be reassigned to either back surround, heights, or zone 2. I reassigned it to heights in order to use the built in amp to power some atmos ceiling speakers. I noticed that when I did this, I lost my rear back surround channels from the preamp out. Is this correct? Is the preamp out for the back surround channel tied to the internal amp selection? If so, this seems odd. Why would selecting what happens to the internal amp affect the pre-outs? I would think the pre-outs would be fixed as there are already pre-outs for heights 1 and 2 present as well as Zone 2. I searched to find an answer to this but could not. Please help. I would like to run my main seven channels (FL/C/FR/SL/SR/BL/BR) from outboard amps and use the assignable amp in the receiver to power a pair of heights. Is this possible? Could I have something configured wrong somewhere else?

Thanks
Mike



Thanks in advance
 

peng

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Hello, I recently purchased a MRX720 to use in my home. I have a question regarding the preamp outputs I am hoping someone can help with. I am upgrading from an MRX700. I have a 7.1 system and am using all external amplification (pre-outs only). I hooked up the 720 in the same way. I read in the manual for the 720 that the rear back channel amp can be reassigned to either back surround, heights, or zone 2. I reassigned it to heights in order to use the built in amp to power some atmos ceiling speakers. I noticed that when I did this, I lost my rear back surround channels from the preamp out. Is this correct? Is the preamp out for the back surround channel tied to the internal amp selection? If so, this seems odd. Why would selecting what happens to the internal amp affect the pre-outs? I would think the pre-outs would be fixed as there are already pre-outs for heights 1 and 2 present as well as Zone 2. I searched to find an answer to this but could not. Please help. I would like to run my main seven channels (FL/C/FR/SL/SR/BL/BR) from outboard amps and use the assignable amp in the receiver to power a pair of heights. Is this possible? Could I have something configured wrong somewhere else?

Thanks
Mike



Thanks in advance

The funny thing is, you probably could find the answer if you read Denon/Marantz/Yamaha's manual.:) If you want to find the answer in the MRX700/1120 manual you probably won't find it (hope I am wrong). That's because from what I could remember Anthem did not provide much details in their manuals though for the basic features, there were adequate information.

My educated guess is, what you found on the pre outs was expected, because the MRX has only 7 channel of internal amps. So when you re-assigned the back surround channel to heights you will of course lose the back surround channel pre out because they would be redirected to drive the height channel.

So it looks like your choice is to not use the re-assign feature this way, unless the MRX720 has an option (like DMY's) to assign the front L/R to pre out, then you can use the front L/R internal amps to power the Atmos/Height channels.

I'll try to find out if it can do it, but again theirs manuals are so skinny...

Edit: Just read the manuals, there is no mentioning of assigning any channels to pre-outs (if true, that's one negative on Anthem's). So it looks like you are stuck with using external amp for the 4 Atmos channels. To be sure I haven't missed anything, contact Anthem. If confirmed then I suppose you could buy a low cost amp such as Emotiva's, to power the Atmos/Height speakers.
 
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MikeF

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"Edit: Just read the manuals, there is no mentioning of assigning any channels to pre-outs (if true, that's one negative on Anthem's). So it looks like you are stuck with using external amp for the 4 Atmos channels. To be sure I haven't missed anything, contact Anthem. If confirmed then I suppose you could buy a low cost amp such as Emotiva's, to power the Atmos/Height speakers."

Thats the thing. I don't want it to reassign the pre-outs. lol I want it to leave them alone and just reassign the internal amp to heights with out that change affecting the pre-outs. I guess I could leave it set to back surrounds and hook my back surrounds up to the anthem and take them off my Acurus 5x100. Then use those two channels for heights. I go from 100w per channel on my rears to 60w but that would save from a separate amp in any event.
 

peng

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"Edit: Just read the manuals, there is no mentioning of assigning any channels to pre-outs (if true, that's one negative on Anthem's). So it looks like you are stuck with using external amp for the 4 Atmos channels. To be sure I haven't missed anything, contact Anthem. If confirmed then I suppose you could buy a low cost amp such as Emotiva's, to power the Atmos/Height speakers."

Thats the thing. I don't want it to reassign the pre-outs. lol I want it to leave them alone and just reassign the internal amp to heights with out that change affecting the pre-outs. I guess I could leave it set to back surrounds and hook my back surrounds up to the anthem and take them off my Acurus 5x100. Then use those two channels for heights. I go from 100w per channel on my rears to 60w but that would save from a separate amp in any event.

According to the manual, Anthem's amp assign function is limited to the following:

1647454231337.png

So if you assign the backs to height, it assumes you are running 5.1.2, and by keeping the backs pre out "live", you would be doing 7.1.2, that is outside the intended scope.

Is there an amp assign menu similar to Denon's shown below? If it has, then may be you can play around with it to see if there are other allowable selections.

index.php
 
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MikeF

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Peng. that is the rub. that is for the Amp assign functions. Why does that choice affect the pre outs? The unit has pre-outs for 7.1.4 so obviously it is capable of full atmos setup. I'm not at home presently to further test the unit right now but if this assigning convention holds, would I also loose my rear back pre-outs if I set the internal amp to Zone 2? I need to test and report back but if so that would be even more strange. Just because I want to use the rear internal amp to drive zone 2 speakers shouldn't mean that I don't want all my 7.1.4 pre-outs all working as intended.
 

peng

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Peng. that is the rub. that is for the Amp assign functions. Why does that choice affect the pre outs? The unit has pre-outs for 7.1.4 so obviously it is capable of full atmos setup. I'm not at home presently to further test the unit right now but if this assigning convention holds, would I also loose my rear back pre-outs if I set the internal amp to Zone 2? I need to test and report back but if so that would be even more strange. Just because I want to use the rear internal amp to drive zone 2 speakers shouldn't mean that I don't want all my 7.1.4 pre-outs all working as intended.

I agree with you. That's why I really think you should play around with the amp assign menu settings to see if there is a setting that allows you to keep the back pre outs on, and if not, then it really is a negative of the 720.

The manual for the MRX740 is still lacking in details, but its amp assign feature description is vague and open ended enough for me to assume that it does have the flexibility to do what you want to do.

On page 33:

Amp Matrixing (740/1140)

This option allows you to assign amplifier channels to different channels of information. This is meant to allow you to replace
certain amp channels with external amplification and still be able to use the amplifier channels to power other speakers, for
example it is common to use an external amplifier to power the Front Left and Front Right speakers if they require more power,
you can use this menu to assign the amplifier channels originally used for these speakers to power other speakers such as
Height or Zone 2. The Centre channel cannot be reassigned because it is a single channel while everything else is a pair.
 
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