Can I use Denon receiver with external amplifier without pre-amp mode

[hmishra]

Hi all,

Here is my situation. I have a Denon AVR-X6700H and currently running in 7.2.4 mode, so I use all built-in amplifiers of the receiver. However, I want to add an external amplifier which will power my LCR speakers but I still want to use built-in amplifier for the rest.

I know Denon has a pre-amplifier setting which disables built-in amps and just uses the pre-outs. However that would also disable all the channels so not a setting I can use for just powering LCRs.

I have read that pre-outs are always active even in non pre-amplifier settings so if I use external amplifier to power LCRs that would be an option. But I have also come across comments/threads where it is not recommended to use in such a way because the voltage in pre-outs is not high enough which apparently leads to clipping. I saw this in a video as well from Audioholics but have seen hints where other users have successfully used it in this way. But I am looking for some advice from knowledgeable folks who know this for a fact and not just anecdotally.

So my questions is, can I use external amplifiers for LCR or more channels (say 7 channels) while still using the built-in amplifier of the receiver to power remaining channels?

 

[DVDdoug]

I have read that pre-outs are always active even in non pre-amplifier settings so if I use external amplifier to power LCRs that would be an option. But I have also come across comments/threads where it is not recommended to use in such a way because the voltage in pre-outs is not high enough which apparently leads to clipping.

I don't know but I wouldn't expect that. If the pre-outs are clipping the the signals to the internal amplifiers are also probably clipping.

However, I want to add an external amplifier which will power my LCR speakers but I still want to use built-in amplifier for the rest.

Why?

...I've heard of people using speaker-outs through an attenuator to drive active monitors, but that's a DIY solution with some "risk" and it probably degrades the SNR. with "unnecessary" amplification and attenuation.

 

[hmishra]

I don't know but I wouldn't expect that. If the pre-outs are clipping the the signals to the internal amplifiers are also probably clipping.

Why?

...I've heard of people using speaker-outs through an attenuator to drive active monitors, but that's a DIY solution with some "risk" and it probably degrades the SNR. with "unnecessary" amplification and attenuation.

To answer your question, I have full range LCRs and I want to feed them more power than built-in amps in the receiver can provide. Plus isn't the sole purpose of pre-outs are so clean signal can be externally amplified?

Plus, I wouldn't think I am adding any risk if I add a Monolith or Emotiva amp, right?

 

[hmishra]

Any other feedback? I am thinking of buying either Emotiva or Monolith 5 - 7 channel amplifier to accomplish what I stated above.

I guess all I am looking for is confirmation that my quest will not end up as fool's errand.

 

[Chrispy]

I thought it was only the 8500 that you could select the channels you wanted to disable the speaker amps for (which provides a bit cleaner output on the pre-outs, at least I think that's what you're referring to?). I think there's a choice for 2ch mode in some. Why are you worried, is the external amp you want not a good match sensitivity wise for the output of the Denon's pre-out levels?

 

[hmishra]

Agreed 8500 has that ability to selectively turn off amplifier for specific channels but 6500 doesn't. So my intention is to connect external amp through pre-outs while all built-in amps are still active albeit in power saving mode.

My only concern was if this way will work because I have not been able to find a definitive source stating that is an approved use case method. Honestly I didn't see any mention of sensitivity #s rated on amps like Emotiva/Monolith other than supported speaker impedances. My only hesitation is with rolling the dice only to find out later that I have to spend even more money replacing the receiver with another receiver or pre-amp.

 

[dougi]

The new Emotiva BasX 3 channel amp says:

• Input Sensitivity (for rated power; 8 Ohm load): 1.25 V.
• Gain: 29 dB.

That would seem to match up well with likely "light clipping" of the Denon AVR pre-outs with the amps still on. Bear in mind that AVRs are generally calibrated so 0dBFS -0dB volume gives 105dBSPL at the listening position. If you do the calcs for your speakers you are likely to find the amp will be clipping before the pre-outs do. (eg a 90 dBSPL/1W@1m speaker will need 500W to get to 105dBSPL at 4m. if your amp is say 140W rated then it may be clipping at -5.5dB on the volume scale).

 

[Mountain Goat]

Any other feedback? I am thinking of buying either Emotiva or Monolith 5 - 7 channel amplifier to accomplish what I stated above.

I guess all I am looking for is confirmation that my quest will not end up as fool's errand.

The first 8 posts on this thread are FAQs on the new Denons.
https://www.avsforum.com/threads/official-2020-denon-avr-owners-thread-faq-posts-1-8.3151088/

I think there's a mode where the the L/R are unhooked on the non-8500 AVRs, but you can't shut off the center without the 8500s ability to turn off any amp at will. (Of course, all the pre-outs still work, no matter what mode the AVR is in on all of them. Just the issue with possible distortion if you need to crank the pres with any of the amps hooked up.)

 

[bigguyca]

Agreed 8500 has that ability to selectively turn off amplifier for specific channels but 6500 doesn't. So my intention is to connect external amp through pre-outs while all built-in amps are still active albeit in power saving mode.

My only concern was if this way will work because I have not been able to find a definitive source stating that is an approved use case method. Honestly I didn't see any mention of sensitivity #s rated on amps like Emotiva/Monolith other than supported speaker impedances. My only hesitation is with rolling the dice only to find out later that I have to spend even more money replacing the receiver with another receiver or pre-amp.

It's not clear how you want to run your Denon X6700H, but if you mean for example:

Use case:

L,C,R - use preamp outputs
Remainder of channels use internal power amplifiers
Don't use ECO mode

The preamp outputs will be limited to about 1.4V output with good THD+N. You will be able to get more than 1.4V output, but the THD+N will be much worse.

Alternative use case:

As above, but use the ECO mode, (is that you mean by power savings?) the preamp output will be limited to about .5V for good THD+N. Over about .5V output will be available, but THD+N will be much worse.

One more use case:

ECO mode on
X6700H set for preamp output on L,R
L,R - use preamp outputs
C - use preamp output

L,R will have an output of over 2.0V with good THD+N - same as in preamp only mode
C preamp output will be limited to about .5V for good THD+N. Over about .5V output will be available, but THD+N will be much worse.

 

[hmishra]

Per above, I will just go with this use case:

Use case:

L,C,R - use preamp outputs
Remainder of channels use internal power amplifiers
Don't use ECO mode

The preamp outputs will be limited to about 1.4V output with good THD+N. You will be able to get more than 1.4V output, but the THD+N will be much worse.

I don't really listen at very high volumes anyway. To give y'all an idea, while I have occasionally cranked volume up to ~ 75 dB on a scale of 0 - 98, I usually go no more than ~ 65 dB anyway. That is plenty loud for my needs. Even at 75 dB, I cannot discern any clipping when using the built-in amps of the receiver so with above info, it seems clipping will not be an issue anyway.

Only reason I was thinking of using ECO was a mistaken belief that it would help with heat situation without needing to drive LCRs using built-in amps but of course, I did not realize that will affect outputs of pre-outs too!

Thank to you all, so much! This helped me tremendously. Appreciate all your valuable information and suggestions.

 

[hmishra]

The first 8 posts on this thread are FAQs on the new Denons.
https://www.avsforum.com/threads/official-2020-denon-avr-owners-thread-faq-posts-1-8.3151088/

I think there's a mode where the the L/R are unhooked on the non-8500 AVRs, but you can't shut off the center without the 8500s ability to turn off any amp at will. (Of course, all the pre-outs still work, no matter what mode the AVR is in on all of them. Just the issue with possible distortion if you need to crank the pres with any of the amps hooked up.)

Thanks for proving the FAQ link. I found this in that thread and this directly answered my question:

Note also that all the main zone pre-outs are always HOT, you don't have to set them to ON in order to add external amps (eg. if you have a 7.1 setup and you want to power the L/C/R speakers externally (X3700H and higher only), then you simply connect the RCA cables to the L/C/R pre-outs, raise the volume on the external amp (if adjustable) to at least 80% of maximum, and then run Audyssey again to account for the different gain structure of the external amp compared to the AVRs internal amps.

 

[dougi]

Per above, I will just go with this use case:



I don't really listen at very high volumes anyway. To give y'all an idea, while I have occasionally cranked volume up to ~ 75 dB on a scale of 0 - 98, I usually go no more than ~ 65 dB anyway. That is plenty loud for my needs. Even at 75 dB, I cannot discern any clipping when using the built-in amps of the receiver so with above info, it seems clipping will not be an issue anyway.

Only reason I was thinking of using ECO was a mistaken belief that it would help with heat situation without needing to drive LCRs using built-in amps but of course, I did not realize that will affect outputs of pre-outs too!

Thank to you all, so much! This helped me tremendously. Appreciate all your valuable information and suggestions.

The Denon volume scale should work such that "80" is 0dB reference (ie the calibrated level so that 0dBFS digital would give 105dBFS). If you generally listen at "65" then that is 15dB below full scale output and well away from pre-amp clipping.

 

[enricoclaudio]

To answer your question, you can totally do what you want to do. Until last week, I was running my X6700H in “mix” mode. Meaning I was using external amps to drive my LCR, surround and rear surrounds while driving my 4 x Revel M55XCs ATMOS speakers with the X6700H internal amps with ZERO issues. Last week got an Emotiva BasX A4 to drive the ATMOS speakers and now I have switched the X6700H to pre amp mode. Results are very similar other than the X6700H runs just a bit cooler. Before the X6700H I was doing the same with a X6500H which is now in my bedroom also driving a few speakers with internal amps and some with external amps. Next week I’ll be running the X6500H also with all speakers driven by external amps, though.

 

[hmishra]

Excellent! That was exactly the corroboration I was hoping for.

I will eventually switch to how you are running your system too except probably sometime next year. I was looking to buy the Emotiva Gen3 XPA-11 so I don’t have to buy multiple external amps but seems they are in extremely short supply currently so I would rather wait.

Oh yes, one other thing. I think I know the answer but just to confirm…. I will also have to run the Audyssey speaker calibration again after hooking up the external amps, right?

 

[enricoclaudio]

Excellent! That was exactly the corroboration I was hoping for.

I will eventually switch to how you are running your system too except probably sometime next year. I was looking to buy the Emotiva Gen3 XPA-11 so I don’t have to buy multiple external amps but seems they are in extremely short supply currently so I would rather wait.

Oh yes, one other thing. I think I know the answer but just to confirm…. I will also have to run the Audyssey speaker calibration again after hooking up the external amps, right?

Yes, you have to run Audyssey again even if you only add LCR external amp. If you switch the amp configuration to Pre Amp mode is even mandatory as Audyssey resets so you have to run it again.

 

[amper42]

Oh yes, one other thing. I think I know the answer but just to confirm…. I will also have to run the Audyssey speaker calibration again after hooking up the external amps, right?

Yes, you will want to create a new Audyssey configuration file each time you change amp or speakers. I use the Audyssey app which allows the user to save as many of these files as you want and you can upload them to the Denon 6700 presets 1 or 2 for easy access.

 

[hmishra]

Yes, you will want to create a new Audyssey configuration file each time you change amp or speakers. I use the Audyssey app which allows the user to save as many of these files as you want and you can upload them to the Denon 6700 presets 1 or 2 for easy access.

I use the app too now. Switched to it just a month or so back and it has made things extremely convenient and IMO, more flexible to control than just doing it through receiver.

Anyway, I will do just that. Now just have to wait for the external amp to arrive.

 

[leonbmx]

To answer your question, you can totally do what you want to do. Until last week, I was running my X6700H in “mix” mode. Meaning I was using external amps to drive my LCR, surround and rear surrounds while driving my 4 x Revel M55XCs ATMOS speakers with the X6700H internal amps with ZERO issues. Last week got an Emotiva BasX A4 to drive the ATMOS speakers and now I have switched the X6700H to pre amp mode. Results are very similar other than the X6700H runs just a bit cooler. Before the X6700H I was doing the same with a X6500H which is now in my bedroom also driving a few speakers with internal amps and some with external amps. Next week I’ll be running the X6500H also with all speakers driven by external amps, though.

Sorry to bring this back from the dead, but I want to do the same as you with the BasX A4.

I currently have my x6700h set up as 7.2.4 with an Outlaw 7000x for the 7 main channels and the 4 atmos speakers (SVS Elevation) hooked up to the AVR.

So I was wondering if there is any value of me getting an Emotiva BasX A4 for the 4 atmos speakers, so I can use the x6700h in PRE-AMP mode and get better pre out signals to the amps, but it sounds like it would be very similar to just running them of the AVR?

The BasX A4 is 4x 100W, whereas the x6700h is rated at 140W (2CH), but Marantz/ Denon claim that in their higher end models that results in ~70% of that value, all channels driven, so in this case, 98W, although that could be even a bit better, since I am only using 4 channels of the 11.

So the question is, since the wattage is very similar, will the all-external-amps scenario yield any tangible/ audible benefits over my current setup, other than the slightly lower temp of the unit itself (which in my case is handled by an AC Infinity T10)?

 

[enricoclaudio]

Sorry to bring this back from the dead, but I want to do the same as you with the BasX A4.

I currently have my x6700h set up as 7.2.4 with an Outlaw 7000x for the 7 main channels and the 4 atmos speakers (SVS Elevation) hooked up to the AVR.

So I was wondering if there is any value of me getting an Emotiva BasX A4 for the 4 atmos speakers, so I can use the x6700h in PRE-AMP mode and get better pre out signals to the amps, but it sounds like it would be very similar to just running them of the AVR?

The BasX A4 is 4x 100W, whereas the x6700h is rated at 140W (2CH), but Marantz/ Denon claim that in their higher end models that results in ~70% of that value, all channels driven, so in this case, 98W, although that could be even a bit better, since I am only using 4 channels of the 11.

So the question is, since the wattage is very similar, will the all-external-amps scenario yield any tangible/ audible benefits over my current setup, other than the slightly lower temp of the unit itself (which in my case is handled by an AC Infinity T10)?

I'm running my X6700H in Pre Amp mode in a 7.3.4 ATMOS speaker setup. Bed channels are driven by 1 x XPA-3 + 2 x XPA-200s. ATMOS channels are driven by a BasX A4. In my bedroom setup I have a X4700H set in pre amp mode as well with a 5.2.4 ATMOS speakers setup using BasX A2, BasX A4 and BasX A4 (ATMOS).

Before adding the BasX A4, I was using the AVR to drive the ATMOS speakers and to be honest, I didn't;t hear any difference in SQ after adding the BasX A4. The only benefit of setting up the X4700H and X6700H in pre amp mode is that it runs cooler and also there is not popping coming our of the speakers when the external amps turn ON.

 

[leonbmx]

Thanks for the reply, so it looks like, for now at least, my money is better spent elsewhere, like on a new rythmik sub to compliment my L22