Denon AVR-4700 Preamp Mode Question

[kevin1969]

This is probably been addressed somewhere on the forum but I can't seem to find it. Are the Tone Controls and Audessy correction still available if the AVR is in pre-amp only mode?

 

[Golfx]

This is probably been addressed somewhere on the forum but I can't seem to find it. Are the Tone Controls and Audessy correction still available if the AVR is in pre-amp only mode?

 

[Golfx]

Yes. Those are functions of the preamp purpose.

 

[amper42]

This is probably been addressed somewhere on the forum but I can't seem to find it. Are the Tone Controls and Audessy correction still available if the AVR is in pre-amp only mode?

You don't lose any Audyssey functionality with Denon "Pre-amp mode". The only item you will need to remember is when the Denon Receiver is in "Pre-amp mode" the speaker configurations are limited to the labels on the back of each speaker terminal.

For example, with Denon Amp Assign you can select a "Front A-B" setup. With Pre-amp mode that option is not available. Or with Pre-amp mode you can select Zone 2 or 3. That's not an option in Pre-amp mode. The rule is if it's not listed on the speaker terminal it's not available in Pre-amp mode. Otherwise, everything else is the same whether using internal amps or Pre-amp mode.

One way you can get around the lack of Zone 2 or Zone 3 with Pre-amp mode is to select multi-channel stereo mode when running multiple-zone configurations.

 

[batfunk]

An other question about preamp mode and i want a definitive answer:
If i assign the 4700 on 11.1 setup, connect a 3 channels power amp to it(with fronts left, right, centre speakers on it), Will the centre give sound ?
If it's yes, which amp powers it, internal denon one or power amp one or both (?). Will sound quality suffer from it, worse than if powered by 4700 internal amp only ?


Me and a friend are in a disagreement...

 

[amper42]

An other question about preamp mode and i want a definitive answer:
If i assign the 4700 on 11.1 setup, connect a 3 channels power amp to it(with fronts left, right, centre speakers on it), Will the centre give sound ?
If it's yes, which amp powers it, internal denon one or power amp one or both (?). Will sound quality suffer from it, worse than if powered by 4700 internal amp only ?

1. If you are using Denon amp assign 11.1 - this is not "pre-amp only" mode.

2. If you use 11.1 amp assign and configure the Fronts as "pre-outs" then your Front pre-out RCA's lead to the external amp and the speakers connect to the external amp. Next, use the Center "Pre-out" RCA to the external power amp and then Fronts and Center will be powered off the external amp.

3. The Denon 4700 "pre-out" RCA's are always live no matter what amp assign mode you select. The difference between using "Pre-out ONLY" mode from any other Denon 4700 Amp assign mode is the internal amp power rails are disconnected in "Pre-out ONLY" mode which offers cooler operation and higher SINAD.

This is what your configuration would look like:
Fronts: Pre-outs:external amp channel 1/2:speakers
Center: Pre-out:external amp channel3:speaker

 

[batfunk]

Strange, i read everywhere that on 11.1 assignement, with power amp connected on the back and fronts assign to preouts, it automatically deactivate Denon front left and right internal amps...

"Next, use the Center "Pre-out" RCA to the external power amp and then Fronts and Center will be powered off the external amp"

You mean that before i connect the center preout rca, L and R are powered by External amp ? After that, L C and R Will be powered by Denon amp ? Sorry, my english is poor...

If i resume, with 11.1 assignement and whatever power amp(3 channels or 5 or 7) behind, speakers connected to power amp Will be powered by the power amp and others by Denon but Will not benefit from the cleanliness of the preamp only mode ? Right ?

 

[Golfx]

PreAMP amp assign mode shuts off ALL internal amps.

 

[Dj7675]

PreAMP amp assign mode shuts off ALL internal amps.

To reduce confusion... instead of shuts off, better to use the term disconnect.

 

[batfunk]

I understood that. My question was simple:

On 11.1 assignement, Can i connect a center speaker on a power amp and benefit from it as with Front Left and right channels ?

 

[Golfx]

Agreed but didn’t know sender’s mastery of English words.

 

[Golfx]

Only Denon 8500 or a110 can selectively shutoff (disconnect) individual channels beyond the LR feature. So even though your LR channel internal amps are disconnected your center channel internal amp would not be disconnected. But would gleefully use any external amp.

 

[batfunk]

Thanks. I assume it's the same with this case:
-11.1 assignement with fronts assigned to preout
-5 channels power amp
-5.1.4 speakers.

5 speakers Will benefit from the watts of the power amp, but only L er R from the cleanliness (better Sinad, less distortion).
The others speakers are powered by the Denon. Right ?

That Will be my Last question

 

[peng]

Thanks. I assume it's the same with this case:
-11.1 assignement with fronts assigned to preout
-5 channels power amp
-5.1.4 speakers.

5 speakers Will benefit from the watts of the power amp, but only L er R from the cleanliness (better Sinad, less distortion).
The others speakers are powered by the Denon. Right ?

That Will be my Last question

That is correct, but keep in mind in practice, even the 3 channels not assigned to pre out because you can't, will still have the same SINAD as the front left and front right that are assigned to pre out at output voltage level up 1.4 V or a little more. At higher output level SINAD would degrade gradually as the internal power amps starting to clip and would be at about 75 dB at about 2 V.

At pre out voltage of 1.4 V, a power amp that has the same 29 dB gain as the internal amps, would output almost 200 W into 8 ohms or 400 W into 4 Ohms.

So for those who don't listen near reference level, sitting not too far (say 10-12 feet) and have speakers that have sensitivity not too low, say 87 to 90 dB, preamp mode, amp assign or neither, SINAD will not really degrade, but of course preamp mode has other benefits even if SINAD is not the issue.

 

[amper42]

Strange, i read everywhere that on 11.1 assignement, with power amp connected on the back and fronts assign to preouts, it automatically deactivate Denon front left and right internal amps...

"Next, use the Center "Pre-out" RCA to the external power amp and then Fronts and Center will be powered off the external amp"

You mean that before i connect the center preout rca, L and R are powered by External amp ? After that, L C and R Will be powered by Denon amp ? Sorry, my english is poor...

If i resume, with 11.1 assignement and whatever power amp(3 channels or 5 or 7) behind, speakers connected to power amp Will be powered by the power amp and others by Denon but Will not benefit from the cleanliness of the preamp only mode ? Right ?

All RCA pre-outs on the Denon 4700 are always live. You can use them in whatever order you want. The only configuration not supported is using both the pre-out and the speaker terminal on the same channel.

As far as selecting the Front Pre-out configuration in 11.1 you are correct the power rail is disconnected from the internal amp in this configuration but all other internal amps are live.

The Denon internal amps are pretty clean on their own. However, if you are trying to reach volume levels 90dB or higher the sound will benefit from using pre-amp only mode or at least on the Fronts especially with low sensitivity speakers.

 

[peng]

As far as selecting the Front Pre-out configuration in 11.1 you are correct the power rail is disconnected from the internal amp in this configuration but all other internal amps are live.

That would be nice, but the fact is, the internal amps will still be connected to the power rail. It is the power amp inputs that get disconnected from the corresponding preamp outputs. This is the same for both amp assigned set to preamp, or in full preamp mode. The difference is, using the amp assign feature, only the front left and front right channels can be assigned to pre out.

 

[batfunk]

Hi again ! Finally another question

With another setup,:
5.1.4 speakers
11.1 assignement
2 power amps, one for left and right, one for centre(purifie mono Block) .

I know that Denon centre preout Will clip at 1.4 vrms(internal amplifier still connected). My centre power amp has a 2.25 vrms input.
Can i compensate voltage difference by increasing output gain in denon setup?How?Is it worth it ? Will i still lose watts to power central speaker compared to internal amplifier capacity ?

Thanks again !

 

[peng]

Hi again ! Finally another question

With another setup,:
5.1.4 speakers
11.1 assignement
2 power amps, one for left and right, one for centre(purifie mono Block) .

I know that Denon centre preout Will clip at 1.4 vrms(internal amplifier still connected). My centre power amp has a 2.25 vrms input.
Can i compensate voltage difference by increasing output gain in denon setup?How?Is it worth it ? Will i still lose watts to power central speaker compared to internal amplifier capacity ?

Thanks again !

Again, the pre out doesn't clip at 1.4 Vrms (the internal power amp will be clipping at that point). Take a look of the center channel of the X3600H, that obviously has the internal power connected:

That's almost as good as the AV7705 (a so called "separate" preamp processor.
Note that the dash board of the AV7705 measurements show about 4 V but that's XLR, had Amir used RCA for that measurement, it would have been 2 V and SINAD would have been about the same, again, as the AVR-X3600H that is an AVR, therefore internal amps would be "clipping" and degrading the SINAD at pre out.

So I really wouldn't worry about your center channel, unless you will be pusing the Purifi amp to output almost 400 W average (800 W peak) into 8 Ohms and you can hear the difference between 75 dB and 95 dB SINAD (I know I can't..).

 

[batfunk]

Again, the pre out doesn't clip at 1.4 Vrms (the internal power amp will be clipping at that point). Take a look of the center channel of the X3600H, that obviously has the internal power connected:

That's almost as good as the AV7705 (a so called "separate" preamp processor.
Note that the dash board of the AV7705 measurements show about 4 V but that's XLR, had Amir used RCA for that measurement, it would have been 2 V and SINAD would have been about the same, again, as the AVR-X3600H that is an AVR, therefore internal amps would be "clipping" and degrading the SINAD at pre out.

So I really wouldn't worry about your center channel, unless you will be pusing the Purifi amp to output almost 400 W average (800 W peak) into 8 Ohms and you can hear the difference between 75 dB and 95 dB SINAD (I know I can't..).

View attachment 128503

View attachment 128504

Hmmm, if i understand, only denon internal amps Will clip if i push beyond 1.4 vrms output. Denon preouts will still power to the max my purifi moblock(2.25 vrms input, 257 watts 4 ohms 2 channels driven) at the expanse of Sinad.

So why this Amirm's recommandation ? :

"As you see, peak performance with the amplifiers off is around 1.1 volts with SINAD of 101 dB which is excellent for an AVR. With the amps on, you are OK up to 1.4 volt output before it nose dives. So when selecting an external amplifier for channels beyond fronts, make sure it can output its maximum power at or below 1.4 volts (usually specified as "sensitivity")."

Was He talking about Sinad only and not power ?

 

[peng]

Hmmm, if i understand, only denon internal amps Will clip if i push beyond 1.4 vrms output. Denon preouts will still power to the max my purifi moblock(2.25 vrms input, 257 watts 4 ohms 2 channels driven) at the expanse of Sinad.

As someone mentioned, it depends on how we define "clip". Someone suggested 0.1% THD, others may say 1%, or 0.05%, so again, it depends..
If I remember right, Amir seems to consider the "clippping" point where THD starts to rise sharply, that means SINAD would start to fall sharply. So if you look at that graph, you can see for the X4700H, it would be 1.4 V. However, if you base it on say 0.05%, that is 66 dB SINAD, then the pre out with the internal amp remain connected does not clip even at 2 V or higher. At that level, if sustained (that would be rare for real word contents) the amp may shutdown, depending on the protection system's design. In my opinion, Amir is not wrong but I don't agree with using the term "clip" until SINAD falls to say less than 80 dB, that is THD+N = 0.01% and Amir would go with that, from the same graph, pre out would be at about 1.6 Vrms. That would still be generous, because it would mean the Marantz AVP "clips" at about the same point as a Denon AVR. I am sure no owners of any Marantz AVRs/AVPs would agree with that. This is just my own opinion and I won't argue with anyone who don't agree with me.

So why this Amirm's recommandation ? :

"As you see, peak performance with the amplifiers off is around 1.1 volts with SINAD of 101 dB which is excellent for an AVR. With the amps on, you are OK up to 1.4 volt output before it nose dives. So when selecting an external amplifier for channels beyond fronts, make sure it can output its maximum power at or below 1.4 volts (usually specified as "sensitivity")."

I think by now, you should know Amir sets his bar at different height than some other reviewers lol!! Again, think about this, so it nose dive from 1.4 V at peak performance, to 74-75 dB SINAD at 2 V? Nose dive or gradual fall, or whatever you'll be the judge on how it compares with the SINAD of some of the AVPs that don't even have internal power amps!!

Was He talking about Sinad only and not power ?

I think the part you quoted was from the X3700H review, and yes he's talking about SINAD of the pre out.