This is my second attempt for such a poll, I started a false one by mistake a few days ago, sorry, and thanks to
@highfigh who pointed out my incorrect assumptions. Hopefully I've got it right this time. Logically speaking I have to be right because if all channel preamp mode is already offered in the AVR-X3700H through X6700H, then it should mean that all the necessary hardware, in this case, the NJU72750AV switches are already in place, wired, and controlled by codes.
Below is some background information for those who may not know the underlying reasons. Those who already know what this is about, please just answer the poll question.
Gene, who is the first as far as I can tell, pointed out potential issue of using an AVR with external power amp is that as the preamp output level reaches about 1.2 V, their internal power amps will be close to their rated output. So at higher output levels, the power amps would clip, and the resulting higher distortions will then cause the distortions of the pre out signal to also be higher. Obviously this does not mean there is no point to add external power amps, but it does, at least on paper, partially negate the benefits of adding a much more powerful external amplifier for the expected benefits of low distortions at higher output level. Based on ASR's measurements on the AVR-X3600H, at preout level of 2 V the difference between with and without the internal power amps disconnected were not insignificant.
With power amp disconnected...............0.00096% THD+N
With power amp connected....................0.018732 %
Note that for a 200 WPC power amp such as Monolith's (28 dB gain), you need 1.6 V to drive it to its rated output into 8 ohms, and you will need 2.25 V to drive a 400 WPC power amp with 28 dB gain (quite common/typical) to its rated output. So whether without the AVR's internal amp disconnected will result in audible degradation in sound quality or not, depends on the individual user's need and whether they consider THD+N of 0.018732% for preamp is acceptable.
2017 through 2019 models such as the Denon AVR-X4400H, Marantz SR7013, SR6014
- These models have the amp assign functions so the switches for disconnecting (note: not turning off) some of the internal power amps are already wired in place.
- Unfortunately, the amp assign functions do not affect the SL, SR and C channel, so there is no point to have the FW upgrade that I am suggesting because there won't be enough switches to disconnect all 9 channels.
2020 models
The upcoming AVR-X3700H through AVR-X6700H, according to Gene/Denon's YouTube video have the full all channel preamp mode, just like the AVR-X8500H's. Presumably, the 2020 Marantz SR6015, 7015 will have the same feature. However, I think D+M can make a lot of potential users (and/or undecided shoppers if they know there is an upgrade path) happier if they would offer a flexible preamp mode, such as one that the AVR-X8500H already offers, though even in that case I believe it was just an unintended consequence of the flag ship AVR's unique fully assignable amp feature.
Thanks to
@DJ7675, and if I remember right someone (may be jdsmoothie) at AVSF too, have confirmed that the AVR-X8500H in fact has such feature. See
Post#44
- Based on what I saw in Gene's Youtube video, the 2020 models offer the all channel preamp mode only, and the more flexible preamp mode will remain unique to the current flagship AVR-X8500H, probably because I might be right that it was actually an unintended consequence of its "fully assignable amps" feature.
So now, I think D+M should offer, perhaps as a paid FW upgrade if they must, the same feature that the AVR-X8500H already offers. My rationale is simple, it is not something I personally need, but based on the almost weekly questions we are getting from members on this forum, that there are a lot of potential users who would want to add an external power amplifier for the perceived benefits whether they actually have the need to or not.
Let's consider the following facts that AVR users (who don't want to go the AVP route) may face:
- Many users have medium size rooms, and want to implement a multi-channel HT system up to 7.1.4 , or a larger room for up to 13 channels.
- Some users have speakers that they believe need external power amps for them to perform better, especially those who use the same system for stereo music.
- Some, probably many, of those users don't believe they need external power amps for each and every channels for reasons including but not limited to the following:
- Their surround, height, Atmos speakers may not need and/or cannot even take more than the rated power output that their AVRs can already deliver with ease.
- They may be sitting much closer to their surround, surround back speakers, like 5 to 8 ft. (for example, in a 12 X 20 ft room, this would be a likely scenario).
- Due to affordability, an user may want to do it in stages, that is, add a 3 channel amp right away, and add more channels later.
A flexible preamp mode that allows all or any channels to be assigned to pre-out with the power amp disconnected, or at least in groups such as FL, C, FR and one group and the remaining channels as the other, will give the users the options to choose a 2, 3, 5, 7 or more channels of external power amps based on their need, without worrying about the resulting higher distortions in the pre-out signals due to the internal amps clipping.
