Power Amp choice for X4700h

[lovinthehd]

I agree, but there is no reason for competitor not to work on their design, layout and parts choice to achieve results better or similar to that of the Denon AVRs. Surely to me SINAD 80 or 100 would make no difference, but to some, under certain conditions, they may hear a difference.

92 or 102 dB (0.0008%THD) may seem "overthought" as you put it, but that's ideal condition, when you factor in the noise from interconnections, power supplies, power amps etc., and at the higher frequencies than those from a 1 kHz fundamental, the overall results may be quite a bit less. So it doesn't hurt to aim higher than one may need for transparency to begin with.

Denon AVR-X6700H AVR Review (Updated) | Audio Science Review (ASR) Forum
Below are the SINAD vs output voltage curves for the X6700H (Amir measured it up to higher than 4 V, but only for the X6700H), I think he assume the 3700/4700/8500 should be similar.

Note that to achieve 4.4 V, he had to set volume to 90, that would be +10, and that's with input signal at 0 dBFS, that would be about 110 dB from the listening position. Nobody does that in the real world I hope.


View attachment 50427

Yeah, I get the part about better engineering and all that....but seems many think it's more than that. Audibility not too likely. Especially at the age many of us are at

 

[panteragstk]

Are any Purifi/Hypex amps made using unbalanced inputs? Don't think I've seen any....

High SINAD is nice, but way overthought (particularly on asr).

ps Forgot about an ATI hypex amp with unbalanced inputs....but can't think of any others...

Honestly, I just used his chart to help me make a cheap/informed purchase. If I were in the market for something more than that, I'd be looking at the ATI stuff for sure.

 

[lovinthehd]

Honestly, I just used his chart to help me make a cheap/informed purchase. If I were in the market for something more than that, I'd be looking at the ATI stuff for sure.

I did the same when I wanted to try an external dac recently. Was a waste of money as expected in that it did not make any audible difference over the two built-in dacs I was using in that setup....but had a high SINAD to cost ratio

 

[daka]

I have listened already and its good but not jaw dropping good. Stereo in pure direct seems to be the best but was exactly wondering about 3.2 min impedance of Kefs plus top power draw could cause higher distortion than expected.

In regards to Emotiva - seen rather positive reviews being great value proposition rather than being audiophile grade and directed more towards HT market. Is there something I missed that should pay more attention to? Would Cambridge 851W give me much greater impact than Emotiva BasX A2? Also Emotiva XPA line seems to be similar proposition to Monolith no?

Monolith I think is not available in UK unfortunately. ATI seems to be in different price league.
Aim would be, since ive spent quite a bit lately for hole setup, to get biggest impact within 1k. Whether it will be going full external amplification (no sure how much difference Denon in full pre-amp mode would make) or giving quality amp for fronts. Volume wise what I have at the moment is enough so more power not needed - more depth yes.

My first thought is you expect too much from installing an external amp; marginal or no difference is quite possible in any case with any power amp. Are you reaching the limits of the avr's amps now?

Well KEFs are rated with min impedance of 3.2 ohms so I would suspect it might struggle a bit.
I do have expectation of getting bit bigger sound stage perhaps by giving it bit more power (like 160w 8ohms vs 100w) and possibly by going full pre-amp - that should provide possibly even cleaner sound.

Is going with integrated amp bad idea when combining with AVR?

 

[daka]

LOL yes sometimes I just say scratch the itch, and if so, get as powerful an amp as you can. An amp that only provides a marginal increase in power just isn't worth the effort IMO. As to using a Purifi or Hypex amp, have to also consider sensitivity may not be ideal.

Yes I believe with x4700v 1.4v is max if not in pre-amp per Amir measurements.
Unfortunately at this point in time I can either go full amp but cheaper amps or better stereo amp
Cambridge 851w I found is second hand one (750) as normally they would cost over 1.6k.
Would that be considerably better than A2?

 

[lovinthehd]

I have listened already and its good but not jaw dropping good. Stereo in pure direct seems to be the best but was exactly wondering about 3.2 min impedance of Kefs plus top power draw could cause higher distortion than expected.

In regards to Emotiva - seen rather positive reviews being great value proposition rather than being audiophile grade and directed more towards HT market. Is there something I missed that should pay more attention to? Would Cambridge 851W give me much greater impact than Emotiva BasX A2? Also Emotiva XPA line seems to be similar proposition to Monolith no?

Monolith I think is not available in UK unfortunately. ATI seems to be in different price league.
Aim would be, since ive spent quite a bit lately for hole setup, to get biggest impact within 1k. Whether it will be going full external amplification (no sure how much difference Denon in full pre-amp mode would make) or giving quality amp for fronts. Volume wise what I have at the moment is enough so more power not needed - more depth yes.

Well KEFs are rated with min impedance of 3.2 ohms so I would suspect it might struggle a bit.
I do have expectation of getting bit bigger sound stage perhaps by giving it bit more power (like 160w 8ohms vs 100w) and possibly by going full pre-amp - that should provide possibly even cleaner sound.

Is going with integrated amp bad idea when combining with AVR?

Is Emotiva readily available in the UK? Why would soundstage be affected by the amp? Difference between 160 and 100 watts is only 2 dB, but better/different 4 ohm capabilities perhaps could be more important than power ratings at 8 ohm. I simply wouldn't expect sound quality difference it just being an external amp in any case. Personally I'd rather have a Crown XLS amp (and use such)

ps as far as using an integrated amp as a power amp, some are more suited to that than others but generally a waste of the capabilities of the integrated amp, usually just better to use a power amp IMO

 

[daka]

If you are going to use the preamp mode then your best choice would seem to be the Hypex or Purifi based power amplifiers. Aside from the top rated (based on specs and measurements) Benchmark AHB2, nothing can touch those class D amps at the moment.

Those talks of how one amp sounds better than another are mostly subjective, often imagined. The fact is, bench measurements don't lie, ears/brains do (obviously unintentionally). That's as long as measurements are done by a credible source, and the reviewer knows how and what to measure.

Measurements by Audioholics.com and Audiosciencereview.com are quite reliable afaic..

Some example of good power amps that cost less, or not much more than Emotiva's:

Review and Measurements of Purifi 1ET400A Amplifier | Audio Science Review (ASR) Forum
ATI AT4002 Class AB and AT522NC Class D Amplifier Review Shootout | Audioholics
ATI AT522NC Stereo Amplifier Review | Audio Science Review (ASR) Forum
Outlaw Model 5000 Five Channel Amplifier Measurements and Analysis | Audioholics

Had a look at Hypex and surprised how affordable they are and small? Any particular model I should be looking at? or avoid?

 

[daka]

By the way, you may be interested in reading another review, aside from the usual AH and ASR's:

For objective measurements:
SoundStage! Hi-Fi | SoundStageHiFi.com - The Purifi Puzzle, Part One: The Measured Performance of the Eigentakt Amplifier

For subjective measurement:
SoundStage! Hi-Fi | SoundStageHiFi.com - Purifi Audio's Pint-Sized Powerhouses

For DIY, you can buy from the following places but there are no schematic as such as those are modules. You only need a soldering iron and a screw driver.

Purifi:
Amplifiers Archives - PURIFI (purifi-audio.com)
DIYclassd.com
ghentaudio --- Purifi EVAL1 Stereo case-kit

Unfortunately you will have to buy the amp modules, power supply and the case from 3 different places, and the power supply apparently is out of stock, may have to wait until November.

Hypex (buy direct)
DIYclassd.com

Hypex (lowest cost OEM)
Buckeye Amps: New US based Hypex multichannel amplifier builder, line-up announcement! | Audio Science Review (ASR) Forum

If I remember right, Buckeye said at one time he would send you the kit for you to DIY, but the saving would be very negligible.

Is Hyperx same as NORD ONE on this. side of the pond?

 

[lovinthehd]

Nord does use Hypex modules....

 

[daka]

Nord does use Hypex modules....

Now makes sense, thanks

 

[daka]

Is Emotiva readily available in the UK? Why would soundstage be affected by the amp? Difference between 160 and 100 watts is only 2 dB, but better/different 4 ohm capabilities perhaps could be more important than power ratings at 8 ohm. I simply wouldn't expect sound quality difference it just being an external amp in any case. Personally I'd rather have a Crown XLS amp (and use such)

ps as far as using an integrated amp as a power amp, some are more suited to that than others but generally a waste of the capabilities of the integrated amp, usually just better to use a power amp IMO

Yes it is readily available. I was thinking it will impact clarity, depth perhaps?
Left KEF r3 when crossed low at 40Hz bass driver does unhealthy sound, like the woofer moves diagonally rather than in straight plane - could that be due to amp not sufficient handling? On the Kef curve it looks like it drops to 3.2 ohms around that point.

 

[lovinthehd]

Now makes sense, thanks

They also have Purifi and ICE modules in some units.

 

[lovinthehd]

Yes it is readily available. I was thinking it will impact clarity, depth perhaps?
Left KEF r3 when crossed low at 40Hz bass driver does unhealthy sound, like the woofer moves diagonally rather than in straight plane - could that be due to amp not sufficient handling? On the Kef curve it looks like it drops to 3.2 ohms around that point.

Not likely, most of the sound quality things come from your speakers and room interaction and ideally the amp has absolutely nothing to do with that in any case. I think the Purifi/Hypex modules do a very good job of being good transparent amps. If you want coloration, use dsp/eq. I'd just get a sub with a speaker with limited bass capabilites like the R3.

 

[PENG]

Is Hyperx same as NORD ONE on this. side of the pond?

In a way, just note that Hypex makes quite a few models, Nord One is just one that is build with the NC500 modules. You can see the photos of the boards and layout on ASR:

Review and Measurements of Nord One NC500 Amp | Audio Science Review (ASR) Forum

 

[panteragstk]

I did the same when I wanted to try an external dac recently. Was a waste of money as expected in that it did not make any audible difference over the two built-in dacs I was using in that setup....but had a high SINAD to cost ratio

I got one because mine died. I'm happy and it was cheap. It sounds better because it's not broken.

 

[PENG]

Yes I believe with x4700v 1.4v is max if not in pre-amp per Amir measurements.
Unfortunately at this point in time I can either go full amp but cheaper amps or better stereo amp

Please do yourself a favor and do not believe that 1.4 V max thing. Just look at the curve I posted earlier and you can see that the maximum is at least 3.5 V, most likely started to clip at just over 4 V.
Power Amp choice for X4700h | Audioholics Home Theater Forums

Amir mentioned the 1.4 V a few times for the Denon AVRs but you have to read the caveats, that at above 1.4 to 1.5 V, distortions and noise levels would start to increase so the peak performance in terms of THD+N is at around 1.4/1.5 V, that is very different than saying 1.4 V is the maximum.

Here's what Gene said about the AVR-X3600H:
Denon AVR-X3600H 9.2CH IMAX Enhanced AV Receiver Offers Best In Class Features | Audioholics

"With the AVR-X3600H configured to reroute the main front L/R internal amplifiers, the preamp is physically disconnected from the power amp. This allows the preamp stage full capability of delivering up to 4Vrms unclipped when connected to external amplification as can be seen in the following output vs distortion plot courtesy of Sound United Engineering."

Cambridge 851w I found is second hand one (750) as normally they would cost over 1.6k.
Would that be considerably better than A2

I don't believe the A2 is any better than the Denon's amp, likely a little worse based on specs and measurements of similar models measured by ASR. I do have confident that the 851W is better.