The SEPARATES vs. AVR Thread

[Bonscott]

Well, I am sure some guys would buy the car with 250HP over a car with 200HP.

Unless we consider Horse Power as “features”, then yeah it’s looks and features.

And these SINAD numbers are also part of the features list.

Yep. Miles per Gallon. Watts per Channel

 

[Cloudreader]

@Cloudreader I'd think the difference may have been the rooms or perhaps setup more than the amp power. OTOH the volume can be somewhat predictable with movies for the volume scale on the avr, but music can be quite a bit different as to levels. When I've added power amps in the 250-450wpc range to my avrs it doesn't magically make the sound better, just a bit more capable at higher levels....ymmv. I know the general idea you can get from a lot of guys swearing that the bigger amp makes a huge difference in sq and all but with four avrs and seven power amps in the house, this simply hasn't been my experience with a variety of speakers....keep in mind to simply raise spl by 3dB means a doubling of power.

Have to absolutely agree with you @lovinthehd now. Having installed the Emotiva XPA-3 and ran room correction from Denon again, the only difference I can hear is that now I am able to hear it louder clearly than I was able to do before. So most likely it was due to room. The room where I auditioned was small. My room is large great room 12'x33' with living and kitchen combined. I sit 14' from the speakers.

 

[pharaon]

AT523NC

It's not that those lower to mid range AVR can't make your speakers sound loud enough, but if the 948's impedance curve is anything like the 936, and I bet they are, likely even worse, the AVR-X1500H would have trouble delivering the needed current in the bass range from around 70-400 Hz. Most people who own those Aria speakers would never know if an AVR without the help of the good power amp can do the job, because they won't even try. I think in most cases they would be right.

Listened to your advice and bought a Micromega AS400 stereo amp(works also as a power amp) 200wpc@8ohm. Could it be that the bass now is cleaner, more detailed and precise? Especially on high (80+ dB) volume. Also it looks like that I have more detailed bass when listening quietly (like 50dB). Could it be true?
Amp specs are here:

https://micromega.com/docs/fiche_technique_uk_as400.pdf

 

[PENG]

Listened to your advice and bought a Micromega AS400 stereo amp(works also as a power amp) 200wpc@8ohm. Could it be that the bass now is cleaner, more detailed and precise? Especially on high (80+ dB) volume. Also it looks like that I have more detailed bass when listening quietly (like 50dB). Could it be true?
Amp specs are here:

https://micromega.com/docs/fiche_technique_uk_as400.pdf

That amp would offer significantly more current capability into low impedance load for sure so yes at 80+, speakers ran full range you should expect better bass. It doesn't have SOTA kind of specs and measurements but shouldn't make things worse audibly I don't think. I don't prefer integrated amps not because they are bad, but because I prefer to go right to separate (dac, preamp, power amp). Integrated amps, even expensive ones like yours, often don't even put a near flagship DAC in their units. The AS400's CS4351's specs don't even come close to that of D+M's entry level AVR.

 

[pharaon]

Integrated amps, even expensive ones like yours, often don't even put a near flagship DAC in their units. The AS400's CS4351's specs don't even come close to that of D+M's entry level AVR.

Interesting thoughts. I'm still debating, which way to choose:
* Listen to music through AS400 and use X3500 just for movies + AS400 as power amp;
* Stream everything through X3500 and use AS400 just as power amp (according to poor AS400 DAC quality you've mentioned).
I was thinking that for stereo listening it would definitely be better to choose first option, but I think I'm wrong right? It should sound better through Denon? If yes, maybe it would also be better to upgrade X3500 to X4500 (for better DAC)?
Thanks Peng,

 

[PENG]

Interesting thoughts. I'm still debating, which way to choose:
* Listen to music through AS400 and use X3500 just for movies + AS400 as power amp;
* Stream everything through X3500 and use AS400 just as power amp (according to poor AS400 DAC quality you've mentioned).
I was thinking that for stereo listening it would definitely be better to choose first option, but I think I'm wrong right? It should sound better through Denon? If yes, maybe it would also be better to upgrade X3500 to X4500 (for better DAC)?
Thanks Peng,

No the AS400's DAC isn't bad as such, just not as good as the AVR's, for comparison of the two important numbers:

AS400's 24 bit CS4351:
THD+N....................-100 dB (0.001%)
DN...........................112 dB

Denon's 32 bit DSD capable AK4458:

THD+N.....................-107 dB (0.0004467%)
DN............................ 115 dB

The CS4351 seems quite old, likely are not dsd capable. It's higher distortions may not be above the threshold of audibility, depending on other factors. The AKM's are almost certainly low enough to be below the threshold.

Denon and Marantz use the same DAC chip in all of their AVRs and AV preamp processor with two exceptions. The X8500H and AV8805 are the only two that use a different one, one that is one notch above the AK4458, the AK4490 was the AKM flag ship chip at launch time, now it has been surpassed by at least two newer models.

The X3500H and X4500H should make no difference to "sound quality" when used well within their limits. I compared the X3400H to my separates, it was hard for me to tell a difference.

 

[pharaon]

No the AS400's DAC isn't bad as such, just not as good as the AVR's, for comparison of the two important numbers:

The CS4351 seems quite old, likely are not dsd capable. It's higher distortions may not be above the threshold of audibility, depending on other factors. The AKM's are almost certainly low enough to be below the threshold.

The X3500H and X4500H should make no difference to "sound quality" when used well within their limits. I compared the X3400H to my separates, it was hard for me to tell a difference.

Strange, that 600$ AVR could have some better quality components than 4000$ Integrated amp
So then I'll connect AS400 as a power amp and stream everything through Denon. Also will make comparison of the DACs, if their differences in parameters are audible to me.
As for X3500 vs X4500 great, then no more upgrades are needed for my system now

Thank you very much for your input!

 

[PENG]

Strange, that 600$ AVR could have some better quality components than 4000$ Integrated amp

Agreed, but then not that strange if you consider the following:

- Benefits of purchasing in large quantities, D+M sells many times more AVRs than integrated amps.
- Simplicity, standardization, extensive use of ICs on the preamp/processor section.
- Much higher production efficiency, again, due to volume/mass production.
- Unlimited technical/engineering resources, relatively speaking, to boutique brands.
- Much lower profit margin that can only be acceptable in mass produced products, just think about how many AS400 are sold each year, and you can do the math to figure out what sort of profit margin would be acceptable.

The list could be longer, but it all point to basically one main factor/principle, i.e., economy of scale.. Micromega probably paid more for that Cirrus Logic DAC chip than D+M paid for the better AKM chip, just an example.

 

[AcuDefTechGuy]

Strange, that 600$ AVR could have some better quality components than 4000$ Integrated amp
So then I'll connect AS400 as a power amp and stream everything through Denon. Also will make comparison of the DACs, if their differences in parameters are audible to me.
As for X3500 vs X4500 great, then no more upgrades are needed for my system now

Thank you very much for your input!

The salient point here is NOT the INAUDIBLE specs or measurements of these DACs and components. They are INAUDIBLE.

The salient point here is that sound quality (SQ) will be quite similar among all these components - AVR vs Integrated Amp vs AVP vs Preamp regardless of price.

So you choose one component over another based on other things besides SQ.

Some choose separates for the sake of separates. Most choose AVR because they are less expensive and a lot less PAINFUL if your components were to fail in a few years. It's a lot more painful if your $4,000 - $8,000 components fail vs a $600 - $1000 components.

 

[pharaon]

Thanks everyone for your inputs, it helped me alot to better understand things about SQ!.

then no more upgrades are needed for my system now

^^ Nooot
So I was happy with the SQ both in movies&music, but. I've found a good deal on Rotel RB985 power amp, so gave it a go. And the question is - could it be, that Rotel sounds different than Micromega (Both Rotel and Micromega are used as power amps from my Denon X3500)? I've did many tests on movies and, to my mind, Rotel recreates bass better - somehow it sounds fuller and bass is more agile(?). When Micromega is used, bass on high levels (90-100dB) sounds boomy and extended.
When listening to music on low levels, I can't tell the differences, but on high levels (80-90dB) the bass feels slower, more extended (with Micromega)

Could my ears be right? If yes, how could Class-D Micromega amp with 200wpc@8ohm sound worse than Class AB power amp with just 100wpc@8ohm? Or is it i.e. room acoustics - Micromega sounds better by producing more bass, but it just feels boomy in my room? Maybe some components in Micromega are worn out and needs to be replaced (better not to). Maybe some parameters are better in Rotel which define bass control? Could it be that Micromega, which has 400wpc@4ohm can't drive my Focal Aria's 948 to very low impedance (like 2-3ohm range)?

 

[Mikado463]

Class D continues to evolve IMO and is far more 'listenable' today than a decade ago. I had a Rogue Hybrid Class D amp on loan a few years back that I really enjoyed also.

 

[AcuDefTechGuy]

Yeah. I think when most people hear “Class D”, they think of those pro-amps that are spec for maximum power output. But the new high-end class D amps have specs that are just like class-AB amps.

 

[PENG]

Thanks everyone for your inputs, it helped me alot to better understand things about SQ!.

^^ Nooot
So I was happy with the SQ both in movies&music, but. I've found a good deal on Rotel RB985 power amp, so gave it a go. And the question is - could it be, that Rotel sounds different than Micromega (Both Rotel and Micromega are used as power amps from my Denon X3500)? I've did many tests on movies and, to my mind, Rotel recreates bass better - somehow it sounds fuller and bass is more agile(?). When Micromega is used, bass on high levels (90-100dB) sounds boomy and extended.
When listening to music on low levels, I can't tell the differences, but on high levels (80-90dB) the bass feels slower, more extended (with Micromega)

Could my ears be right? If yes, how could Class-D Micromega amp with 200wpc@8ohm sound worse than Class AB power amp with just 100wpc@8ohm? Or is it i.e. room acoustics - Micromega sounds better by producing more bass, but it just feels boomy in my room? Maybe some components in Micromega are worn out and needs to be replaced (better not to). Maybe some parameters are better in Rotel which define bass control? Could it be that Micromega, which has 400wpc@4ohm can't drive my Focal Aria's 948 to very low impedance (like 2-3ohm range)?

Do you have the gain spec of the Micromega amp? The power amp PW400's gain is only 26 dB so if you it with the X3500H's RCA output you would put it at disadvantage. Other than that I am not familiar with Micromega amps at all and couldn't find any reviews with measurements to look at.

The AS400 is an integrated amp, how did you bypass its volume control? I don't like the idea of using integrated amps with AVRs. The ones with the so called HT bypass or similar feature is not as bad, but It is better to use power amps.

 

[mazersteven]

Yeah. I think when most people hear “Class D”, they think of those pro-amps that are spec for maximum power output. But the new high-end class D amps have specs that are just like class-AB amps.

In the past 10 years Class-D amps have come a long way. I would be willing to say in the next 5 years you'll see more affordable consumer Class-D amps incorporated into Audio-H/T systems

 

[pharaon]

Do you have the gain spec of the Micromega amp? The power amp PW400's gain is only 26 dB so if you it with the X3500H's RCA output you would put it at disadvantage. Other than that I am not familiar with Micromega amps at all and couldn't find any reviews with measurements to look at.

Sadly, but no, I don't have detailed specs of AS400, but is the same as Micromega IA-400, sxcept this one doesn't have integrated AirPlay. Spec-wise they are identical. I found one website in Polish language (looks like Google Translate works well) about IA-400 tests and its specs:

MICROMEGA IA-400

O firmie Micromega w jej nowej odsłonie HD pisaliśmy już kilka razy. Testowany wzmacniacz IA-400 to absolutna nowość. Przesłano nam jeden ...

audio.com.pl

Btw I think, that PW400 power amp specs should be identical to AS400's.

The AS400 is an integrated amp, how did you bypass its volume control? I don't like the idea of using integrated amps with AVRs. The ones with the so called HT bypass or similar feature is not as bad, but It is better to use power amps.

Yes, it has function called PRO-IN, which when turned on, switches everything off except that big powerhouse. Volume control knob doesn't work either, everything goes through AVR. So it's HT bypass right?

If it has low gain spec, does it mean that is not good to work as power amp? Or is it not good to anything?
Thanks,

 

[warnerwh]

A gain of 26 is fine. Actually there are advantages to the lower gain. There is NO difference in sound quality that is audible at all between a gain of 26 or 29 all else being equal.

 

[PENG]

A gain of 26 is fine. Actually there are advantages to the lower gain. There is NO difference in sound quality that is audible at all between a gain of 26 or 29 all else being equal.

My point about the 26 dB gain vs the 29 dB gain of most AVRs only because if the user listen really loud and cranks the volume right up, the one with the lower gain could be (depending on other factors too..) at disadvantage as the AVR's preamp output will have to be about 42% higher in order to get the same power amp output.

From many bench test results including Gene's right here on Audioholics.com, we know AVR's distortions could increase quite sharply at higher voltage, such as pass 1.4 V and approach 2 V, especially in some Yamaha models.

 

[PENG]

Yes, it has function called PRO-IN, which when turned on, switches everything off except that big powerhouse. Volume control knob doesn't work either, everything goes through AVR. So it's HT bypass right?

In that case, yes it would be similar to the HT bypass thing.

If it has low gain spec, does it mean that is not good to work as power amp? Or is it not good to anything?
Thanks,

Possibly, but it depends.. See my post above for more details.

 

[pharaon]

Possibly, but it depends.. See my post above for more details.

Ok, so I understand, that to make most of Micromega I should find preamp with bigger preout voltage and then it should sound WAY better? Does i.e. Denon X4500 (mine is X3500) has it higher or is it the same?
But the main question still persists - why Rotel drives basses better than Micromega? Is it just because of lower(?) gain than Rotel and when I crank up the volume distortions begin? Like @warnerwh said gain between 26&29dB should make no audible difference. I'm really confused..

Btw, maybe you know from practice (I couldn't find anywhere), what gain Rotel has?

P.S. Volume knob when playing movie on Rotel is -8dB, Micromega -10dB, so distortion shouldn't be higher than Rotel? Sound level average is about 85dB.

 

[PENG]

Ok, so I understand, that to make most of Micromega I should find preamp with bigger preout voltage and then it should sound WAY better? Does i.e. Denon X4500 (mine is X3500) has it higher or is it the same?
But the main question still persists - why Rotel drives basses better than Micromega? Is it just because of lower(?) gain than Rotel and when I crank up the volume distortions begin? Like @warnerwh said gain between 26&29dB should make no audible difference. I'm really confused..

Btw, maybe you know from practice (I couldn't find anywhere), what gain Rotel has?

P.S. Volume knob when playing movie on Rotel is -8dB, Micromega -10dB, so distortion shouldn't be higher than Rotel? Sound level average is about 85dB.

I don't have the gain spec of the Rotel. Both amps you have are don't have much published specs online, unfortunately. My comments on the 26 dB vs 29 dB gain is about the Micromega amp vs the Denon's internal amp, and is about the effects of the pre out quality at higher output level above the sweet spot that, for your X3500H appeared to be about 1.2 to 1.4 V. The pre out voltage you need would depend mainly on:

- your seating distance
- speaker's sensitivity spec
- power amplifier gain
- the spl you listen to, and the max peak spl you listen to

If you provide the above information, I would be able to give you some idea of how high your pre out voltage needs to go and remain pristine. With the info, and without knowing the detailed specs and/or bench measurements, I could only mention some potential causes, such as the gain difference, in terms of plausibility only.

I know enough above Rotel amps, to say that if the unit is not defective, it should be so transparent that in a blind comparison listening test you won't likely be able to tell a difference between it and another well design amp regardless of price.