Marantz "sound" and measurements

[Emiyanez]

Hi all,

This is my very first post so, before starting, I would like to thank you all for the hard work that you put on this site!

Going straight to the topic, I am a Marantz kid. Currently, I have a PM-8005 that I am very happy with connected to a pair of Dali Oberon 5. Long story short, I am mostly listening to digital sources (Tidal and Quobuz streamed over a Wiim Pro into a Topping E30II and finally the PM-8005) so I do not need all the inputs and features of a proper integrated amp. After reading a lot in the forum, I decided to give a go to an Hypex Ncore based stereo amp block from Audiophonics, because of the small footprint, consumption and great measurements.

When I plugged it in (in this case I am using the Topping E30II as pre-amp for volume control), I was blown away by the difference in sound in comparison to the Marantz. I did some volume-normalised A/B test as good as I could and, without going into adjectives that may create some controversy, the two amplifiers sounded really different to my ears (also to my wife's).

I have learnt in this forum that good amplifiers are not supposed to sound and about the need of having good response and flat frequencies across the spectrum. However, we listen to music with our ears and I still like the "muddy" sounds coming out of the PM-8005 in my system.

My question is what I should look for in amp's measurements to explain such signature in case I decide to move away from Marantz in the future. What's the science behind the sound? I have seen some measurements of the PM-8006 but I cannot identify which is the main source of the sound difference compared to, for instance, the Ncore-based module (it was reviewed by Amir).

Thanks a lot in advance!

 

[Thomas_A]

If you go into clipping you might get audible differences. But before that you should try to make it level-matched and blind to confirm what you heard...

 

[Emiyanez]

Thanks! I knew more or less this is the answer I will get in this forum.

I am a scientist myself (nothing related with audio processing) so I am well aware of subjective biases and the need for control conditions in experiments. Funnily, the sound difference was so obvious to me (with levels matched as good as I could) that I honestly though it could not be pure subjectivity. I guess this is exactly the definition of subjective perception...

Quick question... Although volume normalised, the source is not exactly the same (Topping E30II in DAC vs pre-amp mode). Could this account for the differences (assuming they are real)? I wanted to use the PM-8005 in power amp mode to discard this possibility but I did not have the time.

Best,
Emilio.

 

[Galliardist]

Firstly, the specs for the PM 8005 suggest that the amp sits slightly outside the lenient definition of transparent, according to the article in common use here (which is based on unreferenced information so is up for grabs itself, as it were). So, the amps in your test may well sound different when blind tested and properly level matched - that has to be done electrically.

It's not, however, really only a "Marantz sound". Once you get far enough up the range - certainly the Model 30 and up, and I suspect the Model 40 as well - you are in transparent amp territory. Having said that, reviewers still hear "the Marantz warmth" with those amps when it isn't there... subjective perception is indeed strong.

The main things that differentiate an amp's sound are the ones that are measured commonly - the distortion spectrum and the noise. You can't do much about the noise, but you can use software and a computer source to add distortion similar to that added by the PM8005 or another recent budget Marantz amp, and see if that makes a similar difference to the sound with the Hypex.

There are some other things to take into account here though. I can't find much in terms of measurements for the speaker, either, but it is nominally 4 Ohms and the PM8005 is an entry level amp, so you may actually be hearing a speaker not being perfectly driven. If the lowest impedance point is in the low bass the speaker may not be being properly driven but not sound as obviously clipping. The speakers may also cause a further change from transparent from that measured if the amp is run into a fixed 8 Ohm load for testing.

I think my initial advice to you at this point, since you own some equipment you like, would be to audition other systems outside of the testing you're doing at the moment. Visit a few local dealers and listen to some systems with speakers and components recommended in the reviews here, and see if there are any you like. That at least points towards whether you have a genuine preference for equipment outside of the transparent range or if it's an "imaginary" preference for a different sound.

I don't think that advice is typical for an ASR response though.

 

[raindance]

Modern Marantz gear is no longer warm sounding, this is just expectation bias ...

 

[raindance]

In fact, I'd say that Yamaha amps with variable loudness are far warmer sounding when that feature is in use. Yes, heresy, I know.

 

[Emiyanez]

Firstly, the specs for the PM 8005 suggest that the amp sits slightly outside the lenient definition of transparent, according to the article in common use here (which is based on unreferenced information so is up for grabs itself, as it were). So, the amps in your test may well sound different when blind tested and properly level matched - that has to be done electrically.

It's not, however, really only a "Marantz sound". Once you get far enough up the range - certainly the Model 30 and up, and I suspect the Model 40 as well - you are in transparent amp territory. Having said that, reviewers still hear "the Marantz warmth" with those amps when it isn't there... subjective perception is indeed strong.

The main things that differentiate an amp's sound are the ones that are measured commonly - the distortion spectrum and the noise. You can't do much about the noise, but you can use software and a computer source to add distortion similar to that added by the PM8005 or another recent budget Marantz amp, and see if that makes a similar difference to the sound with the Hypex.

There are some other things to take into account here though. I can't find much in terms of measurements for the speaker, either, but it is nominally 4 Ohms and the PM8005 is an entry level amp, so you may actually be hearing a speaker not being perfectly driven. If the lowest impedance point is in the low bass the speaker may not be being properly driven but not sound as obviously clipping. The speakers may also cause a further change from transparent from that measured if the amp is run into a fixed 8 Ohm load for testing.

I think my initial advice to you at this point, since you own some equipment you like, would be to audition other systems outside of the testing you're doing at the moment. Visit a few local dealers and listen to some systems with speakers and components recommended in the reviews here, and see if there are any you like. That at least points towards whether you have a genuine preference for equipment outside of the transparent range or if it's an "imaginary" preference for a different sound.

I don't think that advice is typical for an ASR response though.

Thanks a lot @Galliardist, super useful information.

Thanks @raindance. I tried to stay away from using adjectives to describe the sound (especially "warm", because this is what people usually say about Marantz). Putting it into words, the Hypex has much better bass definition and better instrument (frequency) separation, which are all probably related with less distortion and better capacity to drive the speakers. I guess I am not really used to the transparent sound of "high end" amplifiers and distortion is my long time friend .

 

[DVDdoug]

I did some volume-normalised A/B test as good as I could and, without going into adjectives that may create some controversy, the two amplifiers sounded really different to my ears (also to my wife's).

Besides level-matching, the test should be blind. And the tests need to be repeatable with statistically valid results. If you your wife is interested in this stuff you could set-up a Blind ABX Test (or a pair of ABX tests).

without going into adjectives that may create some controversy...

...I still like the "muddy" sounds coming out of the PM-8005 in my system.

That's a common problem and it doesn't help that "audiophiles" use a dictionary-full of nonsense terminology!

To me "muddy" implies boosted bass and maybe distorted bass (?).

With electronics, there are only 3 characteristics that affect sound quality - Noise, distortion, and frequency response.* Frequency response and distortion are usually better than human hearing unless an amplifier is over-driven into clipping/distortion. Sometimes there is audible noise (hum, hiss, or whine, in the background). Noise is usually the "give away" in an ABX test.

With speakers and acoustics, things get more complicated but the difference or weakness is usually frequency response (again, assuming it's not over-driven).

Lossy compression (MP3, etc.) is also "unusual" and you can get compression artifacts that don't show-up in the basic, noise, distortion, and frequency response measurements.




* See Audiophoolery

 

[Emiyanez]

@DVDdoug super interesting reading, thanks a lot!

 

[Blumlein 88]

How did you match levels? By ear is not good enough. Typically if you get a 1 db or slightly less difference they sound of equal loudness. Yet .2 db or greater is enough to cause a perceived quality difference when the only difference is volume.

Matching within 1 % voltage at the speaker terminals using a 400 hz tone is the way to go.

 

[Putter]

Firstly, the specs for the PM 8005 suggest that the amp sits slightly outside the lenient definition of transparent, according to the article in common use here (which is based on unreferenced information so is up for grabs itself, as it were). So, the amps in your test may well sound different when blind tested and properly level matched - that has to be done electrically.

It's not, however, really only a "Marantz sound". Once you get far enough up the range - certainly the Model 30 and up, and I suspect the Model 40 as well - you are in transparent amp territory. Having said that, reviewers still hear "the Marantz warmth" with those amps when it isn't there... subjective perception is indeed strong.

The main things that differentiate an amp's sound are the ones that are measured commonly - the distortion spectrum and the noise. You can't do much about the noise, but you can use software and a computer source to add distortion similar to that added by the PM8005 or another recent budget Marantz amp, and see if that makes a similar difference to the sound with the Hypex.

There are some other things to take into account here though. I can't find much in terms of measurements for the speaker, either, but it is nominally 4 Ohms and the PM8005 is an entry level amp, so you may actually be hearing a speaker not being perfectly driven. If the lowest impedance point is in the low bass the speaker may not be being properly driven but not sound as obviously clipping. The speakers may also cause a further change from transparent from that measured if the amp is run into a fixed 8 Ohm load for testing.

I think my initial advice to you at this point, since you own some equipment you like, would be to audition other systems outside of the testing you're doing at the moment. Visit a few local dealers and listen to some systems with speakers and components recommended in the reviews here, and see if there are any you like. That at least points towards whether you have a genuine preference for equipment outside of the transparent range or if it's an "imaginary" preference for a different sound.

I don't think that advice is typical for an ASR response though.

First of all, the Marantz is nowhere outside the definition of transparent, lenient or otherwise. The spec is 0.02% THD full range at 70 wpc. This corresponds to -74db well below the threshold of audibility which is 1% on test signals.

Second the Marantz PM80 is specified for 4-ohm speakers. The spec given by Dali is that it's a 6 ohm speaker which usually means it may reach 4 ohms at some frequencies, but is mostly above that. This spec is usually accurate, primarily because it keeps Marantz and Dali from having too many warranty claims.

Having said all this that the Marantz vs. the Topping/Marantz combo should have no audible differences, there is an advantage to the combo setup even if it's inaudible in an improved S/N and THD.

 

[Galliardist]

First of all, the Marantz is nowhere outside the definition of transparent, lenient or otherwise. The spec is 0.02% THD full range at 70 wpc. This corresponds to -74db well below the threshold of audibility which is 1% on test signals.

Second the Marantz PM80 is specified for 4-ohm speakers. The spec given by Dali is that it's a 6 ohm speaker which usually means it may reach 4 ohms at some frequencies, but is mostly above that. This spec is usually accurate, primarily because it keeps Marantz and Dali from having too many warranty claims.

Having said all this that the Marantz vs. the Topping/Marantz combo should have no audible differences, there is an advantage to the combo setup even if it's inaudible in an improved S/N and THD.

You’re right about the Dali. Thanks for the correction.
I got 4 from our local dealer website which I had open at the time: I’ve sent them tbe correction.

The definition I’m looking at for transparency includes noise. The PM-8005 (not tbe PM-80, I presume your own typo) will have highish noise from the HDAM modules given results for similar models.

Without proper independent measurements- especially of actual impedance in tbe bass - while you may be right, I’d still say there is a chance of audibility in this combination.