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Hegel H95 Review (Streaming Amplifier)

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amirm

amirm

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Indeed, as @KSTR also mentioned, the DAC measurements are not correct and would advice @amirm to either re-measure at 550mV as 0dB or remove the line-out measurements or make a note stating that the line-out is 550mV FSD instead of the usual 2V.
The DAC measurements are correct. I fed the unit digital data and it converted them to analog and output them via line out. That it has a limitation of 0.55 mv is a problem in the design, not instrumentation. I note the same in every AVR I review. Some of those companies took note and now let you power down the amplifier so that the line out is not impacted when the amplifier clips. Hegel needs to do the same. Otherwise there is no point in getting a more powerful external amp and take advantage of the streaming/DAC subsystem here.

Note also that the DAC measurements showed high noise floor which was also reflected of the same when I used digital input to measure the amplifier. So they are definitely instructive of the performance of the DAC.
 

TOR

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First of all thank you for taking the time to measure the H95. Immediately upon seeing the measurements we realized that something was very different to our own. We could not recognize ourselves in the results or in the conclusion.

Please consider this as a manufacturers comment. One where we totally respect the work that has been put down, and peoples views on the product. But where we want to comment the findings, where these does not match our own. So this will typically be our only comment on the issue.

We promised our own findings today. I will therefore present what we disagree on and why.

1) All the DAC measurements are in our mind misleading. They were measured at a level where the amplifier is clipping. In our view, they should be dismissed completely.

1.1) There has been some debate on how we can allow the RCA pre out to be optimized at 550mV, which actually is a fair question. The reasoning behind this is that we mainly see this as a subwoofer connection. Obviously you can debate wether that is a good or a bad choice.

When the pre amp output is more than 550 mV, the speaker output will be clipping and that will influence the performance of the pre out.

The pre-out on the H95 is taken directly from the power amplifiers input stage. See figure below:

View attachment 168201
When the power amplifier starts clipping, this will reflect in the RCA pre out as well. As such, the RCA pre out can NOT be used as a 2V DAC output. When we measure the DAC performance we connect Audio Precision directly to the output stage of the DAC board. You can of course also measure the DAC on the RCA output, but with a lower setting than 98 and it will include factors from the preamp.

Notes on why;
We used to have a lower output level on the RCA Pre out (earlier models), but since we have 32 dB gain in our power amplifiers we had to raise it to allow for easier subwoofer integration.

Actually we used to run the output from the preamp at a level where it never really started clipping (also earlier models), but on a 60w/pc amplifier consumers did not like to have the volume control at “98” to play loud. And what if you played an old Pink Floyd piece, with low gain… it would never be loud enough.


2) The stability measurement THD + N from ASR claims that the amplifier never reaches stability after warm up.

This measurement is, in our view, wrong. This is how it should look (our own test on AP 2722 today)

View attachment 168202
We have only almost managed to recreate the ASR measurement if we wiggle the speaker cables in the H95 terminals or tap the output relays.

We disagree with the comment about the power amplifier not being stable. The Hegel output stage is a no-feedback design, and since the distortion characteristics of the power transistor change somewhat with temperature, the total distortion will have a small increase with temperature. In a high open loop gain feedback-design this effect will be much smaller.


3) Distortion measurements in analog mode. These do match ours and are in our minds absolutely fine. We only have some comments.

We could obviously also achieve a super low 0,0001% THD by using lots of feedback. That is a fairly easy design.

But we don’t and the reason is that global feedback amplifiers, in our minds, doesn’t sound very good. Subjective, we take that, but it is our experience. So, we use our SoundEngine to dynamically reduce distortion instead. In the integrated amplifiers the soundEngine is only used in the output stage where we believe it is most important.

Finally, thank you for reading this rather long feedback. I am sure not all f you will agree in our thoughts and comment above. That is fair and it is really what a forum is about. Debating ones hobby.

And if you are ever in doubt, we urge you to visit your Hegel dealer for an audition.

Hegel Music System AS
Anders Ertzeid
VP Sales & Marketing
Regarding point #2, is the measurement done with your in house prototype unit?
If yes, may be you should queue up some units from your distribution channel and see if they measure the same.

Manufacturing deviation/error is the biggest headache especially if it is out-sourced.
 

deprogrammed

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I wonder why we see so many reviews of Boutique expensive snake oil products?
They are almost universally bad and this is not even surprising.
Why not Focus on cheaper consumer or professional products.

If a "transparent" >120dB SINAD DAC can be bout for example can be bougt for <200€ hat is the Point to review 2000$ DAC
To the ear it cant be better if the 200€ DAC is already perfectly transparent.
It can only measure better. And if they want to convince someone to spend 10x the price for better measurements it schuld be on them to provide this information.
After this this clams can be tested.
That would be boring. It is nice to have data points from different price points, makers, periods of time. Builds a complete picture.
This is a streaming amplifier in one box. Not just a dac. There is a market for that. I see comments here about people want to buy, almost bought, and own. Good to know the truth. I think popularity should be a factor. Maybe not as much as potential, but a factor.
 

PeteL

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The DAC measurements are correct. I fed the unit digital data and it converted them to analog and output them via line out. That it has a limitation of 0.55 mv is a problem in the design, not instrumentation. I note the same in every AVR I review. Some of those companies took note and now let you power down the amplifier so that the line out is not impacted when the amplifier clips. Hegel needs to do the same. Otherwise there is no point in getting a more powerful external amp and take advantage of the streaming/DAC subsystem here.

Note also that the DAC measurements showed high noise floor which was also reflected of the same when I used digital input to measure the amplifier. So they are definitely instructive of the performance of the DAC.
It does show a problem with the design of the line out functionality, but it’s simply not a measurement of the DAC. You would have get the same results if you had fed a analog input and try to measure SINAD at 2V, so it does not tell us anything about the DAC. It shows one problem, the way gain structure is implemented for line out. Which is not benign but not DAC related.
As for the second DAC measurement in the amp chain, it is a DAC measurement, but although there is lots to be critical about this integrated, With a reference tone being a whooping 24 dB below full scale for this test, These Hegel guys would be magicians f it didn't impact SNR.
 
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fcracer

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I wish some Hi-Fi companies would accept and market their products for what they often are, a men’s version of jewellery or high fashion. I don’t understand why they need to make nonsense claims when people are more than happy to spend thousands of dollars on shoes, bags, and other luxury items.

There’s nothing wrong with someone spending $2k on this Hegel if they like the minimalist appearance and acceptable, albeit not SOTA, sound quality. However, when marketed as SOTA audio performance and waxing poetic about capabilities it clearly doesn’t have, it’s misrepresentation.

Given that even poorly designed amps have performance that typically stays under our audible threshold, Hi-Fi companies should focus their marketing on features, build quality, materials, warranty, after sales service, special editions, and exclusivity. They can still make lots of money, while doing it with integrity. They should look to the luxury brands for new business models.
 

Chrispy

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I wish some Hi-Fi companies would accept and market their products for what they often are, a men’s version of jewellery or high fashion. I don’t understand why they need to make nonsense claims when people are more than happy to spend thousands of dollars on shoes, bags, and other luxury items.

There’s nothing wrong with someone spending $2k on this Hegel if they like the minimalist appearance and acceptable, albeit not SOTA, sound quality. However, when marketed as SOTA audio performance and waxing poetic about capabilities it clearly doesn’t have, it’s misrepresentation.

Given that even poorly designed amps have performance that typically stays under our audible threshold, Hi-Fi companies should focus their marketing on features, build quality, materials, warranty, after sales service, special editions, and exclusivity. They can still make lots of money, while doing it with integrity. They should look to the luxury brands for new business models.
I somewhat agree, altho I don't find Hegel worth the kind of money they cost for what you get....but there is a market for it. I would like more specific specs/measurements from the manufacturer on which to base decisions on, tho. Or to judge why something like a simple pre-out is so different from most implementations....while I have a couple sub amps that don't need a lot of input, but still 1V is a better goal than .5V, I have some others that need 1.4V....is calling it a variable line out a decent excuse? I dunno.
 

tjf

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Well, I guess I was wrong about the Lyngdorf. :eek:

IIRC, Amir's review of the Lyngdorf 3400 mentioned a very beneficial "In-Room" listening result from the Lyngdorf's Room Perfect DSP...

The 2 products below should absolutely be considered if you've been thinking you'll need to settle for an AVR to make a reasonably priced 2.2 system with room correction -- I'm sure more than a few of you have thought about this.

** New NAD C399 w/ MDC2 Blu-OS-D -- The "D" is for Dirac, plus 180 watts/ch from a Hypex-ish amp, ESS DAC, dual sub/2.2 integration and bass mgmt. thru Dirac -- US $2,550 with the MDC card.

** Lyngdorf TDAI1120 - $2500 -ish I think? Room Perfect room correction, 60 watts/ch @ 8 ohms -- uses Lyngdorf's variation of the T.I. "power DAC" or PCM-to-PWM class D power amp, so keep the speakers small and use subs, again 2.2 configurable with pretty flexible bass mgmt. settings along with the full Room Perfect DSP.

And most of you already know about Mini-DSP products.

And I really hope we'll soon see a "Magnum Opus" from Amir -- testing, measurements, and listening comparisons of Dirac and Room Perfect systems!
 

sam_adams

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0.0001% THD is fairly easy. :facepalm:
Maybe in simulation.

tarconi.jpg
 
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BDWoody

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Rottmannash

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Do you have measurements that support that? Just out of interest. It's possible because it's a THX certified amp, and THX has strict requirements when it comes to levels and headroom.
I should have been more clear. One can choose " absolute" level or "relative" level. "relative" goes from -82 to +16.5 and "absolute " goes from 0 to 98.5. 82.5 on the absolute scale equals 0 dB on the relative scale.
 

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