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Hegel H95 Review (Streaming Amplifier)

solderdude

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The outputs marked 'line out' are not line-outs as most think about 'line-out' functionality for instance such as not volume controlled DAC output.
They are pre-outs (so volume controlled) and are intended to drive Hegel amps that have a sensitivity of 500mV or so.
They are intended for (volume controlled) subs for instance.

Alas... it looks like they are line outs and can actually put out 2V (but with increased distortion above 550mV) but the, always coupled power amp section, at that point, is already severely over-driven.

Too bad Hegel did not think a little further than their own amplifier line-up.
Too bad the 'line out' labelled RCA outputs are not suited as line-out for other equipment.
Too bad the product specifications are incomplete and say nearly nothing about real specifications.
Too bad the DAC itself is not better than your average USB dongle in performance nor is it really needed given the amp measurements. These are a bit high (from an ASR standpoint) due to the design philosophy. It falls under 'good enough' for me.

Maybe @Hegel Music System pays attention and will better themselves.
 
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JRS

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That other amplifier might be more powerful and you want to use the streaming/digital functions from this one.
yes, but why would one ever use a second preamp/amp combo? I can see using a more powerful amplifier--integrated amps are often bought as entry level audiophile items that allow for an easy upgrade path. As such they need to have sufficient line out voltage to get peak output from whatever future amp is chosen, not just same brand amps. Seems like a sneaky (and ethically dubious) way to keep future purchases in the fold as it were.
 

zeppzeppzepp

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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

not perfect but understandable.
just don't be afraid to declare all things similar as above when marketing.
maybe too difficult for most of the hifi brands.
 

Geert

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it's not a standard because no hifi brand cares about it.
-10 dBV was often noted in consumer grade products of audio production, not hifi.
it doesn't matter if it's a standard or something, the gain structure in hifi world is a whole different thing that you already knew.
We gave you the history and did the math to explain the relationship between -10dBV and the 2V used as a reference in this test. If there's no reference or anything close to it, than what's everyone complaining about? It's clear lots of people aren't happy when an amplifier output can't support the referred level.

And as a side note, how I would design a sub output: of course you make it a buffered output, and you provide the usual line output level (2V to make you happy). And if you assume some sub's don't have a volume control you implement one on your output, although in this budget range that's very unlikely. Don't know why different brands are struggling with this.
 

MerlinGS

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Looking at the manual (which contains a handful of photos of people in the mountains for some reason), the only time it mentioned the line-outs is for subwoofer usage. And their webpage states “a variable pre output for connecting a subwoofer or other equipment,”. If Hegel really did intend for this to be mostly for subwoofers, they should have labeled it as a sub out, as not sure what “other equipment” means...

This amp does not have a general purpose preamp output.
Their "line out" is just an auxiliary helper output which is compromised by design when used as a normal preamp output. Of course that is a arbitrary decision by Hegel, they sure could have made the path up to and including the volume control and preamp buffer stage completely distortion-free.
Often times I will buy a product similar to this with line-outs. The reason being is that I would like to have the option to add a more powerful amplifier if need be in the future. In a similar vein, I would not likely purchase an AVR, even if excellent, if it did not have line-outs (the only AVR I have purchased had full line-outs). This unit, on the surface, has many qualities that would make it worthy of consideration for many of us, but if the line-outs matter, and all indications from the manufacturer on its own website are that this has proper line-outs, then one would fully expect fully functional (i.e. not distorting to a point of mediocrity, especially considering the price) line-outs and not be limited to using the unit's line-outs with subs or Hegel's own amps. If that is the case it should be clearly stated everywhere (manual, website, specs.) and the consumer should also be informed how poorly the unit performs when used through its line-out (as a "preamp"). Considering how many AVRs (usually higher-end) and quality integrated amps have proper line-outs, I'm clearly not alone in the marketplace as regards my expectations and line-outs.
 

PeteL

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What's a bit strange here is that the DAC itself obviously did not reach 0dBFS at 550mV but rather was able to put out 2V (as can be seen from the measurements by Amir) but the output voltage of the DAC itself is 'loaded' a bit by the poweramp causing the signal to flatten a bit above 550mV and higher distortion above 550mV.

Its a strange way to use a DAC (having 11dB of unused headroom)... buffering would have helped.
I am not defending this preamplifier and the decision to put such a low headroom line out. But there isn't 11 dB of unused headroom at the DAC, or at least those measurments don't show that. It do not reach 0dBSF à 550mV, in this measurment, but it's under the assumption that Amir left the volume pot at 98 and made a generator level sweep. You have an analog attenuator. You can Have 0 dB SPL at 550mV, or lower if you want.
 

The Jniac

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The way that they managed to screw up basically everything has to be worth some kind of medal. It is as if they blew the entire budget on the case, then had the rest thrown together by an unpaid intern who was halfway through a Bachelor's in EE.
 

Geert

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I am not defending this preamplifier and the decision to put such a low headroom line out. But there isn't 11 dB of unused headroom at the DAC, or at least those measurments don't show that.
It refers to the IMD graph, where distortion suddenly rises at -11dB. According to the comments of Hegel this is caused by the power stage starting to clip. Which means you're not expected to drive the volume any further than that although the DAC still seems to have headroom left. (It manages to output 2V, even 2,4V actually).
 

JRS

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It's also not beer snobby enough not to get called out by beer geeks.
It's also not beer snobby enough not to get called out by beer geeks.

Budvar isn't even that great.

Pilsner Urquell, baby.


Budvar isn't even that great.

Pilsner Urquell, baby.
iu

Here's to real Pilsners and not some wuss American version, which never give good head, and forgot that the beer needs to taste of the malt used to make it!
 

DanielT

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Damping factor of more than 2000. Is so much needed? Whats the point?

Or maybe most new amplifiers have such a high damping factor?

Damping factor: More than 2000 (main power output stage)

 

Geert

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Damping factor of more than 2000. Is so much needed? Whats the point?

Or maybe most new amplifiers have such a high damping factor?
No.

No.
 

pma

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Damping factor of more than 2000. Is so much needed? Whats the point?

Or maybe most new amplifiers have such a high damping factor?

Damping factor: More than 2000 (main power output stage)

Damping factor single number is again a pointless number without showing output impedance plot vs. frequency. It is the output inductor that defines output impedance and damping at high frequencies. If the output inductor is omitted, then damping factor may accelerate to rocket highs, however stability with capacitive load would be questionable.
 

dr0ss

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Dont agree.
Offering 96 kHz is maybe good enough if the jitter is low but not up to date 2021.
I don't disagree with this, that Tenor is nowhere near SOTA. I was just reacting to why the other poster whose gear has this chip thinks it sounds good: the chip is fine, within its sampling limitations. I used mine to add a USB input to an old system, were I doing this today for sure I would use something newer and more capable.
 

Mathias

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I'd like to ask if it has been mentioned anywhere why amirm measures the SINAD (at 5W output) of integrated amplifiers at low input signal levels. For both analog and digital input. In this case ~0.157V for analog input and -24dBFS for digital input.
I mean I use sources with an output of around 2V for an integrated amplifier. And amirm is also measuring sources like DACs at this output level. And I use digital inputs without volume control before the input. So I can get 0dBFS signal going to the digital input. And that's how amirm measures DACs.
And if I want 5W output I use the volume control of the integrated amplifier to the right extent.
I think this is the real world usage.
I think this is how most people use an integrated amplifier.
I think that measuring with a low input signal levels in case of integrated amplifier is not relevant for me. And I don't think it is for most people either.
Don't you think that integrated amplifiers should be measured with input signal levels around 2V and 0dBFS to better match real-world use?
 

Lambda

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And if I want 5W output I use the volume control of the integrated amplifier to the right extent.
I would also try to decrease analog gain and experiment wit digital input levels from -18 to 0dBFS to see in what range the performance is the best.
 

DHT 845

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Very good to know that hegel makes such disasters. I wonder how mamy other companies
I think the problem isn't that they haven't measured their own gear. The problem is that they have NOT measured other people's gear! Or read our site as a substitute. If they had, they would have realized how far behind they are in DAC and headphone amplifier categories. And how their distortion-less amplifier has a lot more distortion than state of the art.

I am also sure that they don't run the comprehensive tests that I run. So naturally there are issues there that they have not seen.
How about hypothesis, that they are "coloring" their gear in purpose. To sound different. Hegel type of sound ;) Maybe 90% of hi-end stuff is made like that.
 
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