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Hegel H95 Review (Streaming Amplifier)

Geert

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They basically said:
"The our customer is to stupid to turn the volume all the way up if the want maximum power so we made it the way that halve volume is full volume and the other halve is unlabeled..
How many hifi amps do you know of have that have an accurately labeled volume control scale (accurate to the reference level published in the specs or labeled next near the input)?

And how many amps do you know of that allow you to plug-in a CD player or streamer and turn the volume control up to 100% without causing clipping? You know they sell RCA attenuation adaptors to solve this issue a lot of people experience?

Just saying, gain structure in HiFi is messy and you can be assured it's not only Hegel's problem. It maybe is an additional thing to test for in the reviews, so the whole industry can improve onto it.
 

KSTR

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I am talking about the output. If the nominal level of the line outputs is -10dBV then the maximum un-degraded level should be 2V. Where am I confused?
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.
 

Amplifier dude

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Pre-outs have their own dedicated gainstage in a proper designed integrated amp. You don’t borrow from and starve the input stage of the amp to feed it. Imagine it was feeding a sub amp with a low input impedance at the same time in Amir’s tests.
 

sarumbear

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This explaines everything we needed to know.
You should include such a block diagram in the product documentation and provide much more complete specs... as you actually have them anyway.

As I said, the days of blunt marketing are over, users want know what's going on, precisely. In this case, it would have totally prevented the chaos which unfolded here.
I missed that 0.55V maximum note. That is -5dBV and it means the line output has just 5dB headroom above the -10dBV nominal operating level. That is a crest factor of just 2. As most tracks have a crest factor of 5 or more, Hegel's line output will distort with most music, especially classical where the crest factor is even larger.
 

pma

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No it's not, yours is. You'll find hundreds of references on the Internet that describe this standard, and hundreds of pro level devices with a -10dB switch with the manual that describes its purpose is to support consumer grade line level connections.

And I know preamp nowadays output 2V, I didn deny that. But that doesn't automatically makes it a standard for all types of analog connetions and it doesn't mean designers are forced to implement it. If that would be the case than please first start a legal case against Naim for using DIN connectors.

Hmmm. Just few to mention:

Denon DCD-2560 CD player
Sidebar 1: Specifications
Description: 20-bit 16x-oversampling CD player. Frequency range: 2Hz–20kHz. S/N ratio: 116dB. Separation: 110dB at 1kHz. Output level: 2V RMS.
Dimensions: 17 3/32" (434mm) W by 4 51/64" (104mm) H by 14 1/64" (360mm) D. Weight: 23lb (10.5kg).
Price: $750 (1992); no longer available (2020). Approximate number of dealers: 450.

Sony CDP-X779ES CD player
Sidebar 3: Specifications
Description: One-piece CD player. Front-panel controls: Digital Output select, track step, forward/reverse shuttle, Drawer open/close, Play, Pause, Stop, Line Out/Phone Level, Play Mode, Display Mode, AC Power. Remote controls: All the above, plus Peak Search, File Recall, Continue, Shuffle, Program, Custom Index, number buttons (0 to 20), program Clear, custom File, Erase file, Fader, Slow/fast search, Index search, A–B Repeat, Time, over-20 numeric, Check. Outputs: fixed and variable single-ended line and fixed balanced line, 2V at 50k ohms, headphones up to 100mW into 32 ohms, coaxial digital 0.5V p–p at 75 ohms, optical digital. Frequency response: 2Hz–20kHz ±0.3dB. S/N ratio: >119dB. Dynamic range: >100dB. Harmonic distortion: <0.0015%. Channel separation: >100dB. Power consumption: 38W.

Naim CD5 XS CD player
Sidebar 1: Specifications
Description: CD player. Analog outputs: 5-pin DIN, 1 pair RCA. Digital outputs: 1 BNC. Frequency response: 10Hz–20kHz, +0.1/–0.5dB. Maximum output level: 2.1V RMS at 1kHz (fixed). Output impedance: 10 ohms maximum. THD+N: <0.1%, 10Hz–18kHz at full level.

Re CD players, it would be possible to list hundreds of them with 2V output voltage.

Now for preamps, even much higher output level is available

Pass Laboratories XP-32 line preamplifier
Sidebar 1: Specifications
Description: Solid-state, three-chassis stereo preamplifier with remote control. Inputs: 5 single-ended (RCA) or balanced (XLR), 1 single-ended (RCA) or balanced (XLR) tape, 1 single-ended (RCA) or balanced (XLR) Pass Thru. Outputs: 3 single-ended line-level (RCA) or line-level balanced (XLR), 1 tape (RCA). Maximum gain: 9.6dB, balanced. Input impedance: 42k ohms, balanced; 22k ohms, single-ended. Output impedance: 50 ohms, balanced; 25 ohms, single-ended. Maximum output: 23V RMS at 0.1% THD.

MBL Noble Line N11 line preamplifier

Sidebar 2: Specifications
Description: Solid-state, stereo line preamplifier with "MBL Unity Gain," remote control, and MBL SmartLink connectivity. Inputs: 5 pairs single-ended (RCA), 2 pairs balanced (XLR), and option for either phono MC (RCA) or 3rd pair balanced (XLR). Outputs: 5 pairs variable outputs in two groups—(Group 1) 2 single-ended (RCA) + 1 balanced (XLR), (Group 2) 1 single-ended (RCA) + 1 balanced (XLR)—and 2 pairs fixed outputs, 1 single-ended (RCA) and 1 balanced (XLR). Input impedance: 2.3k ohms (CD-In), 10k ohms (XLR-In), 50k ohms (Aux-In), 100 ohms (optional MC-In/internally adjustable). Output impedance: 100 ohms (RCA), 200 ohms (XLR). Voltage gain: For RCA and XLR out, 0dB in Unity Gain, 8dB in Regular Gain. Frequency range: DC–200 kHz (RCA and XLR) for all line-level inputs and outputs. S/N (A-weighted): 123dB (RCA), 117dB (XLR) in Unity Gain mode. THD+N: <0.001% for all line in and out in Unity Gain Mode. Maximum output: 8V RMS (XLR and RCA).

Benchmark LA4 line preamplifier

Sidebar 2: Specifications
Description: Solid-state, stereo line preamplifier with touch-screen and remote control. Inputs: 2 pairs single-ended (RCA), 2 pairs balanced (XLR). Outputs: 1 pair stereo single-ended (RCA), 1 pair stereo balanced (XLR), 1 mono balanced (XLR). Input impedance: >50k ohms (balanced/unbalanced). Output impedance: 60 ohms (balanced); 30 ohms (unbalanced). Frequency response: –0.005dB at 10Hz, –0.001dB at 20kHz (balanced); –0.008dB at 10Hz, –0.005dB at 20kHz (unbalanced). S/N (A-weighted): 137dB (balanced), 116dB (unbalanced). Output noise (20Hz–20kHz): <2.1µV (balanced), <8µV (unbalanced). THD+N (20kHz bandwidth): –115dB (balanced). Maximum output: 19.5V RMS (balanced), 3.2V RMS (unbalanced).

Source: reviews at www.stereophile.com
 

sarumbear

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So even if some measurements may be a bit below SOTA, the whole package can still make sense, but you won't find any of that detail in a review here.
You are missing the entire raison d'etre of ASR. It is a technical review site. Technically Hegel amp fails miserably. A line output effected by the power amplifier clipping to an open load is not below SOTA it is terrible. That is what is reported and that is what I wanted to know. I'm an engineer and I am interested in how an amplifier measures.
 

sarumbear

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Just saying, gain structure in HiFi is messy and you can be assured it's not only Hegel's problem. It maybe is an additional thing to test for in the reviews, so the whole industry can improve onto it.
Show us one example of a an amplifier that distorts at full volume when fed a 0dBFS signal other than this Hegel and I show you another bad designed amplifier.

The problem here is not because audio levels are messy. It is because the design is!
 

Geert

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Hmmm. Just few to mention:

Denon DCD-2560 CD player... .
-10dBV is a standard. People were saying it isn't, and that's what I've been fighting. As explained a page back it's a nominal reference level. If you add 16dB of headroom (as indicated 19 pages back) it gives you 2V. So yes, CD players can output 2V, which I literally confirmed. But it still refers to the -10dBV standard.

And also questioned before, what does it matter if the designer deliberately decides to use a different gain structure. We can respond we're not happy with that choice, but it doesn't make sense to apply what we think should be the standard during measurements knowing we're saturation the DUT.

Also mentioned pages back, also NAD's sub outs don't output 2V (from what I conclude from other discussions). But we didn't notice during the review because we don't test for it.
 

KSTR

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Hegel's line output will distort with most music, especially classical where the crest factor is even larger.
It doesn't matter much when used as intended, that is feeding a subwoofer. By the time the line out starts to degrade, you have already exceeded the main amplifier's capabilities and it runs in full clipping... and before that, you will have reached deafening levels anyway.

I do not defend Hegel's approach, actually it escapes me why they did it like that. They could have placed all their open-loop magic in the power stage proper with no problem -- other than using dreaded OpAmps with high feedback levels up to that point.

--------------

And for that distortion discussion in general, their point is moot. Properly(!) designed high-feedback amplifiers do not degrade the sound, there is no way how they could do that. An amp that doesn't introduce any errors doesn't introduce any errosr, period.

@Hegel Music System, Why not simply state what's really going on here: We subjectively prefer the sound from a low feedback design and we know it's actually less correct, technically.
Especially in a power amp this is a totally viable standpoint.
 

Geert

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Show us one example of a an amplifier that distorts at full volume when fed a 0dBFS signal other than this Hegel
There's a good chance the answer is all integrated amplifiers. Who ever tests this (in measurements I mean)? And according to Hegel's response it's a deliberate choice, to give you the opportunity to boost lower than 0dBFS signals.

The problem here is not because audio levels are messy. It is because the design is!
I didn't say audio levels are messy, gain structure and standards in HiFi is. Starting with not specifying the reference levels being used.
 

caught gesture

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What I find interesting is that in the original review there are 24 graphs. In the rebuttal from Hegel there is one graph and one block diagram handwritten on a white board plus a lot of words. I would expect a manufacturing company that highly values measurements (their words, “measurements and striving for low distortion is a driving factor at Hegel”) to come up with something more substantial in the way of a rebuttal. Surely they have tests on file that they could post showing the different scenarios that they imagined the amplifier would be expected to perform with?
 

DanielT

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But you, in the thread, who know amplifiers. An amplifier can of course be constructed in slightly different ways, but the only criteria that determine the sound are: Level of distortion and noise as well as frequency response? Or have I missed something?

I do not understand why Hegel says that negative feedback makes a worse sound? Despite that, they say that distortion will be lower with negative feedback?! What? How does that work? Is the frequency response negatively affected ... by negative feedback? Ability to handle loads from speakers ... like then ... well I do not understand this.

Seriously, I would be grateful for an answer to this, for me mystery. :)
 
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DanielT

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And for that distortion discussion in general, their point is moot. Properly(!) designed high-feedback amplifiers do not degrade the sound, there is no way how they could do that. An amp that doesn't introduce any errors doesn't introduce any errosr, period.
Thanks. I missed you writing about negative feedback. See my post above.:)
 

Jim Shaw

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Conclusions
Let's quickly agree that both the DAC and headphone amplifiers are junk. They are better off leaving both out. You can do better with hundreds of products that cost the same as the shipping or tax of the H95. I watched one video where the youtuber said he preferred the sound of Hegel DAC to his Chord Mojo in some ways. Wonder what he thinks now.

The amplifier in H95 is good as far as noise and distortion but nothing to write home about. Continuous power is very low for an amplifier costing $2000 however.

This is just a bad attempt all around.

I can't see any reason to recommend Hegel H95. Company needs to go back to the drawing board and design performant DACs and headphone amplifiers as a minimum. On amplification, they are being left behind by proper feedforward designs and excellent class D with tons of power.
I have never heard a Hegel amplifier. But because of their PR and dozens of subjective reviews over many models, I was inclined to offer them some respect. It surprises me greatly that they would let a product like this dissolve that reputation so quickly. I have to wonder if their other products are junk (with high prices).

Subjective-only reviewers are always impressed by price. ALWAYS. And hardly anyone ever actually tests the McIntosh's or Rotel's high-enders.
 

JRS

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Exactly how Amir stated in conclusion of many other products. Maybe this one just doesn't cut it.
2x4HD review
Conclusions
As a core audio platform, the miniDSP 2x4HD has OK performance. It has no glaring faults but also doesn't match the best-in-class products either. Seeing how this functionality is part of the larger DSP platform and that component can add noise of its own, this is to be expected. Personally I wish there was a plus version that had better execution on DAC side

Don't we all.? I have been begging them for a 4x10 with analog outputs and digital inputs, all using the upgraded chips used in the SHD series. Be a killer product many of us are waiting for. Throw in some networking capability as an optional upgrade.
 

PeteL

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I have never heard a Hegel amplifier. But because of their PR and dozens of subjective reviews over many models, I was inclined to offer them some respect. It surprises me greatly that they would let a product like this dissolve that reputation so quickly. I have to wonder if their other products are junk (with high prices).

Subjective-only reviewers are always impressed by price. ALWAYS. And hardly anyone ever actually tests the McIntosh's or Rotel's high-enders.
Look at this list compiled by a member here. Mac MC452 has the 3rd highest Sinad and the most Powerful of the top ones. Ahead of all Purifi and Hypex design. Expensive don't have to be bad.
 
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zeppzeppzepp

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-10dBV is a standard. People were saying it isn't, and that's what I've been fighting. As explained a page back it's a nominal reference level. If you add 16dB of headroom (as indicated 19 pages back) it gives you 2V. So yes, CD players can output 2V, which I literally confirmed. But it still refers to the -10dBV standard.

And also questioned before, what does it matter if the designer deliberately decides to use a different gain structure. We can respond we're not happy with that choice, but it doesn't make sense to apply what we think should be the standard during measurements knowing we're saturation the DUT.

Also mentioned pages back, also NAD's sub outs don't output 2V (from what I conclude from other discussions). But we didn't notice during the review because we don't test for it.

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.
 
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