I found the problem with Hegel!

[EB1000]

OK

We all saw the terrible measurement results of the H95:

Hegel H95 Review (Streaming Amplifier)

This is a review and detailed measurements of the Hegel H95 integrated amplifier with DAC and streaming support. It is on kind loan from a member and costs US $2000. The H95 looks pretty nice: I really like the large, high resolution and very responsive graphic display. What I don't like is...

www.audiosciencereview.com

I think I found out the problem that cause their amps to have very low SINAD. The problem goes by the name of Bent Holter:

just watch these 23 minutes of standup comedy by this Hegel engineer and amp designer.

He says that conventional amps use negative feedback to reduce output distortion, which is true. Then he says that because of time delay, the feedback loop correction is done not in the correct time, which increases distortion. Then comes the punchline. He shows Hegel's miraculous solution, called the SoundEngine... But all he does, is redraw the feedback loop diagram...

So the Hegel solution to avoid negative feedback is to use negative feedback, but just call it "the sound engine", because they use "analog computers" in the feedback loop, which they don't use...

I say, this guy is the problem with Hegel...

 

[Helicopter]

Lots of audio myths about timing seem to come from confusion about how fast electricity flows compared to how fast sound waves move. In a domestic setting, if you're not aligning sound waves with other sound waves, then the timing stuff in your audio circuit is probably BS.

 

[Ambientwks]

Aw man, I thought Hegel were one of the good ones!

 

[Doodski]

Lots of audio myths about timing seem to come from confusion about how fast electricity flows compared to how fast sound waves move. In a domestic setting, if you're not aligning sound waves with other sound waves, then the timing stuff in your audio circuit is probably BS.

The speed of light is a general speed estimate for electricity. That versus the speed of sound and claimed phase issues in feedback loops becomes a silly point. If there is more to this engine I would love to hear about it although I'm not holding my breath.

 

[Longshan]

OK

We all saw the terrible measurement results of the H95:

Hegel H95 Review (Streaming Amplifier)

This is a review and detailed measurements of the Hegel H95 integrated amplifier with DAC and streaming support. It is on kind loan from a member and costs US $2000. The H95 looks pretty nice: I really like the large, high resolution and very responsive graphic display. What I don't like is...

www.audiosciencereview.com

I think I found out the problem that cause their amps to have very low SINAD. The problem goes by the name of Bent Holter:

just watch these 23 minutes of standup comedy by this Hegel engineer and amp designer.

He says that conventional amps use negative feedback to reduce output distortion, which is true. Then he says that because of time delay, the feedback loop correction is done not in the correct time, which increases distortion. Then comes the punchline. He shows Hegel's miraculous solution, called the SoundEngine... But all he does, is redraw the feedback loop diagram...

So the Hegel solution to avoid negative feedback is to use negative feedback, but just call it "the sound engine", because they use "analog computers" in the feedback loop, which they don't use...

I say, this guy is the problem with Hegel...

Didn't Marx already fix Hegel by inverting his philosophy?

Asking for a Comrade-er-I mean friend.

 

[EB1000]

The delay in a digital control system can be somewhat controlled, by increasing the sampling frequency as well as the switching frequency of the class-D amplifier.

If you watch the whole video, you'll see that he's suggesting "feedforward" to overcome loop delay, but I've never seen a feed forward control implemented in such way.

The feedforward controller is fed from the conventional feedback error signal (output - input), so if the plant (amp) introduce delay, the delay will propagate into the error signal (current output state - previous input state). This error signal is then amplified and inverted to be added to the output signal. But the output signal of an amplifier is an already processed and amplified signal. To add more signal to it, they must use a second amplifier (more delay, more distortion), additional to the one they're trying to improve. So why not use the second amplifier instead?

No wonder the Hegel 95 has a 53dB of SINAD. Couldn't Hegen afford better engineers?

 

[Sisay]

The delay in a digital control system can be somewhat controlled, by increasing the sampling frequency as well as the switching frequency of the class-D amplifier.

If you watch the whole video, you'll see that he's suggesting "feedforward" to overcome loop delay, but I've never seen a feed forward control implemented in such way.

The feedforward controller is fed from the conventional feedback error signal (output - input), so if the plant (amp) introduce delay, the delay will propagate into the error signal (current output state - previous input state). This error signal is then amplified and inverted to be added to the output signal. But the output signal of an amplifier is an already processed and amplified signal. To add more signal to it, they must use a second amplifier (more delay, more distortion), additional to the one they're trying to improve. So why not use the second amplifier instead?

No wonder the Hegel 95 has a 53dB of SINAD. Couldn't Hegen afford better engineers?

53? do not confuse sinad dac with amplifier

 

[Matias]

Hegel amps are not bad measuring, they are "good" from 80 to 87 dB SINAD. That is a little above average. We are just lucky to have alternatives that are measuring "very good" and "excellent", while also being cheaper.

Amplifier SINAD list ASR + 3rd parties

List Name,THD+N (5W, 4 ohms),SINAD (dB) (5W, 4 ohms),Power (W) (1% THD+N, 4 ohms),Price (USD),Source Topping LA90 (stereo, bypass, low gain),0.00009%,121,90,900,<a href="https://www.l7audiolab.com/f/topping-la90/">L7 Audio Lab</a>,Suggestions, corrections and more info here: Topping LA90 (stere...

docs.google.com

 

[steve59]

Who said anything was wrong with hegel?

I guess I'm at a disadvantage using my ears to select hifi products. I took home multiple brands and while I didn't try $20k int's there were a couple twice the price and they all sounded neutral til I put the hegel back in then they were warm or bass heavy or grainy or dull.

Maybe the speakers in my system at the time were colored and the hegel compensated, idk. They were the salon1's. and the combo was enlightening.