• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Benchmark AHB2 / Class D Purifi Eigentakt / Mark Levinson 333 - Listening impression & Conclusion

Serg

Member
Joined
May 5, 2021
Messages
15
Likes
6
Adding a capacitor anywhere (either series or parallel) over speaker leads is only going to handicap one amplifier with respect to the other. It'll either act as an HPF (series- high value) or a LPF (parallel- low value).

EQ'ing out frequency response anomalies makes the entire "test" useless. So, he made the amplifiers sound the same, excludes the amplifiers with residual noise (all of them), handicaps the powerful ones and wonders why nobody can claim the prize in his stacked 2x12 correct ABX challenge? :facepalm:
My exact sentiments!
 

don'ttrustauthority

Senior Member
Forum Donor
Joined
Feb 10, 2021
Messages
343
Likes
193
Your first assumption is invalid. It is a myth that we actually know our expectations, or to what extent our unconscious expectations may dominate over our conscious expectations.

If we don’t hear a difference, and that corresponds to measured effects, then claiming a difference requires something additionally persuasive.

If we do hear a difference, and that difference is explained or indicated by measurements, then claiming no difference requires something additionally persuasive.

If what we hear contradicts what we measure, then it seems to me that we have the burden of first demonstrating that we can hear it consistently in a controlled test.
A myth? For you maybe. Why do we have a burden to prove something is objective? What is wrong with including our subjective preferences in our purchases? Are you suggesting that rational choice implies a weighed, measured evaluation vs a subjective choice based on 'unconscious' expectation (idiot) is going to result in a purchase decision that fulfills an individuals preference curve (which can be measured).
 

rdenney

Major Contributor
Forum Donor
Joined
Dec 30, 2020
Messages
1,001
Likes
1,550
A myth? For you maybe. Why do we have a burden to prove something is objective? What is wrong with including our subjective preferences in our purchases? Are you suggesting that rational choice implies a weighed, measured evaluation vs a subjective choice based on 'unconscious' expectation (idiot) is going to result in a purchase decision that fulfills an individuals preference curve (which can be measured).

I didn’t say anything about subjective vs. objective, and please don’t put words in my mouth. I suggested that subjective observations should be controlled for bias, both conscious and unconscious, if we are going to tell people they are real and relevant to others, and if we want to have confidence that our money is making a difference we will continue to enjoy in the future.

One thing I notice about those who eschew measured performance and controlled subjective testing: they continue to chase the Holy Grail, insisting they have finally found it and then moving on to the next one next month or next year. Then they tell the world that the new thing is finally the Holy Grail.

I was arguing that no matter how well we think we understand our expectations and how they bias our perceptions, we don’t. The difference may be great enough to persuade us anyway, but then why the reluctance to demonstrate that with the addition of bias controls?

But it’s your money.

Rick “not trusting authority” Denney
 

Worth Davis

Active Member
Forum Donor
Joined
Apr 8, 2019
Messages
112
Likes
140
Here is my subjective review…I can’t tell the difference between any amps and a receiver or a basic crown/emotiva/Craigslist amplifier

since I put all my gear in a hidden room I forget it’s there for a long time until something misbehaves…buy speakers, placement, maybe panels, and dsp…
 

restorer-john

Master Contributor
Joined
Mar 1, 2018
Messages
7,621
Likes
20,018
Location
Gold Coast, Queensland, Australia
since I put all my gear in a hidden room I forget it’s there for a long time until something misbehaves

You have a hidden room? Sounds creepy. How do you get to it? Through a trapdoor in the cupboard or do you remove floorboards underneath a rug in the loungeroom? What other stuff do you hide in your hidden room? People? ;)
 

pjug

Major Contributor
Forum Donor
Joined
Feb 2, 2019
Messages
1,228
Likes
1,020
deleted, need to read the whole thread.
 

Worth Davis

Active Member
Forum Donor
Joined
Apr 8, 2019
Messages
112
Likes
140
You have a hidden room? Sounds creepy. How do you get to it? Through a trapdoor in the cupboard or do you remove floorboards underneath a rug in the loungeroom? What other stuff do you hide in your hidden room? People? ;)

LOL it’s a nice closet with 3 racks off my main room…hidden from view!
 

Matias

Major Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
2,637
Likes
4,327
Location
São Paulo, Brazil

MaxBuck

Senior Member
Forum Donor
Joined
May 22, 2021
Messages
492
Likes
541
Location
SoCal, Baby!
This latest article from Archimago is exactly what I wanted to see from amplifier reviews: real speaker loads to check if a flat frequency response in a resistive load translates to a flat frequency response being measured in the listening position. And it does not!

http://archimago.blogspot.com/2021/08/summer-musings-no-not-all-amplifiers.html
It also begs the question of how different cables might affect frequency response, especially as the reactive component of impedance varies among them. One thing I notice about some of the ultrahigh cost cables is they have very low inductance.

YES, CABLES!!!111ONES!!
 

NTK

Major Contributor
Forum Donor
Joined
Aug 11, 2019
Messages
1,171
Likes
2,370
Location
US East

phoenixdogfan

Major Contributor
Joined
Nov 6, 2018
Messages
1,576
Likes
1,533
Location
Nashville
You have a hidden room? Sounds creepy. How do you get to it? Through a trapdoor in the cupboard or do you remove floorboards underneath a rug in the loungeroom? What other stuff do you hide in your hidden room? People? ;)
Chains with manacles attached to the floor the eye bolts?
 

Matias

Major Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
2,637
Likes
4,327
Location
São Paulo, Brazil
That was a Nelson Pass First Watt SIT-2 with a whooping damping factor of 1.6!
Fair enough. Maybe he used extreme examples to make his point. But the point is made and the difference is measurable and the amplitude of the difference is very significant. Next would be to measure more in between examples and check where the differences are still audible and where they cross a point where they don't matter anymore.
Still an excellent article and opens the way for many others.
 

tw99

Senior Member
Joined
Mar 13, 2019
Messages
330
Likes
690
Location
West Berkshire, UK
The view on here typically is that all well designed amplifiers used within their constraints will sound the same. Archimago was just showing the opposite is true also.
 

pogo

Active Member
Joined
Sep 4, 2020
Messages
252
Likes
60
We have too little information/measurements from real operation, see also here:
Link
 

Geert

Senior Member
Joined
Mar 20, 2020
Messages
395
Likes
456
The view on here typically is that all well designed amplifiers used within their constraints will sound the same. Archimago was just showing the opposite is true also.
The Pass Labs has a damping factor of 1.6. That doesn't qualify as well designed. This is what's Archimago article demonstrates. It also demonstrates the importance of using an amp 'within it's constraints'.

Conclusion 5: "While I can show and hear a difference between the Pass SIT-2 and my Hypex nCore quite easily, realize that within reasonable objective operating parameters, amps will sound alike! Likely, you'll find such "clean" amps will be indistinguishable in a volume-controlled blind test with actual music regardless of whether they're Class A or AB or D. Tube or solid-state. Lower or higher feedback".

So to me Archimago confirmed the general rule. Where do you see him demonstrating the opposite?
 
Last edited:

Matias

Major Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
2,637
Likes
4,327
Location
São Paulo, Brazil
Again this is a worst case scenario he measured. Now we need to see how in between amps measure too.

Delta FR difference between Hypex vs nCore - In Room Paradigm S8.png
 

sq225917

Senior Member
Joined
Jun 23, 2019
Messages
416
Likes
408
That's a nice open minded piece by archimago, as usual. He uses an extreme pairing to show the case, which I like, and explains that the pass labs unit is an edge case, but it gives you a grasp of the potential truth of lab measurements and points us to digging out damping factors for DUT.

In a great believer that audio component testing might get greater acceptance if at least one device below and above the DUT were included in the setup as that potentially unearths chained differences that device-device interactions highlight.

I know ncore hypex amps have more bass slam than my class ab amps, into my speakers, despite both having a flat measured FR in the lab.
 
Top Bottom