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The September 2016 issue of Absolute Sound contains a review by Robert Harley of David Berning's 845 amp. For those of you that have heard it you know it has exceptional transparency and totally gets out of the way of the music. Harley was totally blown away. Below is an excerpt from the review. Kudos to David.

Tom

Jim Gerfin and myself were lucky enough to hear this amp at a friend's house, we were flabbergasted by how great it sounded, congratulations David!

Did the reviewer compare all of the amplifiers he has ever heard in a double blind test, conducting each test with at least 20 samples? If not, how do we know it is the best he's ever heard?

In fact, how do we know anything at all unless we test every parameter, then listen?

Is it any better than a T-amp?

Don't they all sound the same, unless overdriven?

At least that's what I've been lead to believe around here recently.



Congrats David, like your ego really needs it! LOL!

But you do deserve it, you have worked hard on that amp and we are all glad you are getting recognition for it! Bravo!

DBTTFMF!

This thread should really be about the great review David got. If anyone is hyper sensitive and wants to start another thread about amplifier testing I would be glad to contribute, but lets keep this about the great achievement for David.

IF all amps sound the same, what's the achievement?

I know amps sound different. Coming from this source, this is surprising.

If Roscoe wants me off of the board or the thread, so be it.

Otherwise, free speech, eh? EVEN if we disagree.

I wonder why this post when Tomp is a huge scientific test believer? One who proves that no difference exists with a simple test.

Stuart:

Since you seem to be unable control yourself enough to take this to another thread I will try to clarify. I do not believe all amps sound the same. There are good and bad amps of all varieties. Goodness is the result of the designer knowing how to create a good circuit design and using the components and construction methods that will allow that design to function as intended. There are great tube and transistor amps. There are also dogs in both categories.

That being said I will re-iterate my two fundamental rules of life:

1. Don't lie
2. If you are going to be stupid enough to violate rule #1 don't be stupid enough to do it to yourself.

Double blind tests are another tool in your bag and will not answer all questions. What a PROPERLY designed and conducted double blind test will do when a difference is detected to a statistically significant level is provide you with the confidence to say that a difference really does exist. If a difference is not detected to that level it does not mean that one does not exist. It only means that given the test conditions used including the listeners, the ancillary equipment, the drive levels, the music used, etc. that a difference was not detected. Under different conditions you might detect a difference.

For example if two amplifiers were identical in performance except for output impedance with speakers such as my RD75s that are essentially a flat 6 ohm resistive load you might not hear a difference. If you used speakers that had large fluctuations in impedance at different frequencies, the resultant output level would fluctuate widely at different frequencies from the amp with high output impedance and not much if any with the low output impedance amp. In fact we did a test between two amps at David's house where Jim G could not hear a difference between Davids amp and another until David changed the output impedance of his amp to raise it significantly and then Jim picked it out 100% of the time which was certainly statistically significant.

Whether or not to use double blind testing is a personal decision but there is no arguing that double blind testing is used in many fields in addition to audio because it eliminates one of the biggest problems in listening tests, listener bias. My personal opinion is that if you have a good tool why not use it? You will ultimately make the decision yourself on which way to go. However, a null result on double blind tests with many listeners should temper the view that earth shaking differences exist between item a and item b. If they are that small that only one person can hear it under a number of tests, that information is itself very useful in your decision making process. Resources for most of us are not infinite and any information can help us make informed decisions on where to spend our money is invaluable.

Enough of this and back to the original thread. David is a person who not only understands what an amplifier needs to do to get great results but he also is an expert on circuit topology, components, and construction methods. As a result, he makes fantastic stuff. Are there others that do that. Yes, but not so many. Because of that, I renew my kudos to David who is not only a great designer but also one of the most honest and helpful people I have been fortunate to know. And BTW after doing tests with my ABX box he was so impressed he build one of his own. Once you get to his level of expertise I will pay a good deal more attention to your opinions. In the meantime, do keep the opinions coming as that is what makes audio so involving.

Tom

Congrats David on the great review! Of course we all already know that David's amps are fine sounding components, but it is nice when widely read professionals like Harley manage to catch up and give praise where it is due.

As for the discussion about DB testing and amps sounding alike, that is best done in person, while drinking a cold beer and listening to music. it really is no fun having to type (peck) up a nuanced argument in an online forum.

You may wish to look at the following -

http://rtaylor.sites.tru.ca/2013/03/20/ ... tware-dsp/

Richard Taylor has some very fine speakers (Linkwitz lx521) which he tri-amps with his own dsp crossover. Perhaps when one talks about hearing the difference between amplifiers one should compare the amplifier used in a bi and tri-amplified system as opposed to used in a system with a passive crossover. Likewise consider a system with and without a sub-woofer.

_________________
Walt

Obviously someone needs to go back to school. Or maybe reading glasses will help.

No one threw anyone under a bus.

Learn to read. Comprehend.

David Berning is brilliant. A great friend, mentor and all around decent guy.

His amps sound amazing. They contain engineer feats we all simply marvel at!

He has patented circuit innovations we use since many of us were just little kids.

He continues to truly innovate in a field where newly discovered interconnect geometry passes for high science. His legacy will outlive him. He has given more to the audio field than the rest of this club combined, by huge multiples.

I have praised his amps from the get-go. I've not yet been fortunate enough to have heard his amp, but I absolutely believe it is a superb piece based on what trusted friends who's ears are better than mine have told me. (Trusted friends: High on the Roberts list). Based on that, and experience with other Berning amplifiers, I absolutely believe that the 211/845 amp is ALL that it is purported to be.

Wake up Walter. I said NOTHING bad about Mr. Berning or his products. (Okay, years ago I didn't like one of his preamps, and told him so. Honesty is kind of important. I'm not licking any boots here).

My response was to tomp. A proselytizing believer in the DB AB test, or it didn't happen.

To post a report about a listening test, not done double AB blind strikes me as ironic.

I found that disingenuous.