Benchmark...first watt....ABX...facepalm!

[Nightlord]

How do they test CD players? Is it only a test of the dac, or also of the transport? Do they test them more or less in the same way as they test amps? My assumption is that a CD-player, when feeding an external dac digitally, can be nothing but transparent. But perhaps I'm mistaken.

That's more difficult, of course. If you can do A/D - D/A and not hear a difference, then the D/A ought to be pretty good.. and if you have one of those, you could compare a CD-player output and the D/A output on the same material. I don't know the procedures they use by memory. I know they do measurements as well, and they've had a series of articles where they've taken a few "classic" cd-players and measured them for fun and comparison to how moderna players/DACs perform.

 

[Deleted member 65]

@LarsS - it's not dormant, the member magazines come out the number of times they should, and if you live around Stockholm, there are mails coming out about local activities there every now and then. The last one from 2016 had a long review of headphones, tested two cd-players, had a convention report, plenty of tips about classical cd:s and some more for instance.

Okey, maybe not as active as they use to be. I'd say somewhat dormant is pretty accurate since their current presence in the audio area in Sweden is not visible for most.

 

[Nightlord]

Okey, maybe not as active as they use to be. I'd say somewhat dormant is pretty accurate since their current presence in the audio area in Sweden is not visible for most.

I don't think there's any particular goal set for LTS to be public, actually. It's more a spillover if they are.

 

[March Audio]

I think LTS is quite dormant these days.

I do personally have experience of nCore NC400 since I built a pair of monoblocks a few years back, now sold. Drove my now current second setup speakers (EA MicroOnes) with them, no great success, thin lifeless sound. As I've now brought the speakers back to life in new room I installed them with my amp from my third setup (summer house), Onkyo A5-VL (Class D, 10.5 Kg) not expensive amp. This new combo beats the nCore monoblocks in my setup with same speakers, could maybe be related to Onkyo's LPS compared to nCore's SMPS.

PS: Found another Onkyo A5-VL at a pawn shop for 80 USD, summer house system now back in order. DS

I like the LTS test methodology, however care does need to be taken with the loading and listening amp input. For exampke, is the input balanced and floating or single ended and potentially grounded?

Interesting result you had with the ncore, its not what I find with them. Nuetral yes, lifeless no.

 

[March Audio]

Do you guys from the Swedish house mafia know whether LTS has tested any of the newer high end class D amps? Which one was the Class D amp from NAD that was deemed as not transparent, for example?

I would be interested in knowing how these fare in the LTS test: Hypex Ncore, Icepower (for example Wyred4Sound), NewClassD ...

I recently built a sub with a minidsp icepower based amp. Now that one,when connected to my main speakers as a test, did sound sound quite cold in comparison to the ncore. Fine for the sub however.

Should note that there is dsp in front of the actual icepepower amp module on this one, so shouldt really draw firm conclusion about the amp itself.

 

[Nightlord]

I like the LTS test methodology, however care does need to be taken with the loading and listening amp input. For exampke, is the input balanced and floating or single ended and potentially grounded?

You can destroy any test by being an idiot, yes. You could also suggest that the listeners had an agenda and therefore chose not to give their best feedback, that's been lifted on a number of silly occasions. It's not the average joe:s in the test panel and given that the goal is to fail it, everything possible to do so will ve tried. And if for some reason everything hasn't been tried, it will be stated in the article. The blind voting statistics are presented even.

 

[Nightlord]

@BE718 - great finish on it. Looks commercial!

 

[Blumlein 88]

No, this is a listening test!

Here's the schematic setup:

Translation:
Källa - > Source
F-volym -> Before-volume
Testobject -> Test subject
Belastning -> Test load. This is an electric circuit that has the same impedance characteristics as a (rather difficult) speaker.
E-volym -> After-volume
F/E-omkopplare -> Before/After switch
Lyssningsförstärkare -> Listening amplifier

Before and after the amp in test is volume matched... and then you switch between listening to the music before the amp... and to how it sounds after the amp. And the only thing you are trying to do is to identify statistically a difference. You can also in this way test the amp at output levels you don't want to listen at... or run it very softly without having to listen at such a low volume.

Yes, that is how I have tested amps a few times. Was describing that when I think it was Amir over at WBF pointed to the fact LTS did it that way.

It is a super good way to test whether an amp has a sound of its own or not. I think magazines should use that method for their reviews to see which amps are transparent or close. Also to describe how an amp fails in transparency. I suppose you would need a filter of some sort to do class D amps that way. The only amp I had completely pass that test was a Spectral though I obviously haven't tested all that many amps that way. I know someone with the Brystons that passed, and they previously had the ARC that almost passed that test. It is less than conclusive and little more than opinion, but I do think the better class D amps would do well on this sort of test. Amps that do well on this type of test have an apparent speed subjectively. It seems to come from not really speed taking up a signal, but rather when one can let go of it without artefacts. Since switching amps by how they function should let go as easily as they take up a transient it should be easy for them. And they sound similar to amps that can do this in some undefined subjective way. But none of that is carefully tested on my part.

I also very much like AD/DA loops to see if the signal sounds different or not vs going straight thru.

 

[March Audio]

@BE718 - great finish on it. Looks commercial!

Thank you!

However I cant claim responsibility for the paint job. I built the cabinet out of 25mm mdf but I found a local cabinet / furniture restorer to do the piano gloss finish.

 

[Dynamix]

I always feel so left out when people start talking different amps and comparisons.

What do mine sound like?

Sunshine and unicorns?

 

[Mivera]

I have the latest and greatest Icepower 700AS amp sitting right here beside the new 502MP Hypex Ncore. Personally I wouldn't use the Icepower for any more than sub duty. Way too much phase shift in the top end. It just sounds wrong.

You can see the Ncore clearly has a superior modulator/filter:

And I think the 1w performance is acceptable:

 

[March Audio]

Whats your opinion of the 502?

I want to get hold of 3 sets of 252s and 100HFs to complete my speakers. Am I correct in saying they are OEM only? Is there any way to get hold of them for DIY?

 

[Mivera]

Whats your opinion of the 502?

Much better than the Icepower. But not near as good as my latest NC-500 build:

 

[Mivera]

It's has a 4 channel fully balanced Slagleformer autoformer based preamp section. And there's an active stage with 4X Weiss OP2-BP discrete opamp's for if weak source gear is used. It's custom built for a tri-amped system, so the dual pre-outs will connect to amps for subs/woofers. And internal amps are for mid/high section. The left digital display controls the set of Slagleformers for the dual preouts. Right is for internal amps. press the left/right arrows on the remote to fade between levels of sub/woofer and mid/high until level is right, then up/down controls both evenly.

Here's the Preamp platform:

And Weiss OP2-BP based active stage:

OP2-BP's are much improved over the OP1-BP's. Here's the OP1-BP Datasheet:

http://www.weiss.ch/files/downloads/op1-bp/OP1-BP-Datasheet-R1.pdf

 

[Mivera]

Whats your opinion of the 502?

I want to get hold of 3 sets of 252s and 100HFs to complete my speakers. Am I correct in saying they are OEM only? Is there any way to get hold of them for DIY?

View attachment 5894

You can buy some from Colin at Nord. He sells finished amps with them cheap enough. But might want to hold off because Hypex is releasing plate amps using this series with advanced SOTA DSP far beyond their old systems. And they will be for everyone.

"
Hypex AS, DS and PSC series replacement:
We are in the process of replacing all the AS, DS and PSC amplifiers. We are currently selling our last stock. With the launch of the NCxxxMP series we created the ideal platform for a new and better plate amplifier range. We are in the midst of developing a brand new DSP board to go with the NCxxxMP to create a truly special sounding plate amplifier way surpassing the old series, but not being much more expensive.

Your sincerely,

The Hypex Team"


https://www.hypex.nl/nieuws/

 

[Dimitrov]

Sorry to bump this thread, but after reading all the responses I'm fascinated that no one picked up that Benchmark were listening to test tones NOT music. They used a 1 kHz tone.

They even say : If amplifier distortion is audible with a test tone, it may also be audible while playing music.". Which is highly unlikely as music is a masking source. Benchmark have not demonstrated their amplifiers sound different or better as used by the general population - listening to music or drama signals which is what the amp was designed for. Sure, if you want to pop 1 kHz tones on, then you a fairly convincing case but who cares?

More importantly, the example they use to compare to their Benchmark amp doesn't seem to exhibit typical performance of a modern A/B amp ( -53 db distortion, come on!).

 

[Nightlord]

Sorry to bump this thread, but after reading all the responses I'm fascinated that no one picked up that Benchmark were listening to test tones NOT music. They used a 1 kHz tone.

They even say : If amplifier distortion is audible with a test tone, it may also be audible while playing music.". Which is highly unlikely as music is a masking source. Benchmark have not demonstrated their amplifiers sound different or better as used by the general population - listening to music or drama signals which is what the amp was designed for. Sure, if you want to pop 1 kHz tones on, then you a fairly convincing case but who cares?

More importantly, the example they use to compare to their Benchmark amp doesn't seem to exhibit typical performance of a modern A/B amp ( -53 db distortion, come on!).

You're not using your logic if you think a more difficult test is irrelevant. It may be unnecessarily tough, but what's the use in complaining about some using tougher criteria than needed?

 

[Dimitrov]

You're not using your logic if you think a more difficult test is irrelevant. It may be unnecessarily tough, but what's the use in complaining about some using tougher criteria than needed?

Amps are used primarily for playback of music/drama signals, not test tones. The test conditions here are pathological. A real world test using music would have been more representative of how amps are actually used. They decided against this and for good reason.

So who cares if the amp can be distinguished by listening to a test tone? Do you listen to test tones?

 

[Wayne]

Benchmark were listening to test tones NOT music. They used a 1 kHz tone.

They even say : If amplifier distortion is audible with a test tone, it may also be audible while playing music.".

So who cares if the amp can be distinguished by listening to a test tone?

I have a question, from a scientific perspective. The best testing would be using test equipment, but lacking such tests or equipment, why wouldn't it be "proper" to use a test frequency (or frequencies) as a listening test to evaluate an amplifier (or system)?

Scientific testing in many cases require a system to be broken into individual smaller systems to provide usable information. In this case a specific frequency test appears to be valid to evaluate the response of the amplifier over a specific (narrow) frequency range. It would seem the argument should be that many additional frequencies should be tested. When music is used, it would seem that evaluating individual frequencies....

Which is highly unlikely as music is a masking source

 

[Dimitrov]

Double blind tests of amplifiers that I've read about involve music which is the mode of operation the amplifier was designed for.

Why don't we see peer reviewed DBTs of people listening to test tones? I've never heard of such a thing.

So the question remains : who cares if an amp can be distinguished in highly pathological conditions using a test tone as a source?

If said amp can't be distinguished by listening to music which is the primary mode of operation then what value can be gained from such a test?

The position that amps sound different by believers is based on using musical signals, not individual test frequencies, so again I fail to see what Benchmarks test proves.