Better Than Class A amp?

[hifial]

Al did you read the whole post? The very first caveat was that the listening was under show conditions. That said, however, perhaps there's something to the sound when one hears the same qualities across many rooms, many shows and many pieces of equipment?

Yes Myles I read the whole post. But just because someone else took issue with the "listening under show conditions" does not mean I can not also take issue with it.

At the same time there are also MANY others that have heard the amps at the very same shows etc and thought they were fine sounding. Are you saying you want it both ways.

As I said in my post TRY them in ones own system. And regardless of what one thinks of one version of NC1200 based amps (though I can vouch for the Veritas) try more then one. I do not think anyone here has tried one version of Class A or a/b or tube amps and left it as that.

 

[hifial]

About six months ago.

OK, but there are no Mola-Mola for sale yet. So how are you hearing a finale version. I know for a fact that they have had major issues with the production of their cases and had to find another supplier that could do a proper job. It is my understand it was not easy and they hope to start shipping in June.

That said you just my not like that flavor of ice cream.

But all I can attest to is the Veritas Amps. Until I hear the Mola-Mola in my system or one I am very familiar I can not say absolute.

 

[dallasjustice]

Actually, the Mola Mola's that I heard were at a show AND in a personal system. In both instances they were less than impressive. I was told they were the final production versions in the latter system.

DaveyF,
I know you are concerned that those of us that may hear good things from the ncore amps in our own system may be suffering from confirmation bias. You explain you position here:
http://www.whatsbestforum.com/showthread.php?14455-Can-we-get-fooled

How do you evaluate gear? Do you only listen at shows or do you listen in your system first before buying? I find it amusing that you are concerned with others suffering from this confirmation bias due to "rave reviews" and yet you've proclaimed an almost identical amp, Rowland 925, as the greatest SS amp available on this forum, without ever hearing it.

 

[garylkoh]

Here are some shots of the mola mola amps lids off from Munich last year. They look like they are transformer coupled as well. I would love to see the lids off of the Rowland 925 or 825, Ncore variants.

That's not transformer coupled. All Class D amplifiers need a LC filter on the output to filter the PWM carrier. That transformer-like thingy is an inductor that blocks the high frequency noise. In the nCore module, it is within the very high global negative feedback loop.

 

[dallasjustice]

That's not transformer coupled. All Class D amplifiers need a LC filter on the output to filter the PWM carrier. That transformer-like thingy is an inductor that blocks the high frequency noise. In the nCore module, it is within the very high global negative feedback loop.

Gary,
I am talking about the input. It looks like there's a toroidal transformer mounted to the front of the case, right?

I am glad you are here because I know you've built some killer hypex amps with your own power supply. Have you worked with the nc1200 module?
Michael.

 

[DaveyF]

DaveyF,
I know you are concerned that those of us that may hear good things from the ncore amps in our own system may be suffering from confirmation bias. You explain you position here:
http://www.whatsbestforum.com/showthread.php?14455-Can-we-get-fooled

How do you evaluate gear? Do you only listen at shows or do you listen in your system first before buying? I find it amusing that you are concerned with others suffering from this confirmation bias due to "rave reviews" and yet you've proclaimed an almost identical amp, Rowland 925, as the greatest SS amp available on this forum, without ever hearing it.

Actually my friend, I said..."that's not too surprising considering these amps are the heir to the great model 9's. I wouldn't be at all surprised if these are the best ss amps available today. I would love to hear them myself.".
I think that's a LONG ways way from "proclaiming" them to be ( or they are) the greatest ss amps available. Like I said, i have NOT heard the model 925's. However, I will say again, knowing Jeff's abilities with amp design, i wouldn't be at all surprised if they KILL your current fave.
Whether I would personally like them...who knows??
How do I evaluate gear...that's easy, BY LISTENING TO IT MYSELF, and NOT caring a hoot about hype.

Michael, I'm done on this subject with you.

 

[puroagave]

Michael, I'm done on this subject with you.

there were too many holes in your deposition, council was bound to have a field day with the witness under cross examination

Dave i'm no class-d fanboi per say, but I have owned the bel canto, Rowland and rogue switch-mode amps just to get a handle on class-d sound. for the most part they were all based on early ICE modules (the rogue used hypex). what they do well, they do really well like bass slam, control and extension. sound staging was very good to exceptional (Rowland) what they all suffered from in one form or another was rolled off highs (Rowland) or a tizzyness or lack of clarity in the treble region. music emerges from the blackest background, self-noise in class-d is nonexistent.

by contrast I've owned more than a few true class-a amps, by 'true' I mean amps that run flat-out class-a all the time even w/o a signal present. they stopped making amps like that a long time ago w/ plateau or sliding bias schemes popular today. I never though pure class-a were particularly special sonic-wise, like anything else some are good, some great but I liked many class a/b just as well.

back to the mola mola and latest ncore based amps, i'm not in the market but just a curious 'phile on the sidelines waiting to jump into class-d again - someday.

 

[DaveyF]

there were too many holes in your deposition,

Rob, it sure felt that way!!!

One thing I will say for Class D amps...they do run cool

 

[mep]

That is a typical dubious and misquoted statement. I know more about distortion, harmonic, and otherwise than I care to remember. I design amps since 1970's, I made folks systems sound any way they wanted. While it may be magic to you, its not to me. Maybe I picked up the phrase from Ben Duncans writings for all I know. But folks like to bring it up here and attribute it to me, so here, on this forum, it is attributed to me. I like the term, no I love the term. It technically describes the sound signature of any device in my book. And I can not help it that you do not understand that you have been listening to HNFB all along. But there it is. Yes negative feedback can be used to lower THD, just ask anyone who has a vinyl cutter about negative feedback, and other audio limiting circuits as well, yeah, negative feedback has and is here, way back when and now, today. Its in your tubes too, its just not agreed the exact term to use to describe it. BTW, I think he said spray of harmonics, perhaps British English is more correct.

Shades of Bob Carver...

 

[garylkoh]

Gary,
I am talking about the input. It looks like there's a toroidal transformer mounted to the front of the case, right?

I am glad you are here because I know you've built some killer hypex amps with your own power supply. Have you worked with the nc1200 module?
Michael.

The toroidal transformer on the front of the case looks like the power supply to a relay driver. The two yellow ones above that are for the SMPS (one is also a ferrous core inductor filter). An SMPS is just a very large Class D amplifier.

I didn't want to get into this thread because amplifier design is still too contentious - the two camps are too vested in their own belly button fluff to consider the view of the other (I guess just like any other debate here). I just wanted to correct a factual error. I hope you don't mind as OP.

I did try the nCore modules. I'm still using the UCD modules, but I modify them.

 

[dallasjustice]

The toroidal transformer on the front of the case looks like the power supply to a relay driver. The two yellow ones above that are for the SMPS (one is also a ferrous core inductor filter). An SMPS is just a very large Class D amplifier.

I didn't want to get into this thread because amplifier design is still too contentious - the two camps are too vested in their own belly button fluff to consider the view of the other (I guess just like any other debate here). I just wanted to correct a factual error. I hope you don't mind as OP.

I did try the nCore modules. I'm still using the UCD modules, but I modify them.

Thanks Gary. The mola mola website says it uses a discrete input stage with "buffers". I don't know what that means. The photo was from a year ago. I believe the amp has changed a bit since then.
Michael.

 

[garylkoh]

Thanks Gary. The mola mola website says it uses a discrete input stage with "buffers". I don't know what that means. The photo was from a year ago. I believe the amp has changed a bit since then.
Michael.

Yes, that is correct. There is quite a bit more global feedback than I like in the nCore design.......

Not that feedback is bad. There is just sometimes too much used, and other times too little used.

 

[dallasjustice]

Yes, that is correct. There is quite a bit more global feedback than I like in the nCore design.......

Not that feedback is bad. There is just sometimes too much used, and other times too little used.

According to Bruno, there's no such thing as too much feedback.

 

[garylkoh]

According to Bruno, there's no such thing as too much feedback.

Like I said - amplifier design is too contentious. I nestle in between the zero and infinity, and try to keep quiet and unnoticed with my amps so that I can enjoy the music

 

[bk12]

Has anyone heard the new Theta Prometheus NC1200 amplifier? It is very interesting, and it looks to have a linear power supply on the front end. I am very curious to see if anyone has heard it. On that note, are there any other NC1200 designs using a linear power supply out there?

 

[dallasjustice]

Has anyone heard the new Theta Prometheus NC1200 amplifier? It is very interesting, and it looks to have a linear power supply on the front end. I am very curious to see if anyone has heard it. On that note, are there any other NC1200 designs using a linear power supply out there?

It looks like it has less power than the nc1200 amps using an SMPS.

 

[bk12]

It looks like it has less power than the nc1200 amps using an SMPS.

Yes, I was wondering the same thing. If you look at the graphs of output vs. distortion on the NC1200 modules, it appears that the output figures match the specs Theta has put out by distortion level at the "worst case" frequency. Theta provides power levels at .01%, .1% and 1% THD, the 250 @ 8 is the .01% rating. Take a look and let me know if I am missing something, because I wrestled with the power ratings vs. published NC1200 specs for a bit myself before finding this info.

 

[GuidoCorona]

Seems that Theta Prometheus outputs 250W/8 and 500W/4. Quite different from the typical 400W to 430W/8 of NCore NC1200 amplifiers. Theta may be using a trickle down NCore module that I have not heard of yet, or one of the Hypex UCD extensions which embody some of the ancillary technologies of NCore. Please note that the amp details page falls slightly short of declaring outright that Prometheus uses NC1200.


http://www.thetadigital.com/prometheus_amplifier_info.shtml

If anyone talks to Theta and finds out more about Prometheus internals, please post them here.

G.

 

[Bruce B]

Heard the Merrill Audio Veritas mono's sound really good over the past couple days. You'd never guess they were Class D amps

 

[dallasjustice]

Heard the Merrill Audio Veritas mono's sound really good over the past couple days. You'd never guess they were Class D amps

I think that pair is coming to my house next.