Hypex NCx500 Class D Amplifier Review

[BR52]

Hmm did you mixing best and very best up?
post#60

 

[Sokel]

The Pre90 has max 16dB gain and 17.7Vrms max output.
To get 10Vrms out of the Pre90, you have to input 1.7Vrms at max gain.

I took a quick look here,truth is is a little confusing.

TOPPING PRE90 Balanced / Single-Ended Preamplifier NFCA Black - Audiophonics

Topping's Pre90 is a high-performance preamplifier based on a fully balanced circuit and high-performance NFCA modules. It also benefits from a high quality volume attenuator and easy control, thanks to its front panel display.

www.audiophonics.fr

 

[Vacceo]

Seriously, those 'preamps' are hardly anything more than obscure products. Their sales would be insignificant and their installed base, even less significant. They are not, nor ever will be mainstream HiFi preamplifiers. Probably sold 10 thousand between all of them.

Let's get real. The standard input sensitivity for domestic HiFi power amplifiers has been 1.0-2.0V for 50 years. Even with balanced, you can double that on a bad day. So 2.0-4.0V. Anything else it utterly stupid.

Yes, I have preamps that will output 30V RMS, but they are outliers and their rated output is 1.5V.

12dB is a joke. Nobody takes that seriously. Power amplifiers are ~26-29dB. Even Amir tweaks his integrated levels to be somewhere near that.

As I read your posts I am realizing I am getting lost in the technical aspects of gain, voltages and signal paths. Can you recommend me where to read a 101 guide on gain and the relation between preamps and amps?

 

[renaudrenaud]

The Pre90 has max 16dB gain and 17.7Vrms max output.
To get 10Vrms out of the Pre90, you have to input 1.7Vrms at max gain.

And what about the A90 or the L70?

 

[pma]

Seriously, those 'preamps' are hardly anything more than obscure products. Their sales would be insignificant and their installed base, even less significant. They are not, nor ever will be mainstream HiFi preamplifiers. Probably sold 10 thousand between all of them.

Let's get real. The standard input sensitivity for domestic HiFi power amplifiers has been 1.0-2.0V for 50 years. Even with balanced, you can double that on a bad day. So 2.0-4.0V. Anything else it utterly stupid.

Yes, I have preamps that will output 30V RMS, but they are outliers and their rated output is 1.5V.

12dB is a joke. Nobody takes that seriously. Power amplifiers are ~26-29dB. Even Amir tweaks his integrated levels to be somewhere near that.

But here, we are rather in the world of toys. Combined with smallest speakers. Computer or phone audio desktop systems.

 

[sernikus]

...I just didn't have the info to do it just yet. Will update the review when I get that info.

Set the 3 jumpers in a "opposite way" to the current pos. - jumping mid pos. and "inner" pos. ... oopss.. 4 jumpers, sorry...

 

[AndreaT]

Lots of power. Some distortion above 10 W tough. As Amir points out, a trade off in favor of Watts. A most excellent review, I am curious to see the follow up with higher amp gains. Still a most excellent amplifier.

 

[Rick Sykora]

I wonder why the XLR body is "grounded" this way??

This is not explicitly Hypex and is my doing as do not trust a series of screws to ensure a solid chassis ground.

 

[BR52]

The next serious question, input impedance: without to know all the impedance's in a signal chain the voltages
are relatively useless. Do we need a "power preamp" because of a low input impedance of the amp?
We can see in the sinad war, manufacturer try to optimize only their single box regardless of the full chain.
Lower input impedance is good for low noise, higher out put impedance saves money > no buffer after analog filtering by DAC's. (See the specs of some DAC's) Topping will give you an answer I know so far, I guess there are more but not all the sinad kings do it.
This is in general a missing point in the measurements here.
Is the APxx able to drive the amp flawless? ............. @amirm know the answer.

 

[Willem]

I think the choice for low power amp gain makes sense, given that good DACs tend to have slightly better numbers than the best power amps. So it makes sense to make the DAC stage work a bit harder.

 

[BR52]

I think the choice for low power amp gain makes sense, given that good DACs tend to have slightly better numbers than the best power amps. So it makes sense to make the DAC stage work a bit hard

I think the choice for low power amp gain makes sense, given that good DACs tend to have slightly better numbers than the best power amps. So it makes sense to make the DAC stage work a bit harder.

I am asking for numbers, not for speculations.

 

[BR52]

In your case, we have to measure the sinad of DAC's (preamps) with lower load impedance like power amps as well.
Without a little standardization of preamps, power amps, DAC input and output parameters we are open Pandora's box.

 

[Rottmannash]

Thanks again for this interesting product's review!

Nice to see such good and powerful amp.

Stupid question:
I guess the noise performance is partly due to very low gain.
So, probably, with the buffer, noise will be higher.
But can the buffer help with the distortion ?
I doubt so, but a quick comparison at same output power would give us a clue.

Also:

I read 116dB SNR, so rather 20dB margin, if I'm not mistaken ?

I too, wondered how it would measure with the buffer.

 

[Vacceo]

Another question about output: is it safe to trust manufacturers when they spec balanced output? The Marantz Cinema 10 states 2.4 V on the balanced, 5V on the McIntosh MX100 while Trinnov, as tested by Amir, can range up to 8V. Are those numbers average (or tops)? Can I really trust them?

 

[BR52]

If it had been measured with the buffer, there would have been people asking, "But how does it measure without the buffer?"

Commercial implementations will (I believe inevitably) arise with different buffers, if for no other reason than advertising copy. This review gives us an unadulterated picture of the intrinsic capabilities of the amp, with no regards to buffer choice.

To measure both ways would have been a greater load on @amirm with little benefit.

Jim

You are right we should not discuss how and what we measure anymore only give simple good numbers someone can use for advertising.
More serious:
I really appreciate @amirm work because he drove the HIFI world very efficient away from bulls..t reviews
in the main press. Please allow some critics, hopefully constructive.
Bernd

 

[Koeitje]

I do. Many, many preamps can output (way) more than 10Vrms. As may some DACs: Benchmark DAC3, RME ADI-2 PRO, Matrix Element X2...

Preamps are a very small part of the market. Same for pro-audio DACs. 99,9% of people will use a power amplifier with something that puts out 2 or 4V. I'd even argue that more people will drive these amps with a source that doesn't even reach 2V than one that goes to 10V.

 

[BR52]

@Rick Sykora please give us a little explanation. What type of building blocks are populated on the "interface board" for me, it seems the "buffer" is on the power module?
would be great because no assembler can mess it up.

 

[juliangst]

Do we know a price yet?

 

[cheapmessiah]

Could I use this as a bass amp?

Recently many companies have developed many preamp style pedals that make the eq section of bass amps redundant and the option of being able to leave the Poweramp section with the cabinets at the studio and moving just the preamp pedal with me when going home is quite convenient, but the problem us that most poweramps in the market are still AB, very heavy and bulky, and not linear at all, specially in the bass region.

 

[Willem]

Preamps are a very small part of the market. Same for pro-audio DACs.

I don't know. I think it does not really make much sense to combine a superb amplifier like this with anything other than a similarly superb DAC/preamp.