2025: Does somebody needs Hypex etc...?

[Mike123]

"Why not? (genuine question)"

Because the TI needs to install a high-quality modulator, high-quality low-noise operational amplifiers and high-current high-speed keys at the output in a cheap, small-sized product. This is very difficult, if not impossible. In integrated amplifiers of class D, the output transistors always have worse parameters than discrete MOSFETs in the TO220 package. Simply by definition. One high-quality MOSFET will cost more than the entire TPA3255 microcircuit. TPA3255 is a budget one and is tailored for the function "satisfactory for little money". And not for the function "excellent for little money".

 

[dominikz]

I guess that depends on what you consider "excellent" vs "satisfactory".

With realistic audio signals, and into common loads, it seems well-designed TPA3255-based amps are capable of extremely clean audio reproduction, as shown here.

But there are indeed other designs that can provide equally clean reproduction even with unrealistic and dificult signals, which can produce more power and drive more difficult loads, and which can dissipate more heat effectively.

Some use-cases may require such capabilities, in which case TPA3255-based designs are simply unsuitable.
In other cases even a good TPA3255 design would be massive overkill.

 

[Hear Here]

Yeah i love those small compact Infineon's GaN FET amplifiers.

I take it from your Avatar and Setup that you're a bit of a NAD Master Series fan.

Me too, although I'm cooling a bit as they seem to be dropping useful features with each new Masters product! For example:

My earlier M12 and M32 allowed me to set a different (or no) crossover when I connected subs. Thus, I could run my main speakers full range while the subs acted to resolve room modes, etc. The M33, M66 (and probably M10) don't allow this. As soon as you mention via Settings there's a sub present you have to specify a single XO and this applies to both the main and all sub speakers. No good if you have paid good money for full-range main speakers only for NAD to cripple them!

The M33 and M50.2 allowed the album artwork or radio station notes to be output to an HDMI-connected TV. This useful feature (especially when you have friends around) is denied us on the M66.

The HTRM-2 remote that was supplied with most earlier Master units offered far more control than the SRM-1 that's supplied with the M66 and I believe the new M33 V2. For example, you can't scroll through the Inputs via the Up and Down buttons as you can with the earlier remote

Volume could be very accurately controlled by 0.5 dB steps with the earlier kit, but the M66 jumps 2 or 3 dB for each touch of the remote or the app volume bar. There are no 0.5 dB steps available.

I've raised these points with NAD following my recent M66 purchase and am anxiously anticipating a fobbing off reply from their Customer Service expert fobbing off team! But perhaps they'll surprise me by saying these missing or reduced features will be restored with the next firmware update - I'm not holding my breath!

I must say I am most disappointed that the M66 falls short of my expectations, specially after being generally very pleased with the M33 and earlier (M12, M32 and M50.2) units.

 

[Mike_Trueman]

I take it from your Avatar and Setup that you're a bit of a NAD Master Series fan.

Me too, although I'm cooling a bit as they seem to be dropping useful features with each new Masters product! For example:

My earlier M12 and M32 allowed me to set a different (or no) crossover when I connected subs. Thus, I could run my main speakers full range while the subs acted to resolve room modes, etc. The M33, M66 (and probably M10) don't allow this. As soon as you mention via Settings there's a sub present you have to specify a single XO and this applies to both the main and all sub speakers. No good if you have paid good money for full-range main speakers only for NAD to cripple them!

The M33 and M50.2 allowed the album artwork or radio station notes to be output to an HDMI-connected TV. This useful feature (especially when you have friends around) is denied us on the M66.

The HTRM-2 remote that was supplied with most earlier Master units offered far more control than the SRM-1 that's supplied with the M66 and I believe the new M33 V2. For example, you can't scroll through the Inputs via the Up and Down buttons as you can with the earlier remote

Volume could be very accurately controlled by 0.5 dB steps with the earlier kit, but the M66 jumps 2 or 3 dB for each touch of the remote or the app volume bar. There are no 0.5 dB steps available.

I've raised these points with NAD following my recent M66 purchase and am anxiously anticipating a fobbing off reply from their Customer Service expert fobbing off team! But perhaps they'll surprise me by saying these missing or reduced features will be restored with the next firmware update - I'm not holding my breath!

I must say I am most disappointed that the M66 falls short of my expectations, specially after being generally very pleased with the M33 and earlier (M12, M32 and M50.2) units.

Yeah, i am using the NAD every day for nearfield listening and i am enjoying the music it plays.
My KEF's need the crossover (HPF).

What do you mean by cripple them? Here are my NAD subwoofer settings.
Do you mean that you can not disable the crossover?

 

[Guddu]

Maybe that 3e Audio has a global feedback, but it's clearly not working well at high frequencies. That 15kHz curve stays at -65dB

View attachment 467281

I am late to this party but is this very graph not very similar for any class D? I mean TPA3255 / Hypex / Purify, specially above 5 KHz*.
*irrespective of the fact if it does not matter much from auditability point of view.

I started a thread sometime back to understand how to read this graph properly for meaningful conclusion and all I could get to is no point in looing beyond 5/10 KHz.
You can think probably 10/15/20 KHz should be excluded to avoid any confusion but probably its there for some purpose.

 

[Hear Here]

Yeah, i am using the NAD every day for nearfield listening and i am enjoying the music it plays.
My KEF's need the crossover (HPF).

What do you mean by cripple them? Here are my NAD subwoofer settings.
Do you mean that you can not disable the crossover?

View attachment 467849

Thanks for your reply. The screenshot you show is similar to those for the M33 and M66 regarding the Subwoofer settings.

What I mean by "crippling" my main speakers is that NAD will cut off the legs of their performance! The main speakers won't receive and therefore can't deliver anything below the chosen XO frequency. Good news for most small main speakers, but if you own ones capable of delivering the full frequency range (as mine can from their twin 12" drivers) you are deprived of the main purpose and justification of your big expenditure in buying these full-range speakers.

By contract, the M12 and M32 (predecessors of M66 and M33) allowed me to choose any XO between 40 - 200 Hz, or No XO at all. Thus I could keep the full range going to my main speakers, while the subs receive bass only. Here's the screenshot from the User Manual. Furthermore, you'll notice that these older units allow the ubs to receive a stereo signal - M33 and M66 are Mono only. Also the relative volumes of Main and Subs can be adjusted. Why has NAD deprived us of these useful (arguably essential) features?

 

[Mike_Trueman]

Thanks for your reply. The screenshot you show is similar to those for the M33 and M66 regarding the Subwoofer settings.

What I mean by "crippling" my main speakers is that NAD will cut off the legs of their performance! The main speakers won't receive and therefore can't deliver anything below the chosen XO frequency. Good news for most small main speakers, but if you own ones capable of delivering the full frequency range (as mine can from their twin 12" drivers) you are deprived of the main purpose and justification of your big expenditure in buying these full-range speakers.

By contract, the M12 and M32 (predecessors of M66 and M33) allowed me to choose any XO between 40 - 200 Hz, or No XO at all. Thus I could keep the full range going to my main speakers, while the subs receive bass only. Here's the screenshot from the User Manual. Furthermore, you'll notice that these older units allow the ubs to receive a stereo signal - M33 and M66 are Mono only. Also the relative volumes of Main and Subs can be adjusted. Why has NAD deprived us of these useful (arguably essential) features?

View attachment 467852

Prolly to keep it simple for people like me.
You could always use speaker cable splitters and the RCA adapters for your sub but yeah it is more work.

 

[TurtlePaul]

I am late to this party but is this very graph not very similar for any class D? I mean TPA3255 / Hypex / Purify, specially above 5 KHz*.
*irrespective of the fact if it does not matter much from auditability point of view.

I started a thread sometime back to understand how to read this graph properly for meaningful conclusion and all I could get to is no point in looing beyond 5/10 KHz.
You can think probably 10/15/20 KHz should be excluded to avoid any confusion but probably its there for some purpose.

I am late to this party but is this very graph not very similar for any class D? I mean TPA3255 / Hypex / Purify, specially above 5 KHz*.
*irrespective of the fact if it does not matter much from auditability point of view.

I think that one of the biggest differences is that Hypex has 40-50 dB of open loop gain across the audio spectrum while TI cites 21.5 dB. The TI PFFB sample implementation shows 6-7 dB of PFFB to keep gain in the high teens. With its huge open loop bandwidth, the Hypex is able to use a ton of negative feedback. If the TIs gain more s falling at higher frequencies, it ends up with little feedback to suppress distortions. I think the low gain on the TI may be because the chip has an internal feedback loop to decrease noise (and that feedback is therefore not available to use post-filter).

Also, Purifi uses a 10% higher self oscillation frequency and has only 20 dB of attenuation at the 500 khz frequency, so they push the LC filter and the associated distortion from the inductor farther out of the audible band.

 

[Hear Here]

Prolly to keep it simple for people like me.
You could always use speaker cable splitters and the RCA adapters for your sub but yeah it is more work.

View attachment 467861View attachment 467859

Yes, of course (in fact the M33 has 2 sets of speaker terminals so no need for splitters) but by doing this, you don't benefit from Dirac or DLBC with the M66

In fact, I'm about to rewire the subs so they get a high level signal direct from the amps

PS - You can't connect subs using amp + and - speaker terminals if the amp is Class D. You have to connect to + and Earth

 

[xrqp]

I think the more expensive class D amps give more power. Music before 1980 has peaks 20 to 30dB higher than RMS.

Are there any listening test comparisons?
https://forum.wiimhome.com/threads/...high-end-class-d.3844/?utm_source=copilot.com
At first, he did not know that nasty loud is different than clean loud.

Regarding the 3E Audio A7, the maker says if you care about heat at high power, you need to add a fan.

 

[Deleted member 97805]

Better measurements. I can be calm with purifi that it is completely transparent and does not affect the music in any way.

So does the Fosi V3, A7 or most other Texas Instruments chip based solutions. Just say you got it for the prestige. Nothing wrong with that.
To clarify things. I finally went out of my way to register here, but was a silent reader for a couple of years now. If you say that they "measure better", which they do, you are still not being entirely truthful. "Better" is relative and in this case "better" does not mean "There is an audible difference". Because there isnt. So to come here and tell people to buy an, lets be honest here, overpriced piece of equipment is just wrong. And I dont mean that you said that people should buy it. But you are claiming improvements, which do exist on paper, but they might as well be entirely esoteric.
Everybody should first try out the Fosi, Aiyima, 3E Audio devices. They neither hurt your wallet, nor do they lack in anything modern amplification needs.

 

[Mike123]

Just say you got it for the prestige.

A Purifi amplifier – is it prestige? Well, really . Of course, there's no prestige in Purifi. Incidentally, I don't own a Purifi or Hypex amplifier. I have something locally made, similar and cheaper than many TPA3255 amplifiers. My second amplifier is also cheaper than the TPA3255 and is built on the MA12070. I prefer the MA12070 to the TPA3255 for a host of reasons. If you look at the topic, you'll see that the question isn't whether the TPA3255 is worth buying. It's whether the Purifi is worth buying. And I went on to explain that it's worth it for the measurements and peace of mind. Few people can hear the difference, if that's even possible. Of course, if it's the last money in the family, it's not worth it. But if you don't need to save, then why save?

 

[Deleted member 97805]

A Purifi amplifier – is it prestige? Well, really . Of course, there's no prestige in Purifi. Incidentally, I don't own a Purifi or Hypex amplifier. I have something locally made, similar and cheaper than many TPA3255 amplifiers. My second amplifier is also cheaper than the TPA3255 and is built on the MA12070. I prefer the MA12070 to the TPA3255 for a host of reasons. If you look at the topic, you'll see that the question isn't whether the TPA3255 is worth buying. It's whether the Purifi is worth buying. And I went on to explain that it's worth it for the measurements and peace of mind. Few people can hear the difference, if that's even possible. Of course, if it's the last money in the family, it's not worth it. But if you don't need to save, then why save?

Fair point. Im not saying a Fosi V3 is as good as a Purifi, Buckeye, Hypex etc. Im not a fool and I know very well that those machines are different beasts and objectively better devices. My point being that not everybody needs, or I should say most people dont need, a Purifi device. If you want one? Go ahead. If you enjoy it, more power to you. Same thing goes for exotic cables and power cables. If people enjoy them and see a benefit, I dont accuse them of anything. Even knowing that they are most likely wrong. Im not making a blank statement here. But im willing to wager that most people dont need 400+ watts stereo in their living rooms. Yes, quality has a cost and people willing to pay for it have every right to do so and be happy about it.

 

[Yevhen]

So does the Fosi V3, A7 or most other Texas Instruments chip based solutions. Just say you got it for the prestige. Nothing wrong with that.
To clarify things. I finally went out of my way to register here, but was a silent reader for a couple of years now. If you say that they "measure better", which they do, you are still not being entirely truthful. "Better" is relative and in this case "better" does not mean "There is an audible difference". Because there isnt. So to come here and tell people to buy an, lets be honest here, overpriced piece of equipment is just wrong. And I dont mean that you said that people should buy it. But you are claiming improvements, which do exist on paper, but they might as well be entirely esoteric.
Everybody should first try out the Fosi, Aiyima, 3E Audio devices. They neither hurt your wallet, nor do they lack in anything modern amplification needs.

Copying my old comment as it fits here:

I would check (with both, measurements and your ears) the THD at the frequencies >5kHz. The class D chips with the local feedback, like TPA, usually suffer from the high THD in the post-feedback inductor.

I'm sure that with the relatively good speaker, you'll hear the difference between those amps. To my ears, the cymbals sound crisp enough only with the THD like -100dB or higher.

 

[Yevhen]

in this case "better" does not mean "There is an audible difference". Because there isnt.

A bit radical judgment. Strongly depends on your physiology and training. A young person used to a good sound (trained in a way) will hear that mud in high end of the spectrum.

What speakers and source do you use?

 

[Deleted member 97805]

Copying my old comment as it fits here:

I would check (with both, measurements and your ears) the THD at the frequencies >5kHz. The class D chips with the local feedback, like TPA, usually suffer from the high THD in the post-feedback inductor.

I'm sure that with the relatively good speaker, you'll hear the difference between those amps. To my ears, the cymbals sound crisp enough only with the THD like -100dB or higher.

Fair point. I have neither device so Im quoting tests and user experiences here. I am the last person here to dismiss personal experience and subjective opinions.
These higher class devices are objectively better machines. Im not disputing that fact. They have higher quality materials, more robust engineering and a very interesting approach. So my statement about "overly expensive" was wrong and I apologize for that. What I actually meant was that the price difference between these devices is stark and should be put into consideration.
"Do I get five times the performance? If not, why should I pay five times the money!?"

 

[Yevhen]

"Do I get five times the performance? If not, why should I pay five times the money!?"

Because you enjoy it and you live once?

 

[Mike123]

My point being that not everybody needs, or I should say most people dont need, a Purifi device.

The last thing should do is tell others what they need. Unless you're a saler . Why buy a TPA3255 and speakers when $10 headphones and a smartphone are enough for high-quality music listening? We'll go that far, and I don't want to.

 

[mocenigo]

There are threads around here regarding dead hypex amps because Hypex uses cheap power supply caps.

Every product can and will fail.

And the more successful a product it, the higher the raw number of failed units will be. It does not mean that it is not a reliable product.

How many Hypex power supplies have failed as a percentage of the number of units sold?

 

[Matias]

IMO it is somewhat easy nowadays to design a PFFB enhanced TI based class D amp. Up to some 200W they may be fine enough, and for a very low price.

But when sensitivities are low and the Purifi woofer extended bass requires big power, or large tower speakers in large rooms, then Hypex and Purifi still have no competition. They rule where money is not a problem or where there is a "buy once, cry once" mentality.