performance of tri-amp vs stereo amp + mono amp

[kenshone]

Hey forum,

I'm considering purchasing a tri-amp as opposed to a stereo amp + mono.

Use case is listening to music in stereo on my towers, and watching TV/movies across tower + center speakers.

As a concrete example, this product was well-reviewed on ASR: https://www.audiophonics.fr/en/powe...ass-d-stereo-purifi-2x400w-4-ohm-p-14393.html

The same company uses the same chips to make mono and tri versions:
- mono: https://www.audiophonics.fr/en/powe...-d-amplifier-purifi-1x400w-4-ohm-p-14951.html
- tri: https://www.audiophonics.fr/en/powe...lass-d-3-way-purifi-3x400w-4-ohm-p-15243.html

The spec sheets for every product are identical (except the tri-amp uses the term "noise floor" whereas the other two use the term "idle noise"). But in practice, can the performance of these 3 configurations actually be identical?

Can someone with some electronics knowledge teach me about the pros and cons of increasing the number of speaker output channels in this context?

 

[HarmonicTHD]

Hey forum,

I'm considering purchasing a tri-amp as opposed to a stereo amp + mono.

Use case is listening to music in stereo on my towers, and watching TV/movies across tower + center speakers.

As a concrete example, this product was well-reviewed on ASR: https://www.audiophonics.fr/en/powe...ass-d-stereo-purifi-2x400w-4-ohm-p-14393.html

The same company uses the same chips to make mono and tri versions:
- mono: https://www.audiophonics.fr/en/powe...-d-amplifier-purifi-1x400w-4-ohm-p-14951.html
- tri: https://www.audiophonics.fr/en/powe...lass-d-3-way-purifi-3x400w-4-ohm-p-15243.html

The spec sheets for every product are identical (except the tri-amp uses the term "noise floor" whereas the other two use the term "idle noise"). But in practice, can the performance of these 3 configurations actually be identical?

Can someone with some electronics knowledge teach me about the pros and cons of increasing the number of speaker output channels in this context?

As both version use the same amplifier module, just in different numbers, I would expect they perform identical.

Increasing the number of channels in this context is merely a matter of convenience. As in your case, if you need three channels, you get it all in one box instead of up to three.

 

[Zek]

watching TV/movies across tower + center speakers

How do you plan to feed a 3 channel amplifier?

 

[HarmonicTHD]

How do you plan to feed a 3 channel amplifier?

Like any other power amp? With for example AVR pre-outs?

 

[-Matt-]

One thing to consider is the number and rating of the power supplies used.

I.e. Three monoblock amplifiers will probably be the most expensive option because this requires three cases and three power supplies. However, this can potentially give slightly better performance in the form of better isolation between channels and probably a higher power supply rating per channel. (It also gives the option of positioning each monoblock very close to its speaker, which could be convenient).

In an amp with three channels that share a 1200W power supply, each channel may perform slightly worse than those in a stereo amp with the same 1200W supply.

With that said, any performance differences are highly likely to be inaudible (unless pushing all channels to max volume). So, personally, I'd probably go for the 3 channel one just to reduce the number of boxes and plug sockets involved.

 

[-Matt-]

In the ones you linked above...

3 channel has 1200W supply (400W/channel),
2 channel has 1200W supply (600W/channel),
1 channel has 600W supply (600W/channel).

So the 3 channel version is, on paper, a bit weaker; however, simultaneous high output on all channels is unlikely and 400W should be adequate for the 1ET400A modules anyway.


Now, to throw a spanner in the works...
How sure are you that you really want all 3 channels? Stereo power amps probably hold their value a bit better (being more commonly desired). Also, for some Denon AVRs, where you may hope to gain SINAD by detatching internal amps (via preamp mode) - this may only be possible for L and R (not centre). So, the stereo version could give you the majority of the benefit that you hope to acheive for music.

 

[kenshone]

The stereo version is on backorder, whereas the mono is in stock. I could see the 3-way being in low demand, and the 2-way being in the highest demand. But I think the mono blocks will have enough demand that I could sell them in the future with a little extra patience.

(I bought 3 monos).

 

[-Matt-]

Hope you enjoy them!

The modular approach of monoblocks is quite appealing. Resale of monoblocks won't be a problem if you decide to at some point.

 

[kenshone]

If they live up to the hype, I'm sure I will enjoy them greatly!

 

[DWPress]

Aside from the power supply issue noted above it is simply, in your case, a matter of convenience. This is not true tri-ampling as all crossovers are intact inside the respective speaker boxes but you are, or do, intend to use this for 3 separate channels in a home theater type environment. There are no real benefits to this other than bypassing internal AVR amps - which is indeed one huge benefit if the speakers warrant it. A less expensive option would be the Hypex line or even Icepower if you want to stick with Class D.

You could just as easily mix and match a 2 channel and monoblock to create the system but (not knowing how you plan to manage them AVR or multi ch DAC & computer?) one big benefit to using 3 of the same amplifier is the same output gain across all amps thus not having to worry to much about matching volume in software or hardware.

The Purify boards are more than adequate for your desired SINAD. Are your speakers worthy of such low distortion coming into them would be my big question.

 

[kenshone]

one big benefit to using 3 of the same amplifier is the same output gain across all amps thus not having to worry to much about matching volume in software or hardware.

Agreed. I wanted to be sure that the front 3 channels are on equal footing for watching shows. The surround speakers will be powered by another amp, but I have room correction software/hardware to handle the balancing act.

The Purify boards are more than adequate for your desired SINAD. Are your speakers worthy of such low distortion coming into them would be my big question.

I believe they are and I will surely upgrade them to even better towers in the years to come.

 

[American Pie]

Hi, first post here.
This is mentioned in the description of the stereo model :

Interface board :

The 2 modules are controlled in phase opposition, to cancel the "Power-Supply Pumping" effect.
This allows greater stability of the power supply, distributing the inrush currents alternately on each rail, and thus increasing its capacities.
We have opted for regulation with 2 voltage levels, to optimize the AOP power supply and the auxiliary voltage supplied to the modules.

But then, in the reviews section I found this :

Rather good, but needs modification
The positive binding post of R Ch is unfavorably connected to GND due to the phase inversion at R Ch for reducing bus pumping.
This is because negative output of 1ET400A is connected to GND internally.

The tri amp model has 3 separate interface boards.
I ordered a tri amp, as it was the only one left (no stereo amps available for the moment), not sure if that was a good choice.
Advice is appreciated!

And if I would add a stereo amp later (for a 5 speaker system). Will all 5 channels play as loud given the same power supply is used for 2 vs 3 channels ?

 

[American Pie]

Okay, so the AudioPhonics HPA-T400ET arrived 3 days ago.

I hooked it up to my Denon AVR X3500H L+R pre-outs and to my 20y old Focal Electra 926s.
(the extra channel is for driving a center channel when watching tv, but I didn't care for now)

As source I used my Matrix Element X connected to the CD analog inputs (RCA) of the Denon.
And I enabled the Denons "Direct mode" of course.

This amp is A-M-A-Z-I-N-G. Neutral, clean, detailed.
I found the fast filters of my dac too harsh. (Those filters were not too harsh when listening to the Denon internal amps).
I just think the amp is more detailed. The slow filters sounded perfect though.

Highly recommend the HPA-T400ET. I doubt the stereo version (HPA-S400ET) will be audibly better than this.

Now I will consider buying an extra amp (stereo or even quad) so I can connect 5 or 7 speakers in total.
Then I will look for another Denon (X3700 or 4700) as those models allow you to disable the internal amps
making their pre out stages much cleaner. (Not possible on my 3500 model unfortunately).

 

[Vincentponcet]

Okay, so the AudioPhonics HPA-T400ET arrived 3 days ago.

I hooked it up to my Denon AVR X3500H L+R pre-outs and to my 20y old Focal Electra 926s.
(the extra channel is for driving a center channel when watching tv, but I didn't care for now)

As source I used my Matrix Element X connected to the CD analog inputs (RCA) of the Denon.
And I enabled the Denons "Direct mode" of course.

This amp is A-M-A-Z-I-N-G. Neutral, clean, detailed.
I found the fast filters of my dac too harsh. (Those filters were not too harsh when listening to the Denon internal amps).
I just think the amp is more detailed. The slow filters sounded perfect though.

Highly recommend the HPA-T400ET. I doubt the stereo version (HPA-S400ET) will be audibly better than this.

Now I will consider buying an extra amp (stereo or even quad) so I can connect 5 or 7 speakers in total.
Then I will look for another Denon (X3700 or 4700) as those models allow you to disable the internal amps
making their pre out stages much cleaner. (Not possible on my 3500 model unfortunately).

Matrix element X has a volume control, so what does the denon brings here in the chain if it is in direct mode ?
It will be better from a measurement perspective to connect the matrix straight to the amp.
The volume control of the denon is <<100db sinad.
If this is audible? Idk.
but worth trying

 

[American Pie]

Matrix element X has a volume control, so what does the denon brings here in the chain if it is in direct mode ?
It will be better from a measurement perspective to connect the matrix straight to the amp.
The volume control of the denon is <<100db sinad.
If this is audible? Idk.
but worth trying

I tried this (matrix as pre amp directly connected to the hpa-t400et) but it still sounded harsh. And in the mean time I found out a lot of class D amps have issues with reproducing treble. I think they are just so "perfect" that imperfect recordings sound bad. (Not forgiving enough.)

 

[Vincentponcet]

I tried this (matrix as pre amp directly connected to the hpa-t400et) but it still sounded harsh. And in the mean time I found out a lot of class D amps have issues with reproducing treble. I think they are just so "perfect" that imperfect recordings sound bad. (Not forgiving enough.)

What the point of buying a top of line dac and amp if it is to reduce the quality by putting a middle quality preamp in the middle ?

 

[American Pie]

What the point of buying a top of line dac and amp if it is to reduce the quality by putting a middle quality preamp in the middle ?

You just proposed to try using the volume control of the Matrix i.e. use the Matrix as a pre amp. I did. Btw the Denon x3500h was tested on asr and its dac was bad but amp stage was very good. So why would there be a huge improvement with another preamp?
It sounded excellent without the hpa-t400et. Just matrix - denon - focals. So it must be the audiophonics amp. Maybe the stereo version is better as it uses bus pumping but couldn't test it yet.

 

[Vincentponcet]

You just proposed to try using the volume control of the Matrix i.e. use the Matrix as a pre amp. I did. Btw the Denon x3500h was tested on asr and its dac was bad but amp stage was very good. So why would there be a huge improvement with another preamp?
It sounded excellent without the hpa-t400et. Just matrix - denon - focals. So it must be the audiophonics amp. Maybe the stereo version is better as it uses bus pumping but couldn't test it yet.

The matrix is using the digital volume control of the ESS chip, it is way better than the analog volume control of an AVR.

 

[American Pie]

The matrix is using the digital volume control of the ESS chip, it is way better than the analog volume control of an AVR.

Its actually a hybrid volume control. Partially digital + analog. (See asr review)

But anyway, even matrix + this triple class D amp were a disappointment. The bass was excellent but treble was harsh. If I can save some money I might try the stereo version, maybe with the Sparkos input buffer. I just bought Focal Sopra 1s and would like to try them with purifi eigentakt but unfortunately Europe is in an energy crisis due to Putlers war so saving money is no longer possible right now. So buying another amp will have to wait...

 

[Vincentponcet]

Its actually a hybrid volume control. Partially digital + analog. (See asr review)

But anyway, even matrix + this triple class D amp were a disappointment. The bass was excellent but treble was harsh. If I can save some money I might try the stereo version, maybe with the Sparkos input buffer. I just bought Focal Sopra 1s and would like to try them with purifi eigentakt but unfortunately Europe is in an energy crisis due to Putlers war so saving money is no longer possible right now. So buying another amp will have to wait...

Maybe you are looking for an EQ, so buy RME ADI-2, and you can change the sound to your taste.
You said you are using it as dual Channel now, so if one channel is not connected, the power supply delivers just the idle power to it, so about 10W, this could not be a limiting factor on a 1200W power supply.
And in 3 channels, 1200W of power in your ears would be a lot, so most probably enough to kill your ears.