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Audiophonics HPA-S400ET or Hypex Nilai500DIY?

Lbstyling

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I understand the ET doesn't have output inductors. Do the other options? I ask as Inductor saturation is audible at almost imeasuable levels as it is energy storage and release rather than instantaneous THD.

The ET designer (the original Hypex amplifier designer up to the NCore gen) admitted even he was surprised by the audibility of this factor.

He has moved on to driver design and continues to focus on it it seams.
 

EdW

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I understand the ET doesn't have output inductors. Do the other options? I ask as Inductor saturation is audible at almost imeasuable levels as it is energy storage and release rather than instantaneous THD.

The ET designer (the original Hypex amplifier designer up to the NCore gen) admitted even he was surprised by the audibility of this factor.

He has moved on to driver design and continues to focus on it it seams.
Inductors other than air cored will introduce distortion, and this I likely to be of the order of 0.3% or so. The output filter on nearly all class D audio amps will use inductors in their output filter which will introduce this level of distortion - however quality amplifiers will employ negative feedback sensing the output of the filter and reducing the distortion by the feedback factor and also removing any frequency response variation with loudspeaker load. The secret is of course how to get the feedback stable when it encompasses the poles of the filter. Look at Bruno Putzeys‘ technical papers and patents etc. to get an understanding of how this is done.
 

KMO

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Why does the Nilai500DIY have one 12V trigger socket and the NCX500 and the Purifi have two?
I think Audiophonics have just fitted a pair of connectors so you can daisy-chain multiple amps, using the sockets as "in" and "thru", if you need to switch more than one amplifier.
 
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ommadusk

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I think Audiophonics have just fitted a pair of connectors so you can daisy-chain multiple amps, using the sockets as "in" and "thru", if you need to switch more than one amplifier.
That's the Audiophonics. I don't understand why the Nilai monoblocks have one socket each? The manual isn't clear. I've asked the shop and I'll post the answer when I get it. I'll probably buy the Nilais on Monday.
 

KMO

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That's the Audiophonics. I don't understand why the Nilai monoblocks have one socket each? The manual isn't clear. I've asked the shop and I'll post the answer when I get it. I'll probably buy the Nilais on Monday.

Because it's cheaper than having two sockets? You only need one.

The second socket is a convenience to save people having to knock up splitter cables to trigger multiple amps.

If one manufacturer was fitting pass-through sockets to their stereo amps but not to their mono ones, I'd question their logic, but this is about different manufacturers, not different number of channels.
 
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ommadusk

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The second socket is a convenience to save people having to knock up splitter cables to trigger multiple amps.
Thank you! That's what I I wanted to know.
 

tmtomh

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IMHO it's pretty simple:
  1. Purifi 400 vs Nilai = whichever is cheaper and/or more convenient, basically interchangeable, measured performance differences inaudible.
  2. Purifi 7040 vs NCoreX = see #1.
  3. Monoblocks vs stereo = stereo. Monoblocks not worth the cost, slightly improved crosstalk measurement inaudible since stereo is already excellent.*
  4. Purifi 400/Nilai vs Purifi 7040/NCoreX = 400/Nilai because they are cheaper - unless you have unusually inefficient speakers and need to play at very loud volume for a distant listening position, or unless you've got speakers that present a 2 ohm load in the bass region and/or throughout a significant part of the frequency range. Even then the Purifi 400 or Nilai will probably be fine, but with the 7040 or NCoreX you can really be safe/confident in that scenario.
(*I suppose monoblocks might have slightly higher power if each one's PSU is the same power as the single PSU in a stereo unit. But (a) my understanding is that this is not usually the case, and (b) even if it is, I'd probably use the extra money to get a stereo Purifi 7040 or NCoreX amp instead.)
 
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ommadusk

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Thank you. That's very useful.

I've got another question. Can you recommend a DAC I can use with these amp in it's low gain mode please? There's the RME ADI-2 DAC FS, are there any others?
 

TheWalkman

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Thank you. That's very useful.

I've got another question. Can you recommend a DAC I can use with these amp in it's low gain mode please? There's the RME ADI-2 DAC FS, are there any others?
I’m running a Topping E70 driving the Audiophonics 400 Purifi. It works great. I‘m using the switched mode between the two to power the amp down when not in use. Aesthetically, the white display matches the white power button on the amp as well.

I’m completely happy with this setup.
 

Rja4000

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Thank you. That's very useful.

I've got another question. Can you recommend a DAC I can use with these amp in it's low gain mode please? There's the RME ADI-2 DAC FS, are there any others?
Not sure which level you need exactly.
The RME ADI-2 DAC may give you +19dBu and, possibly, +22dBu.
If you need more, you'll need the ADI-2 Pro fs R or the ADI-2/4 Pro SE. Both may output 24dBu (>12V).

In general, the best Pro DACs and interfaces may push 19dBu or more.

They won't be cheaper than the RME and probably much less convenient for HiFi use, though.

NB: using intermediate gains will be all fine
 

tmtomh

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Why run the Audiophonics amp in its lowest-gain mode? Its buffer stage is excellent and its default/medium gain mode provides about 20dB gain, which is plenty for any balanced DAC's 4V output.

By running the amp in low-gain mode, you are assuming that the DAC's analogue stage is quieter than the amp's input buffer - and that's not necessarily the case.
 

Rja4000

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You made me look that up. It obviously depends on a number of things. I found this thread https://www.audiosciencereview.com/forum/index.php?threads/audibility-of-changes-in-volume.38040/#:~:text=But according to this study,3db change is barely audible By my count, there are 6 people claiming they can hear the difference and 2 people who don't give an opinion. The consensus is that the difference is audible, at least with regard to tones, without music masking. Should I discount that?
You can't compare audibility of a difference
of level and audibility of noise or distortion.

You'll never hear the difference between 102dB SINAD and 105dB SINAD.
CD material is around 96dB anyway.

This is important to understand.

The SINAD excellence is used here mostly as an indicator of Excellence in engineering.
But it should not, in my opinion, be used as a hard criteria for hardware selection, or, at least, not as the main criteria. For power amps, power, load tolerance and gain adequacy are at least as important.

As long as it's clearing CD dynamic range at 5W -which, for a powerful amp, is already quite an achievement- without any other issue, I'd consider it as good enough.
(That's all the amps in blue on the ranking chart)

This is where I'd personally set my own (arbitrary) limit.
 
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Rja4000

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Why run the Audiophonics amp in its lowest-gain mode? Its buffer stage is excellent and its default/medium gain mode provides about 20dB gain, which is plenty for any balanced DAC's 4V output.
I agree
By running the amp in low-gain mode, you are assuming that the DAC's analogue stage is quieter than the amp's input buffer - and that's not necessarily the case.
That won't be an issue with the RME though.
 
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ommadusk

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I've got the Topping DX7 Pro+ which has a quiet analogue stage and I've been informed that works well with the Nilai. The other two amps I'm looking at are the Audiophonics HPA-S400ET and Audiophonics HPA-S600, the latter is ever so slightly cheaper. I got the impression in the reviews that Amir favours a 5v output, and perhaps even more, is that wrong? I've got two options.
1) Get an Audiophonics or Nilai and use with my 4v DAC in medium gain mode, or high mode in the case of the HPA-S600.
2) Get an Audiophonics or Nilai amp, sell my current DAC/HA and buy another DAC so I have at least 5v and use it in low gain mode. I've decided to get a better headphone amp so I'm only keeping the DX7 Pro+ for it's line output capability. I decided that after comparing it to the Topping L50. I'm not sure I'll need the RME's DSP functions because I can do that with software and I haven't looked closely at its headphone amp measurements so I don't know how it compares to the L50.

I could sell the DX7 Pro+ for around £500 and buy the Topping E70 for the same price or buy the RME and not have to buy a headphone amp which might also work out around the same price. The easiest option would be to keep my current DAC and buy a separate headphone amp.
 
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ommadusk

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Not sure which level you need exactly.
The RME ADI-2 DAC may give you +19dBu and, possibly, +22dBu.
If you need more, you'll need the ADI-2 Pro fs R or the ADI-2/4 Pro SE. Both may output 24dBu (>12V).

In general, the best Pro DACs and interfaces may push 19dBu or more.

They won't be cheaper than the RME and probably much less convenient for HiFi use, though.

NB: using intermediate gains will be all fine
Amir says in the review for the Audiophonics HPA-S400ET/Purifi 'If you have a pro interface that goes up to 10 volts out, you can utilize the low gain mode'.
By running the amp in low-gain mode, you are assuming that the DAC's analogue stage is quieter than the amp's input buffer - and that's not necessarily the case.

What's the point of DACs having higher voltages then? If it's not to make amps sound better what is it for or to put it another way is there any case in which it would be beneficial to have a higher voltage?
 

Rja4000

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I got the impression in the reviews that Amir favours a 5v output, and perhaps even more, is that wrong? I've got two options.
For measurements, yes.
For facility, certainly not.

The difference in SINAD between those gains is negligible for real use.

1) Get an Audiophonics or Nilai and use with my 4v DAC in medium gain mode, or high mode in the case of the HPA-S600.
That's a no brainer (and what I do, although my RME is able to push more than 12V).
 
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Rja4000

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I've decided to get a better headphone amp so I'm only keeping the DX7 Pro+ for it's line output capability.
What exactly do you expect to improve ?

A real improvement would be to get an RME and its DSP power.
Other than that, you'll end up splitting hairs.
(And making your life more difficult than it has to be. But that's your life.)
 
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ommadusk

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What exactly do you expect to improve ?

A real improvement would be to get an RME and its DSP power.
Other than that, you'll end up splitting hairs.
(And making your life more difficult than it has to be. But that's your life.)
I had the L50 for a while and using my Fidelio X2HR headphones the silence and sound was incredible. Using the DX7 Pro+ it's very very enjoyable but it doesn't have that wow factor. Admittedly, I'm basing this from memory and I didn't use the correct gain setting on the DX7 Pro+. So what gain setting do you use on your RME, what's your system if you don't mind me asking?

Edit. And I also tried them with my Monolith 1060 headphones. Actually I think I must have experimented with the gain setting on the DX7 Pro+. I had a blocked ear at the time so I returned the L50 to the shop because I thought the channels were mismatched LOL! (They may have been, I won't know. The shop tested it and didn't think so.)
 
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ommadusk

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For measurements, yes.
For facility, certainly not.

The difference in SINAD between those gains is negligible for real use.


That's a no brainer (and what I do, although my RME is able to push more than 12V).
I haven't given the DX7 Pro+ headphone amp much of a listen because it's not beside me. Thanks for all the contributions so far. I realise this is a very complicated subject with so many variables. Everyone's saying these differences don't matter and perhaps they're right. I'm getting some longer XLR cables so I'll be able to listen to the headphone amp. I haven't decided on the poweramp yet.

Correction. It uses a USB input so I don't need the XLR cables for that purpose.

I don't know if the possible gain differences explain the big difference I heard with the L50. It was a while ago. At the time I wasn't sure whether it was channel imbalance was the amp or my hearing. I was sure there was a channel imbalance with the L50 and I wasn't so sure with the DX7 Pro+ so I was hearing the L50 clearer.
 
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tmtomh

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Amir says in the review for the Audiophonics HPA-S400ET/Purifi 'If you have a pro interface that goes up to 10 volts out, you can utilize the low gain mode'.


What's the point of DACs having higher voltages then? If it's not to make amps sound better what is it for or to put it another way is there any case in which it would be beneficial to have a higher voltage?

The point of DACs having higher voltages is twofold:
  1. To make a preamplifier irrelevant and to allow full/loud playback volume with power amps that don't provide the 27-29dB of gain that a lot of traditional Class A/B stereo amps provide (or the 29dB of gain that's the THX standard for home theater and such). Even at high gain, most Class D amps, including the Audiophonics unit, provide abut 25-26dB of gain. And at medium/factory-default gain, the Audiophonics provides about 20dB of gain (as do many other Class D amps). This lower gain translates into small differences in max perceived playback volume, but they are differences nonetheless.
  2. To take advantage of the lower noise floor of the DAC compared to most amps, especially when the DAC is outputting at high voltage, as the noise tends to stay relatively constant, which means that the noise floor of the DAC goes down relative to the voltage of the signal it's outputting goes up. But the Audiophonics amp, as tested by Amir, has extremely low noise of its own, and in some respects it even beats the Purifi EVAL board, which some folks here have suggested means that the Audiophonics buffer and/or circuit layout are implemened in a very clean, low noise manner.
So putting those two points together, there is certainly nothing wrong with maximizing the output of the DAC and running the Audiophonics in low-gain mode, where it provides only about 12-13dB of gain. But this amp is so good that you don't need to restrict yourself to DACs that can output 10V. Also keep in mind that for reasons of standardization and consistency, Amir generally tests devices (like DACs) at 4V output. A well-designed DAC capable of outputting 10V will probably have equal or better noise performance at 10V than 4V, but this is not certain. Some devices - for example the MiniDSP SHD - actually clip if their output is set to full gain (I believe the SHD clips at -6.5, which for that unit is over 4V but not much over), Others are more knowledgeable than I am about how various DACs achieve up to 10V output, but if they are doing so by adding extra amplification, then they are basically preamps, and in that case there's no guarantee that their extra amplification performs better than the input buffer in the Audiophonics amp.

Any DAC that has excellent measured performance and balanced outputs (enabling 4V output) can pair with the Audiophonics amp set to medium/default gain, and the sonic result will have a noise floor totally indistinguishable (by human hearing) from a 10V DAC output paired with the Audiophonics in low-gain mode. So that opens up your DAC options, enabling you to consider options that might cost less, or have different/better usability, and so on. But of course the RME units are always an excellent choice - they're just not always necessarily the most economical choice,
 
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