Audiophonics HPA-S400ET Class D Purifi amp

[ririt]

Good to know since I am also hesitating between the 2 versions of the purifi amp....

 

[Aldo]

My 110v model HPA-S400ET Purifi amp just arrived today. My experience so far:

• [/ QUOTE]

congratulations!
What are you using as a preamplifier?

 

[ririt]

I am on the way to build a system dedicated to 50% Hifi / 50% HC. Amps will be a combo of Purifi (L/R) and Hypex NCore (remaining channels). For pre-amp I am still hesitating between 2 processors: the Anthem AVM60 or the Emotiva XMC2. Powerful room correction system (either ARC or DIRAC) associated with audiophile capabilities are my main criteria. And I want to stay away from Arcam and related (JBL...) because I do not like the way the user interface is build.

 

[tmtomh]

congratulations!
What are you using as a preamplifier?

I currently use only digital sources - optical discs and a music server - so I use my Oppo BDP-205 as a preamp. A few years ago I had a standalone preamp in the chain, but I found it raised the noise floor a bit. So I tried going direct from the Oppo to the power amp and found that in addition to lower noise, the sound of the system was slightly cleaner. Even if that part was my imagination, the sound certainly was no worse without the preamp, so I figured lower noise and a simpler signal chain was the way to go.

Plus now I have gone from a power amp that produced its own low-level, volume-independent hiss, to one that is silent - and so I assume that putting the preamp back in the chain now would make the noise it adds even more conspicuous.

BTW, when I say that the new Audiophonics amp is silent, I am not exaggerating. If I turn my head so my ear is directly facing the speaker, and position my ear so that it's lined up at the same height as the tweeter driver, I have to get within 2-3 inches of it to hear anything at all - and even then it's at a low level. I'm sure others have experienced a noise level that low from amps, but I never have, so it's pretty cool!

If I ever found myself wanting or needing a separate preamp, I would consider the Schitt Freya S - Amir's measurements indicate it's got a price to performance ratio that's hard to beat.

 

[tmtomh]

Aside from the case (and the price), is there any difference between the HPA-S400ET and the LPA-S400ET?

I don't think so either. The internal components are the same, and the price difference is only 117€, which suggests that the price difference is just from the smaller and presumably less-expensive case.

The only other differences I see from the photos are that the LPA seems to have a slightly different speaker terminal (though it could just be batch to batch variations from their supplier), and the LPA has an externally accessible fuse on the back.

Personally I am with @ririt - the LPA showed up just before I purchased the HPA, but I went with the HPA anyway because for my setup I like the component-width case, along with the heatsinking, the airspace inside, and the internal component layout. However, that said, these things run so cool compared to Class A/AB amps, and I doubt the smaller form factor would get very hot or have much negative impact on the longevity of the components.

 

[Aldo]

Thanks for your feedback.

I'll be changing speakers in a few weeks, and I'm already planning a new amplification...

The choice of the class D titillates me +++, and of course the 1et400a (already dealt with audiophonics )

Lately I had put aside my preamp in favor of my DAC dx7 pro. Out of curiosity, I reinstalled my old analog preamp on my class AB amp and it seems to me to have gained in sound stage opening?!... here's why this question.

Would the result be different for the class D?

I'll try again with the new more stable speakers to feed ...

Good listening to you

 

[tmtomh]

Thanks for your feedback.

I'll be changing speakers in a few weeks, and I'm already planning a new amplification...

The choice of the class D titillates me +++, and of course the 1et400a (already dealt with audiophonics )

Lately I had put aside my preamp in favor of my DAC dx7 pro. Out of curiosity, I reinstalled my old analog preamp on my class AB amp and it seems to me to have gained in sound stage opening?!... here's why this question.

Would the result be different for the class D?

I'll try again with the new more stable speakers to feed ...

Good listening to you

I think you'll need to try your new setup with and without your preamp. I guess with a preamp it's a question of whether or not the preamp's performance audibly degrades the system's noise and distortion performance on the one hand, and whether the preamp might change the gain-staging and/or the impedance your power amp sees at its inputs in a way that could improve the perceived sound on the other hand. Good luck - and have fun!

 

[Guddu]

Price for Audiophonics Purifi Stereo amplifier is too good to be true, many other manufacturer are selling their monoblock around the same price as Audiophonics Purify Stereo amplifier using same dual module.
So what is the catch?

 

[samsa]

Price for Audiophonics Purifi Stereo amplifier is too good to be true, many other manufacturer are selling their monoblock around the same price as Audiophonics Purify Stereo amplifier using same dual module.
So what is the catch?

One power supply, instead of 2; 1 case instead of 2, etc.

And, if you compare their prices on (say) Hypex amplifiers, you see that they are also significantly cheaper than much of the competition.

I own one of their Hypex NC252MP amps. It seems very solidly engineered.

 

[tmtomh]

Possibly stupid question for @Audiophonics or anyone else who knows: I just read the following info on the Audiophonics web page for the input buffer/interface card on the HPA-S400ET amp I recently purchased:

"To suit all uses we opted for 3 gain settings, adjustable by jumper on the interface card:

• Gain of + 7.2dB, for a total of 20dB (default) - Maximum power reached with a signal of ~ 4.2V RMS
• Gain of + 12.5dB, for a total of 25.3dB - Maximum power reached with a signal of ~ 2.2V RMS
• Bypass: in this case the signal passes directly from the inputs to the modules, allowing the lowest possible gain of 12.8dB. This mode can be interesting when using a powerful preamplifier, capable of driving a load of 2 to 4kOhm and reaching a voltage of ~ 10V RMS

Is this information current? In other words, if I'm using the unbalanced inputs and feeding the amp with an approx 2.1V signal from a digital source component, then in addition to flipping the RCA/XLR switches on the back of the unit, I should also be opening up the unit and changing the gain jumper on that interface card to the high gain setting, yes?

 

[rodtor]

Possibly stupid question for @Audiophonics or anyone else who knows: I just read the following info on the Audiophonics web page for the input buffer/interface card on the HPA-S400ET amp I recently purchased:

"To suit all uses we opted for 3 gain settings, adjustable by jumper on the interface card:

• Gain of + 7.2dB, for a total of 20dB (default) - Maximum power reached with a signal of ~ 4.2V RMS
• Gain of + 12.5dB, for a total of 25.3dB - Maximum power reached with a signal of ~ 2.2V RMS
• Bypass: in this case the signal passes directly from the inputs to the modules, allowing the lowest possible gain of 12.8dB. This mode can be interesting when using a powerful preamplifier, capable of driving a load of 2 to 4kOhm and reaching a voltage of ~ 10V RMS

Is this information current? In other words, if I'm using the unbalanced inputs and feeding the amp with an approx 2.1V signal from a digital source component, then in addition to flipping the RCA/XLR switches on the back of the unit, I should also be opening up the unit and changing the gain jumper on that interface card to the high gain setting, yes?

I believe so, and, yes, I think you should send them a note to confirm that. They are said (here) to be quick in answering.

 

[tmtomh]

Thanks!

 

[kukocz]

Good finding! I haven't noticed that at first look at specs.
Although first usecase is not so bad (you just won’t be able to utilize full power), then second case will be more dangerous as with max gain reached at 2.2V (Gain of + 12.5dB, for a total of 25.3dB - Maximum power reached with a signal of ~ 2.2V RMS) you will clip amp very quickly using XLR.

 

[tmtomh]

Good finding! I haven't noticed that at first look at specs.
Although first usecase is not so bad (you just won’t be able to utilize full power), then second case will be more dangerous as with max gain reached at 2.2V (Gain of + 12.5dB, for a total of 25.3dB - Maximum power reached with a signal of ~ 2.2V RMS) you will clip amp very quickly using XLR.

Thanks - and great point. In fact, I’m guessing that’s why Audiophonics makes the lower, 20dB total gain setting the default: far better for customers using unbalanced connections to give up 5dB of gain than for those using balanced connections to risk clipping or worse.

Still, it seems that with an unbalanced connection - and a Post-It note in the back of the amp as a reminder for the future - it could be worthwhile to switch it to the higher gain mode.

 

[Audiophonics]

Lower gain also avoid to magnify the noise coming from the preamplifier.
As most customers will never reach full power, the low gain setting should be ok for most uses.

If you are reaching 0dB on your DAC (2V RMS most of time), and volume is not enough high (what I doubt), you can switch to higher gain.
When using analog preamp, some can provide more than 2V RMS, which will allow you to reach full power even with low gain setting.

 

[tmtomh]

Lower gain also avoid to magnify the noise coming from the preamplifier.
As most customers will never reach full power, the low gain setting should be ok for most uses.

If you are reaching 0dB on your DAC (2V RMS most of time), and volume is not enough high (what I doubt), you can switch to higher gain.
When using analog preamp, some can provide more than 2V RMS, which will allow you to reach full power even with low gain setting.

Thank you - very helpful. So far I’m happy with the default gain, but it’s good to have the higher-gain option and the bypass/lower-gain option too, to enable optimal gain-staging with different setups. Also helps the amp be useful for longer, as a single owner can just change the gain setting if their preamplification or speaker-efficiency situation changes over time.

 

[rodtor]

Lower gain also avoid to magnify the noise coming from the preamplifier.
As most customers will never reach full power, the low gain setting should be ok for most uses.

If you are reaching 0dB on your DAC (2V RMS most of time), and volume is not enough high (what I doubt), you can switch to higher gain.
When using analog preamp, some can provide more than 2V RMS, which will allow you to reach full power even with low gain setting.

Thank you for this response. I have a similar question in relation to the pass through setting on your purifi amp. It requires about 10 Vrms to reach maximum power, or 22.2 dbu. The RME DAC (non-pro version) can, according to its manual (p. 37), deliver a maximum of 21.5 dbu -- with its 19 dbu setting boosted by the extra 2.5 dbu available to it. This falls a bit short of the purifi amp's requirement at the pass through setting. But is the resulting power shortfall unlikely to be consequential for most listeners, especially since we usually listen at well below the 0 db level? Conversely, is the RME likely to handle the resulting voltage demand comfortably?

 

[TabCam]

How much power do you need and do you need it at maximum? The pass through or using the input buffer with a little gain is not a big deal as it is quite transparent in both situations. And to be honest is 0.5 dB inconsequential in volume.

 

[TabCam]

Price for Audiophonics Purifi Stereo amplifier is too good to be true, many other manufacturer are selling their monoblock around the same price as Audiophonics Purify Stereo amplifier using same dual module.
So what is the catch?

The casing is ok but there are a lot of screws to get to the inside for changing the jumpers (for pass through or different gain settings) or opamps. It is unlikely to be often but still an annoyance. It also wobbles a bit and the rubber dampers are too loosely attached to the feet.

The cheapest NordAcoustics Purifi amplifier has a better looking case (matter of taste) and posibbility for a 12V trigger.

 

[Guddu]

Is voltage 110/230 v adjusted though jumper on psu?