Audiophonics HPA-S400ET Review (Stereo Amplifier)

[TheWalkman]

I really like the idea of just an amp and a pi with a variable DAC HAT too but I don’t trust the software enough to get a setup like this.
I need a physical volume knob that gives me the illusion that I have control over volume and don’t blast my speakers

So if you want a knob, here’s your Pi Based Plan B (and I’m using this very setup as I type this response):

Raspberry Pi Zero 2W (running Volumio) => (via USB cable to a) Topping D30 (with a knob) => Audiophonics S400 Amp.

No need for the Allo DAC.

Everone seems to want to use a Pi4 as a streamer and it’s an overkill.

If you’re worried that a Pi Zero 2 W isn’t enough computer to stream, here are the realtime stats from my streamer running Volumio with a 64gb, internal high endurance SD card loaded with approx. 300 CDs:

• CPU info
• Brand: BCM2837
• Speed: 1Ghz
• Number of cores: 4
• Physical cores: 4
• Average load: 10%
• Temperature: 43°C

• Memory info
• Memory: 470728 Ko
• Free: 50580 Ko
• Used: 420148 Ko

• Storage info
• INTERNAL storage - Size: 56585Mo
• Used: 24446Mo
• Available for storage: 29216Mo (52%)

I also have a Sangean HD receiver (HDT-20) attached to the system so I’m using the Topping as a DAC/ preamp.

Speakers: Elac UF5 floorstanders.

This set up sounds absolutely phenomenal. Like end game phenomenal. I am completely satisfied with this system.

QED

 

[juliangst]

So if you want a knob here’s your Pi Plan B (and I’m using this very setup as I type this response):

Raspberry Pi Zero 2W (running Volumio) => (via USB cable to a) Topping D30 (with a knob) => Audiophonics Amp.

No need for the Allo DAC.

Everone seems to want to use a Pi4 as a streamer and it’s an overkill.

If you’re worried that a Pi Zero 2 W isn’t enough computer to stream, here are the realtime stats from my streamer running Volumio with a 64gb, internal high endurance SD card loaded with approx. 300 CDs:

• CPU info
• Brand: BCM2837
• Speed: 1Ghz
• Number of cores: 4
• Physical cores: 4
• Average load: 10%
• Temperature: 43°C

• Memory info
• Memory: 470728 Ko
• Free: 50580 Ko
• Used: 420148 Ko

• Storage info
• INTERNAL storage - Size: 56585Mo
• Used: 24446Mo
• Available for storage: 29216Mo (52%)

I also have a Sangean HD receiver (HDT-20) attached to the system so I’m using the Topping as a DAC/ preamp.)

Speakers: Elac UF5 floorstanders.

This set up sounds absolutely phenomenal. Like end game phenomenal. I am completely satisfied with this system.

QED

My current setup is:
LS50
Denon integrated
Smsl Sanskrit (soon DO100)
and a Raspberry Pi with a Hifiberry digi 2 Pro.

it works fine as a desk setup but when I’m moving towards a bigger setup I want to control everything including volume with the streaming app I’m using.
The only options would be controlling it digitally or getting some streamer that can control volume in the analog domain.

 

[TheWalkman]

My current setup is:
LS50
Denon integrated
Smsl Sanskrit (soon DO100)
and a Raspberry Pi with a Hifiberry digi 2 Pro.

it works fine as a desk setup but when I’m moving towards a bigger setup I want to control everything including volume with the streaming app I’m using.
The only options would be controlling it digitally or getting some streamer that can control volume in the analog domain.

The setup I just laid out for you allows you to control the volume three * ways:
1) via Volumio - software slider;
2) via the knob on the Topping D30;
3) via the Topping remote control.

*4) you can always pull the power cord out, I suppose. Not recommended.

Nor sure what else I can offer…

 

[Caliban]

Does anyone know if this seemingly perfect partner to my HPA4 can be configuered to power up by itself when the mains comes on ?
I am not sure how the power button works, is it a mechanically bistable (then no problem and this ends here..) or does it work another way ?
There is a common power on/off mains-switch to all my audio gear and the Benchmark stuff I have is configured to power up automatically when the mains is applied.
And - yes - I know about the trigger input, but does the amplifier powers up if the trigger signal goes high a few seconds after the mains comes on ?
I intend to connect the trigger out from the HPA4 to the Audiophonics. HPA4 would be configured as master.
The trigger from HPA4 goes high about 2-3 seconds after power is applied (that is during boot). Would this delay be enough or do I need to do some magic to extend that ?
Well, any of you guys that have this amplifier that can enlighten me ?
Maybe this has been clarified earlier in this thread, sorry if so, it is 33 pages long..

 

[nemesis.ie]

The mono version has a trigger input. I don't think my Stereo ones do.

They sell a €30 IEC pass through box with a trigger input (I have 3 or 4 of them) that work perfectly.

The power button itself is either on or off physically. On the mono, with the trigger, you leave it in the off position to control it via the trigger, if you have the button on, it's permanently on.

Search - Audiophonics

Search page

www.audiophonics.fr

AFAIK 12V triggers need to stay at 12V all the time for an on state, once they go low, the device goes off.

Edit: The large case stereo version has trigger in/out, the small case one has neither.

 

[Caliban]

The mono version has a trigger input. I don't think my Stereo ones do.

They sell a €30 IEC pass through box with a trigger input (I have 3 or 4 of them) that work perfectly.

The power button itself is either on or off physically. On the mono, with the trigger, you leave it in the off position to control it via the trigger, if you have the button on, it's permanently on.

Search - Audiophonics

Search page

www.audiophonics.fr

AFAIK 12V triggers need to stay at 12V all the time for an on state, once they go low, the device goes off.

Edit: The large case stereo version has trigger in/out, the small case one has neither.

Thank you for swift response, case closed !

 

[juliangst]

Just out of curiousity: Are there any audible differences between this Purifi amp and a hypex amp like the NC502?
The audiophonics hypex amp costs a lot less than the purifi so I'm not sure if it's worth the extra money.
The LA90 would be another alternative in that price range but I'm not sure if it has enough power for 85db efficient speakers.

 

[amper42]

My ears hear a tiny bit of additional clarity with the Purifi vs NC502MP. Both amps need to be setup in an AB test where I can easily switch between them with the same CD playing to tell a difference. On the other hand, I totally enjoy the NC502MP and wouldn't think twice about using it instead of the Purifi. If you want to save money I would highly recommend the NC502MP. I have four Buckeye NC502MP stereo amps and one Purifi. To me, the NC502MP is a bargain and most will not notice a difference between it and the Purifi.

The biggest difference I notice with the Purifi is it runs cooler than the NC502MP and uses 16W at 81db with my Revel F328Be vs 24W with the NC502MP to reach the same SPL. The Purifi has the ability to use less energy at lower volume levels where the NC502MP uses close to 23W at idle. The Purifi also runs cooler than the NC502MP. Put your hand on both after an hour run and the Purifi is barely warm while the NC502MP generates noticeably more heat.

 

[Svensson]

Just out of curiousity: Are there any audible differences between this Purifi amp and a hypex amp like the NC502?
The audiophonics hypex amp costs a lot less than the purifi so I'm not sure if it's worth the extra money.
The LA90 would be another alternative in that price range but I'm not sure if it has enough power for 85db efficient speakers.

I did not try the NC502, but I did try Topping PA5 vs Purifi HPA-S400ET for 2 weeks. No difference noticable with AB testing when matching for same db at different db levels until much higher db over 85-95db. Even then with strictest possible AB testing, only then, possibly, very smallest advantage for Purifi. So small, it may not be real except in my my mind. I kept Purifi, but only because it might be or should be better. Speakers are Arundal 1723THX.

 

[juliangst]

I did not try the NC502, but I did try Topping PA5 vs Purifi HPA-S400ET for 2 weeks. No difference noticable with AB testing when matching for same db at different db levels until much higher db over 85-95db. Even then with strictest possible AB testing, only then, possibly, very smallest advantage for Purifi. So small, it may not be real except in my my mind. I kept Purifi, but only because it might be or should be better. Speakers are Arundal 1723THX.

Isn’t the Purifi 1000€ more? I wouldn’t keep for that much money if the only difference is on paper

 

[Svensson]

Isn’t the Purifi 1000€ more? I wouldn’t keep for that much money if the only difference is on paper

I agree. Topping was £369 and Purifi was £1100 (not VAT added to costs). Purifi was £730 more in absolute terms or 3x more than Topping in relative terms. In retrospect, I maybe should have kept Topping. The Topping 125W at 4ohm closely matched Purifi 400W at 4ohm too with db produced at same pre-amp settings. Only advantage required higher db listening and when AB testing. I am lucky and can afford to keep Purifi for the marginal (if any) advantage..

 

[mdunjic]

How one can choose gain without need to open the box and mess with jumpers?

 

[Caliban]

How one can choose gain without need to open the box and mess with jumpers?

Not possible. If that is a must, maybe this NAD amplfier is a better choice for you ?
However - I have owned its predecessor M22.2, it sounded REALLY good, but NAD QC is not really top of the line..
I returned two before I finally got what I had paid for.

M23 - NAD Electronics

Building on NAD’s long tradition of identifying and developing cutting-edge amplification technology, the M23 HybridDigital Stereo Power Amplifier features Purifi Audio’s Eigentakt™ design, a once-in-a-decade innovation that virtually eliminates harmonic and intermodulation distortion. Noise is...

nadelectronics.com

 

[mdunjic]

Not possible. If that is a must, maybe this NAD amplfier is a better choice for you ?
However - I have owned its predecessor M22.2, it sounded REALLY good, but NAD QC is not really top of the line..
I returned two before I finally got what I had paid for.

M23 - NAD Electronics

Building on NAD’s long tradition of identifying and developing cutting-edge amplification technology, the M23 HybridDigital Stereo Power Amplifier features Purifi Audio’s Eigentakt™ design, a once-in-a-decade innovation that virtually eliminates harmonic and intermodulation distortion. Noise is...

nadelectronics.com

Thanks, not a must. Just wondering what's default gain setting out of the box

 

[Caliban]

Thanks, not a must. Just wondering what's default gain setting out of the box

I understand, I think that information can be found elsewhere in this thread.

 

[Svensson]

Thanks, not a must. Just wondering what's default gain setting out of the box

@mdunjic I have copied and pasted what you seek below. The link takes you to the pictures and descriptions. I am using pre-amp with 4.2v output so removed 1 jumper from each card. If your pre-amp outputs 2v, then I would leave as it is.


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 - Maximum power reached with a signal of ~ 4.2V RMS
• Gain of + 12.5dB, for a total of 25.3dB (default) - 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

 

[nemesis.ie]

@mdunjic If you ask the very helpful pre-sales people and put a note on your order, they can preset the jumpers for you.

I managed to get most of mine pre-set for bypass, which works beautifully with an Altitude 32 - finally silent tweeter bliss.

 

[mdunjic]

I understand, I think that information can be found elsewhere in this thread.

Fair enough, I just thought, if someone already knows, it could save me hours of reading previous posts ... thanks

 

[mdunjic]

@mdunjic If you ask the very helpful pre-sales people and put a note on your order, they can preset the jumpers for you.

I managed to get most of mine pre-set for bypass, which works beautifully with an Altitude 32 - finally silent tweeter bliss.

Yes that's my plan for sure

 

[Satyadhara]

@mdunjic If you ask the very helpful pre-sales people and put a note on your order, they can preset the jumpers for you.

I managed to get most of mine pre-set for bypass, which works beautifully with an Altitude 32 - finally silent tweeter bliss.

That's what I did as well, they pre-set the amp in bypass mode to use with my RME ADI-2 FS. I even got a white instead of a blue LED, as wished!