Audiophonics HPA-S400ET Review (Stereo Amplifier)

[egellings]

Even though my Topping Pre90 can ostensibly deliver 10+ volts I do prefer my Audiophonics MPA-M400ET monos with buffer in place.

That's more than enough signal voltage. Question is, can it deliver the necessary drive current.

 

[JohnnyNG]

That's more than enough signal voltage. Question is, can it deliver the necessary drive current.

Not sure if you can tell anything from the review below but it surely doesn't sound happy for lack of a better term.

https://www.audiosciencereview.com/forum/index.php?threads/topping-pre90-review-preamplifier.18283/

 

[egellings]

Either it doesn't like the load it's driving, maybe due to too low a load impedance on it or just possibly, it may be oscillating.

 

[peaceonearth]

Hi. I've got a question and I think the answer will be it's difficult. I've got two of these amps and they both have a white led at the front. Is it possible to change the led for a yellow one? I've asked audiophonics and they won't do it which I understand.

I've searched the thread for the answer. One person said it looks like it's soldered on but they may have been referring to the blue leds inside the case.

I realise there's a jumper to switch it off but I'd like to have it on.

Thanks!

 

[jools]

Hi. I've got a question and I think the answer will be it's difficult. I've got two of these amps and they both have a white led at the front. Is it possible to change the led for a yellow one? I've asked audiophonics and they won't do it which I understand.

I've searched the thread for the answer. One person said it looks like it's soldered on but they may have been referring to the blue leds inside the case.

I realise there's a jumper to switch it off but I'd like to have it on.

Thanks!

Audiophonics sell the switches and may have different colours. I bought a similar switch with an orange LED on eBay and replaced mine - it was soldered but it's not a difficult soldering job. It would probably void your warranty, though.

 

[Salt]

You may use a Edding with the colour of your choice and "paint" it.
Using the non permanent version you can change the colour easily.

 

[peaceonearth]

Thanks. I'll use a pen.

 

[AweLoi]

It seem like Audiophonics now have changed the LM4562 opamps to the OPA1656 in the HPA-S400ET when I look at their website. The OPA1656 is the opamp Bruno Putzeys (the designer of the Purfi modules) prefers as he has stated in a couple of interviews. Maybe that´s why they made the change.

I have the older version with LM4562 but recently ordered the OPA1656 opamps and swapped them myself yesterday. I don't know if there is an audible difference but if the man says they are the best I gotta have em hehe. They sound great but so did the LM4562. I think OPA1656 sound a little better but most likely it is just in my mind.

 

[peaceonearth]

I've recently bought the RME Adi-2 DAC FS which goes up to 10v on balanced connections. I previously had the Topping DX7 Pro+ which gives about 4v and I was using that in low gain because that gave me the best sound. The low gain is 20+dB.

Do you know why Amir's original post says "If you have a pro interface that goes up to 10 volts out, you can utilize the low gain mode" if 4v can be used with low gain? There's also a bypass mode which it's supposed to be better than low gain so isn't the bypass mode for 10v? I'm testing my setup with bypass and low gain mode. I think the bypass sounds natural but it's also exposing the limits of the source material (cds mainly) so I might need to compare to other sources and pick the best ones if I'm going to select bypass.

P. S. Audiophonics says

Gain	Input sensitivity needed for max power
20dB	4.19Vrms

 

[JohnnyNG]

o you know why Amir's original post says "If you have a pro interface that goes up to 10 volts out, you can utilize the low gain mode" if 4v can be used with low gain?

The 12dB/bypass mode is what Amir is referring to as "Low Gain". He refers to 20dB as "medium gain".

 

[peaceonearth]

The 12dB/bypass mode is what Amir is referring to as "Low Gain". He refers to 20dB as "medium gain".

I'm confused because he compares the low gain on this amp to the low gain on the Topping PA5 which is 19.5dB and similar to the 20dB 'medium gain'?

 

[JohnnyNG]

You can see the gain he's referring to in the SINAD chart under each measurement. "Low", "Medium", etc. have no strict definition and it's mainly semantics.

 

[wyup]

It is not just the 9V voltage to get max power, It is the capacity of current to drive the 12db Purifi bypassed, because that is 4.4k/2.2k ohm balanced/single-ended, too high a load. You need a source of at most 440/220 ohm, or better less for better performance. So it's not just volts for max volume, it is impedance ratio mostly and current capable. I am talking bypassed only.

RME ADI2 has 150/100 ohms output impedance, so it should be ok in theory. But it does not look like a powerful line preamplifier, with big transformers like others, you know. Sources expect impedances like 47 k, not 2.2k, so it is a bit uncertain.

Please share if it does sound better unbuffered than buffered/20db gain. I am curious.

What do you mean exposing the limits? Better or worse than pre-amplified by the Purifi op-amps buffer?

Most people say it sounds better with the buffer gain, otherwise it sounds lack of verve, languid or weak.

 

[peaceonearth]

You can see the gain he's referring to in the SINAD chart under each measurement. "Low", "Medium", etc. have no strict definition and it's mainly semantics.

I see your point. I think it's wrong though to say they have similar gains when the Benchmark ABH2 which he also compares this to has a gain of only 9.2v. Of course, he's tested the PA5 on it's lowest gain so the result is all that matters in the end.

I found out he tested this amp when it only had 3 gains including the bypass and he had to open up the case to change them but the current amp has more gains.

 

[Salt]

The provided data by Amir all show transparency independent from gain stage, so there would be only a difference if a Preamp is driven into clipping, but not by the Poweramp by itself.

 

[magchiel]

Running the LPA-S400ET in bypass with an ADI 2/4 Pro set to auto ref level, and it sounds absolutely glorious. No "lack of verve, languid or weak", whether the source is redbook, hires or vinyl. Just what's there in the mix (or not) is there.

 

[wyup]

When you say 'what's there on the mix', does it mean clinical, analytical sound or 'realistic'?
I have an impression that while these class D amps have improved, they are still about analytical, dry sound. I bought a Hypex and returned it because of that. My AB amp just sounds more realistic to the sound of instruments that I hear. The Hypex, less distortion and whatever you want, sounded coarse, dry. A violin sounded more like a electric violin. That is not what's in the mix for me.

Getting back to buffer or not, I feel that the RMI straight to the Purifi without a preamp or a buffer that 'infuses' some warmth might be too 'clean'. Maybe I'm wrong. I dont mean to stir a debate, I know this is not the place, but I'd like to know your opinion as you listen to vynil.

 

[JohnnyNG]

I have an impression that while these class D amps have improved, they are still about analytical, dry sound.

I find my 400ET to be the opposite of that and as good as the source. My LPs sound rich, detailed, and dynamic.

 

[peaceonearth]

The RME Adi-2 DAC FS has a 200/100 impedance. I've think I've decided I prefer this amp in bypass mode. I don't know what the cause is but there is a difference in sound between having bypass and buffer. I'm using Kef R5 Meta speakers. Wyup, this is a great amp. I can't speak about the Hypex but if you're looking for a new or better amp I would consider buying this one (it comes in two variations) with the RME (I bought mine secondhand on Ebay) and trying it out and returning them or selling them if you don't like it. I think you'll like it.

I'll edit this post if I change my mind about preferring the bypass but when I first put it on bypass I had to get used to it and now I'm getting used to it I don't think I'll go back to using an additional gain.

Edit. Do have a look at other amps too in the reviews because I haven't heard them. I can only say this is better than all my previous amps and sounds great.

 

[peaceonearth]

You may use a Edding with the colour of your choice and "paint" it.
Using the non permanent version you can change the colour easily.

The non permanent pen hasn't worked for me because it's rubbed off so I'll have to try something else.