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Audiophonics HPA-S400ET Review (Stereo Amplifier)

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 1 0.2%
  • 2. Not terrible (postman panther)

    Votes: 4 0.8%
  • 3. Fine (happy panther)

    Votes: 38 7.9%
  • 4. Great (golfing panther)

    Votes: 438 91.1%

  • Total voters
    481

TjindarSingh

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Can I use it with a DAC with volume control which outputs 4v or do I benefit from a preamp?
 

nemesis.ie

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I've not used one.

There would be nothing preventing you using e.g. the Audiophonics amp and if you then found "something" was missing you could add a pre-amp later if there was some real benefit.

Edit: If you mean this one: https://www.stereophile.com/content/topping-pre90-line-preamplifier it seems to have a volume control and display, so that might be nice if your DAC doesn't have a display.

What DAC is it?
 

TjindarSingh

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I've not used one.

There would be nothing preventing you using e.g. the Audiophonics amp and if you then found "something" was missing you could add a pre-amp later if there was some real benefit.

Edit: If you mean this one: https://www.stereophile.com/content/topping-pre90-line-preamplifier it seems to have a volume control and display, so that might be nice if your DAC doesn't have a display.

What DAC is it?
Sabaj a20d I've now tested with or without the preamp and my subjective feeling is that's better with the pre90 . Don't know why there is so but it feels/sounds a little better.
 

nemesis.ie

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With one of these Audiophonics amps? A blind test might be useful?

If you already have the gear and have tested it, I'm not sure what you are asking?
 

TjindarSingh

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With one of these Audiophonics amps? A blind test might be useful?

If you already have the gear and have tested it, I'm not sure what you are asking?
Just wondering if there's a benefit with the preamp in between. I will do a test later.
Thanks
 

nemesis.ie

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That's probably a) very subjective and/or b) depends on how the Topping pre compares with nothing/other preamps. ;)
 

nemesis.ie

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<Futurama style> "Good news everyone!"

I opened up the 4 channel unit today and as expected, the jumpers were all set to max gain (2-3, Gain+ on).

I first tried removing gain + and got a small improvement - the Purifi with the Trinnov on now had similar hiss to the Emotivas with the Trinnov off (but connected).

Next up, "bypass" and bingo, almost zero hiss, with the ear placed right on top of the woofer with the Altitude 32 on, there is the faintest amounbt of his, but nothing 2 cm further out. Previously it was very audible 40cm away and still audible at 3m seating with the 3 fronts all hissing (no attenuators).

All I had to do was put the calculate 16.3 dB gain into the Trinnov's output setting and it still plays content as loud as the room/ears can take.

I'm finally a hiss-free happy camper. :) So now to try and order another one with the bypass pre-set during the build, the 16 screws and jumpers underneath the cables was not fun at all.

On the plus side, black tape did get applied to the blue LEDs ... now that I think about it I should have used liquid tape, but too late. ;) I decided to just use tape on the front LED too, just in case I do sell it for some Apollon 12-ch ones in the future so I won't need to open it up and reconnect if a buyer wants the light on.
 

Rottmannash

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Glad you got it sorted- happy listening!
 

fourdogslong

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<Futurama style> "Good news everyone!"

I opened up the 4 channel unit today and as expected, the jumpers were all set to max gain (2-3, Gain+ on).

I first tried removing gain + and got a small improvement - the Purifi with the Trinnov on now had similar hiss to the Emotivas with the Trinnov off (but connected).

Next up, "bypass" and bingo, almost zero hiss, with the ear placed right on top of the woofer with the Altitude 32 on, there is the faintest amounbt of his, but nothing 2 cm further out. Previously it was very audible 40cm away and still audible at 3m seating with the 3 fronts all hissing (no attenuators).

All I had to do was put the calculate 16.3 dB gain into the Trinnov's output setting and it still plays content as loud as the room/ears can take.

I'm finally a hiss-free happy camper. :) So now to try and order another one with the bypass pre-set during the build, the 16 screws and jumpers underneath the cables was not fun at all.

On the plus side, black tape did get applied to the blue LEDs ... now that I think about it I should have used liquid tape, but too late. ;) I decided to just use tape on the front LED too, just in case I do sell it for some Apollon 12-ch ones in the future so I won't need to open it up and reconnect if a buyer wants the light on.
That's good news!
How does it sound with music?
 

nemesis.ie

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That's good news!
How does it sound with music?

Great! As did the previous amps, but at low volumes it's better without the hiss - although attenuators did help with that, it's not 99.9% fixed versus maybe 90%. :)

Zero to complain about, detailed and power (punch) when needed, kick-drums are perfect for example. I kind of feel it's "more responsive" and a "little tighter" than the Emotivas but that could be placebo and I've not had enough listening time or used similar material to be sure. I'll have a better idea when we watch the next Obi-Wan. :)

Also worth noting that I'm only running LCR and sometimes LR + FH with this amp for now, so there are still another 11 to 13 Emotiva driven speakers working in the room.

I have ordered another 4ch and a monoblock (for C) now and hope to have some friends over to do a blind test.

The plan is to set up a single speaker fed with a mono signal (or worst case 1/2 a stereo (!) and do a blind ABCXXX with Audiophonics Purifi, Emotiva XPA HC-1 and UPA-100. All monoblocks and different.

Purifi 400W D, SMPS
XC-1 600W, A/AB, SMPS
UPA-100, 300W A/AB, linear

I will not feed them from the Trinnov though, I'll use something that doesn't produce hiss, probably a simple DAC from my phone. Also using the purifi on max gain and then maybe switching it to bypass and adding it to the mix - but I suspect my listeners (or two of them anyway ) may be disinterested at that point.

So that could be a bit of fun. Maybe @amira would be interested in the results. If he was closer I'd send them over for testing/comparison.

Actually, I have an XPA-100 as well.
 

delgesu

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<Futurama style> "Good news everyone!"

I opened up the 4 channel unit today and as expected, the jumpers were all set to max gain (2-3, Gain+ on).
Mine are still on the way ... but: shouldn`t the default be the "middle" position, not max?
 

nemesis.ie

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Per the blog post with the settings, the middle "setting" of the 3 shown is the default one, which is the max gain one (with gain+ on).

Another thing to note, on the buffer board, the jumper layout is different on the two channels, one looks like those posted, the other is different with the 123 jumpers side by side instead of inline. i.e. the 2-channel buffer board in my 4 ch unit is different to the one in the blog pic.

I also note that it says "bridge" on two of the 4 connectors (the other two have "link"; so it seems if you connect only the two bridge outputs instead of all 4, you can bridge these. Maybe @Audiophonics can confirm that? A 4 channel unit could be great as a 2 x 800W (if that's what you get in bridged mode) if needed.

Configuration 2 (default)​

purifi_bypass_gain_2.jpg


Here is the high gain configuration for Audiophonics amplifiers equiped with Purifi modules.

By default the Purifi module applies a gain of 12.8dB to the signal.

The BUFFER jumpers in position 2/3 activate the operational amplifiers and add + 7.2dB of gain to the signal.

The active Gain + jumper brings the total gain to 25.3dB and the maximum power of the module is reached with a source signal of ~ 2.25V RMS.
 
Last edited:

anphex

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For the question about preamp usage: I use a SMSL Su-9n directly plugged into the Purifi amps, using its preamp mode. If your DAC outputs about 4 Vrms, like almost all good DACs do, the bypass gain setting should be optimal, even for very high levels.

I recommend it this way since you get SINAD for free and run all devices at their optimum.
Oh, and Purifi vs. Emotiva is just an unfair comparison :eek:
 

delgesu

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Would you recommend me using the bypass mode for my setup: DAC90SE ≥ PRE90 ≥ audiophonics ?
 

delgesu

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Sorry, but i have only very basic knowledge in technology. Here is a quote from audiophonics:
"The bypass mode is relevant in cases where the Purifi amplifier is used with a strong preamplifier supporting a load of 2 to 4kOhm with a voltage ~ 10V RMS."
Can someone please tell me the relevant output voltage of the Topping Pre90 - i cannot find it. Is it able "to support a load of 2 to 4kOhm with a voltage ~ 10V RMS"?
In case of questions: yes, i will use the Pre90 itogether with the DAC90SE as opposed to the DAC90SE alone.
 
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