Gain setting on Purifi power amplifier for WiiM Pro Plus

[layer9]

Hey guys,

I am switching from a WiiM Amp to a WiiM Pro Plus with Apollon 1ET400A Purifi power amplifier. My speakers are Elac FS 409.2 with 89db sensitivity.

The power amplifier comes with switchable gain settings: 12,8/20,5/27,5/29,0db.

Does anybody have a clue what might be the correct gain setting for the WiiM Pro Plus and for my speakers?

Thanks
Michael

 

[Mr Ee]

Hey guys,

I am switching from a WiiM Amp to a WiiM Pro Plus with Apollon 1ET400A Purifi power amplifier. My speakers are Elac FS 409.2 with 89db sensitivity.

The power amplifier comes with switchable gain settings: 12,8/20,5/27,5/29,0db.

Does anybody have a clue what might be the correct gain setting for the WiiM Pro Plus and for my speakers?

Thanks
Michael

The starting point for that would be the pro plus analog out setting.
0.5v? 1v? 2v?
Then comes how loud you want it to go and how quickly you want the volume to change.
With the volume slider in the wiim app you can, obviously, change volume very quickly to a given level.
With phone/tablet volume buttons it's more gradual.

Personally, I see no reason not to set the power amp gain as low as possible so that the wiim can be set to 2v, 100% volume limit and full volume such that your speakers are playing super loud but not 'dangerously' loud.
i.e. set up so that even if, for whatever reason, the wiim put out full volume then you'd still have your eardrums and your speakers
Some might prefer setting the wiim gain down a bit and the amp gain up a bit. tbh, I can't coment on the different merits of either approach.

Basically, I'd suggest starting low and working your way up to what seems most sensible / suitable for you.

 

[VintageFlanker]

Does anybody have a clue what might be the correct gain setting for the WiiM Pro Plus and for my speakers?

If you want the highest SINAD : WPP set at 2Vrms, then the Purifi at 27.5dB Gain.

In all cases, always check the output volume in WiiM app before turning on the power amp.

 

[bherren]

Hey guys,

I am switching from a WiiM Amp to a WiiM Pro Plus with Apollon 1ET400A Purifi power amplifier. My speakers are Elac FS 409.2 with 89db sensitivity.

The power amplifier comes with switchable gain settings: 12,8/20,5/27,5/29,0db.

Does anybody have a clue what might be the correct gain setting for the WiiM Pro Plus and for my speakers?

Thanks
Michael

I have a similar setup with a Pro Plus & Apollon NCx500.

With a 4V DAC output, I used initially 20.5dB and had plenty of volume. Then realised I could reduce it to 12.8 and I was still comfortable across the volume range, with no risk of blowing my speakers.

I took out the DAC and left the gain there with 2V and it's still pretty good for my room & my listening habits

I suggest you start with the lowest gain and if it's loud enough then leave it at that otherwise crank it up one notch.

Basically the higher the gain on the amp, the higher the noise/distortion. Those are so good it's probably inaudible but at least on paper, your SINAD will be better with the lower gain.

On the WiiM side, unless your PEQ settings cause clipping, it's the other way around. Since it's a digital volume, you should be better off having it as high as possible (minus margin for aforementioned PEQ caused clipping). Now the way WiiM implements the digital volume in the 32bit DAC means it probably doesn't matter, though it could matter if you used an external DAC. Again on paper, probably inaudible in practice

 

[bherren]

I have a similar setup with a Pro Plus & Apollon NCx500.

With a 4V DAC output, I used initially 20.5dB and had plenty of volume. Then realised I could reduce it to 12.8 and I was still comfortable across the volume range, with no risk of blowing my speakers.

I took out the DAC and left the gain there with 2V and it's still pretty good for my room & my listening habits

I suggest you start with the lowest gain and if it's loud enough then leave it at that otherwise crank it up one notch.

Basically the higher the gain on the amp, the higher the noise/distortion. Those are so good it's probably inaudible but at least on paper, your SINAD will be better with the lower gain.

On the WiiM side, unless your PEQ settings cause clipping, it's the other way around. Since it's a digital volume, you should be better off having it as high as possible (minus margin for aforementioned PEQ caused clipping). Now the way WiiM implements the digital volume in the 32bit DAC means it probably doesn't matter, though it could matter if you used an external DAC. Again on paper, probably inaudible in practice

Oh and I forgot, set the Pro Plus analog out to max (2V)

 

[layer9]

Thanks guys,

that helped me a lot. I will start with 12.8db then and check if it is enough for me. And I will always check the volume

Michael

 

[layer9]

Got the Purifi now: 12,8db is absolutely fine for me.

 

[rccarguy]

Thanks guys,

that helped me a lot. I will start with 12.8db then and check if it is enough for me. And I will always check the volume

Michael

Low gain on the power amp means you have to drive the pre amp higher

 

[rccarguy]

Is this as a guide

https://www.avforums.com/threads/how-much-input-voltage-does-a-power-amplifier-need.2395932/

 

[harkpabst]

Low gain on the power amp means you have to drive the pre amp higher

So, what?

 

[rccarguy]

So, what?

Due to the very low gain what is required voltage needed to the power amp and is the pre amp capable of that?

 

[rccarguy]

If he sets gain to 12.9, max pre out voltage 2V, 40W is the maximum he'll get when it's set to only 19db.

Need someone with bit more understanding of best setting relative to SINAD, and suitable gain setting

WiiM Pro Plus - Review & Measurements (Streamer)

WiiM Pro Plus - Review & Measurements Hi Folks, Here is another review, measurements-based, today about the WiiM Pro Plus (or "Pro+"). While some rumors already mentioned it for the last couple of months, it is just launched today (August 8) officially. The WiiM Pro Plus comes with a $220...

www.audiosciencereview.com

 

[Aquarius]

Low gain on the power amp means you have to drive the pre amp higher

That is exactly what you want with a digital volumecontrol so you loose as few bits as possible. High gain poweramp means that you can only use low volumes on pre/streamer and then will theoretically will lay in the dangerzone of losing bits.

 

[VintageFlanker]

Need someone with bit more understanding of best setting relative to SINAD, and suitable gain setting

Then quoting my review ?...

 

[layer9]

Is there an advantage in setting the gain higher than 12,8db? From a loudness perspective it gets as loud as I want it to get with 12,8.

 

[VintageFlanker]

Is there an advantage in setting the gain higher than 12,8db?

Yes. You can't reach max power out of 1ET400A with 2Vrms input.

From a loudness perspective it gets as loud as I want it to get with 12,8.

But apparently, you don't need that max power.

 

[layer9]

Thanks. Could there be an advantage having more power available for dynamics? I guess 40W is not much headroom. But still pretty loud with music tbh…

And: Will the amplifier clip sooner at lower gain settings due to power limitations?

 

[bherren]

Is there an advantage in setting the gain higher than 12,8db? From a loudness perspective it gets as loud as I want it to get with 12,8.

None at all, on the contrary. The input buffer is op amp based, increasing the gain will only increase noise and distortion. The idea setup is lowest gain on the power amp and highest digital volume on the streamer

 

[bherren]

Thanks. Could there be an advantage having more power available for dynamics? I guess 40W is not much headroom. But still pretty loud with music tbh…

And: Will the amplifier clip sooner at lower gain settings due to power limitations?

No it won't, at all.

The gain and power are different things

Gain is purely the multiplier the amplifier with apply to the input signal voltage. That's it. It defines your wanted "volume" in conjunction with your volume knob / settings. This is all about setting the signal voltage.

Note that how loud the sound is is yet something else and depends on both the 'volume' (gain) and your speakers sensitivity.

After that we are talking about the ability of your system (amp + speakers) to deliver the amplified signal through your speakers.

The power is the voltage multiplied by the current, the current is dependent on the voltage and ... the impedance well it's a mess, but basically think of it this way to simplify:

To deliver your desired signal, the amp will have to be able to generate an amplified signal with enough current to satisfy the speakers need (impedance).

If the amp doesn't have the power, it's won't be able to deliver the current, causing the voltage to drop and thus cause distortion.

Now the impedance of your speakers varies across the frequency range. The nominal impedance is just that. Some specific frequencies, esp around the crossover, might require more current (lower impedance).

the power of your amp determines its ability to deliver that current/ power.

So to summarise you set the gain to the volume you want to listen, if it means you don't use all the power available in the amp, so be it, it won't hurt you. It does mean though that at certain frequencies where the speaker impedance is lower than nominal the amp will have no problem delivering the extra current.

You are always better off using a lower gain on an amp. Always.

 

[layer9]

Thank you very much for that detailed explanation. Very much appreciated!