Pro Plus: Line Out Level

BadMan

Major Contributor
Joined
Jul 31, 2023
Messages
59
Hello, I am using Heed Elixir integrated amp with an input sensivity of 135 mv. Which line out level should I choose in your opinion on my WiiM Pro Plus?
Are there any sonic differences between the 4 line out levels?
Thank you
 
I don't know about sonic differences between the different levels on a pro plus (try them!), but otherwise I'd suggest you choose the level that allows you to adjust the amplifier's volume with the precision you require, and to play at the volume you require.
e.g. 2v output might mean a small change in amp volume knob rotation produces a large change in volume.
0.5v might mean it's never loud enough.
Maybe one of the measurement freaks (you know I mean it nicely ;)) can comment on any impact of different output levels.
 
sensitivity is correct, using volume limiter no fixed volume output possible right?
It can fixed or variable. The volume limiter tells what's the max volume level possible.

Of course you can also use higher output levels, but it will increase the risk of clipping when amp volume knob is set too high.
 
It can fixed or variable. The volume limiter tells what's the max volume level possible.

Of course you can also use higher output levels, but it will increase the risk of clipping when amp volume knob is set too high.
Thank you, think will use 500 mVrms and fixed volume, do I get then bitperfect output?
 
Best advice I have heard and followed for many years is that it best to send the highest level, just below distortion level, out of each device in the chain, digital and/or analog, this allows the highest resolution and dynamic range at the end point, the speakers thus into our ears.
 
Best advice I have heard and followed for many years is that it best to send the highest level, just below distortion level, out of each device in the chain, digital and/or analog, this allows the highest resolution and dynamic range at the end point, the speakers thus into our ears.
Yes, especially in the analog world . Its a bit different if digital attenuation is needed, I think. One has to try and listen what sounds best.
 
I have a similar situation (amp with 150mv inputs) I set my pro plus to 500mv with the volume in the “fixed” setting. This makes the WiiM the same volume as my turntable. That’s a win in my book.
 
I also got a 150mv sens amp on inputs, anyone know best line out voltage &/or volume limiter to use with this
 
no, not to my knowledge, was just wondering if anyone as some magical mathematical method of working out what the best line out voltage is between the 4 options in the app settings, to avoid clipping but be as close as possible with that amps 150mv sensitivity, but still using the ‘fixed volume output’ enabled
 
no, not to my knowledge, was just wondering if anyone as some magical mathematical method of working out what the best line out voltage is between the 4 options in the app settings, to avoid clipping but be as close as possible with that amps 150mv sensitivity, but still using the ‘fixed volume output’ enabled
It won't clip even if its 2vrms on a 150mv input, unless you are listening very loudly.

There's a post about this on audio karma, but basically if the input voltage is higher than the amps input sensitivity, it will reach maximum volume before the dial is at max.
 
It won't clip even if its 2vrms on a 150mv input, unless you are listening very loudly.

There's a post about this on audio karma, but basically if the input voltage is higher than the amps input sensitivity, it will reach maximum volume before the dial is at max.
That's it.

For purely psychological many people prefer to only use the lower half of there volume knob (virtual or not). It gives them the feeling of a more beefy amp (even if it isn't). They will even "hear" how tied up and congested an amplifier (or any other device) sounds, just because the volume control setting has reached the upper half ...

Digital clipping OTOH must be strictly avoided in any case. It will sound awful immediately.
 
That's it.

For purely psychological many people prefer to only use the lower half of there volume knob (virtual or not). It gives them the feeling of a more beefy amp (even if it isn't). They will even "hear" how tied up and congested an amplifier (or any other device) sounds, just because the volume control setting has reached the upper half ...

Digital clipping OTOH must be strictly avoided in any case. It will sound awful immediately.
This reminds me of the volume "advertising" that many vintage amps suffer from. The sort that have 0 - 10 rather than db measurements, where 1 is quiet 2 is loud 3 is very loud and 4-10 doesn't really do anything
 
Something I have missed about voltage matching is peak rms. You need to multiply by square root of 2 the rms voltage : Eg. 2v=1.977rms -> Peak rms 1.977x sqrt2= 2.8v
 
Something I have missed about voltage matching is peak rms. You need to multiply by square root of 2 the rms voltage : Eg. 2v=1.977rms -> Peak rms 1.977x sqrt2= 2.8v
Strictly speaking there's no such thing as peak rms. A value is either provided as the root mean square (rms) or as peak (more alternatively: peak to peak or pp).

The constant factor of sqrt(2) is valid for a pure sine wave, only (Vrms = 1/sqrt(2) * Vp = 1/(2 * sqrt(2)) * Vpp).

Most importantly, you have to know how input sensitivity has been specified, rms or pp. Usually amplifier's sensitivity should be given in Vrms, not Vpp or VP.

(Edited, because original version was rather confusing.)
 
Last edited:
Strictly speaking there's no such thing as peak rms. A value is either provided as the root mean square (rms) or as peak (more precisely: peak to peak or pp).

The constant factor of sqrt(2) is valid for a pure sine wave, only.

Most importantly, you have to know how input sensitivity has been specified, rms or pp. Usually amplifier's sensitivity should be given in Vrms, not Vpp.

Yes indeed it is peak voltage and rms is the average . But you need to take into consideration the peak voltage that can be output from the dac to avoid clipping
 
Back
Top