Any advantage to adding a passive preamp for Pro+?

[hoppy]

I have a simple stereo system with a WiiM Pro Plus feeding directly into a Adcom power amp then to vintage ProAc speakers. Only source is the WiiM for streaming Spotify and Amazon Music HD. Since I use the Pro+ as the volume control I have "fixed volume output" disabled.

Would there be any benefit to adding a basic passive preamp like the Schiit SYS so I can enable "fixed volume output" and control the volume in the preamp? Or is "fixed volume output" irrelevant if your audio output is "line out" because with "line out" the WiiM DAC is converting the signal to analog anyway?

 

[cooky560]

It depends on how the pro plus adjusts the volume, a pre-amp that's entirely analog can remove the bit reduction that occurs when lowering the volume digitally, and allow your source to remain bit perfect.

That said if you are happy with the sound as is, no point in spending more money.

 

[Balthazar B]

IMO, it is almost always better to handle volume and equalization control in the analog domain. It's largely a matter of principle, since I like to maintain a bit-perfect signal from the source to the DAC.

 

[harkpabst]

I'm a bit of a convert here. I used to claim how bad digital volume control is (or more precisely: must be, since I didn't have it), but my little Lyngdorf TDAI-1120 proofed me all wrong. 96 kHz 24 bit internal processing and the result is by far the best sound I ever had in my home.

 

[Mr Ee]

How do you (like to) control the volume?
Right now I assume it's likely to be from your phone/tablet, but possibly from the pro buttons?
With the Schiit I'd assume you couldn't do this 'remotely' as it doesn't have remote control (I think!).

 

[hoppy]

How do you (like to) control the volume?
Right now I assume it's likely to be from your phone/tablet, but possibly from the pro buttons?
With the Schiit I'd assume you couldn't do this 'remotely' as it doesn't have remote control (I think!).

It would certainly be easier to control the volume with the WiiM remote that comes with the Pro Plus, but I'm fine with using the volume knob on a device. As you mentioned, the Schiit SYS doesn't have a remote.

I'm willing to give up the remote volume control if the sonics would be better using a preamp.

 

[Mr Ee]

It would certainly be easier to control the volume with the WiiM remote that comes with the Pro Plus, but I'm fine with using the volume knob on a device. As you mentioned, the Schiit SYS doesn't have a remote.

I'm willing to give up the remote volume control if the sonics would be better using a preamp.

Want better sound?
Upgrade those vintage speakers

 

[hoppy]

Want better sound?
Upgrade those vintage speakers

Sure, but I’m trying to use gear I already own and not spend too much

 

[harkpabst]

Sure, but I’m trying to use gear I already own and not spend too much

Nothing to say against this.

But even if you are still interested in comparing the digital to analog volume control (if just for the warm and cosy feeling the words analog volume and control send down our spine and chest ), the Schiit SYS might just not be the perfect choice. Why? Because it's not a pre-amplifier.

It's an input switch and a (totally bog-standard) potentiometer. Not only doesn't it amplify anything (also see below), but more importantly it does not buffer (which in the analog world means as much as decouple) anything. It will increase the output impedance of the source as seen by the power amp and - depending on setting of the pot - will make it variable. This can potentially increase the influence of cable characteristics (in particular cable capacity) and will introduce a new dependency on volume setting. Plus you need to use two runs of cable instead of one now. This might or might just not be audible, but it's a degradation in any case, not magically right just because it's analog.

How are your typical volume setting right now when seriously listening to music? If your power amp's input sensitivity is very high (the voltage needed for full output power, low voltage = high sensitivity) and the volume control of your Pro Plus is usually in the 1 digit numbers percent range, then there might be a benefit in using a pre-amplifier. Obviously, you would not need additional amplification then (see above), but attenuation. In this case a passive "pre-amp" could work, but I would still prefer an active design (even with no additional gain) just to ensure a low output impedance.

 

[harkpabst]

If your power amp's input sensitivity is very high (the voltage needed for full output power, low voltage = high sensitivity) and the volume control of your Pro Plus is usually in the 1 digit numbers percent range, then there might be a benefit in using a pre-amplifier.

Re-reading my own post: Even in this case it it should be the better solution to adjust the maximum output voltage of the Pro Plus for 0 dBFS digital signal. I'm pretty sure it can be set to 2 V, 1 V and possibly even lower values.

 

[Steve Woodhouse]

IMO, it is almost always better to handle volume and equalization control in the analog domain. It's largely a matter of principle, since I like to maintain a bit-perfect signal from the source to the DAC.

With 10-band OEQ, that’s an absolute sh*t show of a signal path, and far more likely to degrade signal quality than a couple of bits in digital. The latter, whilst not being bit perfect, should only alter the EQ.

Analogue preamp? If it’s good, far less of an issue, and most certainly inaudible.

 

[steadyshot]

Volume control in Wiim pro plus is lossy . Reducing it few percent is alright but having it at 30-50% to adjust for desired listening volume with your power amp will definitely harm the sound . You need proper volume control… therefore an analogue pre amp

 

[hoppy]

Thanks everyone for your tips. In the end, I decided to get a passive preamp, the Schiit SYS. It's working great.