Better Volume Control

I have a Pass Lab Preamp that controls the volume and a Denefrips Venus ll DAC. I just selected ‘Device’ control on the Devise Setup. The rooDial will respond to turning but it doesn’t change the volume when I am using DSD or anything else in the ROON DSP options. When I disable all other DSP options in ROON the rooDial works fine. Sadly, it seems it is one or the other- rooDial volume control or Usampling in ROON.

I’m I missing something?

That is indeed incorrect.

Lumin actually allows you to choose between two kinds of volume control. For analog output of X1, T2, or S1, you can choose the on-chip standard 32-bit ESS volume control (with Leedh setting off), or the Lumin proprietary Leedh implementation that takes advantage of hardware architecture (with Leedh setting on).

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Quite Interesting,
in this case I wonder what Leedh processing stands for? I am not interested in marketing speach but in technology behind it. Is there any material you can share? If necessary I am willing to sign a NDA.

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Hi Peter,
I thank you so much for your information.

I got, that needing less bits and despite of that having a perfect volume control is the idea behind Leedh volume control. great :slight_smile: I also understood the advantage of this approach implementing volume control in silicon :+1:

Would you please explain why this should be better as calculating volume with floating point math as Roon does with its DSP volume? Doing volume control in a CPU I don’t have to care about additional bits!

Here are some measurements I took regarding this topic and I have no idea where volume control might be improved above that:
The final truth about DSP Volume Control in Roon | Audio Science Review (ASR) Forum

I wonder how the graphs would look like measuring Leedh volume control?

Best DrCWO

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If I understand this correctly, a fundamental assumption is that the least significant bits in traditional calculation, although mathematically accurate, become noise due to the DAC hardware limits.

Whether this is true or not can only be verified by subjective listening tests. So far the majority feedback by reviewers and users are really positive. A few users even sold their preamp after being satisfied with this free firmware upgrade (but costs EUR5000 from another manufacturer).

As described above, Lumin allows you to choose the traditional 32-bit volume done by ESS vs the Lumin proprietary implementation of Leedh Processing Volume for analog outputs. It is designed in a way to facilitate A/B comparison if you have a Lumin. Users can determine for themselves whether this is audibly superior or not.

thank’s for your answer.

Yes, this is my assumption. So having a digital volume control where noise is far below the DACs (and even worse the amplifier’s) noise this seems to be OK for me.

For sure I understand that reviewers have to listen. I also did at a friend’s home who owns a X1 and the Lumin AMP.

My question just was about objective measurements and if an improvement can be seen there?

Best DrCWO

Hi, in terms of absolute Sound quality, what’s the best way to control volume? My amp doesn’t have a volume control…my two options are either to do volume control via my DAC (digital I presume) and keep Roon core at fixed volume or to keep my DAC in Pre-amp mode and control volume via the Roon app on phone.

Which one should sound better? I often can’t tell a difference so wanted a more informed answer.


If you can’t hear a difference I would do what’s easiest for you. Asking other peoples opinions will lead to dozens of different answers, none of which relate to your system in your room.


Some DACs support analogue attenuation. What DAC do you have?

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Hi, it’s a SMSL SU-9. It’s digital as far as I know.

The chain is Roon Rock to a IFI Zen streamer to SU-9 DAC via USB to the power amp.

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If you’re using a non Roon Ready solution, see which way allows you to adjust the volume without breaking DSD and MQA integrity.

Thanks. Not sure if Roon certification covers the volume management aspects as well ie that the certification ensures signal integrity when the volume is managed from Roon app…as I would imagine that would be same for all end points (volume being managed from Roon ROCK while DAC/device is in direct out mode). I could be wrong! Thanks

Hi, I am exploring the RooExtend solution for volume control and that’s where I am trying to understand that when doing it via the way you’ve implemented it (at Roon app via say with the MS Dial)…would that be superior or inferior compared to volume control via the preamp/DAC in terms of Sound Quality.


You will need to find that out for your own DAC, the connection method you’re using and your signal path, especially if it is not (network) Roon Ready, which is a different thing from Roon Tested.


I have a Microsoft Surface Dial arriving later today so that I can give rooDial a try. As far as I can tell, there’s nothing magical about how @DrCWO has implemented his solution apart from how it integrates beautifully with Roon. You’ll be using volume control features currently available in the Roon UI, including “Device Volume” (if supported by your DAC) or “DSP Volume”…in your case, I suspect the latter.

The only thing I don’t like about DSP Volume is that level calculations are done on the endpoint. The signal-path does not show this, but the signal is converted back to 64-bits, samples recalculated, and then converted to the bit depth the DAC driver expects, with dithering. This has two minor negative effects: CPU usage can nearly double on the endpoint, and the signal will be dithered twice if any processing is done on Core before sending to the endpoint (eg., volume leveling or format conversion).

The effects are small and probably not audible, but this is irksome to audiophiles who aspire to achieve bit-perfect playback. :wink:


Well, I am an audiophile who likes bit perfect audio for sure. I just tried the DSP volume control on Roon with my SMSL SU-9 DAC and I SW that dreaded green bulb for high quality. If Roodial is the same…Roon will say it’s High Quality (Green) in the signal path…and that I believe is not what I am looking for.

Btw, seems my DAC isn’t a great preamp :stuck_out_tongue_winking_eye:. Am in the market for a transparent balanced preamp or preamp + DAC that doesn’t suffer from Preamp volume control…

This is how I adjust volume with Roon for the best sound quality to my ears (Your ears may be different). It is NOT convenient. I use this method because I also use the Roon Parametric EQ for my speakers, so I am taking the hit of additional dither and processing already.

I use the Headroom Management instead of the Roon volume control. This is a different process than the Roon volume control and I think its higher quality (again, there is some debate about this). This works for about 75% of my listening. For listening at low volume, I need to add some Roon Volume control. But that listening is really not as critical anyways so I don’t mind it.

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Yes. I was too. I went with the excellent Topping Pre90/Ext90. Performance is beyond reproach. The main chassis is has a single pair of XLR and RCA inputs, and same for outputs. The optional Ext90 adds three more pairs of XLR inputs and another pair of RCAs. I’ve never heard a preamp that’s this transparent.

Good news is that at $600 (+ $250), it won’t break the bank. Here it is with my Gustard X16 DAC:

Decent range on the simple remote control as long as you make some attempt to point it in the right direction. :slight_smile:

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