Roon or DAC best volume attenuation

[adriano_longo]

Hi everyone, my name is Adriano and I write from Italy.

I would kindly have some questions about the various ways to attenuate the signal coming from the D30pro Topping DAC that goes into the preamplifier with a sensitivity of 270mv. Being very sensitive I have a hard time listening at low volumes and then it seems to me that if I turn up the volume a little the amp goes into saturation too soon. Hence the need to attenuate the signal from the DAC.

I state that I use Roon, I move on to the questions:

1. I understood that without using any volume adjustment on Roon I get a bitperfect signal, while if I use DSP volume it is no longer bitperfect, but I don’t seem to hear any difference. right?

2. If I use “device volume” , Roon tells me it’s going bit perfect, but is it really like that? I mean, once the DAC does digital attenuation it’s no longer bitperfect right?

3. If I use “fixed volume” and then use the DAC knob to regulate volume, am I attenuating in the same way as the previous point?

4. Is it possible that the digital attenuation of Roon is better than that of the DAC (or vice versa) or are digital attenuations are all the same?

[Suedkiez (Just a fellow user like you)]

@adriano_longo

I understood that without using any volume adjustment on roon I get a bitperfect signal, while if I use dsp volume it is no longer bitperfect, but I don’t seem to hear any difference. right?

Roon uses volume adjustment in 64-bit space and while artifacts are unavoidable, they are far beyond anything a DAC can resolve

@adriano_longo

if I use “device volume” , roon tells me it’s going bit perfect, but is it really like that? I mean, once the dac does digital attenuation it’s no longer bitperfect right?

Roon only knows what happens up to the DAC. If there is digital volume control in the DAC, it’s necessarily not bit perfect, but Roon doesn’t know about that

@adriano_longo

is it possible that the digital regulation of roon is better than that of the dac (or vice versa) or in digital the attenuations are all the same?

It’s possible that one is better. Digital volume controls are definitely not all the same. Roon’s is very good, though. Here is an analysis by a fellow forum member:

https://www.audiosciencereview.com/forum/index.php?attachments/whitepaper-roon-dsp-volume-measurements-pdf.131355/

[Marian (I stand with Ukraine)]

@Suedkiez

If there is digital volume control in the DAC, it’s necessarily not bit perfect

That would depend on how it’s implemented. In theory, it could be a digitally controlled analog gain, although I admit I don’t know how D30pro does it.

[Suedkiez (Just a fellow user like you)]

That’s true, but I wrote “If there is digital volume control in the DAC”, based on the OP’s “once the DAC does digital attenuation”. In your case it would not be a digital volume control but a digitally controlled analog one. If the OP has that in the DAC, it’s certainly worth considering. Now where is my Naim Statement

[adriano_longo]

Thank you for your comment and for the very interesting measurements attached

[adriano_longo]

Thank you…can you explain to me what means digitally controlled analog volume control? Is a kind of passive preamp?
M2tech young mk3 has this kind of volume control, for ex.

[Suedkiez (Just a fellow user like you)]

Naim Statement has this for example (and the new NSC222 that inherited it), in this case a switched resistor volume control. The volume is adjusted in the analog domain by reed relays, but the switching of the relays is controlled digitally. So you can have an analog volume control but can do digital volume adjustment from an app, e.g. within Roon.

There are other ways to do that (you could have a simple analog potentiometer that is turned by a digitally controlled motor)

[CrystalGipsy (Resisting the flow!)]

The Atom, Star and Nova all have a digitally controlled analogue volume control.

[adriano_longo]

Ok I understand, more or less
So this kind of attenuation is to prefer (having a dac that has it) to the dsp of Roon?

[Suedkiez (Just a fellow user like you)]

True, the Statement and NSC222 have the fancy switched-relay one

[Marian (I stand with Ukraine)]

(The term “digital volume control” is ambiguous, since it’s not clear whether the volume is digital or only the control.)

The D30Pro does have a preamp feature, but again, it’s not clear to me how it’s implemented, and I suspect the OP doesn’t know for sure either:

[Suedkiez (Just a fellow user like you)]

@adriano_longo

So this kind of attenuation is to prefer (having a dac that has it) to the dsp of Roon?

Not necessarily. Only if its a very good analog (digitally adjusted) one. There are poor analog volume controls, too. It depends on your DAC

[adriano_longo]

Another solution could be an external attenuator like the Rothwell rca attenuator

[Marian (I stand with Ukraine)]

Since you have Roon and also have a DAC that can attenuate the output, I don’t think another piece of hardware is necessary.

[Bill_Janssen (Wigwam wool socks now on asymmetrical isolation feet!)]

An example of a digitally controlled analog volume control chip: CS3308/18 | Cirrus Logic

[WiWavelength (Andrew J Shepherd)]

@adriano_longo

I would kindly have some questions about the various ways to attenuate the signal coming from the D30pro Topping DAC that goes into the preamplifier with a sensitivity of 270mv.

What kind of a preamp is overdriven by a standard 2 V single ended output from a DAC? Are you familiar with voltage sensitivity specs and citing this figure properly? Are you actually experiencing issues or just being overly concerned?

AJ