Is a preamp needed?

[March Audio]

I've mentioned this many times for people. Go away for a holiday, come back, sit down to listen to music and your D/A has defaulted to 0dB. Boom! Power cuts can do this also. There's no substitute for a real volume control in my opinion, especially if you have a lot of power on tap and expensive speakers.

The likelyhood of this is no greater, probably less so, than leaving an analogue volume up high, or being accidentally knocked, and yes I have done this on a number of occasions and blasted the bejesus out of me.

How many bits of kit have digital volume controls? There isn't an AV amp out there that has an analogue volume control. Do you ever hear of them defaulting to full volume? No. Does your TV default to full volume? Phone, car radio?

Real world digital volume is a non issue, noise levels with good dacs are below audibility. Channel balance will be way better with digital.

See here for Roon volume V Alps pot.

https://www.audiosciencereview.com/...-to-dig-that-is-the-question.5951/post-133165

In my experience, FWIW, is that taking the pre amp out and driving directly has never degraded audio quality and most of the time improved it.

 

[Kal Rubinson]

Just found in user manual that there is a volume memory function.
This basically say that after a restart, if volume was set below zero it will get back to the volume set last time... So no issue if well implemented

The exaSound DACs have this feature.

 

[Kal Rubinson]

Physical controls can also be easily knocked whilst the system if off, e.g. when cleaning. There isn't a perfect solution, unless the digital system implements well thought through safe guards.

I am currently using two physical volume controls with my JRiver-based system. One is USB connected to the host PC and the other is a BT knob. Both will adjust the 64bit VC in Jriver or the VC in my exaSound e38 DAC. Both send Volume up/down signals when rotated so the physical position of the knobs is irrelevant as is what you do with them when the system is not up and running. As a result, after powering down intentionally or consequent to power failures, the system starts up where it left off.

 

[BeepPeep_61]

Hi everyone, I have been using the DAC for years (first an OPPO Sonica and now a miniDSP SHD) connected directly to my two Mc Intosh MC601 finals, and I must say that I prefer this solution to the one that included a pre MX119 inserted on the line of preamp.
"To my ears" the reproduction appears more defined and also the dynamics seems to have enjoyed it (this obviously without considering the contribution of DIRAC with the new DAC)!
Even the SHD miniDSP keeps the memory of the last set volume level at least up to 24 hours of disconnection, while when it arrived, at the first power on default it started from -98dB.
Here in Italy it is 17.03 and in this late afternoon I am listening to the latest Tine Skolmen album - Here’s to Life., To listen to !! ... I'm crazy about female jazz voices !!

 

[Soniclife]

I am currently using two physical volume controls with my JRiver-based system. One is USB connected to the host PC and the other is a BT knob. Both will adjust the 64bit VC in Jriver or the VC in my exaSound e38 DAC. Both send Volume up/down signals when rotated so the physical position of the knobs is irrelevant as is what you do with them when the system is not up and running. As a result, after powering down intentionally or consequent to power failures, the system starts up where it left off.

I think I'd describe those as software volume controls, just much nicer to use than traditional RC remote, similar to my Devialet remote.

The software defines startup source and volume, and how the volume responds when changing input.

 

[Novak]

the other is a BT knob... will adjust the VC in my exaSound e38 DAC.

How do you do that? Do you have a reference?

 

[Kal Rubinson]

I think I'd describe those as software volume controls, just much nicer to use than traditional RC remote, similar to my Devialet remote.

Yes but with a physical knob.

 

[Kal Rubinson]

How do you do that? Do you have a reference?

Microsoft Dial.

 

[Novak]

Microsoft Dial.

This looks nice but how can it interoperate with your Dac?

 

[Kal Rubinson]

This looks nice but how can it interoperate with your Dac?

Ah. The (not so) secret is that exaSound has an applet that lets JRiver (and some other players) to control the volume on their DACs if using exa's ASIO driver. I simply programmed the Dial to output the keystroke codes that Jriver uses for Volume UP/DOWN and MUTE.

Without an exa DAC or applet, it would control the internal 64bit VC in JRiver.

 

[ernestcarl]

Am I the only one...to always check volume before turning on my power amp?!

I don't check as often as I used to before since there are several safeguards that I've set in place -- e.g. each speaker is volume calibrated, default startup volumes in place (works with crashes and resets), even with 0dBFS signal volume from SW applications and HW chain levels should never exceed 90- to a little above ~100dB. Using only active speakers that have built-in protection helps e.g. Neumann KH120s have
"independent thermo limiters for woofer, tweeter; woofer soft clip and excursion limiters; amplifier overheat" as well as an alarming front (red flashing) light indicator.

 

[bennetng]

This looks nice but how can it interoperate with your Dac?

Absolutely, I prefer to do that way. When modifying "DSP volume", Roon says the signal is no more "lossless" . I don't know if this is of any importance but when using DSP effects gains : no such issue.

It seems to me that you prefer to use the volume control on the DAC rather than the one on the playback software.

It also seems to me that your interpretation on "lossless" (despite how Roon describes it) made you prefer to use the volume control on the DAC rather than the one on the playback software.

However you should interpret these things in a different way. Think about PI. It can be represented in 3.14, 3.1415927, 3.141592653589793 and so on, but these numbers are all lossy.

You should instead interpret "lossless" as "lossless at a certain precision". For example 3.1415927 is a lossless representation of PI at 32-bit float precision. -6.0206dB is a lossless representation of 50% volume reduction at 32-bit float precision.

Aftermarket DAC chips nowadays accept up to 32-bit fixed point data, so you can only feed these DAC chips up to this precision and range to achieve a "lossless" data transfer. Quite a number of software players support up to 64-bit float precision and they have no problem in representing 32-bit fixed point data.

Try these files (and read the replies up to page 5):
https://www.audiosciencereview.com/...y-of-software-volume-control.5922/post-172865

...and try this calculator:
https://www.audiosciencereview.com/...depth-should-i-set-my-dac-to.8956/post-255104

If you need a physical volume controller, Google "HID volume control". It is the standard used in the Media keys (including volume control) on typical USB keyboards. You just need to find a standard compliant controller in the form you like (button/knob/fader etc) and use a playback software capable of receiving the control signals.

 

[Kal Rubinson]

If you need a physical volume controller, Google "HID volume control". It is the standard used in the Media keys (including volume control) on typical USB keyboards. You just need to find a standard compliant controller in the form you like (button/knob/fader etc) and use a playback software capable of receiving the control signals.

I have been using this with JRiver:

 

[Burning Sounds]

I have been using this with JRiver:

Yes, I use this too, very reliable. I also have an MS Surface Dial, but find this inexpensive USB unit is more responsive. I wish there was a WiFi version.

JRiver's startup volume setting is excellent and even with the very rare instances when my PC has crashed or frozen it has never sent 0db signal to my poweramp on restart. After a certain period of inactivity JRiver also reverts to the startup volume setting. The inability to set a startup volume in Roon was one of the reasons I decided to stick with JRiver.

My Mytek 8 channel DAC also enables me to set output levels for each channel using trimpots - that way I can optimize JRiver's internal 64 bit volume control.

 

[Kal Rubinson]

Yes, I use this too, very reliable. I also have an MS Surface Dial, but find this inexpensive USB unit is more responsive. I wish there was a WiFi version.

I agree about all this but, for now, the combination works for me.

 

[Burning Sounds]

I agree about all this but, for now, the combination works for me.

Your BT connection may be better than mine. I fine the Dial takes a few turns to wake up sometimes.

 

[MRC01]

...
1) good analog volume control has less distortion for low level set and does not create digital spuriae in spectrum,
2) very good preamp may have lower output noise then digitally controlled DAC volume
...

This is worth repeating. Some of the best DACs measured here have a significant reduction in SINAD at the low to medium output levels actually used during listening. As you turn down the volume, you're turning up the noise (relatively speaking - the SINAD drops with volume). In some cases it's close to 1:1, for example a DAC that has a 120 dB SINAD at its max output of 2 Vrms, might drop to around 88 dB at 50 mV (32 dB quieter, 32 dB worse SINAD). We don't listen at full output and the SINAD usually drops when you turn it down, even if the drop isn't always 1:1.

In this sense it's a bit misleading to say that a DAC has a 120 dB SINAD if you're not listening at full output and the SINAD is only 88 when you turn the volume down to actual listening levels.

With such a DAC, it's worth considering not using its own volume control, but driving its full output into a separate component (preamp, passive attenuator, whatever) that attenuates the signal with less drop in SINAD. A preamp doesn't always add noise & distortion, compared to the path the signal would have without the preamp. It's at least possible that a really good preamp may be cleaner than the attenuation built into some DACs.

 

[Filio45]

Some of the best DACs measured here have a significant reduction in SINAD at the low to medium output levels actually used during listening. As you turn down the volume, you're turning up the noise

That applies to the ADI-2 on rca/xlr out?

 

[MRC01]

That applies to the ADI-2 on rca/xlr out?

In a word, yes. The ADI-2 has significantly lower SNR at low to moderate output, than it does at full volume. Its 1/4" output measured 117 dB SNR which is excellent. But when you turn it down to normal listening levels (50 mV), the SNR drops to 85 dB.

The ADI-2 also has a dedicated IEM output that reduces noise at low output levels. It measures 93 dB SNR at 50 mV.

This all straight from Amir's review: https://www.audiosciencereview.com/...ents-of-rme-adi-2-dac-and-headphone-amp.7546/

 

[orangejello]

This is worth repeating...
With such a DAC, it's worth considering not using its own volume control, but driving its full output into a separate component (preamp, passive attenuator, whatever) that attenuates the signal with less drop in SINAD. A preamp doesn't always add noise & distortion, compared to the path the signal would have without the preamp. It's at least possible that a really good preamp may be cleaner than the attenuation built into some DACs.

That is exactly what I do with my RME. I use a passive preamp that was custom built with excellent attenuators and switches. If you don’t have impedance matching issues with your amp this kind of setup has vanishingly low noise and distortion and allows the DAC’s SINAD to be put to optimal use. It also works for my phono setup.