When is a lower voltage DAC better?

[olds1959special]

I've noticed DAC's have varying output levels. My SMSL DL200 is way louder at max volume than my SMSL SU-1 or Qdelix 5K.

 

[staticV3]

Only scenario I can think of is if you're using a Power Amp with high amount of gain.

In that case, a DAC with low output voltage would help maximize SNR, and minimize the risk of accidental sound explosions.

 

[DVDdoug]

If you have an analog volume control following the DAC, no difference.

But if you are attenuating digitally, you loose 1 bit of resolution for every 6dB of attenuation. (Analog attenuation isn't "perfect" either, but it's a little complicated and it's really any re-amplification after attenuation that's the problem.)


...You also lose resolution when the program drops in level- If you're playing a CD (16-bits) and a song fades-down to -48dB, you're down to 8-bits! But it still sounds fine unless you have some way of re-amplifying by 48dB at that point in the song. ...The analog noise on a vinyl record would be EVEN WORSE amplified by 48dB!

 

[olds1959special]

Only scenario I can think of is if you're using a Power Amp with high amount of gain.

In that case, a DAC with low output voltage would help maximize SNR, and minimize the risk of accidental sound explosions.

I was using the balanced output of my SMSL DL200 into a Fosi ZA3 and it was super loud even when barely turning up the knob making it unsuitable for low level listening. Then I plugged in the SU-1 into the RCA input of the ZA3 and used that instead and the issue improved somewhat. It's still super loud with the volume turned almost all the way down on my system, but there's a bit more room now, and channel imbalance with low volumes is not as much of an issue.

 

[MaxwellsEq]

I've noticed DAC's have varying output levels. My SMSL DL200 is way louder at max volume than my SMSL SU-1 or Qdelix 5K.

Very old preamplifiers designed before digital expect line level signals in the 1V range and can be overloaded or have very limited volume control rotation with high output DACs.

 

[solderdude]

I was using the balanced output of my SMSL DL200 into a Fosi ZA3 and it was super loud even when barely turning up the knob making it unsuitable for low level listening. Then I plugged in the SU-1 into the RCA input of the ZA3 and used that instead and the issue improved somewhat. It's still super loud with the volume turned almost all the way down on my system, but there's a bit more room now, and channel imbalance with low volumes is not as much of an issue.

Lower the volume in the software player.. or use an attenuator between the DAC and amp... or buy an amp with a lower sensitivity.
Problem solved.

 

[jed1]

I have a similar issue but it's not as severe as OP's case. For me, max volume on DO100 Pro is about 75% when feeding Kali IN-8 V2 at 0dB input gain. At max, I probably loose 1 bit out of 24 bit, which shouldn't be audible. But, if I want to optimize the gain structure, I probably need about either 3 or 5dB pad. I found the following article (line level case) useful. One can solder 3 small resistors inside of XLR connector (U-pad)

https://www.audiotechnology.com/tutorials/on-the-bench-pads

This method is likely the cheapest solution without modifying DAC and Amp. I hope this helps. Let us know if you implement this type of inline pad.

Thanks,

 

[Chrispy]

What voltage are you referring to particularly?

 

[jed1]

I use SMSL DO100 Pro with 5.2Vrms for balanced output. It's too hot for Kali IN-8 V2. 75% output volume at DAC seems to be maximum volume I can listen when Kali IN-8 V2 input gain is set at 0dB. That translates to 3.9Vrms (75% of 5.2Vrms). I need -2.5dB inline pad. That's a small amount of attenuation. If I bought a DAC with 4Vrms output, that would be perfect.

 

[Davide]

If the residual dynamic range of the DAC, net of the digital attenuation used for listening, is greater than or equal to the dynamic range of the amplifier there is nothing to worry about.
But even if it is lower you will hardly be able to hear problems...
Typically the dynamic range decreases as the digital volume decreases, but even for our ears are more difficult to hear what tends towards noise floor.
In practice, DACs have more and more output voltage than necessary, or amplifiers have a lower input sensitivity than necessary, if you want to see it in reverse.
The technically best way to match them could be an analog attenuation pad. But the resulting impedance of the circuit and the accuracy of the resistors could introduce worsening as well as those you would have with digital attenuation.
To do this it would be ideal to have a high-level output like 20dBu, so you can use a high attenuation pad that involves fewer impedance problems than a low attenuation one.
Let's say that the pad is not recommended under 10dB of attenuation. But with a DAC that comes out at 4 or 5 Vrms 10dB it's too many to reach 100% of the amplifier output.
But it may also be enough to reach the desired listening level, depending on the gain of the amplifier.

It is all very specific and must be evaluated on a case-by-case basis.

 

[olds1959special]

I just tried the low gain setting of my SMSL DL200 and it helped with the issue.

 

[Bleib]

I just tried the low gain setting of my SMSL DL200 and it helped with the issue.

Isn't that just for headphones?

 

[Stereodude]

I use SMSL DO100 Pro with 5.2Vrms for balanced output. It's too hot for Kali IN-8 V2. 75% output volume at DAC seems to be maximum volume I can listen when Kali IN-8 V2 input gain is set at 0dB. That translates to 3.9Vrms (75% of 5.2Vrms). I need -2.5dB inline pad. That's a small amount of attenuation. If I bought a DAC with 4Vrms output, that would be perfect.

What does "75% output volume at DAC seems to be maximum volume I can listen" mean? Your ears can't take it any louder or you encounter a distortion problem? And how are you determining that you're at 75% of the 5V voltage output? Did you measure it?

Unless you're clipping the input stage of the amplifier in the powered monitors you don't have an issue with the output from your DAC being too hot. Turn down the input gain on your powered monitors.

 

[Stereodude]

Only scenario I can think of is if you're using a Power Amp with high amount of gain.

In that case, a DAC with low output voltage would help maximize SNR, and minimize the risk of accidental sound explosions.

Or if you're clipping the input of whatever the DAC is plugged into.

 

[olds1959special]

Isn't that just for headphones?

Apparently not. I changed to low gain and the XLR output got quieter.

 

[Bleib]

Apparently not. I changed to low gain and the XLR output got quieter.

Hmm, because manual states

Headphone Gain
low gain 0dB
high gain 11dB

 

[restorer-john]

A low output or adjustable level D/A converter is useful if you have a number of sources with different fixed output levels and a traditional preamplifier or integrated where individual source level controls are not catered for.

Nothing worse than going from one source to another with massive changes in level for the same volume position.

For people these days with hardly any sources and many without a preamplifier at all, or level controls, they probably don't consider it an issue.

Good preamplifiers from the past had level control adjustments on the rear panels for different inputs, and most good source components had adjustable output levels either on the front or the rear panels. Back then, manufacturers didn't cheap out on the important things.

 

[JIW]

I was using the balanced output of my SMSL DL200 into a Fosi ZA3 and it was super loud even when barely turning up the knob making it unsuitable for low level listening. Then I plugged in the SU-1 into the RCA input of the ZA3 and used that instead and the issue improved somewhat. It's still super loud with the volume turned almost all the way down on my system, but there's a bit more room now, and channel imbalance with low volumes is not as much of an issue.

The Fosi ZA3 has the same gain for XLR and RCA input - 26 dB or 20x - but XLR levels tend to be twice as high. This is not the most clever design. It reaches maximum output at an input of around 1.4 V RMS or 3 dBV. The RCA output of SU-1 is 2 V RMS or 6 dBV but the XLR output of the DL200 is 5 V RMS or 14 dBV.

Unless you have a noise issue with the RCA connection, use the DL200 with RCA connection and set the volume control to 88 which is -5 dBr or 3 dBV output. Then set the volume control on the amplifier so that is as loud as you would ever want it or you hear distortion. After that, control volume via the DL200. If you have a noise issue with RCA, use XLR but set volume to 74 which is -11 dBr instead and do as above.

 

[JIW]

I have a similar issue but it's not as severe as OP's case. For me, max volume on DO100 Pro is about 75% when feeding Kali IN-8 V2 at 0dB input gain. At max, I probably loose 1 bit out of 24 bit, which shouldn't be audible. But, if I want to optimize the gain structure, I probably need about either 3 or 5dB pad. I found the following article (line level case) useful. One can solder 3 small resistors inside of XLR connector (U-pad)

https://www.audiotechnology.com/tutorials/on-the-bench-pads

This method is likely the cheapest solution without modifying DAC and Amp. I hope this helps. Let us know if you implement this type of inline pad.

Thanks,

The value 75 is not the percentage of the maximum level. If it is coded like other SMSL DACs like the D-6s and the DL200, it is -11.5 dBr or 2.5 dBV - around 1.33 V - and not 75% or 4 V.

Also, the internal data path of the DAC is 32 bit so there is no loss of bits before 48 dB attenuation for 24 bit files and 96 dB attenuation for 16 bit files.

You can also just reduce the input gain of the KALIs.

 

[Miguelón]

I use SMSL DO100 Pro with 5.2Vrms for balanced output. It's too hot for Kali IN-8 V2. 75% output volume at DAC seems to be maximum volume I can listen when Kali IN-8 V2 input gain is set at 0dB. That translates to 3.9Vrms (75% of 5.2Vrms). I need -2.5dB inline pad. That's a small amount of attenuation. If I bought a DAC with 4Vrms output, that would be perfect.

Same thing on my Ifi DAC signature, my Genelecs are very sensitive and even at minimum gain never turn the DAC volume beyond 50%.

May RCA output be better for the case? Scarifying balanced circuits I can reduce voltage to a half