I thought I’d share some thoughts here some might find helpful:
To illustrate: my amplifier, a benchmark AHB2 can be set to have an input sensitivity of 22 dBu, or 14.2 dBu, or 8.2 dBu.
If I select 22 dBu, my DAC, can only output a maximum of 20 dBu. I lose 2 dBu which is not great.
So I have chosen the second option, 14.2dBu. I set my DAC to an output of 20 dBu. My Audiolense correction at the present time is set to 0 dB, so I have dialed 5.8 dB attenuation for headroom in Roon.
This ensures that the effective output from my DAC is 20-5.8= 14.2dBu. This improves my signal-to-noise ratio, and gives an exact match for my amplifier’s input. It also prevents any intersample overs, i.e. no clipping.
If I chose 8.2 dBu, I would have even more room to play (say 4 dB headroom in Roon for intersample overs, 8 dB for Audiolense correction). The downside is my amp’s SNR would be a bit worse.
This might be self evident to some, but I thought it might help some people (esp if you have an adjustable DAC output like a MOTU or Lynx Hilo, and/or adjustable amp input sensitivity).
- If your Dac has an adjustable output voltage (my Motu has a trim that varies output from -4 to + 20 dBu), you should adjust it to match your amp’s input sensitivity. Too low and you won’t get as loud as you could, or conversely too high, your amp will clip.
- The higher the dBu output of your DAC, the better signal to noise ratio.
- Audio signals can exceed 0 dBFS due to intersample overs. This becomes more obvious when you upsample your 44.1 kHz source. Programs like Roon, and DACs like benchmarkmedia have headroom management to get around that.
- Audiolense attenuates your signal depending on the configuration settings you choose (often people pick 6-10 dB, I’ve presently set mine to 0 dB). If your amp doesn’t have enough gain, or your speakers are not sensitive, you might not be able to play as loud as you’d like.
To illustrate: my amplifier, a benchmark AHB2 can be set to have an input sensitivity of 22 dBu, or 14.2 dBu, or 8.2 dBu.
If I select 22 dBu, my DAC, can only output a maximum of 20 dBu. I lose 2 dBu which is not great.
So I have chosen the second option, 14.2dBu. I set my DAC to an output of 20 dBu. My Audiolense correction at the present time is set to 0 dB, so I have dialed 5.8 dB attenuation for headroom in Roon.
This ensures that the effective output from my DAC is 20-5.8= 14.2dBu. This improves my signal-to-noise ratio, and gives an exact match for my amplifier’s input. It also prevents any intersample overs, i.e. no clipping.
If I chose 8.2 dBu, I would have even more room to play (say 4 dB headroom in Roon for intersample overs, 8 dB for Audiolense correction). The downside is my amp’s SNR would be a bit worse.
This might be self evident to some, but I thought it might help some people (esp if you have an adjustable DAC output like a MOTU or Lynx Hilo, and/or adjustable amp input sensitivity).
