User's Manual

User’s Guide ADI-2 DAC v2.2 © RME

31.13 Operation in the Hi-Fi Environment

Do the advantages of the ADI-2 DAC's fully symmetrical design still exist when using

unbalanced connections (RCA)?

Yes. On the output side RME uses a specially developed servo-balanced DAC filter, which pro-

vides both paths of the balanced design with full noise and distortion ratios. Therefore the tech-

nical specifications are reached even if the balanced XLR output is used unbalanced, discon-

necting one pin - the required signal optimization is already done in the unit. At the RCA output

an additional conversion balanced to unbalanced is performed directly at the output. These

efforts guarantee the supreme sound quality of the ADI-2 DAC to be available in all operation

and connection scenarios.

Which level setting is recommended?

There are a total of four hardware reference levels available, with the XLR output having a 6 dB

higher level. With Hi-Fi the setting +7 dBu (equals +4.78 dBV or 1.73 V RMS) is recommended.

This setting causes an ADI-2 DAC to output level similar to that of many CD-players. In case it

is still too low simply change to +13 dBu (+10.8 dBV, 3.46 V RMS).

Doesn't a low hardware reference level cause a significant increase in noise?

Usually yes - but not with the ADI-2 DAC. Switching the reference levels is done in the analog

domain, in hardware. The circuit has been optimized for maximum signal to noise ratio even at

the lowest reference level, -5 dBu. Detailed values can be found in chapter 30.2.

Fixed Output Level – Lock Volume

The option Lock Volume in the I/O menu allows to lock the analog output level to a specific

value, a change via the VOLUME knob is no longer possible. The Volume adjustment within the

menu is used to set the 'fixed' output level.

For example when the analog output should operate like a typical HiFi unit @ 2 V output level

(equals +8 dBu), set the hardware Ref Level to +7 dBu and Volume to +1 dB. Or +13 dBu and

Volume to -4.5 dB. More examples:

1 V (0 dBV, +2.2 dBu): Ref +7 dBu, Vol -5 dB

0.775 V (0 dBu, -2.2 dBV): Ref +1 dBu, Vol -1 dB

0.5 V (-3.8 dBu, -6 dBV): Ref +1 dBu, Vol -5 dB

0.315 V (-10 dBV, -7.8 dBu): Ref -5 dBu, Vol -3 dB

Note that most analog reference levels (except 2V) usually offer a lot of headroom. Therefore

matching the levels to 0 dBFS might result in too low volume. Also note that the above table is

no longer valid when PEQ and Bass/Treble are in use. The digital level will be higher and might

even overload, which can be clearly seen on the output's level meter. Volume has to be further

reduced then.