torbenscharling wrote:KSTR wrote:It is in the manual, though a bit hidden.
Full clockwise, PH out is +19dBu @0dBFS, as is line out in "Hi Gain" mode. In "-10dBV" mode line out goes down to +2dBV @0dBFS, so a headroom of 12dB.
Hence dial in the volume knob to result in 14.8dB (+19dBu=+16.8dBV, so correction needed is +16.8dB - +2dB = 14.8dB) less signal than fully clockwise. How do you do that? Measure (-14.8dB=18.2%), in some way or another ;-)
Thanks for that explanation. So it's not in the manual, as stated.
Kinda funny (and a little bit sad for human kind) that no one can answer this simple question other than "measure"
Because there is no reproducible way to set the volume knob other than full, the only way to set an exact level is measuring.
MC already suggested, the use of the loopback to ADI-2’s inputs makes for a quite precise measurement.
On the other hand:
A common standard consumer line level does not exist.
If you go for the Tascam level -10 dBV you have to keep in mind that this level is meant to be used with analog tape machines which have a headroom of about 12 dB for peaks above reference level.
Therefore: -10 dBV + 12dB = +2 dBV =~ +4 dBu.
There is a preset on ADI-2 for +4 dBu reference level for the line out.
Now compare, and set the same loudness for headphones out, done.
BTW: a typical CD player puts out +8.2 dBu (2 V).
Annotation:
dBV is referenced to 1 V
dBu is referenced to 0.775 V (or 1 mW into 600 Ohms)