Owner`s manual

The reason to have a selectable threshold for ‘over’ indication relates to the particular application at hand. For
example, when recording percussive instruments with sharp transients, some engineers don’t mind having the
transients go ‘over’ for a few consecutive samples. In fact, some engineers record that way on purpose! In this
case, set the over threshold to, say, 3 or 4 samples. The natural reaction when you see an over is to pull the
level down, and while tracking this may not be quite as necessary.
You may also want to use SOFT LIMIT to enable you to get a hotter level without overs. But remember that
even while recording percussion, you don’t want too many consecutive overs, because harsh digital distortion
can occur. Listen to the audio and see if it’s distorted.
On the other hand, in a mastering application, it is often critical that all overs be dealt with and therefore, in
this case, the threshold would best be set to one, so that every sample that is over indicates an over on the
meter.
5. Rosetta 96 Only: DIP Switch 5 DOWN selects the Word Clock output to be equal to the selected sam-
ple rate. UP selects the Word Clock output to be 44.1/48 kHz only, irrespective of whether the sam-
ple rate is set to 44.1/48 or 88.2/96 kHz. Some devices requiring Word Clock synchronization can only
sync to 44.1/48 kHz, even if they are running at higher rates. In addition, when recording 88.2/96 kHz
stereo signals on a conventional MDM using ABS 96 bit-splitting (see next page) a TDIF MDM such as
the DA-88 will require Word Clock at 44.1/48 kHz, even though the unit is being used to record two
24/96 channels via bit-splitting.
6. Rosetta 96 only: DIP Switch 6 UP selects double-wire operation, while DOWN selects single-wire (dou-
ble-fast) operation at high sample rates. Check that this switch is set correctly to suit the high sample
rate implementation of your recording device.
AC CONNECTOR
Accepts IEC type AC plug. Check that the voltage setting is correct for your location. The voltage set at the
factory is indicated next to the AC connector. Be sure that if the internal voltage selector is changed, this indi-
cation is updated.
Recording High-Density Signals on your MDM
Rosetta 96 only
A major challenge when you want to use high sample rates is, simply, “What can I record it on?” There
are still not too many 88.2/96 kHz sample rate recorders, and even fewer affordable ones. Luckily, with
the Rosetta 96, you can use the eight tracks of your existing 16-bit, 44.1/48 kHz sampling modular digital mul-
titrack (MDM) to record two channels of 24-bit, 88.2 or 96 kHz sampling. We call this technique “ABS 96” –
Apogee Bit Splitting for 88.2 and 96kHz sampling. ABS 96 is engaged automatically on the ADAT Optical and
TDIF interfaces when the Rosetta 96 is set to 88.2 or 96 kHz sample rates. To record with ABS 96, simply select
the desired sample rate on the Rosetta (88.2 or 96 kHz). Insure that your MDM is locked to the external digital
clock. If you are using the TDIF interface, connect a Word Clock cable from the Rosetta to Word Sync In and
note the setting of DIP Switch 5 (see p16). Remember to record on all eight tracks of the MDM to capture a two
channel, high density signal.
While the Rosetta 96 includes the capability of recording an ABS 96 signal, it is an A/D only, and as a result has
no means of decoding the ABS 96 tracks and re-assembling them into a stereo 24/96 stream. To do this, you
will need an Apogee D/A converter such as that in the Apogee PSX-100. Of course, if you are mastering with
the Rosetta 96, you can inform your mastering house that you are using ABS 96 and they can employ their own
Apogee unit to recover the stereo data.
Rosetta AD User’s Guide
Page 17