Ver. 2.0 - ©Phædrus Audio Ltd. 2015 All rights reserved.
Operating levels
Because of the vintage of the PHILTER design, and its
origin in German manufactured broadcast television and
radio equipment, the
envisaged operating
level for this
equipment is slightly
lower than modern
recording industry
standards. When
feeding downstream
equipment, the
output level should
be set to a nominal
0dBu (0.775V RMS).
This means that if monitoring the output on a standard
VU instrument, the input attenuator should be set so
that the output level reads around -4VU, with occasional peaks to 0VU on programme. On a digital meter, this is
equivalent to signal peaks r6dB above recording industry st4dBu alignment level. This is
equivalent to +10dBu (or -8dBFS on equipment aligned to EBU R64-1992 standard and -14dBFS on equipment
aligned to SMPTE RP155 as illustrated). On a broadcast standard PPM, peaks should be set to read 6 on the BBC
scale, or +8 on the European EBU scale. Output level is sufficient easily to modulate semi-pro' equipment (mixers,
DAT, solid-state recorders and many sound cards) to 0dBFS.
