4 Group, 4 channel PPM
4 Channel PPM Q22-SW
Photo shows Quad PPM Q22-SW
4 Group, 4 channel PPM
4 Channel PPM Q22-SW
Photo shows Quad PPM Q22-SW
For applications where the "Type 19" meters as used on our Pico, PPM6, Mini-Mon2 and EZ-MON HD may be considered too small, Murraypro has developed an elegant, full specification, PPM Unit using "Type 22" meters that performs a range of vital audio monitoring functions. "Touch Latch" selection between any of the 4 Quad channel Groups provides continuous physical Ch1&2 and Ch3&4 Peak Programme Metering with phase verification as dual stereo pairs and Peak indication on each. Additionally each stereo pair can be aurally monitored via the volume control, which furnishes a fully buffered headphone output and balanced stereo drive for external monitoring speakers. Jacking into the local headphone socket automatically mutes the external loudspeaker drive, and either Left or Right channels may be independently muted if required. The selected 4 channel audio Group is buffered and available on the rear panel in balanced format. An AES input option is also available and fitted on Group 3 & 4 and this, in 8 channel analogue format, is also available on the rear panel as a balanced signal at 0dBU.
PEAK LEVEL INDICATOR
Four independent red LEDs indicate peak input signal levels in excess of +8.15dBU for each channel.
PHASE VERIFICATION
Correct A1:A2, A3:A4, phasing is indicated by green illumination of the respective indicator. Incorrect phasing of any channel pair is immediately obvious as the respective PPM indicator changes colour to red. The phase indication is reliable, and is vital in a busy Operational environment, where critical listening may be compromised. The phase indicator(s) extinguish when both signals of a stereo pair are below approximately -24dBU, preventing nuisance triggering on low level.
ALWAYS VIGILANT
The highly visual Murraypro "Traffic Light" logic polices this vital information continously, problems are flagged immediately and nothing relevant is missed, preventing horribly expensive mistakes which may only become apparent much later!
-20dBFS SMPTE and -18dBFS EBU Reference Levels
Programme material may be encountered with a variety of different "Operating Levels", and the similarity between the EBU Reference at -18dBFS and SMPTE at -20BFS may confidently anticipated to cause operational monitoring confusion. Both are equally valid, but only in their respective domains. The Murraypro Q22-SW is fitted with a +2dB normalising switch that increases the monitoring gain of the PPM Unit when working with -20dBFS SMPTE Reference'd material, the input programme material itself remains at the original level, and only the PPM's gain is modified to normalise to the more usual European -18dBFS Standard. The function of the PHASE monitoring and trigger point of the PEAK LEDs remain unaltered.
Analogue and AES interfaces
XLR3-F audio inputs are provided for Groups 1 & 2, and for maximum flexibility parallel access to each is also available on a multiway D-15F. Similarly, Group 3 input is available on XLR3-F and D-15F when the AES option is not fitted.
Due to space limitations when the AES feature is fitted, the AES is input via the XLR3-Fs fitted in the location co-shared with Group 3's analogue input XLRs. Group 3 & 4 require no analogue input port as it is derived internally, and their demodulated DAC'd utility analogue outputs are available on the Group 3 & 4 D15-M. Care should be taken not too load these analogue output ports unduly, as they are also used internally for metering purposes.
POWER
PPM Q22-SW is fitted with an IEC 320 mains connector and an internal SMPSU accepting inputs from 110~240Vac @ 50/50Hz. Power drain is 10VA nominal.
PHYSICAL
The 2U high rack width, PPM-Q22-SW conforms with the CE marking requirements and is 482W x 88H x 200mm deep, and weighs approximately 2 KGm.
© Murraypro August 2009
