INTRODUCTION Thank you for your purchase of the 5012 Duo Mic Pre. Everyone at Rupert Neve Designs hope you enjoy using this tool as much as we have enjoyed designing and building it. Please take note of the following list of safety concerns and power requirements before the use of this or any Portico SeriesTM product. Safety It’s usual to provide a list of “do’s and dont’s” under this heading but mostly these amount to common sense issues.
FEATURE LIST 5012 Duo Mic Pre - Front Panel SILK Reduces negative feedback and adjusts the frequency spectrum to provide a very sweet High Pass Filter and musical performance.
5012 DUO MIC PRE The PORTICO TM Series The new RND “Portico”TM modular preamplifiers and analogue audio processors constitute a range of building blocks that may be used independently or in combination to provide key elements that were traditionally included in large format Sound Control Consoles. Your 5012 Duo Mic Pre Microphone Input The microphone input is balanced but not floating, being a variant of an instrumentation amplifer using a “Transformer-Like-Amplifier” (T.L.A.
012 DUO MIC PRE High Pass Filter The High pass filter is a valuable aid in any signal chain but particularly so in a microphone preamplifier. Signals between 20 and 250 Hz can be attenuated, leaving the range above this unaffected. This gets rid of building rumble, air handling motor hum etc.
5012 DUO MIC PRE SPECIFYING THE NOISE PERFORMANCE OF THE RND 5012 Noise: is specified in 3 ways: With Gain at Unity Better than –100 dBu With Gain at 66 dB Better than –62 dBu Equivalent Input Noise Better than –128 dBu Decibels are used to express relationships and to make comparisons. One could state that amplifier “a” has 3 dB less noise than amplifier “b” but unless you have a point of reference for one of the two amplifiers, you would not know how good they were by comparison with other amplifiers.
5012 DUO MIC PRE There are two ways to provide more information about the noise performance of a microphone amplifier: THERMAL V MEASURED NOISE The difference is NOISE FACTOR -118 -120 Noise: dBu -122 -124 -126 -128 -130 -132 -134 -136 -138 -140 -142 -144 -146 -148 -150 -152 -154 1 2 4 8 16 32 64 128 256 Input Resistor Ohms Thermal Noise 5012 Measured 512 1,024 A graph can be drawn showing Noise against Resistance.
5012 DUO MIC PRE DYNAMIC RANGE Traditionally, high quality microphones such as ribbons, had very low source impedances – as low as 30 ohms at the output of a ribbon matching transformer. Moving coil microphones were higher but had not been standardized as they are today. Condenser microphones, before the days of semiconductors, used tube head amplifiers that were coupled to the outgoing line with a transformer.
SPECIFICATIONS Frequency Response: Main Output, no load, –0.2 dB @ 10 Hz –3 dB @ 160 kHz Buss Output measured at the 5014 Monitor Buss-mix Amplifier Output –0.2 dB @ 10 Hz –3 dB @ 160 kHz Noise: Measured at Main Output, unweighted, 22Hz-22kHz, Terminated 150 Ohms. With gain at unity better than –100 dBu With gain at 66 dB better than –62 dBu Equivalent Input Noise better than –128 dBu Noise Factor 1.5dB High Pass Filters: Continuously variable swept frequency from 20 Hz to 250 Hz.
MIC IN GAIN 0-66dB INPUT TRANSFORMER PHASE REVERSE TRIM +/-6dB HIGH PASS FILTER 12dB / Oct.
PRODUCT WARRANTY Rupert Neve Designs warrants this product to be free from defects in materials and workmanship for a period of one (1) year from date of purchase, and agrees to remedy any defect identified within such one year period by, at our option, repairing or replacing the product.