Rupert Neve Designs Portico 511 500 Series Mic Pre with Silk

Rupert Neve: “While creating functional 500 series modules is relatively simple, designing those modules to equal their non-500 series counterparts with the current, voltage and space restraints is quite challenging. In creating our own 500-Series Modules, we experimented with a number of different transformer and circuit designs to achieve the same presence and sweetness found in the Portico Series of modules. The result of these efforts is that outside of the slightly lowered headroom, our 500 series modules are nearly indistinguishable from standard Portico Series modules, and are perfectly suited for studios of the highest caliber.”

Input Section
Input signals may be derived from Mic or Line sources (make sure 48V is off for line sources!). The input has a 10K Ω non-reactive input resistance that handles a full 22dBu signal without the need for a pad. The pre-amp is a TLA non-reactive design that precludes the loading of microphones with limited driving capability. A primary gain control provides 66dB of gain in 6dB increments for easy recall, with a +/- 6dB trim for fine adjustment. For condenser microphones and powered DIs, there is +48V phantom power. A transient-optimized HPF continuously covering the range from 20-250Hz is included to tame rumble and proximity effect.

Texture
One of the key developments in the 511 is the Red Silk / Texture control from the Portico II Channel. Building on the “Silk” mode found in the Portico Series mic pre-amplifiers, Texture is designed to adjust the actual amount of harmonic music content from the source material, in effect, providing wide range of tonal options for the preamplifier. Like the original Portico Silk, the Silk Red / Texture works by reducing negative feedback on the output transformer and adjusting the frequency response to more closely resemble Mr. Rupert Neve’s vintage designs. With the 511, the Texture control allows these techniques to be pushed further than previous designs, adding about 10 times the desirable THD of the original silk control at its maximum setting.

With that said, we have taken great care to ensure that the musical integrity of source material itself will not be compromised by these harmonic controls (these are not to be confused with controls from other manufactures that may “incinerate”, “demolish” or “destroy” source material), and we believe they can be confidently utilized to fit the personality of any song, instrument or engineer.

Noise: Measured at Main Output, un-weighted, 22Hz-22kHz, source impedance 150 Ohms balanced. Noise performance can vary depending on the 500 series and / or interference from stray magnetic fields.

Unity Gain              Better than -103dBV
With Gain @ +66dB           Better than -60dBV
Equivalent Input Noise          -125dB

Frequency Response
Main output, no load Main Output +/- 0.1dBu from 10Hz to 31.5kHz -2.6dB @ 120kHz

Maximum Output Level +23dBu

Total Harmonic Distortion and Noise @ 1kHz, +20dBu output level, no load. Better than 0.0025% @ 20Hz, +20dBu output level, no load. 0.025% Typical (2nd and 3rd harmonic)
Total Harmonic Distortion and Noise with SILK engaged TEXTURE @ min
@ 100Hz, +20dBu input level, no load 0.015%, mostly 3rd harmonic (typical)

TEXTURE @ max   
@ 100Hz, +20dBu input level, no load    2%, mostly 2rd harmonic (typical)

Gain Unity up to +66dB in 6dB steps. Trim continuously adjustable from -6dB to +6dB.
Phantom Power Supplied by the 500 series rack power supply. Switch selectable on faceplate.
High Pass Filter Continuously variable swept frequency from 20Hz to 250Hz.
Slope: 12dB/Octave
Power Requirements @ +/-16VDC 100mA