Rupert Neve Designs 5042-H
Portico "True Tape" FX 2-Channel Horizontal Emulator/Line Driver

Rupert Neve Designs' Portico 5042, winner of the 2006 TEC award for signal processing hardware, provides a remarkable simulation of true tape sound through the inclusion of genuine tape drive circuitry.  When the Tape circuit is not engaged, the 5042 may be used as a full, transformer-coupled, high-performance line amplifier that includes a Gain range of + and – 12 dB.  The Portico 5042 Two Channel "True Tape" Emulation and Line Driver unit's emulation circuit provides the nostalgic rounding and compression usually only achieved by the use of tape.  This typically offsets the harshness often found in digital recordings.  The Portico 5042 incorporates an actual tape drive circuit that feeds a tiny magnetic "head" which, in turn, is coupled to a correctly equalized, replay amplifier. The only thing missing is the tape itself!

The Portico 5042 consists of two identical Line Driving amplifiers having transformer balanced inputs and outputs.  The sonic quality of these amplifiers is such that, by providing galvanic isolation, simple single-sided circuit topology and freedom from grounding problems they are capable of enhancing the sonic quality of many signal sources, especially those of digital origin.  The sonic "signature" is one of extreme purity and the image is consistent with that of Rupert Neve's original designs of 35-40 years ago.

The Portico 5042 host line amplifier has a much higher output level capability than the "tape" circuit embodied within it.  The gain of the Record and Replay amplifiers has been adjusted so that with the TRIM control set to 0 dBu, and the ENGAGE TAPE button out, an incoming signal of 0 dBu, will cause the first meter LED to illuminate.

Now, with the ENGAGE TAPE button pressed and the SATURATION control at MIN, the same first meter LED will continue to light regardless of whether the meter button is set to INPUT LEVEL or TAPE LEVEL.  This is the minimum recommended record level.  When the SATURATION control is rotated to MAX, this is the maximum recommended record level.

An input signal level that is appreciably below 0 dBu (the 0 dB LED on the meter not lighting at all), for example, if you are feeding the Portico 5042 from a consumer Hi-Fi source, the tape effect still works but you might have to make up gain elsewhere in your system.  Of course this would tend to bring up noise, just as it would on a real tape recorder.

If the incoming signal is low, (for example from a consumer Hi-Fi source), it is recommended that you rotate the TRIM control clockwise to bring the incoming signal level up to the point where the first, or LINE UP LED is just illuminated.  However, with the meter switched to TAPE LEVEL, when you rotate the SATURATION control clockwise the TAPE LEVEL meter progressively illuminates.  At MAX, with an incoming 0 dBu signal, the Tape circuit is running just below clipping point.

Main Outputs

The main output signals come from the output transformer secondary which is balanced and ground free.  A ground-free connection ensures virtual freedom from hum and radio frequency interference due to ground loops.  Ideally the output of this module should be fed to a balanced destination such as the input to another Portico module or one of the many high quality vintage modules still in current use.  The main outputs may be used with one leg grounded without any change in performance.

Maximum output level of the Portico 5042 is + 25 dBu, which provides a large margin over and above the likely maximum requirement of any destination equipment to which the Portico 5042 is connected.

An eight-segment LED bar graph meter is fitted for each channel, calibrated with two scales selected by the adjacent Push Button switch:

Input Level

Calibrated: 0 dB, 2dB, 4dB, 6dB, 10dB, 14dB, 18dB 22dB

Tape Level indicates the signal level being fed to the Tape circuit, or magnetic Induction level.

Trim provides + or - 12 dB adjustment of gain to compensate for incoming signal levels prior to feeding the TAPE circuit.

Engage Tape

Inserts the "tape" circuit when pressed (illuminated).The meter push button switch then selects the meter to display INPUT LEVEL or TAPE LEVEL.  When INPUT LEVEL is selected the meter displays the balanced signal level at the input of the Portico 5042.  When TAPE LEVEL is selected the meter shows the signal level sent to the simulated "Tape Head" (Equivalent to the record level on a real tape recorder).

Line Up

The incoming signal level should be set by adjusting the TRIM control so that the first LED starts to light (0 dB).  When the meter selector is set to TAPE LEVEL there is no meter reading unless the ENGAGE TAPE push button is pressed.

7.5 IPS - 15 IPS selects the emphasis/de-emphasis, Record/Replay Tape characteristic.

Saturation controls the signal level or magnetization being sent to the magnetic "tape head".  At the same time the gain of the replay amplifier is reduced.  As the SATURATION level increases, the replay gain is reduced so that the overall IN/OUT signal level remains more or less constant.  In a real tape recorder, you would adjust the Record and Replay gain controls separately.  In the Portico 5042 the Record and Replay gain controls are coupled so that the overall IN/OUT signal level only varies as the "tape" saturation level changes.  But as you approach the maximum SATURATION setting, the overall signal level will drop due to the effect of extreme saturation.

Line Amp Specifications: (Measurements with tape circuit disengaged)

• Noise: measured at main output, unweighted, 400Hz-22kHz, terminated 40 ohms balanced.
  - with gain at unity: better than 100 dBu
• Frequency Response: Measured at +10dBu, trim at unity.
  - Main Output @ 10 Hz: 0.50 dB
  - Main Output @ 160 kHz: 3 dB
• Maximum Output Level: Balanced and Floating Transformer Output: +25 dBu.  
• Total Harmonic Distortion and Noise:
  @ 1kHz, +20 dBu output level, no load: Better than 0.0015%
  @ 20Hz, +20 dBu output level, no load: 0.250% typical. Mostly 2nd and 3rd Harmonic
• Crosstalk Measured Channel to Channel: Better than 90 dB @ 16kHz  
• Buss Output: Output is designed to feed the RND 5014 Buss-mixer, Monitor Amplifier at the internal system level of 2.5 dBu.  Output level of the Rupert Neve Designs 5014 is then equal to that of the 5042.

Tape FX Specifications: (Measurements with tape circuit engaged)

• Maximum Output Level:
  - Gain trim at Unity, Saturation at Min: +25 dBu
  - Gain trim at Unity, Saturation at Max: +6 dBu  
• Noise: Measured at Main Output, un-weighted, 400Hz-22kHz, input terminated 40 Ohms Balanced
  - With Gain at Unity, Saturation control at Min: Better than 70 dBu
  - With Gain at Unity, Saturation control at Max: Better than 90 dBu  
• Frequency Response:
  - Tape engaged, 7.5 IPS: -3 dB @ 16 kHz
  - Tape engaged, 15 IPS: -3 dB @ 20 kHz
  Low frequency response varies with input gain and saturation settings.
• Total Harmonic Distortion and Noise:
  Tape Engaged: Approximately 1-2% 2nd and 3rd Harmonic below 1 kHz
• Crosstalk Measured Channel-to-Channel, Maximum Saturation: Better than 80 dB @ 16kHz