Rupert Neve Designs Portico 5017 User manual

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By:
Serial #:
Operations Manual
Portico 5017
Mobile DI / Pre / Compressor

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Portico 5017: Mobile DI / Pre / Compressor User Guide
Thank you for your purchase of the 5017 Mobile DI / Pre / Compressor. Everyone at Rupert Neve De-
signs 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
Series product.
Safety
It’s usual to provide a list of “do’s and don’ts” under this heading but mostly these amount to common
sense issues. However here are some reminders:
The Portico 5017 dissipates about 7 watts, which means that it will get warm in use. The heat generated
is radiated through the case work. To avoid overheating Portico™ modules should not be stacked imme-
diately above or adjacent to other equipment that gets hot. Also bear in mind that other equipment may
radiate strong hum elds which could spoil the performance of your Portico module.
Don’t operate your Portico™ module in or around water! Electronic equipment and liquids are not good
friends. If any liquid is spilled such as soda, coffee, alcoholic or other drink, the sugars and acids will
have a very detrimental effect. Sugar crystals act like little rectiers and can produce noise (crackles,
etc.). SWITCH OFF IMMEDIATELY because once current starts to ow, the mixture hardens, can get very
hot (burnt toffee!) and cause permanent and costly damage. Please contact support as soon as possible
at [email protected] for resolution.
Don’t be tempted to operate a Portico module with the cover removed. The cover provides magnetic
screening from hum and R.F. stray elds.
Power Requirements
Each Portico 5017 module has a high quality DC to DC converter that provides carefully stabilized and
ltered +/– 17.5 VDC for the ampliers. The meticulous audio quality of your Portico is protected by
the internal converter and does not depend primarily on the external mains power supply. The input is
protected from reverse polarity. The connector center pin must be positive. The converters will work from
any DC supply from 9 to 18 volts that is reasonably “clean”. The power supply normally provided with
the 5017 is a high quality, robust, and very reliable switched mode power supply. There are no special
requirements for the Portico low voltage units other than that they must be of good quality, reliable, and
able to supply enough current for the number of modules in use.
The great advantage of this system is that there are no common D.C. supply rails that are directly shared
by other modules.
In a traditional console, large, bi-polar regulated supplies were used, necessarily having a shared com-
mon 0 “ground” wire. Crosstalk between modules resulted, often accompanied by R.F. interference due
to the unbalanced loop “antennas” that were inevitably present. This interference, in some cases, could
actually be heard, but even at low levels below audibility there was a potential intermodulation with the
desired signal. Of course this represented both a quantitative and subjective intrusion affecting sound
quality.
One of the advantages of the Portico method of feeding equipment is that external power units will work
from almost any of the very wide range of mains supply voltages and frequencies that are found world-

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wide. While many different types of mains power wall sockets are found in different countries, Portico
5017 module power units leave the factory with standard US plugs. If required, any suitable connecting
cord may be substituted. Avoid using a mains power outlet that is on the same circuit as air conditioning
of other equipment that regularly switches on and off. Unplug your Portico power units during a thunder
storm or if it will be unused for a long period.
Portico modules can alternatively be powered from a 12 volt battery, in which case the supplied AC
power unit is not needed. When using a 12 volt battery, choose one that has enough capacity to power
your Portico 5017 - or your complete assembly of Portico modules - for the expected duration of your
session.
Portico 5017: Block Diagram

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Portico 5017: Front Panel
DC Input
12V DC Input
Center Positive
Mic Input
TLA Fully Balanced Input
1=GND, 2=HOT 3=COLD
Line/Blend Output
Transformer Coupled
Fully Balanced and Floating
1=GND, 2=HOT 3=COLD
Ground Lift
Switch lifts the ground
connection for the instrument
input
48V
Provides Phantom Power on
the microphone input
Mic Output
Transformer Coupled
Fully Balanced and Floating
1=GND, 2=HOT 3=COLD
MAX
VARI
BLEND
SILK
COMP
THRESHOLD
INST MIC
MIC GAININST GAIN
MIN -20 +10
INST
THRU
PHASE
PHASE SWEEP
INST MIC
Mobile Pre/DI/Comp COMP
Instrument Gain
Provides 0 to 30dB gain with a
continuously variable pot
Microphone Preamp
Provides 66dB of gain in 6dB
increments
Blend
Continuously variable mix
control between DI and Mic
Signals.
High Pass Filter
Reduces signals by
12dB/octave
Threshold
When signals exceed the
“threshold” level, the gain is
reduced at a 2:1 ratio, with a
constant attack and release
times.
Direct Input
1/4” input and thru for
instruments and line level
signals
Vari-phase
Continuously rotates the
phase of the instrument
signal
Silk
Adds nostalgic warmth and
presence to both outputs
when engaged
Portico 5017: Back Panel

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MICROPHONE PREAMPLIFIER DESIGN NOTES
In former years, before the introduction of solid state ampliers, transformers were necessary to
step up to the very high input impedance of tubes, and to provide a balanced input for the
microphone line. An input impedance of 1,000 or 1,200 ohms became established for microphones
having a source impedance of 150 or 200 ohms, with connection being made on a twisted twin
screened cable (This type of cable, while excellent for low impedance work, has high capacitance
between its conductors and between each conductor and screen. Resultant high frequency losses
are excessive with piezo pickups and may cause resonances with magnetic pickups.) Thus
microphones were not heavily loaded. Condenser microphones worked off high voltage supplies
(300V!) on the studio oor which polarized the diaphragms and powered a built-in pre-amplier.
More and more microphones were needed as “Pop” music gained ground and this led to the popular
and efcient method of 48-volt “Phantom” powering that was built into the multi-channel recording
Console – in place of numerous bulky supplies littering the studio, a miniature pre-amplier now
being tted inside the microphone casing.
The 48-volt supply was fed to the microphone through balancing resistors so it was impossible for
this voltage to actually reach the microphone, resulting in low polarizing volts and virtual starvation of
the little pre-amp inside the microphone. Nevertheless amazingly good microphones were designed
and made, becoming the familiar product we use today. If a low value resistive load is connected to
the output of an amplier, that amplier has to produce power in order to maintain a voltage across
that load. Obviously if we want more voltage (output from the microphone) we need to provide a
larger supply for the amplier or settle for a lighter load. A microphone is a voltage generator, not a
power amplier. Most microphones give their most accurate performance when they are not loaded
by the input impedance of a traditional preamplier. If the microphone uses an electronic circuit
(transformerless) output, a low value of load impedance can possibly stress the little microphone pre-
amplier, causing slew rate and compression at high levels.
On the other hand, a high value of load impedance allows the microphone to “breathe” and give of
its best, this being particularly advantageous with very high level percussive sounds. If the microphone
has an inductive source (such as would be the case if it has a transformer output) a low value of load
impedance causes the high frequencies to roll off due to leakage inductance in the transformer in
addition to the above amplier distortion (This can be an advantage with some microphones!).
For this reason we have provided a high value of input impedance that will load microphones to the
smallest possible extent and makes the best possible use of that limited “Phantom” 48-volts supply.
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 ampliers that were coupled to the outgoing line with a transformer. Microphone ampliers,
such as in a mixing console, also used tubes and these typically have a high input impedance.
Microphones are Voltage generators, not Power generators. It is always desirable to deliver the
maximum possible signal voltage into the amplier. It was traditional to provide an amplier input
impedance of about 1,000 or 1,200 ohms; about 5 or 6 times the source impedance of the microphone.
This provided relatively low loading on the microphone – whatever its type – and went a long way to
avoid voltage loss.

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In the early 1960’s when the “Pop” music scene was exploding and sound levels in the Studio became
very high, there was concern that the head ampliers in Condenser microphones would overload if the
Console input impedance was too low. In the early days of Consoles I was asked to provide higher input
impedance than the normal 1,000 ohms. This of course, resulted in less “step-up” in the Console input
transformer and there were then fears that we would lose out at the other end of the scale; Noise. The
fact that microphones were less heavily loaded allowed an increased microphone signal. The reduced
loading also resulted in less deviation of frequency response due to variation of microphone impedance
and consequently less distortion at high levels.
The Portico 5017 microphone amplier provides an input impedance of 10,000 ohms which means that
variations in microphone source impedance with frequency, have only a very small effect on the sonic
quality. This high input impedance has minimal effect on microphone output and loading with the result
that microphone distortion is very low adding up to a noticeable improvement in “transparency”.
A NOTE ON DISTORTION
The human hearing system is a remarkably complex mechanism and we seem to be learning more
details about its workings all the time. For example, Oohashi demonstrated that arbitrarily ltering out
ultrasonic information that is generally considered above our hearing range had a measurable effect on
listener’s electroencephalo-grams. Kunchur describes several demonstrations that have shown that our
hearing is capable of approximately twice the timing resolution than a limit of 20 kHz might imply
(F=1/T or T=1/F). His peer reviewed papers demonstrated that we can hear timing resolution at
approximately with 5 microsecond resolution (20 kHz implies a 9 microsecond temporal resolution,
while a CD at 44.1k sample rate has a best-case temporal resolution of 23 microseconds).
It is also well understood that we can perceive steady tones even when buried under 20 to 30 dB of
noise. And we know that most gain stages exhibit rising distortion at higher frequencies, including
more IM distortion. One common IM test is to mix 19 kHz and 20 kHz sine waves, send them through
a device and then measure how much 1 kHz is generated (20-19=1). All this hints at the importance
of maintaining a sufcient bandwidth with minimal phase shift, while at the same time minimizing
high frequency artifacts and distortions. All of the above and our experience listening and designing
suggest that there are many subtle aspects to hearing that are beyond the realm of simple traditional
measurement characterizations.
The way in which an analog amplier handles very small signals is as important as the way it behaves
at high levels. For low distortion, an analog amplier must have a linear transfer characteristic, in other
words, the output signal must be an exact replica of the input signal, differing only in magnitude. The
magnitude can be controlled by a gain control or fader (consisting of a high quality variable resistor
that, by denition, has a linear transfer characteristic.) A dynamics controller - i.e. a compressor,
limiter or expander - is a gain control that can adjust gain of the amplier very rapidly in response to
the uctuating audio signal, ideally without introducing signicant distortion, i.e. it must have a linear
transfer characteristic. But, by denition, rapidly changing gain means that a signal “starting out” to be
linear and, therefore without distortion, gets changed on the way to produce a different amplitude.
Inevitably our data bank of “natural” sound is built up on the basis of our personal experience and
this must surely emphasize the importance of listening to “natural” sound, and high quality musical
instruments within acoustic environments that is subjectively pleasing so as to develop keen awareness
that will contribute to a reliable data bank. Humans who have not experienced enough “natural”

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sound may well have a awed data bank! Quality recording equipment should be capable of retaining
“natural” sound and this is indeed the traditional measuring stick. And “creative” musical equipment
should provide the tools to manipulate the sound to enhance the emotional appeal of the music without
destroying it. Memory and knowledge of real acoustic and musical events may be the biggest tool and
advantage any recording engineer may possess.
One needs to be very careful when one hears traces of distortion prior to recording because some avors
of distortion that might seem acceptable (or even stylish) initially, may later prove to cause irreparable
damage to parts of the sound (for example, “warm lows” but “harsh sibilance”) or in louder or quieter
sections of the recording. Experience shows that mic preamps and basic console routing paths should
offer supreme delity otherwise the engineer has little control or choice of recorded “color” and little
recourse to undo after the fact. Devices or circuits that can easily be bypassed are usually better choices
when “color” is a consideration and this particularly is an area where one might consider comparing
several such devices. Beware that usually deviations from linearity carry at least as much long-term
penalty as initial appeal, and that one should always be listening critically when recording and generally
“playing it safe” when introducing effects that cannot be removed.
1. Tsutomu Oohashi, Emi Nishina, Norie Kawai, Yoshitaka Fuwamoto, and Hishi Imai. National
Institute of Multimedia Education, Tokyo. “High Frequency Sound Above the Audible Range,Affects Brain Electric Activity and
Sound Perception” Paper read at 91st. Convention of the A.E.S.October 1991. Section 7. (1), Conclusion.
2. Miland Kunchur,Depart of Physics and Astronomy, University of South Carolina. “Temporal resolution of hearing probed
by bandwidth restriction”, M. N. Kunchur, Acta Acustica united with Acustica 94, 594–603 (2008) (http://www.physics.
sc.edu/kunchur/Acoustics-papers.htm)
3. Miland Kunchur,Depart of Physics and Astronomy, University of South Carolina.Probing the temporal resolution and
bandwidth of human hearing , M. N. Kunchur, Proc. of Meetings on Acoustics (POMA) 2, 050006 (2008)
5017 USAGE NOTES
The 5017’s small size and feature set allows it to be used in many different ways, in both studio and live
environments. The diagrams on the following pages show how to use the 5017 as a single channel or
dual channel module. Here are some creative things to try:
For vocals, take two mics, your favorite condenser plugged into the Mic Input, and a SM57 or SM58 set
up 6 inches closer to the vocalist and plugged into another mic pre, then into the 5017 Inst Input. Adjust
Vari-Phase to taste, and maybe add some light compression from the 5017 followed by your usual vocal
compressor, which may behave even nicer because of that touch of “pre-compression” from the 5017.
For synth(or another instrument), set the signal chain as seen for single channel use(Page 8), but
place the mic a little further than normal from the amp, or pointed away from the amp to incorporate
more room reections. With the mic even further away, we might suggest using the Mic Pre Output
sent to a separate track and the Blend control set to INST so you end up with separate “dry” and a
“room” tracks(See Page 9 setup). In the latter example, the Phase Sweep may be rather subtle and the
compressor can be set to operate on either the DI (dry) or mic (room) signal depending on the internal
jumper. With the compressor set to the mic path, you may nd this accentuates the room nicely, and
if you are changing jumpers, you might want to audition the “slow” compressor jumper setting while
you are there. This may work also work well for “re-amping” some tracks already recorded on the DAW,
especially given the Phase Sweep and Compressor in the 5017.

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DI
THRU
MAX
PHASE HPF
VARIPHASE
BLEND
SILK
COMP
THRESH
O/L
DI MIC
MIC GAIN
GAIN
MIN
DI-Z
DI MICCOMP
-30 +4
ToRecorder
orMixingBoard
Single Channel Use Blended DI and Mic Signals
Whenusedforinstruments,the5017canbeusedtophasealign,
combineandcompressdirectandmicedinstrumentsignals.To
achievethis,usetheDIfortheinstrument’sdirectsignalandthemic
preampforthespeakercabinetsignal.Connecttheexternalampli-
fiertothepassiveDIthruonthe5017faceplate.Theblendcontrol
isusedformixingdirectandamplifiedsignalstoachievethedesired
tonalityofthetwosources,andthevariphaseisusedtominimizeor
extenuatephasecancellationsbetweenthetwosignals.Tocompress
theblendedsignal,theinternalcompressorjumpermustbesetto
theblendpath(thisisthedefaultsetting).Thistechniquecouldalso
beusedtocreateasingle,mixedoutputofaguitarandvocals.
Instr. In
Mic In
Amp Mic

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DI
THRU
MAX
PHASE HPF
VARIPHASE
BLEND
SILK
COMP
THRESH
O/L
DI MIC
MIC GAIN
GAIN
MIN
DI-Z
DI MICCOMP
-30 +4
Independentvox
andguitarsignals
ToRecorderor
MixingBoard
Dual Channel Use - Vocal and Instrument
Usedasatwochanneldevice,aleadsinger/guitarplayer,cantake
theclassicstudioqualityofthe5017wherevertheygo.Inthis
scenario,thevocalwouldusethemicinput,thecompressorand
micoutput,whiletheguitarwouldusetheinstrumentinputand
blendoutput.Toachievethis,theblendcontrolshouldbeselected
asfullyDI,andaninternaljumperneedstobesettothemicpath.
Whenengaged,Silkmodewouldeffectbothvocalandguitartracks,
andtheHPFcontrolwouldaffectonlythemicpath.

Vocal Mic
BLEND
DI MIC
For the vocal and guitar tracks to be seperate,
the blend control must be set to fully DI
Mic In
Instr. In

10
5017 FEATURES
MICROPHONE INPUT
The microphone input is balanced but not oating, being a variant of an instrumentation amplier.
Our well-proven “Transformer-Like-Amplier” (T.L.A.) conguration is used, which includes an
accurate toroidal Common Mode Low Pass Filter that rejects Common Mode signals and excludes
frequencies above 150 kHz. (There are high powered broadcast transmitters at and above this
frequency in several Continents and, even if you can’t hear them, any vestigial intermodulation
products must be excluded!)
When the Mic Gain switch is set to Unity (0 dB), the Portico 5017 microphone pre-amplier can handle
a balanced input signal of more than +20 dBu without an input attenuator pad! This is a unique feature
that enables this input to double as an additional line input.
THE MIC AND INSTRUMENT / BLEND OUTPUTS
The main output signal comes from the output transformer secondary which is balanced and ground
free. A ground free connection guarantees freedom from hum and radio frequency interference when
connected to a balanced destination such as the input to another Portico module or a high quality ADC.
However the transformer may be used with one leg grounded without any change in performance. It
is not necessary to “ground” one leg at the Portico output. It would normally get a ground connection
when fed to equipment that is not balanced. Maximum output level is + 22 dBu, which provides a large
margin over and above the likely maximum requirement of any destination equipment to which the
5017 is connected.
MIC GAIN
A 12-way precision rotary switch covering from Line (0) and Mic from 0 to 66 dB in 6 dB steps.
DI GAIN
Continuous gain control from 0dB to 30dB
IN and THRU 1/4” PHONE JACKS
These 2 jacks are used for DIRECT INJECTION (DI) or INSTRUMENT inputs and are simply paralleled
and wired together. Inserting a plug into either jack breaks the normal MIC input and the user has the
full range of MIC GAIN and TRIM. These jacks have a 3 mega ohm input impedance that will provide
less loading (better highs) than most DI boxes, and the sheer amount of gain that is available makes
these inputs extremely versatile.
THRESHOLD
When signals exceed the “threshold” level, the gain is reduced at a controlled 2:1 ratio, with attack and
release time constants set to standard or fast depending on the internal jumper setting.
SILK
Much could be written about this feature, sufce to say, that it gives a subtle option to enhance sound
quality in the direction of vintage modules. The silk button reduces negative feedback and adjusts the
frequency spectrum to provide a very sweet and musical performance. We suggest you try it and make
your own judgment.
BLEND

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Combines the Mic and DI signals on the DI / Blend Output. When Blend is set to fully DI, the 5017
operates with two separate channels.
+48V
Back panel switch makes phantom power available at the microphone input.
PHASE
Push button inverts the polarity of the signal path. The symbol “Ø” is often used to denote opposite
polarity.
HPF IN
The high pass lter is a valuable aid in any signal chain but particularly so in a microphone preamplier.
Signals below 80hz can be attenuated at a rate of 12db / octave, getting rid of building rumble, air
handling motor hum etc.
INDICATORS
Indicators on the 5017 denote signal presence and clipping on both DI and mic signals, as well as
compressor activation.
INTERNAL JUMPERS
Two internal jumpers in the 5017 can be set to change the compressor from the mic channel to the di /
blend channel, and to change the compressor time constant from fast(default) to slow.
To change the compressor time constant to slow, move the J1 jumper(top of picture) away from the front
faceplate.
To change the compressor position from di / blend to mic, us a pair of tweezers to move the jumper block on J2,
J3 and J4 (behind the mic signal presence LED) to the right (when facing the faceplate).
Threshold HPFComp /Mic LED
J1: Changes compressor at-
tack/release from fast(closer to
faceplate) to slow
J2/3/4: Changes compressor
circuit from the DI / Blend
path(left side as viewed from
the front) to the Mic path

12
SPECIFICATIONS
Frequency Response:
Main Output, no load,
–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 Filter:
Frequency: 80Hz
Slope: 12 dB/Octave Bessel
Maximum Output Level:
Maximum output from 20 Hz to 40 kHz is +23 dBu.
Total Harmonic Distortion and Noise:
@ 1kHz, +20 dBu output: Main Output: Better than 0.001%
@ 20Hz, +20 dBu output: Main Output: Better than 0.002%
Silk Engaged: Better than 0.2% Second harmonic
Crosstalk:
Measured channel to channel: Better than –90 dB @ 15kHz.
Phantom Power:
+48 Volts DC +/- 1%
Power requirements:
12VDC is optimal voltage, but 9-15VDC is acceptable
Current consumption:
@ 9VDC Current is 1.3 A typical: Power = 11.7W
@ 12VDC Current is 1.0 A typical: Power = 12.0 watts
@ 15VDC Current is 800 mA typical: Power = 12.0 watts
Compressor
Threshold: Continuously Variable from -20dBu to +10dBu
Ratio: Fixed at 2:1
Attack & Release:
Fast Mode Attack 40ms , Release 40ms
Slow Mode Attack 100ms , Release 350ms

13
5017 RECALL SHEET
MAX
VARI
BLEND
SILK
COMP
THRESHOLD
INST MIC
MIC GAININST GAIN
MIN -20 +10
INST
THRU
PHASE
PHASE SWEEP
INST MIC
Mobile Pre/DI/Comp COMP
MAX
VARI
BLEND
SILK
COMP
THRESHOLD
INST MIC
MIC GAININST GAIN
MIN -20 +10
INST
THRU
PHASE
PHASE SWEEP
INST MIC
Mobile Pre/DI/Comp COMP
MAX
VARI
BLEND
SILK
COMP
THRESHOLD
INST MIC
MIC GAININST GAIN
MIN -20 +10
INST
THRU
PHASE
PHASE SWEEP
INST MIC
Mobile Pre/DI/Comp COMP
MAX
VARI
BLEND
SILK
COMP
THRESHOLD
INST MIC
MIC GAININST GAIN
MIN -20 +10
INST
THRU
PHASE
PHASE SWEEP
INST MIC
Mobile Pre/DI/Comp COMP

Rupert Neve Designs
PO Box 1969
Wimberley TX 78676
www.rupertneve.com
tel: [phone]
fax: [phone]
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 identied within such one year period by, at our option, repairing or replacing
the product.
LIMITATIONS AND EXCLUSIONS
This warranty, and any other express or implied warranty, does not apply to any product
which has been improperly installed, subjected to usage for which the product was not
designed, misused or abused, damaged during shipping, damaged by any dry cell battery,
or which has been altered or modied in any way. This warranty is extended to the
original end user purchaser only. A purchase receipt or other satisfactory proof of date of
original purchase is required before any warranty service will be performed. THIS
EXPRESS, LIMITED WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES,
EXPRESS OR IMPLIED, TO THE EXTEND ALLOWED UNDER APPLICABLE
STATE LAW. IN NO EVENT SHALL RUPERT NEVE DESIGNS BE LIABLE FOR
ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES RESULTING
FROM THE USE OF THIS PRODUCT. Some states do not allow the exclusion or
limitation of consequential damages or limitations on how long an implied warranty lasts,
so this exclusion may not apply to you.
WARRANTY SERVICE
If you suspect a defect in this product, please call us at 512-847-3013 or email us at
[email protected] to discuss the suggested defect (it is possible that a suspected
defect could be due to improper usage) and to obtain a return authorization number. It
shall be your responsibility to pay for shipping the product to us, and, if the product is
determined to be defective, our responsibility to pay for shipping the product back to you.