Rupert Neve Designs 5254 User manual

Operations ManualOperations Manual
5254
Dual Diode Bridge Compressor

1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a dry cloth.
7. Do not block any ventilation openings. Install in accordance with the
manufacturer’s instructions.
8. Do not install near any heat sources such as radiators, heat registers,
stoves, or other apparatus (including amplifiers) that produce heat.
9. Do not defeat the safety purpose of the polarized or grounding-type
plug. A polarized plug has two blades with one wider than the other.
A grounding-type plug has two blades and a third grounding prong.
The wide blade or the third prong are provided for your safety. If the
provided plug does not fit into your outlet, consult an electrician for
replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched particularly at
plugs, convenience receptacles, and the point where they exit from the
apparatus.
11. Only use attachments/accessories specified by the manufacturer.
12. Use only with a cart, stand, tripod, bracket, or
table specified by the manufacturer, or sold with
the apparatus. When a cart is used, use caution
when moving the cart/apparatus combination to
avoid injury from tip-over.
13. Unplug this apparatus during lightning storms or
when unused for long periods of time.
14. Refer all servicing to qualified service personnel. Servicing is required
when the apparatus has been damaged in any way, such as power-
supply cord or plug is damaged, liquid has been spilled or objects have
fallen into the apparatus, the apparatus has been exposed to rain or
moisture, does not operate normally, or has been dropped.
15. This apparatus shall not be exposed to dripping or splashing, and no
object filled with liquids, such as vases or beer glasses, shall be placed
on the apparatus.
16. Do not overload wall outlets and extension cords as this can result in a
risk of fire or electric shock.
17. This apparatus has been designed with Class-I construction and must
be connected to a mains socket outlet with a protective earthing
connection (the third grounding prong).
18. This apparatus has been equipped with a rocker-style AC mains power
switch. This switch is located on the rear panel and should remain
readily accessible to the user.
19. The MAINS plug or an appliance coupler is used as the disconnect
device, so the disconnect device shall remain readily operable.
20. NOTE: This equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against
harmful interference in a residential installation. This equipment
generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment o and
on, the user is encouraged to try to correct the interference by one or
more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and the
receiver.
• Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician for
help.
CAUTION: Changes or modifications to this device not expressly
approved by Rupert Neve Designs LLC, could void the user's authority to
operate the equipment under FCC rules.
21. This apparatus does not exceed the Class A/Class B (whichever is
applicable) limits for radio noise emissions from digital apparatus as
set out in the radio interference regulations of the Canadian Department
of Communications.
ATTENTION — Le présent appareil numérique n’émet pas de bruits
radioélectriques dépassant las limites applicables aux appareils
numériques de class A/de class B (selon le cas) prescrites dans le
réglement sur le brouillage radioélectrique édicté par les ministere des
communications du Canada.
22. Exposure to extremely high noise levels may cause permanent hearing
loss. Individuals vary considerably in susceptibility to noise-induced
hearing loss, but nearly everyone will lose some hearing if exposed to
sufficiently intense noise for a period of time. The U.S. Government’s
Occupational Safety and Health Administration (OSHA) has specified
the permissible noise level exposures shown in the following chart.
According to OSHA, any exposure in excess of these permissible limits
could result in some hearing loss. To ensure against potentially
dangerous exposure to high sound pressure levels, it is recommended
that all persons exposed to equipment capable of producing high
sound pressure levels use hearing protectors while the equipment
is in operation. Ear plugs or protectors in the ear canals or over the
ears must be worn when operating the equipment in order to prevent
permanent hearing loss if exposure is in excess of the limits set forth
here:
Important Safety Instructions
CAUTION AVIS
RISK OF ELECTRIC SHOCK. DO NOT OPEN
RISQUE DE CHOC ELECTRIQUE. NE PAS OUVRIR
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK DO NOT REMOVE COVER (OR BACK)
NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL
ATTENTION: POUR EVITER LES RISQUES DE CHOC ELECTRIQUE, NE PAS ENLEVER LE COUVERCLE.
AUCUN ENTRETIEN DE PIECES INTERIEURES PAR L'USAGER.
CONFIER L'ENTRETIEN AU PERSONNEL QUALIFIE.
AVIS: POUR EVITER LES RISQUES D'INCENDIE OU D'ELECTROCUTION, N'EXPOSEZ PAS CET ARTICLE
A LA PLUIE OU A L'HUMIDITE
The lightning flash with arrowhead symbol within an equilateral triangle is
intended to alert the user to the presence of uninsulated "dangerous
voltage" within the product's enclosure, that may be of sufficient magnitude
to constitute a risk of electric shock to persons.
Le symbole éclair avec point de flèche à l'intérieur d'un triangle équilatéral
est utilisé pour alerter l'utilisateur de la présence à l'intérieur du coffret de
"voltage dangereux" non isolé d'ampleur suffisante pour constituer un risque
d'éléctrocution.
The exclamation point within an equilateral triangle is intended to alert the
user of the presence of important operating and maintenance (servicing)
instructions in the literature accompanying the appliance.
Le point d'exclamation à l'intérieur d'un triangle équilatéral est employé
pour alerter les utilisateurs de la présence d'instructions importantes pour le
fonctionnement et l'entretien (service) dans le livret d'instruction
accompagnant l'appareil. WARNING — To reduce the risk of fire or electric shock, do not
expose this apparatus to rain or moisture.
Duration,
per day in
hours
Sound Level
dBA, Slow
Response
Typical Example
8 90 Duo in small club
6 92
4 95 Subway Train
3 97
2 100 Typical music via head phones
1.5 102
1 105 Siren at 10 m distance
0.5 110
0.25 or less 115 Loudest parts at a rock concert
PORTABLE CART
WARNING

Table of Contents
Introduction
Block Diagram
Front Panel
Rear Panel
5254 Features
Specications
Limited Warranty
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1
2
3
4
6
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Rupert Neve Designs 5254: Dual Diode Bridge Compressor
Thank you for purchasing the Rupert Neve Designs 5254 Dual Diode Bridge Compressor. We hope you enjoy using this
product as much as we have enjoyed designing and building it. The 5254 features custom Rupert Neve Designs trans-
former-coupled inputs and outputs, Class-A analog signal paths, and full-wave rectication in the compressor sidechain.
1
5254 Block Diagram
2
C
H 1 LINE IN
+ +
+
+
+
-6 TO 20dB
CW
BLEND
+
-
-
GND
+
TIMING
FAST
MF
MED
MS
SLOW
AUTO
+
RATIO
1.5:1
2:1 3:1 4:1 6:1 8:1
+-
-
+
HPF
20-250Hz
SC HPF
+
2 1
4
3
G
CH 1 LINE OUT
2
C
H 2 LINE IN
+ +
+
+
+
-6 TO 20dB
J?
SIDE CHAIN SND/RTN B
J?
+
+
SC INSERT
-2.5dB
CW
BLEND
+
-
-
GND
+
TIMING
FAST
MF
MED
MS
SLOW
AUTO
+
-
THRESHOLD
RATIO
1.5:1
2:1 3:1 4:1 6:1 8:1
+-
-
+
HPF
20-250Hz
SC HPF
+
2 1
4
3
G
CH 2 LINE OUT
LINK
-33.5dB
-8.5dB
-33.5dB
-8.5dB
COMP IN
COMP IN
COMP IN
COMP IN
CH 2 VU
LVL/GR
-
J?
SIDE CHAIN SND/RTN A
J?
+
+
SC INSERT
-2.5dB
CH 1 VU
LVL/GR
-
GND LIFT
+ +
-
THRESHOLD
CH 1 PEAK CH 2 PEAK

5254 Front Panel
2
RUPERT NEVE DESIGNS
MASTER
LINK
OUTPUT
REDUCTION
HPF
20Hz 250Hz
S/C INSERT
THRESHOLD
RATIO
BLEND %
TIMING
S/C HPF
GAIN dB
6:1
4:13:1
2:1
1.5:1 8:1
SLOW
MSMED
MF
FAST AUTO
-2
-25 +20
+12-18
+6
0
-6 +20
50
0 100
FAST
LEFT PEAK RIGHT PEAK
COMP IN
HPF
20Hz 250Hz
S/C INSERT
THRESHOLD
RATIO
BLEND %
TIMING
S/C HPF
GAIN dB
6:1
4:13:1
2:1
1.5:1 8:1
SLOW
MSMED
MF
FAST AUTO
-2
-25 +20
+12-18
+6
0
-6 +20
50
0 100
FAST
VU SELECT
5254
DIODE BRIDGE
COMPRESSOR
S/C HPF
Illuminated push-button switch
that engages the compressor
side-chain high pass lter
HPF
31-detent potentiometer that
adjusts the side-chain high pass
lter range from 20 Hz to 250 Hz
VU SELECT Push-button switch that toggles between metering the compressor output level (OUT) and gain reduction (IN)
RATIO
6-position rotary switch that adjusts
the compressor ratio from 1.5:1 to 8:1
TIMING 6-position rotary switch that adjusts the compressor attack and release times
VU METER
Illuminated VU meter displays compressor
output level or gain reduction
COMP IN
Illuminated push-button switch that engages both channels of the compressor
LINK Push-button switch that engages compressor stereo link mode
S/C INSERT
Push-button switch that engages the S/C INSERT SEND and RETURN jacks on the rear panel for external side-chain processing
FAST Illuminated push-button switch that modies the compressor time constants by 70% of their original values
THRESHOLD 31-detent potentiometer that adjusts the compressor threshold from +20dBu to -25dBu
BLEND %
31-detent potentiometer that controls
the wet/dry mix of the compressed signal (wet) to the input signal (dry) *Fully CW is compressed signal only
GAIN
31-detent potentiometer that
adjusts compressor make-up
gain from -6 to +20 dB
PEAK
Peak LED warns when signal levels are
peaking 3dB below clip point

5254 Rear Panel
3
LINE INPUTLINE INPUTLINE OUPUT S/C INSERT LINE OUPUT
LEFT
GND
LIFT
LEFT
RIGHT RIGHT
SEND
RETURN
POWER
100-240 VAC
50/60Hz
45 Watts
MADE IN USA
Rupert Neve Designs, LLC
Model 5254
CAUTION
Risk of Electric Shock
Disconnect from outlet
before removing cover
5254-00001
Rupert Neve Designs, LLC
Model 5254
POWER
AC Power inlet with power switch
100-240 VAC
50/60 Hz
LINE OUTPUT
Custom Rupert Neve Designs
transformer-coupled line output
LINE INPUT
Custom Rupert Neve Designs
transformer-coupled line input
S/C INSERT RETURN Compressor side-chain insert RETURN jack for connecting the output of an external processor (ex: EQ)
S/C INSERT SEND
Compressor side-chain insert SEND jack for connecting to the input of an external processor (ex: EQ)
GND LIFT
Ground lift switch that
lifts XLR LINE OUT Pin 1
from chassis ground

4
5254 Front-Panel Features
Threshold
The THRESHOLD control is a 31-detent potentiometer that allows the user to adjust the point at which compression
occurs, between -25dBu and +20dBu. Turning this control counter-clockwise will increase the amount of compression;
turning it clockwise will decrease the amount of compression. If the input signal is lower than the set threshold, no
compression will occur.
Ratio
The RATIO control is a 6-position rotary switch that allows the user to set the slope of the compressor curve, ranging
from 1.5:1 through 8:1. This ratio range allows the user to dial in a wide range of compression characteristics for their
specic application.
Timing
The TIMING control is a 6-position rotary switch that allows the user to manipulate the attack and release times of the
compressor simultaneously. Each TIMING setting has a dierent attack and release time range associated. Due to the
nature of this topology, these time constants will adapt based on several factors: compression ratio, threshold, and
source material. This allows the diode bridge compressor to remain exible within a wide range of source material. We
encourage the user to experiment with dierent combinations of RATIO, TIMING, and THRESHOLD settings to achieve
the desired result.
Gain
The GAIN control is a 31-detent potentiometer that allows the user to add make-up gain to compressed signal in order
to match the compressed signal level with the input signal level. It is much easier to evaluate the eect of compression
when these levels are matched for proper A-B comparison.
Blend
The BLEND control is a 31-detent potentiometer that allows the user to adjust the ratio of the compressed (wet) signal
with the uncompressed (dry) signal to achieve parallel compression. Turning the BLEND control fully counter-clockwise
shifts the mix toward the fully dry, uncompressed signal. Turning the BLEND control fully clockwise shifts the mix to-
ward the fully wet, compressed signal.
Fast
The FAST illuminated push-button switch modies the attack and release times available on the TIMING control by 70%
of their original values, eectively doubling the range of TIMING settings made available to the user.
Link
The LINK switch engages stereo link mode. In stereo link mode, the compressor channel that is actively compressing the
input signal the most will control the other channel in order to maintain a properly balanced stereo image.
Comp In
This illuminated push-button engages both channels of the compressor. This enables the user to AB the compressed
and uncompressed signal while dialing in the proper compression characteristic for the given source material.
S/C HPF
The side-chain high-pass lter employs a 12dB/octave Sallen-Key lter that allows the user to control the amount of low
frequency energy that hits the compressor side-chain. The 31-detent HPF potentiometer is continuously variable from
20Hz to 250Hz. The side-chain HPF is engaged when the S/C HPF push-button switch is set to the IN position.

5254 Front-Panel Features
S/C Insert
This push-button switch enables the S/C INSERT SEND and RETURN jacks on the rear-panel of the compressor. This
allows the user to patch in additional external processing gear into the compressor side-chain (such as an external EQ).
The side-chain insert level is -3dB referenced to the input level.
VU Select
These push-button switches toggle the VU meter displays between compressor output level and compressor gain re-
duction. VU Reference Standard: 0VU = +4dBu
Peak LED
The Peak LED will illuminate RED in order to warn the user that the output stage signal level is peaking 3dB below clip
point.
VU Meter Endstop Adjust
Important: The recessed black adjusters below the VU meters come factory trimmed and should not need further ad-
justment. These adjusters allow for VU meter needle bottom endstop calibration (one tick mark below -20 VU).
Power
IEC standard 3-pin grounded AC power inlet with power switch. 100-240VAC 50/60Hz input range with a maximum
power consumption of 45W.
Line Input
Neutrik XLR combo jack line input utilizing custom Rupert Neve Designs transformer-coupled, balanced inputs. Maxi-
mum input signal level is +26.7 dBu at 1kHz.
Line Output
Neutrik XLR jack line output utilizing custom Rupert Neve Designs transformer-coupled, balanced outputs. Maximum
output signal level is +26.7 dBu at 1kHz.
S/C Insert Send and Return
Neutrik TRS jacks utilized for compressor side-chain insert. These jacks are enabled by pressing the S/C INSERT push-but-
ton switches located on the front panel. A 1/4”TS cable should be used to make patches to and from external process-
ing gear. The side-chain SEND jack should be connected to the INPUT of the external processor (EQ). The side-chain
RETURN jack should be connected to the OUTPUT of the external processor.
S/C HPF
The side-chain high-pass lter employs a 12dB/octave Sallen-Key high pass lter that allows the user to control the
amount of low frequency energy that hits the compressor side-chain. The 31-detent HPF potentiometer is continuous-
ly variable from 20Hz to 250Hz. The side-chain HPF is engaged when the S/C HPF push-button switch is set to the IN
position.
Ground Lift
The ground lift switch can be used to interrupt a ground loop if encountered in the studio environment. In the LIFT
position, Pin 1 of the XLR line outputs are disconnected from chassis ground.
5
5254 Rear-Panel Features

XLR Line Input to XLR Line Output (Compressor Bypassed) ZSOURCE= 40 Ω Balanced
Input Impedance 10 kΩ
Output Impedance 40 Ω
Maximum Input Level (+4dBu Selected) +26.7 dBu typical
Maximum Output Level +26.7 dBu typical
Noise (22 Hz - 22 kHz BW) -104 dBu typical
Frequency Response (10 Hz to 120 kHz) +/- 0.25 dB typical
THD+N @1 kHz @ Maximum Level (22 Hz - 22 kHz BW) 0.0008% typical
Compressor Noise Specications ZSOURCE= 40 Ω Balanced
Noise @ 0dB Make-Up Gain (22 Hz - 22 kHz BW) -84.5 dBu typical
Noise @ +20dB Make-Up Gain (22 Hz - 22 kHz BW) -64.5 dBu typical
Compressor Timing Specications
Note: TIMING measurements represent the full range achievable between 1.5:1 and 8:1 ratio and FAST mode
FAST Attack 250μS - 2 mS // Release 100mS - 200mS typical
MF (MEDIUM FAST) Attack 1mS - 5mS // Release 100mS - 200mS typical
MED (MEDIUM) Attack 3mS - 18mS // Release 350mS - 700mS typical
MS (MEDIUM SLOW) Attack 5mS - 40mS // Release 600mS - 1S typical
SLOW Attack 10mS - 80 mS // Release 800mS - 1.5S typical
AUTO Attack 5mS - 40mS // Release T1 400-900mS, T2 1-2S typical
Product Dimensions (W x D x H) 19” (48.3 cm) x 8.25” (20.9 cm) x 1.65” (4.2 cm)
Shipping Dimensions (L x W x H) 24”(61 cm) x 13” (33 cm) x 4” (10.2 cm)
Shipping Weight 10 lbs. (4.5 kg)
6
5254 Specications

7
5254 Specications (continued)

8
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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, LIMITEDWARRANTY IS IN LIEU OF ALL OTHERWARRANTIES,
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 ser[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.
Rupert Neve Designs
PO Box 1969
Wimberley TX 78676
www.rupertneve.com
tel: [phone]
fax: [phone]-00040 Rev A
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