Union Audio Orbit.6 User manual

2
Obit.6User Guide Issue 1
Copyright © 2022 Union Audio Limited. All rights reserved
To the best of our endeavors, we believe the informaon contained in this user guide to be true and accurate but we do not assume responsibility for
inaccuracies or omissions, and reserve the right to make any changes deemed necessary.
This product has been designed to comply with the applicable standards, regulaons, and direcves for the countries where the product is
marketed.
NOTE: Changes or modicaons to this mixer, or its associated power supply, could negavely impact compliance and the user’s authority
to operate it.
Designed and manufactured in the United Kingdom by:
Union Audio Limited
Unit 10 Barncoose Industrial Estate
Redruth
Cornwall
TR15 3RQ
UK
hp://www.unionaudio.co.uk

3
Limited Two-Year Manufacturer’s Warranty
Union Audio warrants the product and accessories contained in the original packaging against defects in materials and workmanship when used in accordance
with this user manual for a period of TWO (2) YEARS from the date of original purchase by the end-user purchaser ("Warranty Period").
Repair or replacement under the terms of the warranty does not provide right to extension or renewal of the warranty period. Repair or direct replacement of
the product under the terms of this warranty may be fullled with funconally equivalent service exchange units.
This warranty is not transferable. This warranty will be the purchaser’s sole and exclusive remedy and neither Union Audio nor any approved service centres
shall be liable for any incidental or consequenal damages or breach of any express or implied warranty of this product.
Condions of Warranty
The equipment has not been subject to misuse either intended or accidental, neglect, or alteraon other than approved by Union Audio. The warranty does
not cover potenometer wear and tear. Any necessary adjustment, alteraon or repair has only been carried out by Union Audio or distributor or appointed
service agent.
The defecve unit is to be returned to the place of purchase, an authorised Union Audio distributor or agent with proof of purchase. Please discuss this with
the distributor or the agent before shipping. Units returned should be packed in the original carton to avoid transit damage.
Check with your Union Audio distributor or agent for any addional warranty informaon which may apply. If further assistance is required please contact
[e-mail]
Any changes or modicaons to the equipment not approved by Union Audio could void the compliance of the product and therefore the users authority to
operate it.

4
Safety Instrucons
Please read and retain these instrucons
• Only use the product for the purposes it is intended and heed all warnings.
• WARNING - To prevent the risk of re or electric shock do not use this mixer near water, or in locaons where it is likely to be exposed to rain or
moisture.
• Always ensure that liquids cannot get spilt over the mixer or its power supply, and keep all objects lled with liquids, such as vases, drinks glasses,
etc. well away from the apparatus.
• Ensure adequate venlaon and ensure all venlaon openings are not blocked or restricted.
• Do not connect the output of ampliers to this apparatus. Always use the correct, high quality cables to connect the mixer to audio sources and
power amplier inputs.
• Do not install the mixer or power supply near any heat sources such as radiators, stoves, ampliers or other apparatus that generates heat.
• When ed to a 19” rack ensure the unit has adequate venlaon and that equipment installed above or below does not generate signicant
amounts of heat or magnec elds that may create hum. If necessary, install a rack mounted cooling fan to prevent excessive temperature build
up within the rack.
• Do not place sharp or heavy objects onto the mixer or power supply as these could damage the controls or cosmecs. Avoid rough handling and
protect both units from vibraon. Retain the original packing in order to protect the unit during shipping or transit.
• Refer all servicing to qualied personnel. Servicing is required if liquids are split onto the mixer or its power supply, objects have fallen into the
apparatus, the unit has been dropped, or does not funcon normally.

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Safety Instrucons
These symbols are internaonally accepted symbols to warn of
potenal hazards with electrical products.
This symbol indicates that a dangerous voltage
constung a risk of electric shock is present
within this unit.
This symbol indicates that there are im-
portant operang and maintenance instruc-
ons in the literature
accompanying this product.
To prevent the risk of electrical shock do not open the mixer or pow-
er supply or remove any covers. no user serviceable parts inside.
Refer servicing to qualied service personnel only.
• Do not remove any covers, either on the mixer or the power supply.
• Install only in accordance with the manufacturer’s instrucons.
• The power supply must have a good safety ground connecon. Do not tamper with or remove the safety ground in the power cord.
• Always use a power cord appropriate to your local mains supply, and ensure the power supply is correctly specied for the local mains voltage.
• Protect the power cord from being walked on, pinched, or stretched.
• Unplug the power supply and mixer during electrical storms.
• Do not leave the apparatus unaended for long periods when powered on.

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Contents
Warranty 3
Safety Instrucons 4 - 5
Index 6
About Orbit.6 7
Why Discrete circuitry? 8
Front and Rear Line Drawing 9
Input Channel Controls 10 - 11
Microphone Input 12
Master Secon 13
Booth and Headphones 14
Rear Panel Input Connecons 15
Mixer Output Connecons 16
Record and Auxiliary connecons 17
Applicaon Diagram 18
Block Diagram 19
Technical Specicaon 20
Notes on Cable Types 21
Index
Contents connued
Europa Power Supply 22
Connecng the PSU to the mixer 23
Care of the Mixer 24
Mixer Dimensions 25
Europa Dimensions 26
Service Record and Notes 27

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The Obit.6 is an esoteric six-channel rack mounted rotary mixer, craftsmen engineered for the discerning audio-
phile DJ and vinyl lover. A fully discrete internal signal path, from Input to Mix -Out, with per-channel thermionic
valve stages, Obit.6 presents a remarkable and distinctive listening experience. Sweet clear highs, warm forward
mids, and extended, driving low end, Obit.6 breathes life into even modest setups while maximising the poten-
tial of high-end sound systems.
The input channels feature an auxiliary send control with pre or post fader routing , a channel level trim, an input
selection switch, a variable High-Pass filter, an IP4 rated illuminated cue button, and a 10 LED VU meter.
Channels one to four have both RIAA and Line inputs, while Channel five and six are Line/Line, with the additional
option of a Microphone input on Channel six.
All channels feature post-fade Direct Outputs for multi-track recording or external summing.
The six rotary channel faders feature a unique damping system providing a silky smooth, heavily weighted feel for the most precise of mix transitions, while the 33mm classically styled
knobs are subtly backlit for easy identification in low light environments.
Obit.6 also features a fully discrete three-band asymmetric Isolator with +6dB of boost and -70dB of attenuation, providing a useful tool for dramatic musical contouring or for audio
equalization adjustment.
The Master Mix control sets the mix output signal level, with the Booth monitor section featuring both level control and two-band equalization. The high powered Headphone Cue
monitor system has both level control and an “Add Mix” function for ease of beat matching.
The mix buss is monitored pre Master Level by two easy to read custom analogue VU meters. The elegant white meter faces are printed using fluorescent inks and backlit by ultraviolet
LEDs, creating a subtle blue/white glow for easy monitoring in low light. To warn of potential overload should the buss signal level exceed +3VU, the meter illumination automatically
switches to bright red.
On the rear panel, the Input and Record Output connections are via gold plated RCA (Phono) connectors, while the channel Direct Outputs , Aux Send, Aux Return and Master Insert
use TRS 1/4” Jack Sockets. Main Mix and Booth outputs feature high quality, metal bodied locking XLR connectors, while power to the mixer from the external linear PSU is via the
Kycon “Snap and Lock” multi-pin connector system for added security.
The striking looking front panel is precision machined from 6mm 5083 Aluminium tooling plate, glass bead blasted, anodised black and white silk-screened, while the rugged steel chassis
is manufactured from 1.5mm Zintec, black texture powder-coated and white silkscreened.
About Orbit.6

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A discrete circuit is one built from individual components, as opposed to an integrated circuit (IC) where all the components are etched onto a single wafer
of silicon.
The basic building block of analogue electronics is the operaonal amplier, or op-amp; a device with a dierenal input and a single output. Commercial op
-amp ICs are complex, containing many transistors, resistors and capacitors to ensure stable, repeatable and consistent operaon in a wide range of dierent
circuit topologies, many of which will not be audio related. A typical mixer will contain dozens of these ICs that the audio signal will have to pass through on
its journey from input to output. And while the added complexity might ensure good
measured performance, it doesn't necessarily translate into what sounds pleasing to the
ear, as each component will have a ny eect on the overall tonality.
A purpose made discrete audio op-amp however, only needs sucient complexity to
perform its intended funcon, and can therefore be designed with far fewer
components.
In addion, each of these components can be individually chosen for best audio
performance, rather than being limited by what can be etched onto a single wafer of
silicon.
The two schemacs (above le) highlight the extremes in complexity between very a
simple discrete op-amp and a typical commercial design. In reality the simple discrete op-
amp, would have limited performance, though it can be made to work quite well.
The heart of Orbit.6 is our own discrete op-amp, designed and manufactured inhouse. In
terms of complexity it is halfway between the two extremes, but oers a similar
measured performance to a commercial IC when used in typical audio applicaons.
Featuring matched transistor pairs, it oers wide bandwidth, high slew rate, low
distoron and high output current, and plays a key role in dening the disncve sound
characterisc of the Orbit.6.
Why Discrete?

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Obit.6 has a total of six Input Channels, each with valve preamp stages and dual stereo
inputs. Channels 1- 4 feature both Line and Phono (RIAA) Inputs, Channel 5 has dual Line
Inputs (Line A and Line B), and Channel 6 accommodates Line A/Mic and Line B inputs. The
Mic Input Select switch is located on the rear panel and overrides the Line A input source.
Aux – The Auxiliary Send controls the channel signal level sent to the Aux Output, primarily
for use with external eects or audio processors.
Pre – The Pre/Post buon selects whether the Aux Send signal level is aected by the
Channel Fader. When Pre is selected, the Aux Send level is not aected by the Channel Fader.
Trim – Controls the level of the input signal from fully OFF to a maximum gain of +10dBu.
Use in conjuncon with the Channel VU Meter to set the opmum signal level, with the
average lighng the green 0VU LED and the peaks just lighng the orange +3VU LED.
RIAA/Line select – (CH1-4) Switches between PHONO (RIAA) Input in the up posion
and LINE in the down posion. The PHONO input has RIAA equalisaon for use with all good
quality moving magnet turntable cartridges
HPF – The channel High Pass Filter adjusts the low frequency cut-o of the channel signal,
and features a two-pole response with a swept frequency range from 10Hz to 1.1kHz.
Input Channel Controls

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Cue – The Cue buon illuminates red when acve, and routes the pre-fader channel signal
to the headphone monitor for audioning. The buon has a toggle funcon and will turn on/
o with each press. Each channel cue is independent and will not be overridden when
pressing other channel cue buons.
Rotary Fader – The six channel faders provide smooth mix transions between the
dierent audio sources. They are not intended to be used to set the channel level being fed
to the main Mix Buss - use the Channel Trim control for this.
Each fader has a range from O, (fully an-clockwise) - to unity, (fully clockwise), with a
progressive logarithmic law. There is no signal gain built into the channel fader, and for best
dynamic range it should be operated fully clockwise on any channel feeding into the mix.
The faders are heavily damped for precise level changes, and are also backlit red for easy
navigaon in low light condions.
Channel Meter – Each channel has its own associated 10 bar LED meter.
The meter is peak reading and is scaled from –25VU to PK (+12VU). For opmal signal to
noise rao (SNR) with minimum distoron (THD) set the channel audio level so that the green
0VU LED is illuminated, and the signal peaks just lighng the orange +3VU LED. Adjustment is
set using the Channel Trim (see page 10).
Avoid running the channel signal level too hot or too cold as it will have a detrimental eect
on the overall audio delity. Especially running the signal level above +9VU will signicantly
increase distoron as it will force the valve stage to start so clipping. Likewise avoid running
the channel level with the red Peak LED illuminang.
Input Channel Controls connued

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Mic Select – Channel Six can be routed to the microphone input (located on the rear
panel) by switching the front panel toggle switch to “Line A/Mic” and by pressing the
“Ch Six Line A to Mic” buon on the rear panel.
The Microphone input is designed to work with any good quality dynamic microphone,
such as the Shure SM58. By default, the microphone input isn’t phantom powered,
but this funcon can be acvated by changing an internal jumper link - contact Union
Audio or an authorised service agent for more details.
Rear Panel Controls
Ch Six Line A to Mic – Pressing in this buon routes the Microphone Input to Channel
Six Line A - NOTE that the LINE A RCA input on Channel Six will be deacvated.
MIC Input XLR – Balanced XLR Input. Pin1 = Ground, Pin 2 = + Hot, Pin 3 = - Cold
Mic Trim– Sets the gain of the pre-amplier from +15dB to +55dB to suit the
microphone used.
Mic EQ– Two-band equalizer to adjust the tonality of the microphone input or as an
aid in liming feedback.
REAR
Microphone Input

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The Master secons sums the audio from the six Channels and controls the output signal
level feeding the main sound system.
This secon features a Master Output Level control, a three-Band Isolator EQ and a pair
of Analogue VU Meters for monitoring the le and right mix buss signal levels.
Addional signal processing can be applied by making use of the Master Insert sockets
located on the rear panel. These sockets break the mix signal path, enabling external
audio processors to be “inserted” into the signal chain and on to the mixer outputs.
Master Level – The Master Output level is adjusted from fully o to +6dBu gain. For best
signal to noise rao (SNR) it is recommended operang the mixer with the knob pointer
at “12 o-clock” or above. If this results in excessive volume then reduce the gain on the
connected power ampliers
Isolator – The asymmetric Isolator oers full signal cut and +6dB of boost over three
frequency bands, High, Mid, Low. Like an EQ the Isolator can be used for audio frequency
correcon, however, unlike an EQ the Isolator completely aenuates the signal when
the knobs are fully an-clockwise. With the knob pointers in the centre posion the
frequency response is at.
Output Meters– The large analogue VU Meters allow for easy monitoring of the le/
right main Mix Buss signal level. The signal level is monitored post-Isolator but pre-
Master Level control. The meter response is the VU (Volume Unit) standard and displays
the average signal level, unlike the channel LED meters which are peak reading. Both
meters feature so ultra violet illuminaon providing a cool blue/white glow for easy
monitoring in low light condions, without being overly bright or distracng.
For lowest distoron and best dynamic range, operate the mixer with the meters reading
between –5VU and 0VU, with signal peaks no higher than +1VU. If the mix buss signal
level goes above +3VU the meter illuminaon will ash bright red as a warning.
Master Secon

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The Booth Output provides for independent local monitoring of the Main Mix buss and
is not aected by the Main Mix Level control. It features a two-band EQ and a level
control.
The headphone output is used for previewing the pre-fader signal level feeding the
input channels, and is acve when any Cue buon is pressed (see page 11). The
headphone output also features an “Add-Mix” control.
Booth Level – Adjusts the signal level of the Booth Outputs from o to +6dBu when
rotated fully clockwise. For best signal to noise rao (SNR), set the level with the
pointer at or above the 12 o’clock posion.
Booth EQ – A two-band shelving EQ oering +/-6dB boost/cut at 100Hz and 5kHz.
Phones Level– Adjusts the level of the headphone output. The Orbit.6 is ed with a
powerful high-quality headphone amplier opmised for use with headphones having
an impedance between 33ohms to 170ohms. Headphones with impedances above or
below the recommended impedance should be avoided, and in parcular headphones
with impedances below 33ohms could cause damage to the circuitry.
WARNING! Avoid operang the mixer with headphones at high volume or
for extended periods of me as this can contribute to severe hearing loss!
Add Mix – The Add Mix control sets the level of the main mix summed with the Cue
Mix. When the knob is fully an-clockwise, only the channel Cue signal will be heard in
the headphones. Turning the Add Mix knob clockwise increasingly adds the mix signal
to the headphones allowing the operator to audion how the Cued channel signal will
sound in the mix before the Channel fader is raised.
Booth and Headphones

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Channels 1-4 – The top row of RCA (Phono) connectors are designed for use with
turntable magnec cartridges and incorporate RIAA (Record Industry Associaon of
America) equalisaon. Do not connect line-level sources to these inputs as it could
cause damage to the sensive circuitry.
The lower row of RCA connectors are for Line level signals within the range of +26dBu
to -10dBu.
Channel 5 – Channel ve has line-level inputs for both A and B.
Channel 6 – Channel six has line-level inputs for both A and B, but addionally Input A
can be switched to the Mic Channel (see page 12).
Channel Direct Out – The channel direct output jack sockets carry the post-fade signal
for each of the six channels . These can be connected to a mul-track recorder or DAW
(Digital Audio Workstaon) enabling each channel to be recorded separately.
Rear Panel Input Connecons

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Orbit 6’s Master and Booth Output XLR connectors are located on the le-hand side of
the rear panel. There is also a pair of Mix Insert patch points for connecon to external
audio processors (compressors, limiters, graphic EQ etc).
Master Out – The Master Output XLRs are electronically balanced, with Pin 2 hot
(posive phase), Pin 3 cold (negave phase), and Pin 1 ground. When the Master Level
control is fully clockwise, with the Meters reading –4VU the output level is
approximately +6dBu.
Important please read!
The Master Out XLRs must only be used on equipment ed with fully balanced
inputs. Never unbalance these outputs by connecng Pin 3 to ground, or use an XLR
to RCA type adaptor. For unbalanced operaon connect only to Pin 2 and Ground and
leave Pin 3 oang.
Booth Out – The Booth Output XLRs are electronically “EBOS” balanced, with Pin 2 hot
(posive phase), Pin 3 cold (negave phase), and Pin 1 Ground. When the Master Level
control is fully clockwise, with the Meters reading –4VU the output level is
approximately +6dBu. These XLR outputs can be used balanced or unbalanced by
connecng Pin 3 to Ground.
Master Insert – The Master Inserts are ed with 1/4” TRS Jacks and follow the
standard convenon of Tip = Send, Ring = Return, and Sleeve the common Ground.
The connector’s normalising contacts by-pass the insert when nothing is plugged in.
Any External Processor should have a nominal operang level between –2dBu to
+18dBu. Be aware that any external equipment plugged into these sockets will have
an impact on audio delity, and we strongly recommend using only studio grade
equipment.
Mixer Output Connecons
NOTE Both the Master and
Booth Outputs have auto-
mung to prevent clicks and
thumps in any connected PA
when powering the mixer on
or o.
Power On mung lasts
approximately 12 seconds,
Power O mung is
instantaneous.

17
Record Out – The Record Output is via an RCA connector with a nominal level of 316mV,
-10dBV (-8dBu) and is compable with most 2-track recorders. The Record output is taken
post Insert and will be aected by the Isolator EQ but not by the Master Level control.
Auxiliary Out – The Auxiliary Output is via a pair of balanced 1/4” TRS Jack sockets
following the standard convenon of Tip Hot, Ring Cold, and Sleeve Ground. The nominal
output level is 0dBu.
Auxiliary Return – The Auxiliary Return is via a pair of unbalanced 1/4” TRS Jack sockets
following the standard convenon of Tip Hot, Ring Signal Ground, and Sleeve Chassis
Ground. The nominal input level is 0dBu
Record and Auxiliary

Applicaon Diagram

19
Block Diagram

20
Distoron plus Noise (THD+N) un-weighted
0dBu, 20Hz to 20kHz, Line In to Mix Out +4dBu 0.008%
Frequency Response
Line in to Mix Out +/-1dB 10Hz to 120kHz
RIAA Accuracy +/-0.2dB 20Hz to 20kHz
Shuto and Crosstalk
Fader Shuto > -85dB
L/R Crosstalk Line in to Mix Out 1kHz <-80dB
Noise 22Hz to 22kHz Un-Weighted
Residual Mix Output noise <-102dBu
Line In to Mix Out Unity <-89dBu
Maximum Output Level Mix Out 0.5% THD +26dBu
Dynamic Range 115dB
EQ and Filter Frequency
Channel High-Pass Filter Fully Clockwise -3dB/1100Hz
Isolator Crossover Frequencies 320Hz and 3800Hz
Booth EQ -3dB/100Hz and 5000Hz
Dimensions
Mixer
Front Panel 482.5mm x 176mm (4U 19” Rack Mount)
Depth 170mm (6 7/10 “)
Weight 6.35kg (14lb)
PSU
Top Panel 200mm x 200mm (7 7/8” x 7 7/8)
Depth 52mm (2”)
Weight 2.2kg (5lb)
Packed Dimensions
Size L x W x H 62cm x 31cm x 38cm (24.5”x 12.2” x 15”)
Weight 12.35kg (27lb)
Headphone Amplier
Maximum output level 1W RMS into 40ohms
Valves
Six High Quality ECC82 (12AU7) Dual Triodes
Specicaons