GOLDEN AGE PRE73 MK3 Microphone preamp

The PRE-73 MKIII is a one-channel vintage style microphone-, line- and instrument preamplifier. The signal path uses only discrete components like resistors, capacitors and transistors. The in- and output is transformer balanced, using two different transformers, each one optimized for its purpose. This is the way audio components were built before integrated circuits became available.

The circuit used in the PRE-73 MKIII is similar to the preamp section in the classical 1073 module with a corresponding sound character that is warm, punchy, sweet and musical. These classic characteristics have been heard on countless recordings through the years and it is a versatile sound that works very well on most sound sources and in most genres.
The essence of this sound is now available at a surprisingly low cost, making it available to nearly everyone.

Features  :

• Vintage Style electronics. No intergrated circuits in the signal path.

• Maximum gain in MIC mode is 80 dB, enough to handle passive ribbon mics with quiet sound sources.

• GAIN switch range 20 - 80 dB. GAIN/LINE mode switch, gain is reduced by 30 dB in LINE mode.

• Selectable two position high frequency AIR boost eq, 3 or 6 dB @ 30 kHz.

• Selectable 6 dB/octave two frequency high pass filter at around 40 (HP1) and 170 Hz (HP2).

• Tantalum capacitors in the signal path.

• Switchable impedance in MIC mode, 1200 or 300 Ohms, will change the tone of most mics. The input impedance in LINE mode is 10 kohm.

• Switchable phantom power and absolute phase.

• A high-impedance instrument input for any sound module, electric guitar or bass.

• A simple but effective 4-step LED output level meter.

• The output level control makes it possible to make fine gain adjustments and also to overload the main gain stage(s) for more character and then lower the signal to a suitable level before the output stage.

• Combo XLR/TRS input jack and separate output XLR and TRS jacks for flexible connections.

• Insert jack for inserting EQ´s and other units.

• Selectable 600 ohm output termination.

• The pcb is prepared for the Carnhill input transformer.

• External power supply to avoid interaction with the audio circuits and transformers.

• A solid build quality that will last many years of normal use.

The MKIII has the following new features compared to the MKII:

• Tantalum capacitors in the signal path.

• Selectable two position high frequency AIR boost eq, 3 or 6 dB @ 30 kHz.

• Selectable two frequency high pass filter, 6 dB/octave at 40 or 170Hz.

• The pcb is prepared for the Carnhill input transformer.

• Revised and less complicated GAIN switch with a separate switch for MIC/LINE selection.

• All GAIN settings can also be used in LINE mode .

At PreSonus, weʼve been designing preamps for a long time, and we always focus on audio quality first. So when we decided to upgrade our popular TubePre V2, we focused on improving an already high-quality sound—without jacking up the price. Like the originalTubePre, the new version is a fully professional tube preamp, with a dual-servo (no capacitors) gain stage that lets you boost the program signal to smoking hot levels without significantly increasing the background noise. Discrete components and high-voltage operation offer dynamic range and detail not found in other single-channel tube preamps in its class.

Housed in a rugged case, the TubePre V2 rear panel sports separate unbalanced, ¼” instrument and balanced, XLR mic inputs and unbalanced ¼” and balanced XLR line outputs. Weʼve included all of the extras you need for professional operation including a high-pass filter, phantom power for condenser mics, polarity reverse switch, and a backlit VU meter.

• • Ultra-high quality 8-channel A/D and D/A interface for virtually any digital recording/mixing environment
  • 8 state-of-the-art MIDAS designed Mic Preamplifiers
  • Phantom power on all microphone inputs
  • Reference-class Cirrus Logic 24-bit converters for ultimate signal integrity
  • Processes 48 and 44.1 kHz sample rates
  • External sample rate synchronization via word clock or ADAT input

• Optical ADAT in/out interface for ultimate compatibility
• All mic/line inputs routed to the ADAT output
• ADAT input routed to all Line outputs
• “Planet Earth" switching power supply for maximum flexibility (100 - 240 V~), noise-free audio, superior transient response plus low power consumption for energy saving
• High-quality components and exceptionally rugged construction ensure long life
• Conceived and designed by BEHRINGER Germany

The U5 high-voltage DI-preamp combines a unique passive tone selector with a variable
gain preamp and filter. The high input impedance accepts a wide variety of signal levels
and instruments from acoustic guitars to high-output active bass guitars and keyboards.
The U5 direct box is loaded with sonic character and user features professionals demand.

U5 FEATURES
Pure Class A, 100% discrete design
Smooth musical detail and sonic excellence
Variable gain preamp to +30dB.
Dual microphone and line outputs
Hi-Z   3,000,000 ohm input impedance
Very low noise -100dB
High headroom +30dB
Six tone bank selections.
DC coupled Class A output for superior bass
High cut switch eliminates noise
LED active signal indicator
Headphone monitor output jack
Low distortion less than 0.5% THD and IMD
High level 400 watt speaker input
Active to thru selector - ground isolation switch
100% discrete power supplies for audio path
Internal toroidal power supply for low noise
Long lasting, stainless steel hardware
 
SONIC EXCELLENCE
The Avalon U5 Pure Class A instrument DI & preamplifier is the most powerful direct box
available today.  Designed to optimize absolute signal integrity and musical performance,
the U5 includes many features and sonic excellence unequaled by lesser designs. The
U5 is ideal for bass guitar and acoustic instruments, electric guitars, keyboards, synthesizers
and low output pickups. 
Features include state-of-the-art, high input impedance input stage for zero load effect on
sensitive pickups and keyboards, 100% discrete, Pure Class A signal amplifiers, practical
user features and rugged hardware designed to deliver true high performance audio for many
years. 
DESIGNED FOR DEEP & CONTROLLED BASS
Avalon U5 DI-preamps have been in use around the world since 1995. They have found their way
into the world's leading musicians rigs and recording sessions and been featured on thousands
of the best selling (and sounding) albums and live performances.
MINIMUM SIGNAL PATH DESIGN
The U5 includes a variable gain Class A preamplifier to boost low level pickup signals and a high
level speaker input for capturing the live sound of the instruments amplifier. Six passive tone-EQ
curves are also included to enhance a variety of acoustic and electric instruments. A high-cut switch
eliminates unwanted acoustic pickup and high frequency noise, while a  headphone monitor amp
has been included for personal listening. Twin DC coupled Class A output amplifiers drive both low
level microphone preamp inputs and high level +4dB inputs for direct to tape recording or processing.
The active-to-thru switch selects either the instrument input directly or sends the boosted-equalized
signal to the amplifier via the front panel jack. A ground isolation switch eliminates any possible earth
loop or AC buzz problems with complete safety.

U5 SPECIFICATIONS
Circuit Topology:  100% discrete, high-voltage Class A 
Gain:  Switched 3dB steps, maximum gain +30dB 
Input Impedance:  3 ,000,000 ohm unbalanced (single ended) 
Maximum Input Level  +24dBu unbalanced, 400w speaker input 
Output Connectors (2):  XLR type, pin 2 hot electronic balanced 
Maximum Output Level (Class A):  +30dBu DC coupled, balanced 600 ohms (mic and line out) 
Headphone Output:  0.5w into 600 ohms 
Noise 20kHz Unweighted:  -100dBu minimum gain position 
Distortion THD, IMD:  0.1% at +10dB 
Frequency Response, -/+0.5dB:  5Hz to 100kHz 
Frequency Response, -3dB:  1Hz to 500kHz (input band limited) 
High Cut Filter:  -3dB at 8kHz minimum phase design 
Tone Selector:  Six position rotary switch, all passive filters 
AC Power:  Internal toroidal AC supply 
Dimensions:  8.5 x 3.5 x 12 in (216 x 88 x 305mm) 
Weight-Packed:  12lbs (5.4kg) 
Rack mount kit (1) RM-1:  Single U5 19 inch rack mount kit (holds one half rack unit) 
Rack mount kit (2) RM-2:  Dual U5 19 inch rack mount kit (holds two half rack units) 

Applications

Console input extending for both Digital and Analog mixing
consoles in Studio, Live and Broadcast
Mic Pre-amps for ADAT/ Hard Disk/ Multitrack Recording
 
Innovation
If you love your compact Digital (or Analog) mixing console, but wish it had
more microphone inputs, ARX has the solution ? the 8 Pre: eight channels
of superb sounding Microphone Pre-amps in a compact 1 RU chassis.
The 8 Pre is the ideal console extender for those times when you need more
microphone inputs. Now you can put those unused line inputs to good use,
and who knows - the 8 Pre pre-amps sound so good that you?ll probably end
up using them all the time instead of the ones that came with your mixer!
Superb Audio Quality
The 8 Pre?s ultra low noise figures come from extensive use of premium
components plus care and attention to board design and layout. The result is
superb, transparent audio quality and the headroom to handle anything that a
mic can throw at it.
Gain is adjustable from 20 db through to 60 dB via a trim control on the front
panel, plus we?ve included a ?20dB Pad switch to tame the hottest condenser
mic output if required. The Clip status LED lights up 1 dB before the onset of
clipping, just to warn you you?re getting close.Phantom power is switchable in
banks of four channels: 1 through 4, 5 through 8. A Phase reverse switch is also
provided on each pre-amp channel to eliminate any close miking problems.
In short, the ARX 8 Pre is the mic Pre-amp that you?ll wish the console manufacturer
had used. It provides a unique solution to today?s multiple Mic Pre-amp requirements.

T E C H N I C A L S P E C I F I C A T I O N S
Input Gain 20dB to 60dB
Input Pad ?20dB
Input Impedance 4 KOhm
Input Headroom +23dB
Output Impedance 300 Ohm
Output Level (Max) +23dB
Frequency Response 20Hz ? 20KHz ±0.2 dB
Signal to Noise ratio (Gain set @ 20 dB)
?93dB Unweighted, ?99dB ?A? weighted
Distortion @ Unity Gain .004%, 20 Hz ? 10 KHz
Dynamic Range 116 dB
Phantom Power 48 VDC
Input Connectors Balanced XLR
Output Connectors Balanced TRS jack
Clip Indicator Illuminates 1 dB prior to clipping
Power Requirements 100/120 V AC, 220/240 V AC
Weight 5 lbs/2.2 Kg
Dimensions 19“W x 1?“H x 6“D, 482 x 44 x 155mm

 The OctaMic II provides 8-Channel 192 kHz / 24 bit AD conversion with eight hi-class microphone and line pre-amplification channels, featuring a combination of sophisticated components and approved RME technology.

Lowest distortion, excellent signal to noise ratio and perfectly linear frequency response transmit and amplify the microphone signals truly unchanged.

The OctaMic II includes some significant enhancements compared to the OctaMic:

The balanced TRS inputs of the Neutrik Combo XLR jacks are phantom power-free and can be operated as real line inputs too. The improved design of the input circuits allows for a maximum input level of +21 dBu with a convenient gain range from 6 dB up to 60 dB.
Improved signal to noise ratio (SNR) ADC 107.5 dB
Improved THD, especially at higher gains
Optimised heat dissipation by a new and larger housing with improved convection
Internal wide range power supply with line filter, insensitive to voltage fluctuations
Super-stable, short circuit proof 48 V phantom power


Features

OctaMic II offers 8 balanced XLR mic / line inputs via Neutrik XLR/TRS combo jacks. Each channel contains switches for 48V phantom power, a low cut filter and phase reversal. Amplification can be set between 6 and 60 dB. LEDs for signal, clip, and activated phantom power give a complete overview on the unit's status. When the special Clip Hold mode is activated, any detected clip-state will cause the corresponding LED to flash once per second. With this, the user gets a long-term peak detection, and no longer needs to constantly watch the LEDs. At the same time momentary overloads are still displayed correctly.

Frontside switches include power on/off and output level, for a choice of -10 dBV, +4 dBu or Hi Gain (+19 dBu) as reference level. This unusual feature offers two advantages. First, the reference level can be easily switched to match any of RME's current interface devices, from HDSP 9632 through Multiface up to the renowned ADI-8 series converters. Second, the Signal to Noise ratio is optimized, and the Clip-LED will exactly match the ones of the ADI-8 (2 dB below 0 dBFS).

The balanced line level output signal is available at the back of the unit via 8 stereo TRS jacks. The specially developed, internal hi-performance switch mode power supply lets the OctaMic II operate in the range of 100V to 240V AC. It is short-circuit-proof, has an integrated line-filter, is fully regulated against voltage fluctuations, and suppresses mains interference.

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AD-Conversion

The 8-Channel AD-conversion of the OctaMic II operates at up to 192 kHz. The digitized signal is available simultaneously at the double ADAT output (S/MUX, up to 96 kHz), and at a DB-25 connector (4 AES/EBU outputs, up to 192 kHz). The digital part can be clocked internally (master) and externally via word clock, AES/EBU and SPDIF.

RME's outstanding SteadyClock(TM) ensures perfect AD-conversion, as jitter on the external sync-sources is nearly completely removed. All settings are done via DIP-switches on the back of the OctaMic II. Analog outputs and both digital outputs operate fully simultaneously. The choice of reference level affects the analog outputs only, the signal/clip indication and the AD-conversion will react only to the Gain-pots.


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Tech Specs

8 balanced XLR/TRS mic/line inputs

54 dB gain range

Input impedance: XLR 2 kOhm, TRS 5 kOhm

Analog input level: from -40 dBu up to +21 dBu

Maximum output level: +21 dBu

Output impedance: 75 Ohm

Output level switchable Hi Gain / +4 dBu / -10 dBV

Signal to noise ratio (SNR): 129 dB EIN @ 150 Ohm

THD:
Large frequency range (200 kHz) with special EMI input filtering

Frequency response -0.5 dB: 5 Hz - 200 kHz

Hi-pass filter: 80 Hz, 18 dB/oct.

Line Out: 1/4" TRS (6.3 mm stereo jack), servo-balanced

Phantom power: +48 Volt switchable per channel

Internal wide range switching power supply 100-240 Volt AC

Unbeatable price/performance ratio!

AD conversion

SNR: >110 dB(A)

Supported sample rates: 28 kHz - 200 kHz

THD:
Sync Sources: AES/EBU (also SPDIF coaxial), wordclock, internal

SteadyClock(TM) ensures best sound quality even with jittery external clocks


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Accessories

Digital breakout cable Pro, AES/EBU, D-sub25 to 4x XLR-3 female + 4x XLR-3 male, 1m/3m/6m (ALVA Audio)
Digital D-sub cable, AES/EBU, D-sub25 male to D-Sub25 male, 1m/3m/6m (ALVA Audio)
Optical ADAT Toslink cable 1m/2m/3m/5m/10m (ALVA Audio)
Word Clock cable, 1 x BNC male to 1 x BNC male, 1m/5m/10m (ALVA Audio)

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Add-On

BOB-32    Universal Breakout Box with 2 x 8 XLR to 2 D-sub connectors (supports TASCAM and YAMAHA format), flip-frame case