“The
only Phono Equaliser to unlock the full potential your vinyl system.”
After years of extensive in-house development and close collaboration
with recording engineers and archivists from the BBC, the British
Library Sound Archive, the Institut fur Rundfunktechnik GmbH and
Sveriges Radio AB, the result is the AMR Reference Class PH-77 Phono
Equaliser.
The PH-77 is the only phonograph source able to lay claim
to exclusively feature a comprehensive catalogue of 22 equalisation
(EQ) curves: every LP record can now be replayed using the one and
only correct equalisation curve.
This along with 8 levels of gain,
64 steps of load, 3 inputs for unprecedented flexibility in cartridge
choice and matching and the onboard 24bit/96kHz Analogue-to-Digital
converter, the PH-77 is undeniably one of the most significant reference
phonograph sources ever produced.
With unorthodox approaches to the
circuit design, using rare and primarily bespoke components, AMR’s
PH-77 Phono Equaliser paints a sonic picture that is so seductively
vivid, beautiful and harmonically rich, that it possesses an enthralling
live performance-like quality that after listening, one is left struggling
for superlatives.
Complete Catalogue
of 22 Equalisations Curves
Contrary to common perception, the introduction
of the RIAA Equalisation in 1954 did not result in all LP’s
being cut using this standardised Equalisation Curve. Even as late
as the 1980’s, several significant record labels (including
USA ones) continued to use equalisation curves that differed from
the RIAA suggestion. In addition, many original “all time classic” issues
precede the widespread adoption of the RIAA Equalisation standard
and so, require a particular equalisation curve.
All such LP’s cannot be reproduced correctly with a phono
stage offering only RIAA Equalisation. The PH-77’s OptiEQ allows
the selection of 22 different EQ curves in real-time via remote control.
This covers all known LP vinyl ever pressed, a true first among reference
phono amplifiers.
One may now finally listen to vinyl recordings the correct and original
way such as:
- The original Mercury Living Presence series (Decca FFSS,
Decca FFRR EQ)
- The original Deutsche Grammophon Classical records
(Decca FFSS, Decca FFRR, CCIR EQ)
- The original Miles Davis records
(Columbia EQ)
- Verve Jazz records, with performers like Charlie
Parker, Count Basie, Ella Fitzgerald, Nina Simone and The Righteous
Brothers etc. (Columbia & AES EQ)
- The original Dave Brubeck
Quartet records (Columbia EQ)
- A significant number of the original
stereo Decca (Europe) records (Decca FFSS, Decca FFRR EQ)
- Rectify
high frequency roll-off and excessive phase shift of all, including
Neumann and Western Electric vinyl cutting lathes (Enhanced RIAA
EQ)
This list* is far from comprehensive
but sheds some light on how the magical musical performance of such
coveted recordings has never been fully realised until now.
*: The
labels on the list also issued many records based on the RIAA equalisation
as well.
Unorthodox Signal Path Design and Bespoke Implementation
 The PH-77 boasts an input stage adopted from extreme low noise circuitry
used in quantum particle research, allowing an exceptionally low
equivalent input noise of -145dBV (0.056uV). This places the PH-77
in the highest echelon of the quietest phono stages ever made.
The
PH-77 is a pure single-ended, class A, zero negative feedback design.
All low level signal connections including the cartridge are coupled
directly. Only two coupling capacitors are employed overall. One
is a custom made silver leaf capacitor that follows the equalisation
block. The output capacitor is the same German-made film and foil
capacitor as used in the multiple award winning CD-77 CD-Processor.
The circuit is designed to preserve absolute polarity at all gain
levels and for all equalisation settings.
All valves used in the
PH-77 are rare NOS valves, e.g. Mullard ECC81/12AT7(2 pcs), and Philips
5687WB(2 pcs), EZ80(2 pcs).
The EQ section (including RIAA) is made
up of custom-made silver leaf capacitors selected to less than 1%
tolerance. For the standard RIAA EQ, all parts are directly soldered
into the circuit using silver solder. The parts adjusting the historical
curves are then switched into the circuit by gold over solid silver
contact relays to ensure the best possible analogue performance with
all EQ curves.
In order to ensure that any remaining dielectric effects
in the capacitors are minimised, all capacitors carry bias voltages
many times that of the signal voltage applied. This unusual approach
operates the capacitors in a mode that is similar to single-ended
Class A operation for amplifiers, to attain maximum linearity at
incredibly low signal levels.
The end result is a signal path that
preserves the purity of the music that is second to none.
Finest Matching and Unparalleled Adjustability
In order to allow easy and precise matching of any cartridge, AMR
has made the PH-77 adjustable using either the included aluminium
remote control or via the front panel controls. The PH-77 offers:
- levels of gain 72dB, 66dB, 60dB, 54dB, 48dB, 42dB, 36dB, 30dB for
complete cartridge compatibility, optimally matching Cartridges with
output levels from below 0.1mV to over 12mV.
- 64 steps of load for
pinpoint resistive and capacitive loading.
- 3 switchable inputs
to select the desired cartridges and tonearm combination, be it
elliptical or spherical stylus cartridges, stereo or mono cartridges,
fixed or flexible tonearms, linear tracking or pivoted with Moving
Magnet or Moving Coil cartridges.
High-Resolution 24bit/96kHz Analogue-to-Digital Converter For Storing
Vinyl to Computer
The PH-77 features a reference grade 24bit/96kHz* Analogue-to-Digital
Converter for the highest quality transfer/archiving of vinyl to
computer. This is achieved through a direct USB connection to a personal
computer for preserving the integrity of the signal. This feature
means the PH-77 is one of the most powerful phono sources with which
to transfer vinyl pressings into the digital domain.
* The PH-77
is currently shipping with a reference 16 bit/48kHz Analogue to Digital
converter; customers will receive a no-cost upgrade to the 24 bit/96kHz
Analogue to Digital converter once it is commercially available from
the semiconductor manufacturer.
Download PH-77 Reference Class Phono Equaliser User Manual
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