Phaedrus Groove Sleuth Adaptor Series User manual

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Groove Sleuth Adaptors
Chapter 1 –Introduction
Phӕdrus Audio Groove Sleuth Adaptors were developed to convert the XLR socket microphone
inputs on commercial computer sound cards to non-equalised phono cartridge inputs. The
adaptors ensure the phono cartridge and the microphone inputs are presented with the
appropriate signal levels and impedances. The 48V phantom-power for microphones is remodelled
to power the miniature Groove Sleuth Adaptor preamplifiers. Groove Sleuth Adaptors were
designed to work with Pspatial Audio’s Stereo Lab software (see Appendix 2). With a wide
dynamic range, they offer a very high-quality solution for recording non-equalised needle-drops.
Three versions exist of the Groove Sleuth Adaptors, their roles are as follows:
Groove Sleuth Adaptor MM - for converting moving-magnet cartridges to a standard
microphone input. Fitted with RED identification pips.
Groove Sleuth Adaptor MC - for converting moving-coil cartridges to a standard microphone
input. Fitted with GOLD identification pips.
Groove Sleuth Adaptor PHLUX - for converting Phaedrus Audio active phono cartridges to a
standard microphone input. Fitted with GREEN identification pips.
Please ensure you have the appropriate adaptor for your cartridge type.

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Chapter 2 –Safety
General
Before using any piece of equipment manufactured by Phӕdrus Audio,
be sure carefully to read the applicable items of these operating
instructions and the safety suggestions. Keep them for future
reference. Follow the warnings indicated in these operating
instructions.
THE USER SHOULD NOT ATTEMPT TO SERVICE THE UNIT. ALL SERVICING SHOULD BE REFERRED TO
QUALIFIED SERVICE PERSONNEL OR FACTORY ONLY.
Phӕdrus Audio products should NEVER be connected to the external power supply or in any other
way energised when the case is opened and/or the circuit boards are accessible.
General Safety Instructions
Do not operate this equipment near any source of water or in excessively moist environments.
Keep this equipment away from babies, children and pets.
Do not let objects do not fall, or liquids be spilled, onto the enclosure.
Situate this equipment away from heat sources or other equipment that produce heat.
Ensure this equipment has adequate ventilation. Improper ventilation will cause overheating, and can damage the
equipment.
When cleaning this equipment, remove all connections to the unit; including power and gently wipe with a clean
lint-free cloth; if necessary, gently moistened with lukewarm or distilled water. Use a dry lint-free cloth to remove
any remaining moisture. NEVER use aerosol sprays, solvents, or abrasives on this equipment.
This equipment should be serviced by qualified service personnel or returned to Phӕdrus Audio when: an object (or
objects) have fallen into the enclosure; or liquid has fallen into, or been spilled into the unit; or the unit has been exposed
to rain or high humidity; or the unit does not operate normally or exhibits a marked change in performance; or the unit has
been dropped, or the enclosure has been damaged
Chapter 3 - Instructions for Use
Caution
Remember 48V phantom-power is a relatively high voltage and there is the risk of electric shock,
to you and to your equipment.
Connect phono leads to the Groove Sleuth Adaptor and plug the adaptor into the microphone input
BEFORE energising the phantom-power. Switching on the phantom-power should ALWAYS be last
item in the connection sequence. See Connecting and using the equipment.
When disconnecting equipment, switching off phantom-power should always be the FIRST item in
the disconnection sequence. Allow a few seconds for the phantom-power charge to leak away
before dismantling the connections. See Dismantling the equipment.
Do not leave this product with nothing connected to the input when plugged into a microphone
input with the phantom-power energised.
NEVER connect a cartridge to a Groove Sleuth Adaptor which is plugged into the microphone input
with the phantom-power energised. Connecting a cartridge to an energised preamp in this way
can damage the phono cartridge.

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Connecting and using the equipment
Do NOT plug in the adaptor to the microphone input straight away. First connect the phono
leads from your turntable to the phono inputs of the Groove Sleuth Adaptor.
Ensure that the phantom-power on the microphone input is not energised.
Plug the Groove Sleuth Adaptor into the microphone input and switch on the phantom-
power.
After a few seconds, your Groove Sleuth Adaptor is ready to use.
Set the microphone levels in the normal way, so that sufficient signal level is recorded
without overloading.
If your turntable has a separate ground wire, see Appendix 3.
Dismantling the equipment
When disconnecting equipment, switching off phantom-power should always be the FIRST
item in the disconnection sequence.
Allow a few seconds for the phantom-power charge to leak away before dismantling the
connections.
Warranty & Service
If you experience a problem with a Phӕdrus Audio product, contact [e-mail]. We will diagnose the
problem remotely and advise you of the warranty status. If a repair or replacement is required, we will issue a Return
Merchandise Authorization (RMA) number and tell you where to send the unit to be repaired. You MUST have an RMA
number before you return the equipment to Phӕdrus Audio's support service. Phӕdrus Audio will not accept responsibility
for loss or damage in shipping or for equipment returned without valid paperwork and/or a valid RMA number. Remember,
warranty is void if product serial numbers have been removed or altered, or if the product has been damaged by abuse,
accident or unauthorized modification and/or repair. There are no user serviceable parts inside.
PLEASE RETAIN YOUR SALES INVOICE. IT IS YOUR PROOF OF PURCHASE COVERING YOUR LIMITED WARRANTY. LIMITED
WARRANTY IS VOID WITHOUT SUCH PROOF OF PURCHASE.
Phӕdrus Audio’s Limited Warranty
Before using a Phӕdrus Audio Groove Sleuth Adaptor, please read carefully the specifications and applications information
in the manual. Improper installation or operation may cause damage to the component, modify its characteristics and
decrease reliability and useful life. Phӕdrus Audio's Limited Warranty does not extend to any Phӕdrus Audio product that
has been damaged or rendered defective due to accident, misuse, or abuse: and, in no event, will Phædrus Audio be liable
for any direct, indirect, special, incremental or consequential damages resulting from any defect in the product or incorrect
operation or installation of the product.
For the latest warranty terms and conditions and additional information regarding Phӕdrus Audio’s limited warranty,
please see complete details online at www.phaedrus-audio.com.

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Appendix 1 –Specifications
Model: Groove Sleuth Adaptor MM
Sensitivity @5cm/s: 5mV RMS
Input load: >47kΩ
Frequency Response: ±1dB: 10Hz to 100kHz
Noise (EIN): 1.0µV A-weighted, 200Ω termination (better than -70dB relative to 5mV RMS)
Headroom: >40dB (relative to nominal level of 5mV RMS)
THD on 5mV RMS signal at 1kHz: 0.003%
Current draw (from 48V phantom): 1.5mA
Model: Groove Sleuth Adaptor MC
Sensitivity @5cm/s: 0.5mV RMS (Gain = 11dB)
Input load: >100R
Frequency Response: ±1dB: 20Hz to 100kHz
Noise (EIN): 100nV A-weighted (better than -65dB relative to 0.5mV RMS)
Headroom: >40dB (relative to nominal level of 0.5mV RMS)
THD on 0.5mV RMS signal at 1kHz: 0.03%
Current draw (from 48V phantom): 1.5mA
Model: Groove Sleuth Adaptor PHLUX (PHLUX-II)
Sensitivity @5cm/s: 5mV RMS
Input load: Suitable for PHLUX/PHLUX-II
Frequency Response: ±1dB: 10Hz to 100kHz
Noise (EIN): 1.0µV A-weighted, 200Ω termination (better than -70dB relative to 5mV RMS)
Headroom: >40dB (relative to nominal level of 5mV RMS)
THD on 5mV RMS signal at 1kHz: 0.02%
Current draw (from 48V phantom): 1.5mA. 0.5mA (PHLUX-II Black)
Phædrus Audio reserves the right to change specifications without notice.
Appendix 2 - Stereo Lab
Groove Sleuth Adaptors are designed to work with Pspatial
Audio’s Stereo Lab software suite for the capture and archiving of
records from the oldest shellac types to today’s high-mass LPs.
In Stereo Lab, RIAA equalisation is not implemented using the
inaccurate analogue equalisation: instead the EQ is implemented
with digital accuracy. Optional rumble-filtering is implemented
with a phase-linear filter; in this case, something you could only
dream of in analogue domain.
In addition, Stereo Lab includes: distortion cancellation algorithms
(which compensate for the way the stylus tracks the physical groove) and cartridge-compensation
algorithms to compensate for the shortcomings of practical phono cartridges. Stereo Lab also
includes a unique, world-class "click and pop" filter to reduce the perceptible effects of surface
damage.
Historic Equalisation Needle-drop Mode
For the record collector, Stereo Lab also includes a Historic Equalisation mode which implements a
comprehensive collection of gramophone-record equalisation curves; enabling the correct de-
emphasis of 33, 45 and 78 RPM recordings made with EMI 78 (HMV 78 or Blumlein), BSI 33/78,

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Decca 78, Decca 33, NAB, RCA 45, BBC Transcription, Columbia and AES equalisation. Not only is this
level of flexibility only available on very expensive hardware phono preamplifiers, but Pspatial Audio
have included the results of their own comprehensive and original research (gained after years of
record collection and studio remastering) to offer equalisation curves not found on any other
equipment.
Support for older, encoded surround-sound formats is also included with Quadraphonic and
Ambisonics decoding to a modern 5.1 system.
For more information (and to download the software)
http://pspatialaudio.com/index.htm
Appendix 3 –Turntable ground-wire
Some turntables have a thin “ground” wire alongside the
phono cables. This wire normally connects to the metal
components of the tonearm and to the plate which carries
the main turntable bearing.
A ground connection to these components is
advantageous for a whole range of reasons. Not only does
it help with electrostatic screening from interfering AC
radiation, it also helps control static electricity build-up on
the plastic disc as it plays.
If this wire is not earthed, the record-deck signal via the
Groove Sleuth Adaptors will often be noisy and “buzzy”.
Because the Groove Sleuth Adaptors transform microphone inputs to phono inputs, there is often
no immediately obvious connection point for this ground wire. Here are two suggestions (which
depend on the complexity and choice of the related equipment):
If the computer sound-card feeds an amplifier, there may well be a suitable connection for
the ground wire on the amplifier itself, perhaps even an earth terminal?
If the computer is stand-alone, ideally the ground wire should be brought to the screen
connection of either the left or right phono plug as illustrated above.

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Appendix 4 –Noise levels with moving-magnet cartridges
If a calibrated 48kHz needle-
drop is made with a moving-
magnet cartridge and
recording levels set so that a
peak velocity of 70cm/s
registers 0dBFS as displayed
on peak reading meters (as in
a DAW), the registered noise-
level is found to be about
-60dB on the meters with
cartridge parked. RMS noise
is about 10dB below peak
reading*. That’s to say, at
-70dBFS. Although this noise
is typically quite inaudible, it
seems quite high in numerical terms. This is due to the noise generated due to the moving-
magnet cartridge having an inductive impedance which rises with frequency.
If the Groove Sleuth Adaptor is terminated in 200Ω, the wideband noise falls to about
-75dBFS (peak meter), or about -85dB RMS. A spectrogram of noise, terminated and
cartridge parked is given. This very clearly illustrates the effect of the moving-magnet
cartridge upon noise. Neither moving-coil cartridges or Phaedrus Audio PHLUX active
cartridges demonstrate this effect, it is a peculiarity of the moving-magnet type. The effect
is even more marked at higher sampling-rates.
* Assuming noise has a Gaussian distribution; the instantaneous voltage lies within ±3 times
the RMS voltage for 99.7% of the time.

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Declaration of Conformity
The Manufacturer of the Products covered by this Declaration is
Phædrus Audio Ltd.
head office address
The directives covered by this declaration are:
89/336/EEC Electromagnetic Compatibility directive
73/23/EEC Low Voltage Equipment directive
The products covered by this declaration are:
Phædrus Audio GROOVE SLEUTH ADAPTORS
The basis on which conformity is being declared:
The manufacturer hereby declares that the products identified above comply with the
protection requirements of the EMC directive and with the principal elements of the safety
objectives of the Low Voltage Equipment directive, and that the following standards have been
applied:
IEC INTERNATIONAL STANDARD 60065 - Audio, video and similar electronic apparatus –Safety
requirements
The technical documentation required to demonstrate that the products meet the requirements
of the Low Voltage Equipment directive has been compiled and is available for inspection by the
relevant enforcement authorities. The CE mark was first applied in 2019.
Signed: Richard Brice . Phaedrus Audio
Date: September 2019