Audiomods Rega conversion The wiring path

Audiomods Rega conversion
The wiring path
Apart from its electrical performance as a signal conductor, the mechanical
performance of the tonearm wiring is also very important and is often overlooked.
An arm must be designed so that it controls and does not feed back energy generated
in the cartridge. But we have wires running inside the armtube that are directly
connected to the tiny, sensitive generator coils of the cartridge, so we need to make
sure that they are isolated as much as possible from the resonances going on within
the armtube.
In a normal armtube, the wires just run loosely down
the tube, usually resting on the bottom and they are
unrestrained for the entire length of the tube. Our
cross-brace discs keep the signal wires running down
the centre of the tube with only two points of contact
where they touch the disc. The result is to
considerably reduce low-level vibration fed back to the cartridge coils. There is also a
shielding benefit to keeping the wires in the centre of the directly-grounded alloy
armtube, helping to eliminate RFI and hum pickup.
For special applications, such as the “Kondo IO” arm,
the cross-bracing discs can separate the signal wires
from the extra exciter wires used by this unusual
cartridge. The signal wires are offset a little towards
the top of the armtube,
whilst the exciter wires,
which are not sensitive to
hum, are held against the bottom of the tube. They exit the
back of the arm tube, so never come into contact with the
signal wires.
After trying a number of alternatives, cartridge tags are from
Michell. These are machined from solid and silver-plated.
www.audiomods.co.uk
jeff@audiomods.co.uk
1

Audiomods Rega conversion
Termination options
Phono sockets
The most popular option is to have the wiring terminated to a phono socket block
which can be fixed to the turntable arm board/plinth or to a mounting plate held by
the arm fixing nut.
This has several advantages:
- you can try different interconnects and decide your favourite. Without getting into
the more exotic arguments about cable choice, it’s reasonable to say that different
cartridge/phono amp combinations might prefer different capacitance/impedance
characteristics.
- features of the perfect tonearm wire like extreme flexibility don’t necessarily make
the best interconnect. This is especially true with very fine cables where simple
resistance might be a factor in interconnect-length application.
- only the fine signal wires are connected to the arm, eliminating another source of
vibration feedback.
For a terminal block to work properly in a
Rega-based installation, it should be able to
pass through the 23mm armboard
mounting hole.
Our terminal block is made in two halves.
The back (top of the picture), which carries
the grounding wire, unscrews to allow the
two parts to pass through the mounting
hole. The block is then fixed to a
convenient point on the plinth.
Five-pin plug
This is the standard “DIN”-type plug used by several
manufacturers. We use one manufactured by Cardas.
It is a very neat solution and one that completely
protects the internal wiring, but it does mean that you
need to use an appropriately terminated interconnect.
This plug increases the height of the base column by
approximately 15mm when the vta is in the fully
lowered position.
Either of these two terminations can use any of our
wiring options, though we recommend the five-pin
when Audio Note wire is chosen because of the
delicate nature of the wire.
www.audiomods.co.uk
jeff@audiomods.co.uk
2

Audiomods Rega conversion
Complete loom
A one-piece run of silver-in-teflon wire from cartridge pins to pre-amp, using the
Isokinetik wiring loom. This provides 1m of interconnect cable built in.
Arms wired in this way will need about 20mm more clearance under the turntable
than the standard Rega arm.
www.audiomods.co.uk
jeff@audiomods.co.uk
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