Rega Research Ios Owners manual

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Contents

Introduction..............................................................................1

Design Innovation.................................................................2-3

Installation................................................................................3

Ventilation................................................................................4

Connections.............................................................................4

Earthing...................................................................................5

Cartridge Selection..................................................................6

Powering Up............................................................................7

Controls.............................................................................8- 10

Troubleshooting................................................................11-14

Specifications....................................................................15-16

Owners Log...........................................................................17

Mission Statement

Rega’s philosophy is to make high quality products at sensible prices, as a means

of reproducing music as faithfully as possible. Rega is committed to the design and

development of new and existing products, both in hi-fi and other areas, that will

perpetuate Rega’s values of quality and value for money.

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1

Introduction

The function of a phono pre amplifier is to match the output
from a pick up cartridge to the input of a line level amplifier. It
is required to amplify the very low signals produced by the
cartridge and also to equalise the in accordance with RIAA
record cutting standard.

Rega believes that moving coil and moving magnet cartridges
require different types of phono pre amplifiers to achieve
optimum performance.

The Ios is therefore dedicated to moving coil cartridges and
avoids compromises.

We have avoided including any superfluous gadgets as they
obstruct the signal path and degrade the sound quality.

The Ios phono pre-amp incorporates remarkable and
innovative design ideas. For those interested in the technical
details, these innovations are described more fully in the
nextsection of this manual.

Alternatively, you can simply switch on, sit back and let your

Ios speak for itself.

Please Note: Read this manual with care - failure to do so may result in operational

difficulties not covered by any warranty.

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2

Design Innovation

The Rega Ios is a four stage all symmetrical amplifier. To
provide optimum performance it is dedicated to amplifying the
very low level signals that are generated by moving coil
cartridges.

The first stage uses a 1:10 step-up transformer, which can be
optimised to the cartridge by the selection of the correct
loading and zobel DC resistance correction network connected
across the MC transformer secondary.

The second stage is symmetrical compound pair class A
amplifier, using paralleled low noise Hitachi transistors in the
input stage. This drives the passive high frequency part of the
RIAA equalisation stage.

The third stage is a symmetrical class A differential amplifier
with a common base driver stage; this is also used as the
active amplifier in the low frequency part of the RIAA
equalisation stage.

The fourth stage is the active filter, this configuration uses the
same circuit as found in the second stage. The filter element
uses a very high bandwidth operational amplifier gyrator as the
simulated inductance part of the tuned filter.

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3

The power supply is a symmetrical discrete tracking power
supply using fast diodes and a low noise voltage reference.
Each stage has it’s own localised power supply, and LED
referenced current generators.

Very high quality, polyproplene capacitors have been used in
the signal path. 1% tolerance polypropylene capacitors are
used in the RIAA EQ stages and audio grade capacitors are
used in the rest of the circuit.

Installation

Ios will work well on most surfaces, such as a shelf or a table,

provided there is sufficient air around it to prevent overheating.

To avoid any possible magnetic interference and increased
hum levels, site the Ios as far away from the turntable as the
tonearm lead will allow. If possible, try to place Ios to the left of
the turntable. Ideally the equipment should be placed next to
one another in a line (Ios to the right). This keeps Ios’s most
delicate electronics away from other transformers.

Try not to stack other Hi-Fi components, (tuners, cassette
decks, power amps or CD players), on top of, or underneath
Ios. If this is unavoidable, use an equipment stand.

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4

Ventilation

The heat produced by the amplifier, although minimal, is
dispersed to the air by the case, particularly the underside.
Ensure that the case has an uninterrupted air passage around
it.

Connections

The inputs and outputs are made via RCA (phono) type
connectors. The input and output sockets are marked by colour
to indicate left and right channels, Black for LEFT and Red for
RIGHT.

If your turntable has a separate Earth wire, firmly connect it to
the terminal provided on the rear panel. (see illustration above)

NB. Always switch both pre and power amps off before
changing the leads.

Phono inputs Phono outputs Power input socket

Turntable earth connection

View of rear panel

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