Dynavector PHA100 User Manual

Dynavector DV- PHA-100

Instruction Manual

The Dynavector phono head amplifier PHA-100 is a complete redesign of our original head amplifier the PE-1, using new

circuitry and the most advanced and highest quality IC’s, resistors and capacitors currently available.

The PE-1 was designed more than 15 years ago using an entirely new patented circuit. During the development of the highly

acclaimed XV-1 cartridge, its performance was optimised through the use of

the original PE-1, making it superior to any other cartridge available.To build

on this, we decided to redesign the PE-1 with the specific aim of making it the

most advanced head amplifier available for the new cartridge. The result is

that the performance of the PE-1 has been significantly improved following

intensive design work and after comparing many prototypes using alternative

components. The result is the PHA-100.

Important factors in reproducing music such as the preservation of natural

ambience, a wide dynamic range and harmonic fidelity are easily overlooked

by conventional methods of amplifying the signal of the cartridge’s output

voltage.There is no shortage of expensive head amplifiers and step up transformers for MC cartridges on the market, all of

which have the aim of amplifying the very low output voltage of MC cartridges with the highest fidelity

In the PHA-100 the maximum current is taken from the cartridge by an active electronic circuit. This current is then

converted to a voltage sufficient to drive a conventional preamplifier For the PHA-100, the current sensitivity of the cartridge

is the most important consideration. By using current amplification, the magnetic distortion of MC cartridges is significantly

reduced but the S/N ratio was still a problem when the PHA 100 was designed 15 years ago. Today, thanks to the latest

technology and components, very low noise operational amplifiers are available and the S/N problem of head amplifiers has

been solved.

SPECIAL FEATURES

 The PHA-100 has an impedance selection switch to provide the correct match for either low or medium

impedance MC cartridges. In this way, users are able to get the best sound from their cartridge.

 The PHA-100 makes use of a unique patented circuit designed to provide the maximum fidelity from vinyl

sources.

 Dynavector is proud of its long record of innovation in the hi-fi field. Our DV-DRT XV-1 cartridge, DV-PHA-

100 head amplifier and DV SuperStereo processors are our answer to a digital industry threatening to destroy

much of the great recorded musical heritage of the last century.

SPECIFICATIONS

Type :Current maximising phono amplifier

Output voltage :Dependent on the current sensitivity of cartridge

Frequency Response :10 - 50,000Hz, (+0dB -0.5dB)

S/N ratio :over 62 dB(FLAT)

Cartridge impedance :position 1 — impedance 4 - 7 ohms

:position 2— impedance 30 - 40 ohmsOptimum position selectable

Power supply :AC 100volts, 115volts, 230volts, 2VA

Size&Weight :Main unit: 120w x 176D x 45H mm,900g

:Power supply unit: 82w x 132D x 45H mm, 800g

Country of origin :Made in Japan

INSTALLATION PROCDURE

1.Connections

1) Connect the tonearm lead phono plugs to the inputs of

the PHA-100.

2) Connect the earth lead of the tonearm to the GND (earth)

terminal of the PHA-100.

3) The output sockets of the PHA-100 should be connected

to the MM phono inputs of the pre-amplifier or the

inputs of a MM phono stage. You should not connect them

to the MC phono inputs.

4) The power cable of the PHA-100 main unit should be

connected to the AC power output socket of the power

supply unit. Please ensure that you lock the power cable

firmly to the power output socket of the power supply unit.

We recommend that the power cable of the power supply

unit be connected to the Switched AC Outlet of the pre-

amplifier where such an outlet is available.

2) Polarity of power supply

We have found that the polarity of the power supply can

influence the character of the sound. Please therefore check

the polarity of the AC plug of the PHA100 when you connect

it to the power outlet. The ground (earth) is indicated by a

white dot mark on the AC plug. Use the polarity which gives

the best result.

3)Note

 Do not use the PHA-100 with a MM cartridge because the

PHA-100 is designed solely for MC cartridges.

 To avoid any hum problems, the power supply unit of the

PHA-100 should be located as far as away as practicable

from the main unit of the PHA-100.

 Before you change the cartridge or operate the impedance

switch of the PHA-100, you should ensure that the volume

control of the pre-amplifier is turned to a minimum or the AC

power to your audio system is turned off to avoid the

possibility of causing any damage.

 Do not connect any components e.g. transformers,

capacitors or resistors between the PHA-100 and the cartridge

because the circuit of PHA-100 is of a design unlike that of

other voltage amplifiers.

2. Adjustments

1) Cartridge Impedance matching

Select the position suited to your cartridge’s impedance.

 upper position 30 - 40 ohms

 lower position 4 - 7 ohms

When the pre-amplifier has a variable impedance, you should

set it to an over 30 Kohms position. Operation below 30Kohms

would cause a deterioration in low frequency response.

3. Positioning

Be sure to locate PHA-100 where:

 there is reasonable air circulation

 it is free from vibration

 it is not subject to magnetic fields.

4. Caution: Note for Reviewers

When the PHA-100 is being used by reviewers for listening

tests, particular care needs to be taken so that neither the

unit nor any part of the audio system suffers damage. This is

because, as mentioned above, the circuit of the PHA-100 is

of unconventional design and dissimilar to other voltage

amplifiers in that the current of the MC’s coil is maximised.

In other words, the MC’s coil acts as though it is short

circuited. If, therefore, the PHA-100 is tested by using the

usual signal generator, the current flow into the PHA-100

would be excessive with the result that the high current

seriously damages the IC’s of the PHA.

The PHA100 is a current maximising head amplifier. This

means that the output voltage of the PHA100 varies according

to the cartridge impedance. Please note that the optimal

output voltage is not achieved unless the PHA impedance

switch is set to match the cartridge’s impedance.

16-15 Iwamoto-cho 2-chome Chiyoda-ku Tokyo

101-0032 Japan

Phone [phone] FAX [phone]

http://www.dynavector.co.jp/