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 the most advanced and highest quality IC's, resistors and capacitors
available at the present time.
The PE-1 was designed more than 15 years ago
using an entirely brand-new patented circuit.
During the development of the XV-1, we
optimized its superb performance through use
of the original PE-1, making it superior to any
cartridge currently available, including our own.
To build on this we then decided to redesign the
PE-1 specifically to become the most advanced
and most favorable head amplifier for the new
cartridge. Now all the weaknesses of the PE-1 have been eliminated after comparing many
prototypes using alternative components. The result is the PHA-100.
Important factors in reproducing music such as the natural ambience, the correct dynamism and
comfortable harmonies are easily overlooked by conventional signal amplification of the cartridge
output voltage. As you already know, there are many expensive and high performance head
amplifiers or step up transformers for MC cartridges.
They are designed to amplify the very low output voltage of MC cartridges as perfectly as possible.
In the PHA-100 the maximum current is extracted from the cartridge by an active electronic circuit,
then this current is converted to a voltage, which is enough to drive a conventional preamplifier. In
the case of PHA-100, the current sensitivity of the cartridge is the most important factor. By using
current amplification, magnetic distortion of MC cartridges can be reduced considerably, but S/N
ratio was still a problem 15 years ago. Today, thanks to latest developments, very low noise
operational amplifiers are available. So the S/N problem of head amplifiers has gone.
PHA-100 has impedance select switch to match either to low impedance and medium impedance
MC. Users are able to get better sound from each MC by this switch.
In PHA-100, a patented circuit for developing more realistic music is employed. DV-DRT XV-1,
DV-PHA-100 and DV SuperStereo are our answers to a digital industry threatening to destroy
much the great musical heritage of our century.
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1.Connections
Input jacks are connected to the tonearm output cable.
1.
GND (ground) terminal is connected to the ground wire of the tonearm cable or that of the
2.
turntable.
Output jacks are connected to the MM phono input of the pre-amplifier.
3.
Do not connect to the MC input.
The power cable of the main unit is connected to the AC power output plug of the power supply
4.
unit. Make sure the output plug is locked stably.
We recommend that the power plug of the power supply unit is connected to Switched AC
Outlet of the pre-amplifier. When Switched AC Outlet is not available on the pre-amplifier,
position the power unit where easy operates is needed.
2.Operations
Impedance matching for the cartridge
1.
Cartridge impedance is selectable. Select the switch to adjust suitable impedance for the cartridge.
upper position 4 - 7 ohms
•
downside position 30 - 40 ohms
•
When the input impedance is selectable on your pre-amplifier, you should select the position as
more than 30Kohms. Operation below the 30K ohms load causes the deterioration of low frequency
response.
As PHA-100 is a current maximizing head amplifier, output voltage is changed by cartridge
impedance. When the switch selection is not correct, optimal output voltage is not obtained.
Polarity of power supply
2.
In our experience the relative polarity of power supply has a great influence on the sound character.
Please check the polarity of AC plug for PHA-100, when you connect to power source. Ground is
indicated with white dot mark on AC plug. Use the power supply as the polarity that you could
obtain good result.
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Note
3.
z Do not use PHA-100 for MM cartridge, because PHA-100 is only designed for MC cartridge.
z To avoid hum problem, power supply unit should be in place as far as possible keeping distance from main
unit.
z When you change the cartridge or operate the impedance switch, you should reduce the volume of pre-
amplifier completely or shut off the power of your system to avoid an unexpected accident.
z Do not connect any sound devices, transformers, capacitor, resistor between PHA100 and the cartridge,
because t
he circuit of PHA-100 is particular circuit not common to other voltage amplifier.
3. Installation
Be sure to locate PHA-100 in the following conditions.
z Locate where reasonable air circulation
z Locate where be protected from vibration
z Locate where be protected from magnetic leakage flux.
4. Caution
When PHA-100 is handed over to reviewers for listening test, the special caution is needed for
avoiding the misunderstanding or abuse. The circuit of PHA-100 is particular circuit not common to
other voltage amplifiers. Current of the MC's coil is maximized. In other words, MC's coil is
imaginary short circuited. When the PHA-100 is tested by using ordinary signal generators or else,
current into the PHA-100 is maximized. As a result, the excessive current gives rise serious damage
to IC's of PHA.
5. Specifications
Type :Current Maximizing phono amplifier
Output voltage :Depending on the current sensitivity of cartridge
Frequency response :10 - 50,000Hz, (+0dB -0.5dB)
S/N ratio :more than 62 dB(FLAT)
Cartridge impedance :1 position --- impedance 4 - 7 ohms
:2 position --- impedance 30 - 40 ohms
:Optimum position is selectable
Power supply :AC 100volts, 115volts, 230volts, 2VA
Size &Weight :Main unit: 120w x 176D x 45H mm, 900grams.
:Power unit: 82w x 132D x 45H mm, 800grams.
Dynavector Systems, Ltd
16-15 Iwamoto-cho 2-chome Chiyoda-ku Tokyo 101-0032 Japan
Phone 0081-3-3861-4341 FAX 0081-3-3862-1650
http://www.dynavector.co.jp/
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