Oracle Audio Technologies
PH200 Mk III phono preamplifier
3
Features
Inputs / Outputs
There is one “INPUT” and one “OUTPUT” and both come in standard RCA format.
RIAA Equalization
The RIAA circuit is designed by following the true RIAA standard.
The accuracy of the RIAA standard curve is +/- 0.1dB.
Important information
It is imperative to always turn off the PH200 Mk III before making changes to the loading settings and it
should even be unplugged from the wall outlet. Turning off the amplifier or setting it on a different input
than the one where the phono amplifier is connected is also a good precaution to take.
Switch-selectable gain setting
The PH200 Mk III phono phono amplifier has 3 gain settings plus one optional setting. The gain must be
adapted to match your cartridge’s output with the input of your phono amplifier to provide an optimal
volume level but also to prevent any overloading which would cause distortion. Those settings are done
by selecting the proper switch position as indicated in the diagram on page 4 of this user manual. The
different gain levels are 42dB, 52dB or 62dB. We added a header that allows you to use a 2 Ohm resistor
to reach a 73dB gain. This can be useful when using a very low output MC cartridge ( between 0,35 and
0,5 mv ) if the preamplifier or the line stage has insufficient gain.
Switch-selectable load settings
There are 5 different standard load impedance settings. This load is adjusted by selecting the proper
switch position as indicated in the diagram on page 4. We added a header that allows you to use a
specific value resistor that would be required for your phono cartridge exact loading. You can replace the
1,5k Ohms resistor with the specific resistor value recommended by the phono cartridge manufacturer.
Capacitive charge
The 47k Ohms setting is coupled with a fixed capacitive charge of 150pF. It is possible to add a capacitor
to the existing one to reach the exact value required by the phono cable you are using. When using an
additional capacitor the switch # 6 must be set at “ON”.
The capacitive charge has no impact on moving coil cartridges.
