Oracle Audio PH200 MkIII Phono Preamplifier

The Oracle Audio PH200 MkIII is a dual-mono moving magnet and moving coil phono preamplifier with a highly regulated external power supply and an extra signal regulation step ahead of its RIAA circuit. Switches set 42, 52 or 62dB of gain, plus an optional 73dB, for cartridges down to 0.35mV.

The PH200 MkIII is the step up in Oracle's Paris-series phono line. It shares its analog modules and RIAA circuitry with the PH100 MkIII, then adds higher-quality operational amplifiers, the regulation step and the outboard supply. It competes with phono stages from Parasound, Lehmann and Musical Fidelity. We recommend it to customers who want a phono stage that will not be the weak link in their vinyl setup.

"The secret behind the overall tonal balance and performance of the Paris phono preamplifier lies in the careful selection and combination of the different components."

Key Features of the Oracle Audio PH200 MkIII

• Two-Stage, Dual-Mono Circuit: A first stage lifts the cartridge signal for the RIAA circuit and a second stage brings it to output level, each designed to optimize signal to noise
• Burr-Brown Operational Amplifiers: OPA228P in the first stage and OPA627AP in the second
• Additional Signal Regulation: An extra regulation step located just before the RIAA circuit input
• External Toroidal Power Supply: Highly regulated and filtered, delivering two 15 VAC at 50VA through a DIN plug
• Switch-Selectable Gain: 42dB, 52dB or 62dB, plus a header for an optional 73dB setting for moving coils between 0.35mV and 0.5mV
• Six Load Settings Plus a Custom Header: 100, 200, 511, 1k and 1.5k ohms for moving coils and 47k for moving magnets, with a header for your cartridge maker's exact value
• Adjustable Capacitance: 150pF fixed at 47k ohms, with room to add a capacitor to match your phono cable
• Selectable Ground Reference: A ground switch chooses the building's electrical ground or a floating chassis ground to help clear hum
• RIAA Accuracy of +/- 0.1dB: The RIAA circuit follows the true RIAA standard
• Three-Year Warranty: Transferable parts and labor limited warranty from Oracle

How Is the PH200 MkIII Circuit Built?

In two stages, in a dual-mono layout. The first stage, built on Burr-Brown OPA228P operational amplifiers, amplifies the faint cartridge signal to a level the RIAA circuit can work with. The second, on Burr-Brown OPA627AP, raises the corrected signal to the PH200's output level. Higher-precision Dale resistors are part of the MkIII parts list.

Oracle designed both amplifying stages to optimize the PH200's signal to noise ratio, which it rates at better than -80dB, and says the result is "a very rapid and high dynamic contrast." Distortion is below 0.05% from 20Hz to 20kHz, frequency response is 20Hz to 20kHz within +/- 1dB, and the RIAA equalization holds the standard curve to +/- 0.1dB. Oracle attributes the PH200's tonal balance to the careful selection and combination of its components, and it uses higher-quality operational amplifiers on the analog amplifying modules than the PH100 MkIII does.

Why Does the PH200 MkIII Use an External Power Supply?

To keep electrical line noise out. Oracle's highly regulated and filtered outboard supply houses a toroidal transformer delivering two 15 VAC at 50VA to the main unit through a DIN plug on an umbilical cable. DC is generated inside the main chassis, where the supply connects directly to the circuit board, shortening the path.

Oracle says extreme care went into eliminating electrical line noise before it can reach the phono stage circuitry, and the additional signal regulation step just before the RIAA circuit input is part of that work. The supply is nearly as large as the main unit, and together they weigh about 8.5 pounds. The PH200 MkIII is still sensitive to the magnetic fields around amplifier transformers and power cords, so Oracle asks that it sit as far as possible from amplifiers and away from power cords.

How Are Gain and Loading Set on the PH200 MkIII?

With rocker and toggle switches, set the same on both channels. Moving magnets use 42dB and 47k ohms. For moving coils Oracle suggests 52dB for 1.5mV to 3.0mV, 62dB for 0.5mV to 1.5mV, and the optional 73dB for 0.35mV to 0.5mV. Only one gain switch should be on at a time.

The 73dB setting comes from a header that takes a 2 ohm resistor, and Oracle intends it for very low output moving coils when the preamplifier or line stage after the PH200 does not have enough gain. The PH200 MkIII is not designed for cartridges below 0.35mV. The five standard moving coil loads are 100, 200, 511, 1k and 1.5k ohms, and a second header lets you replace the 1.5k resistor with the exact value your cartridge maker recommends. At 47k ohms the input carries a fixed 150pF; add a capacitor at the marked positions and set switch 6 on, and its value adds to the 150pF, so 150pF more gives 300pF. Capacitance has no effect on moving coils. Oracle asks that you switch the PH200 off, and preferably unplug it, before changing any setting, and encourages experimenting between gain settings to find the comfortable range for your cartridge.

How Do You Connect the PH200 MkIII?

The turntable's RCA cable goes to the inputs, the outputs go to an auxiliary line input, never a phono input, and the turntable's ground wire goes to the knurled ground post. The external supply plugs into the rear through its cylindrical DIN connector. The RCA interconnect is not included.

If you hear hum, the ground switch gives you two paths. Use "ON" when the amplifier or preamplifier has a three-pin power cord, so the PH200 references the building's electrical ground through the third pin. Use "OFF" with a two-pin power cord, for a floating ground referenced to the PH200's chassis. Oracle calls a good ground fundamental. Power up sources first and the amplifier section a moment later, and power down in the reverse order, to avoid thumps.

Finishes and Build

The PH200 MkIII has an elegantly sculpted aluminum cabinet, slightly reshaped for the MkIII, that carries the design of Oracle's Paris series. It measures 9.5 x 12.25 x 2.25 inches. Choose Textured Black, Black with Brushed Aluminum (a brushed aluminum front panel on a textured black case), or All Brushed Aluminum with a clear lacquer.

Oracle designs and builds the PH200 in Sherbrooke, Quebec, and backs the MkIII with a transferable three-year parts and labor limited warranty. Keep your bill of sale from an authorized dealer; without it, coverage runs two years and six months from the factory ship date shown by the serial number.

The Listening Room Difference

We're a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on exceptional service and relentless passion for hifi. Whether you're visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don't just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.

Oracle Audio PH200 MkIII Specifications