Home > Rack Gear > Preamps > Accessories >

John Hardy MPC-600 Mic Preamp Card

John Hardy MPC-600
John Hardy MPC-600
List Price: $325.00
Our Price: $325.00

Availability: Usually Ships in 1 to 2 Weeks
Product Code: 9999-10188


John Hardy MPC-600 Mic Preamp Card

The John Hardy MPC-600 Mic Preamp Card is a direct replacement for MCI 600-series console mic preamp cards.

John Hardy MPC-600 Mic Preamp Card Details

A superior plug-in replacement for MCI 600-series console mic preamps. The John Hardy MPC-600 Mic Preamp Card drastically improves performance by using a combination of the Jensen JT-16-B mic input transformer (Jensen's best mic input model), the 990C discrete class-A op-amp, and the total absence of coupling capacitors in the signal path. Just plug it in!

The Jensen JT-16-B Input Transformer is Jensen's best mic-input model. Jensen is known worldwide for their superior audio transformers. If you thought transformers were a compromise, you haven't heard the JT-16-B!

The JT-16-B is a large, low impedance ratio (150:600Ω) transformer made with a proprietary 80% nickel (nickel-iron-molybdenum) core material. The large size allows it to handle extremely high signal levels: +12dBu at 30Hz and above, +8dBu at 20Hz. The low ratio provides less distortion, flatter frequency response and more linear phase response than more typical high-ratio transformers (150:15kΩ). The proprietary 80% nickel core material is far superior to, and much more expensive than the steel often found in other transformers.

The JT-16-B outperforms transformerless mic preamps because it eliminates the input coupling capacitors that are required with transformerless designs. Capacitors degrade the audio signal because they have a property known as dielectric absorption, where some of the signal passing through the capacitor is absorbed by the dielectric of the capacitor, then released a short time later. This smears the signal. Transformerless designs require these capacitors to keep the phantom supply voltage from reaching the circuitry of the preamp. Transformers inherently block DC voltages, eliminating the need for the capacitors.

The JT-16-B provides better common mode rejection than transformerless designs, important in electrically noisy environments. It handles common mode voltages as high as ±300V peak. Transformerless designs are usually limited to maximum voltages equal to their power supply voltages, typically ±15V to ±18V.

The 990 Discrete Class-A Op-Amp is faster, quieter, more powerful and better sounding than the typical monolithic op-amps found in other equipment. Each individual (discrete) transistor, resistor, diode, capacitor and inductor of the 990 has been carefully chosen for its task. This provides a level of performance that is not possible in a monolithic op-amp where all components are fabricated on the same tiny chip of silicon. The 990 can drive long cables and loads as low as 75Ω, something monolithic op-amps cannot do. See the 990 data package for further information.

Elimination of All Coupling Capacitors from the Signal Path results in less degradation of the audio signal. Two superior techniques are used to accomplish this:

1. Input bias current compensation circuitry nulls out the small DC currents (thus voltages) that flow from the inputs of the 990 (or any op-amp), voltages that could cause noise when operating the gain controls. This circuitry also reduces the DC offset voltage at the output of the 990. Most other mic preamps use coupling capacitors to block the input bias currents, resulting in signal degradation.

2. DC servo circuitry nulls out the DC offset voltage at the output of the 990, eliminating the need for a traditional output coupling capacitor to block that voltage. The signal degradation caused by that capacitor is also eliminated.

John Hardy MPC-600 Mic Preamp Card Downloads

Click here to view all John Hardy products

You may also need...
Colossal Cable Colossus Speaker Cable HotWires Microphone Cable (25 Foot) ADK TT Multi-Pattern Tube Microphone Stedman Proscreen PS101 Popfilter
Our Price: $115.00

Our Price: $11.95

Sale Price: $762.00

Our Price: $38.99

Colossal Cable Colossus HotWires Microphone Cable ADK TT Stedman PS101