John Hardy Jensen Twin Servo 990 2-Channel Microphone Preamp

John Hardy

(No reviews yet) Write a Review
Product Code: 2400-Ohm
Adding to cart… The item has been added
Built To Order

This item is built to order and may have a lead-time before shipping, but we will get it to you as quickly as possible. Go ahead and place your order and we will follow up with an ETA as soon as we have it. If you have a deadline then please contact us before placing the order so we can meet your expectations.

Got Questions? Need Support?

888-228-4530 Contact Us!

The John Hardy Jensen Twin Servo 990 2-Channel Microphone Preamp is considered the world's finest mic preamp by audio experts. It's the ideal integration of advanced design software, hardware, engineering know-how, and carefully controlled 'golden ears' tests.

Transformer enhanced technology for superior sonic performance. Bringing science to sound. It has earned high marks for sonic performance since its introduction in 1988. The basic circuit was originally published as an application note by Jensen Transformers for their finest microphone input transformer, the JT-16-B. Each channel uses two precision 990C operational amplifier modules, developed and patented by Deane Jensen, to achieve one tenth the distortion and twice the bandwidth of a single stage design. The Jensen Twin Servo 990 mic preamp has a 19" wide mainframe rack-mount chassis (1.75"H x 19"W x 8"D) and can be ordered with 1 to 4 channels. Additional channels can be easily added later up to the total capacity of the mainframe.

John Hardy Jensen Twin Servo 990 2-Channel Microphone Preamp Features

  • JT-16-B Input Transformer. Jensen's best mic input model.
  • Two 990 Discrete Op-Amps Per Channel. Faster, quieter, more powerful and better sounding than typical monolithic op-amps.
  • Elimination Of All Coupling Capacitors From The Signal Path. Results in less degradation of the audio signal.
  • JT-11-BMQ Output Transformer. Jensen's best line output transformer.
  • Input Bias Current Compensation Circuitry And DC Servo Circuitry. Eliminates signal degrading coupling capacitors.
  • Standard Features:
  • Fully Sealed Conductive Plastic Gain Control. Provides smooth continuous gain adjustments from 16dB to 60dB.
  • 20 OHM MIC switch or 20dB PAD switch.
  • PHANTOM POWER switch.
  • All Front Panel Switches Are LED Illuminated.
  • Gold Plated XLR Connectors for maximum reliability.
  • Ground Lift Switch On Each Channel. Helpful for eliminating ground loops.
  • VU-1 meter. Very accurate and informative 20 segment LED meter, with separate Peak LED, for monitoring preamp output.
  • Toroidal Power Transformer With Additional Shielding. Eliminates hum problems so no external power supply is needed.
  • Universal Power Supply. Internal switch provides six primary voltage choices to accommodate use anywhere in the world.
  • Chassis Ground Isolation Switch. Helpful for eliminating ground loops.
  • Pin 2 Or Pin 3 High. Internal jumpers make changes in the field easy.

John Hardy Jensen Twin Servo 990 2-Channel Microphone Preamp Options

  • -20dB PAD: This really should be the option of choice for 95% of users. This will be very handy if you are recording potentially loud sources such as drums, guitar amps, and jet engines.
  • 20 Ohm Switch: This option is to help optimize microphones that have extremely low output impedances (such as Schoeps models that have 25 Ohm outputs) to work with the Hardy preamps. Optimally, a preamp will work best with these microphones if it sees the microphone as having a 150 Ohm output. This switch makes that so, and the sound opens up quite nicely. The Hardy M2 with the 20 Ohm Switch option is perhaps the finest choice you can make for use with these microphones. But if you don't have extremely low impedance microphones such as these, then go with the Default -20dB PAD option.

John Hardy Jensen Twin Servo 990 2-Channel Microphone Preamp Includes

  • Jensen Twin Servo 990 2-Channel Microphone Preamp
  • IEC Power Cable
  • Warranty Information

No review yet, Be first to Write a Review

What We Think


The Hardy preamps are on the clean side, with fast response well suited to acoustic instruments, drums, well lots of things!

Front End Audio, Your Ultimate Pro Audio Dealer

Got questions? Call us at 1-888-228-4530 we are here to help!