Audible Illusions Modulus 3B MC

Manufacturer Info
Ready for Audition


9 out of 10
Used Price

Forty years ago Audible Illusions began production of the first Modulus preamplifier, a component that set new standards for sonic performance and reliability. To date over 20,000 Modulus preamps have been manufactured with over150 excellent product reviews from audio critics around the world.

Adhering to our circuit design philosophy that “simpler is better” and based on the proven superiority of single-ended, triode-tube designs our engineers have continuously refined the preamp. To list all the innovations brought forth by our designs would be difficult. The elimination of cathode followers, buffers, negative feedback, paralleling tube output stages, designing new Teflon film capacitors and exploring better mechanical interfaces are but a few innovations that has made Audible Illusions a pioneer in modern-day tube technology.

Compared to previous generations the new M3B adds a host of features and refinements. Circuit boards have been redesigned to further simplify the signal path, improve switching and reduce vibration. This latest design utilizes special direct relay switching resulting in improved definition.

Today the M3B is one of the few full-function preamplifiers made. For vinyl record and CD lovers alike this preamp offers unparalleled musical performance. It is the finest preamplifier we have ever made and continues to be the benchmark by which many others are compared.

Control Functions:Dual-Mono Left & Right Stepped Attenuator Volume Controls, Subsonic Filter, Tape-Source, Stereo-Mono, Muting, On-Off.Input Selection: CD, DAT, Phono, Tuner, Video, Auxiliary, Tape

Output Selection: Main (2) Tape

Optional: Internal, gold-plated L&R channel circuit boards for low-output M/C cartridges. Rack Mt.Faceplates available as a special order.


  • Circuit Design is Dual-Mono, Class A, Single-Ended Triode, Open Loop.
  • External Power Supply, housing three separate supplies, prevents unwanted AC induced distortions.
  • Main Chassis has five separate, fully-regulated FET power supplies in addition to separate filament supplies.
  • Audio Circuit has No Cathode Followers or Buffers.
  • Standby Soft-Start Circuit prolongs tube life and circuit components.
  • Automatic-Timed Muting.
  • Control Knobs have Low-Light Backlit Illumination.
  • Separate Volume Controls are Precision Stepped Attenuators.
  • Proprietary gold-plated RCA Jacks with Teflon Insulators.
  • All circuit boards are Hand-Soldered with silver-bearing solder.
  • All Polypropylene, Teflon, and Polystyrene capacitors are Proprietary Designs.
  • Completely handcrafted in USA.

These “gold-plated” circuit boards were especially designed for Audible Illusions by John Curl using his proprietary technology.

When installed in the Modulus 3b Preamplifier they optimize the preamps standard phono stage for specific use with low-output moving coil cartridges. Overall phono-stage gain is increased to approximately 60dB of gain, enough to amplify M/C cartridges with outputs ranging from .1mV to .8mV.

Much improvement in M/C cartridge design has taken place during the past few years. High-quality moving coils are now wound under intense magnification using ultra-fine wire. This manufacturing process allows for coil mass to be less than half of what it was several years ago. There also has been considerable improvement in magnet design. The net result is improved voltage output from less mass which allows the styli to trace a records grooves much more accurately.

When coupled to the outstanding tube phono stage of the Modulus 3b, one can now hear the resolution of low-level-detail present in many analogue recordings. For the audiophile with a sophisticated audio system this technology brings a new dimension to the listening experience.

  • Complimentary JFET technology.
  • High Overload Capacity.
  • Gold-plated circuit boards are hand-soldered using the finest silver solder.
  • Polypropelene and polystyrene capacitors are proprietary designs of Audible Illusions.
  • Resistors are precision Holco and Roederstein.

M/C Board Gain: 30dB adjustable +/- 5dB

Input Impedance: 47k oHms
Provision for adjustment with 1% resistors provided

Signal Phase: Non-Inverting

Distortion: .0015 at .5V rms, 20-20kHz
Less than .015 at 1.5V rms, 20-20kHz

Serial number:



Unit is in perfect working condition excluding CD input. On CD input right channel is out due to defective relay. Problem is simple however to replace this simple relay unit will need to taken completely apart. Since most of customers will be buying this for its phono stage and there is still 5 additional line inputs we decided to offer this unit for lower price and without fixing CD input.

If you interested in having CD input repair we can arrange that for additional cost.

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