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Furman IT-Reference 20i

20-amp power line conditioner and surge protector with isolation transformer

2 Reviews | 1 question - 1 answer

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Item # 756ITREF20

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Our take on the Furman IT-Reference 20i

The IT-Reference 20i is Furman's biggest and baddest power conditioner, tipping the scales at a grunt-worthy 81 pounds. It thoroughly cleans and conditions the AC power that is every audio/video component's lifeblood. Its twelve rear-panel AC outlets can accommodate 20-amp or standard 15-amp AC plugs. Furman originally built their reputation by developing equipment to meet the extreme AC power demands of professional recording, film, and broadcast studios.

Furman IT-Reference 20i back panel

The IT-Reference 20i has 12 rear-panel AC outlets. A built-in "isolation transformer" feeds noise-free regenerated power to eight of the outlets.

Rock-solid protection for your home theater investment

The IT-Reference 20i is Furman's biggest and baddest power conditioner, tipping the scales at a grunt-worthy 81 pounds. It thoroughly cleans and conditions the AC power that is every audio/video component's lifeblood. Its twelve rear-panel AC outlets can accommodate 20-amp or standard 15-amp AC plugs. Furman originally built their reputation by developing equipment to meet the extreme AC power demands of professional recording, film, and broadcast studios.

Isolation transformer

An isolation transformer regenerates pristine AC power for your most sensitive gear

All electronic components operate best with a steady supply of clean AC power, and high-definition video equipment like Blu-ray players, flat-panel TVs, and projectors are notoriously finicky. The IT-Reference 20i addresses this issue with a built-in "isolation transformer" that feeds noise-free regenerated power to eight of the rear-panel outlets. That puts a stop to noise-inducing ground loops, and power supply backwash between connected components. You'll see noticeably improved picture detail and deeper black levels.

Power Factor Technology: Like a turbocharger for your amplifiers

Truly exciting sound requires wide-open dynamics. To reproduce instantaneous sonic peaks or "transients" cleanly, like a car crash or a cymbal crash, an amplifier needs lots of high-current power. During these moments, amplifiers — including those in receivers and powered subwoofers — may require more current than is available from your home's AC line.

Solution? Plug your amplifier into one of the IT-Reference 20i's high-current outlets. Furman's unique Power Factor Technology creates a "current reservoir" capable of delivering over 80 amps of peak current. Your amplifier gets the current it needs when it needs it most.

Protection for every pathway

The IT-Reference 20i constantly monitors incoming AC, and if an overvoltage condition is detected, power is automatically shut off to all connected equipment. And Furman's rugged surge suppressor circuitry can withstand multiple catastrophic high-voltage spikes and keep right on protecting your system. Three sets of coaxial inputs and outputs protect your satellite, cable TV and antenna connections. And one pair of protected jacks prevents spikes from sneaking in through your phone line.

Product Highlights:

  • 12 AC outlets with five isolated banks:
    • one bank of 8 Discrete Symmetrically Balanced Power outlets for sensitive audio and video components (unswitched)
    • one bank of 4 high-current outlets with Power Factor Correction peak current charging (unswitched, compatible with 15-amp and 20-amp AC plugs)
  • AC outlets use hospital-grade connectors to grip plugs firmly
  • Series Multi-Stage Protection surge suppression system can withstand multiple catastrophic voltage spikes
  • Extreme Voltage Shutdown circuitry monitors incoming AC and automatically cuts off power to connected equipment if overvoltage is detected
  • Power Factor Technology "current reservoir" for amplifiers, receivers, and subwoofers (over 80 amps peak charge)
  • wide-bandwidth EMI/RFI noise filtering for clearer sound and picture
  • 3 sets of coaxial RF connections for cable TV, satellite, and antenna
  • RJ-11 phone line input and output (module is detachable)
  • 7-ft. AC power cord with NEMA 5-20P plug (requires a 20-amp circuit and a 5-20R T slot receptacle)
  • maximum current rating: 20 amps
  • 17"W x 5-7/8"H x 18-3/8"D
  • weight: 81 lbs.
  • warranty: 5 years
  • Our 60-day money-back guarantee

What's in the Box:

  • Power Conditioner
  • 7' AC power cord with NEMA 5-20P plug (requires 5-20R T-Slot receptacle)
  • 2 Piece power cord bracket
  • 2 Machine screws
  • 2 Rack mount brackets
  • 6 Rack mount machine screws (each with star lock washer attached)
  • Owner's guide (English/ French)
  • Warranty registration card

Featured Video


Furman IT-Reference 20i Reviews

Average Customer Review(s):

(2 Reviews)

Save your money

ChrisB from Texas on 11/28/2015

Crutchfield Customer Review (What's this?)

I followed the advice of the previous reviewer and had an electrician install a dedicated power 20 A line to this power conditioner. Then I connected my electronics components expecting to be wowed by an improved fidelity. I Was Totally Disapointed. There was absolutely no improvement in definition, even when powering PSB Synchrony Ones with NAD Master Series amplifier and preamplifier from a Blu-Ray audio disk played on an Oppo Blu-Ray player. Save your money and don't buy this beast because it's not worth it.

Pros: You can use the Furman for bench pressing and strengthen your chest muscles.

Cons: A lot of money for no measureable improvement.

beast mode of a power line conditioner!

SteveO from Everett on 2/23/2015

This is a beast (83 pounds worth) of a power line conditioner intended for protection and quality of your top of the line equipment. Incredible performance and noticeable improvement of sound and video! This unit is for serious audiophiles who want to maximize the performance of your system! This unit rocks!

Pros: Amazing quality of performance. Protection for your valued equipment. Will not have to worry about exceptional performance.

Cons: Best way to run the 20 amp power line conditioner is to run a dedicated line so you don't have to worry about stressing your electrical system. Having just had an electrician do the work it is the best way to go.


Hands-on research

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Controls and Indicators


Power Factor Technology: Although it's rare for amplifiers to draw more than 4 Amps continuously, for superior performance it is vital that an amplifier's AC filter have low impedance and the capability to accommodate peak current demands far in excess of the RMS (continuous) current rating. The IT-Reference 20i's Power Factor Technology circuitry effectively creates a current reserve in excess of 80 amps (peak) that is cleaner and faster than a dedicated line from your local power station, benefiting any connected amplifiers' performance.

Discrete Symmetrical Power: While differential AC noise (such as electromagnetic and radio frequency interference) can be effectively reduced with a low-pass filter, common mode AC noise (the cause of ground loops and video hum bars) requires a more advanced solution. Effectively reducing common mode noise requires the use of an isolation transformer, the most effective of which is a symmetrically balanced isolation transformer. Furman's Discrete Symmetrically Balanced Power is achieved by routing the incoming AC into a 1:1 isolation transformer with a precisely placed center tap on the transformer's secondary. The incoming voltage (120V on the line terminal and 0V on the neutral and ground) is split into perfect halves on the transformer's output. The AC line now has 60V on the line and 60V on the neutral when referenced to the new center-tapped ground, which remains at 0V AC. What is significant about this is that the two 60V AC terminals are now in opposite polarity, completely canceling all common mode noise from the incoming AC line. This noise reduction is efficient and linear across a huge frequency range; the result is perfectly clean power devoid of ground loops and AC hum noise.

Series Multi-Stage Protection (SMP): SMP is maintenance-free surge suppression, offering AC protection without sacrificing itself in the event of a catastrophic surge. The SMP circuit senses voltages so high that operation is impossible and turns the power off before damage can occur; if the voltage exceeds 137 volts power is removed from all the outlets.

12 AC Outlets: The Furman IT-Reference 20i features 12 rear-panel outlets in five banks:

  • Discrete Symmetrical Power: four banks of two outlets each are filtered with Discrete Symmetrical Power and GFCI protected; each bank is isolated from the others and from the high current bank
  • High Current: four outlets, designed for amplifiers, receivers, and powered subwoofers; offers Power Factor Technology with a low impedance filter and current reserve in excess of 80 amps (peak) to accommodate amplifier demands

Transient Voltage Surge Protection: The IT-Reference 20i features transient voltage surge suppression for standard telephone lines, coaxial cable TV lines, and coaxial satellite lines. There is one pair of phone input/output jacks and three pair of coaxial input/output jacks. The coax jacks are bi-directional and pass both DC carrier signals and high bandwidth HD signals with an insertion loss of less than 0.1 dB. All the in-line surge suppressors feature Furman's exclusive Zero Ground Contamination technology; this helps eliminate audio buzzing and video hum bars that can result from typical in-line suppressors.

Rack Mount: Brackets are included to rack mount the IT-Reference 20i.

Controls and Indicators

Front Panel:

  • Power: power switch; turns all outlets on/off
  • Power LED: a blue LED bar in the center illuminates when the power switch is on and voltage is applied to the outlets
  • GFI Test: button to test the Ground Fault Circuit Interrupter

Rear Panel:

  • Reset: button to reset GFCI circuit


Rear Panel:

  • Discrete Symmetrical Outlets: eight 3-prong outlets (standard NEMA 5-15)
  • High Current Outlets: four 3-prong NEMA 5-20R T-Slot outlets
  • Phone Jacks: input and output for standard telephone line
  • Coaxial Jacks: 3 pair of threaded F-type coax input and output terminals


AC Power:

  • Current Capacity:
    • Input: 20 amps
    • Output: 12-20 amps RMS (continuous, all outlets combined)
  • Linear Noise Attenuation:
    • Transverse (Differential) Mode: from 0.05 to 100 ohm line impedance
      • 1 kHz - 2 kHz: >20 dB
      • 2 kHz - 100 kHz: >40 dB
      • 100 kHz - 1 GHz: >80 dB
    • Common Mode:
      • 10 kHz - 50 kHz: >95 dB
      • 100 kHz - 1 GHz: >40 dB
  • Power Consumption: 8.5 watts for display and control circuits (plus actual load)
  • Over-voltage Shutoff Threshold: 137 volts AC (+/-3 volts)
  • Weight: 83 pounds


Connected Equipment: Furman Sound's Connected Equipment Warranty covers equipment that is damaged by a transient voltage while properly connected through the Furman IT-Reference 20i to a properly wired AC power line with a protective ground in an indoor location. Furman's Connected Equipment Warranty is limited to the amount of the deductible on the Purchaser's personal property insurance policy, up to $500.00. The Connected Equipment Warranty is in effect for a period of five years.

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If you purchased the product from Crutchfield, feel free to contact our Tech Support team. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: Or try our online support center: [ Kenny  Nov 19, 2016 ]  Staff