IT-20 II Balanced Power Conditioner

The Furman IT-20 II Balanced Power Conditioner is designed for the most critical, ultra-low noise installations. The IT-20 II can supply 20 amps of balanced AC power for recording studios, broadcast stations, or video production facilities. To understand the incredible need for clean noise-free AC power, it's important to note that today's sophisticated studio equipment features tremendous dynamic range. Most of the signal content that defines high resolution such as harmonics, instrument timbre, high-frequency extension, spatial cues, and fast transient attacks in audio are inherently low in signal level. Further, when AC noise is induced into audio processors, preamplifiers, microphones, powered monitors, computers, and mixing consoles these all important low level signals are distorted or masked. Once signals are masked there is no way to retrieve the lost content. Advanced AC filtering is critical when audio or video resolution is at stake. With Furman's IT-20 II, you will hear audio content and see video images as they were meant to be--pristine. Add to this Furman's SMP non-sacrificial surge suppression, E.V.S. protection, Linear Filtering Technology (LiFT), and laboratory grade digital voltmeter, and you will be assured that AC noise and surges are a thing of the past.

Balanced AC Power

In much the same way that balanced audio lines can reduce the pickup of hum and other types of electromagnetic interference (EMI), the use of balanced AC power lines in sensitive audio, video, or computer installations can make an enormous difference in system noise and signal integrity. But power distribution in North America, unfortunately, is not balanced. The distribution standards currently in use were derived from practices established over a century ago, when electric power use was limited to lighting and motors--long before any AC noise sensitive applications existed. The emphasis then was on convenience (from the power utilities--standpoint) and safety, but not noise cancellation. The result was a three-wire distribution scheme in which 120V branch circuits have a hot wire and a neutral wire, with the neutral tied to a third wire connected for safety to an earth ground. The third wire does not carry any current unless there is a fault. This unbalanced scheme can create hum in audio circuits for two main reasons. First, the current flowing in the hot wire induces hum in any other nearby wires, which may carry vulnerable low-level audio or video signals. Second, because the impedance of chassis and cable shielding to ground is always greater than zero ohms, ground current flowing from power supply capacitors and from EMI pickup causes a voltage drop at 60Hz and its harmonics. This low level noise becomes part of the audio signals.

With a center-tapped isolation transformer, the AC power feeding a studio can be balanced at its source. The current-carrying wires then are no longer "hot" (120V) and "neutral" (0V), but two 60V lines of opposite polarity (referenced to ground connected to the center tap), whose difference is 120V. This type of power, when run around a room, does not induce hum into nearby audio wiring, because the two conductors induce equal and opposite voltages that cancel each other out. Similarly, ground currents are all but eliminated by the same common-mode cancellation effect. No longer is it necessary to adopt cumbersome and expensive star-ground systems or use massive bus bars or heavy ground rods. Further, with features such as the center tap ground lift, ground induced noise may be reduced even further.

Of course, balanced AC power is only the beginning of a system free of AC noise. Asymmetrical noise or what is called "differential mode" is responsible for well over half of the noise present in today's AC lines. For this reason, Furman employs exclusive Linear Filtering Technology (LiFT). This assures that your audio, video, or computer signals are as pure and uncorrupted as possible.

SMP+ (Series Multi-Stage Protection Plus)

Furman's SMP+ surge suppression virtually eliminates service calls. Traditional surge suppression circuits sacrifice themselves when exposed to multiple transient voltage spikes, requiring the dismantling of your system, and repair of your surge suppressor. Not so with SMP+. With Furman's SMP+, damaging transient voltages are safely absorbed, clamped and dissipated--no sacrificed parts, no service calls, no down time.

Unique to Furman's SMP+ is its unparalleled clamping voltage, even when tested beyond the grueling specifications of - USA/CIDA's A-1-1 test. While other designs offer clamping voltages that are well above 300VAC peak (far beyond long accepted professional standards), Furman's SMP+ clamps at 188VAC peak, 133 VAC RMS even when tested with multiple 6000VAC--3000 amp surges. This unprecedented level of protection is only available with Furman's SMP+ technology.

LiFT (Linear Filtering Technology)

Traditional AC filter/conditioners have been designed for unrealistic laboratory conditions. Prior technologies could actually harm audio and video performance more than they help, due to the resonant peaking of their antiquated, non-linear designs. Under certain conditions, these designs can actually add more than 10 dB of noise to the incoming AC line! Worse still, lost digital data, the need to reboot digital presets, or destroyed digital converters are frequently caused by excessive voltage spikes and AC noise contaminating the equipment ground. Furman's SMP+ with LiFT takes another approach, ensuring optimal performance through linear filtering and no leakage to ground.

E.V.S. (Extreme Voltage Shutdown)

Furman's trusted overvoltage circuitry protects against all too frequent accidental connections to 208 or 240VAC by shutting off the incoming power until the overvoltage condition is corrected.