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Undertone Audio UnFairchild 670M II
The Fairchild circuit could be one of the most coveted and time tested compressors of all time. It has proven its extraordinary universal musicality for over 5 decades on countless genres of music. The beauty of its design is in its simplicity. The audio path, primarily consisting of only 2 transformers and 4 paralleled vari-mu tubes, can provide a gentle smoothing of levels or an explosive, energizing compression that will make any recording leap out of the speakers. The UTA UnFairchild is a painstaking recreation of the classic sound of this circuit.
€10,204.55 tax excl.
Flexible
There are a few limitations of the original Fairchild that UTA set out to address. First, they have made careful adjustments to the circuitry that greatly improve the lifespan and reliability of the tubes. Additionally, they've added a whole host of exciting new features that have never before been available on a Fairchild. The UnFairchild sports 6 original preset Time Constants and 4 variable Time Constants (attack and release), MS function, side chain processing, a true bypass, fine adjustment of left/right balance, user adjustable "DC Threshold", and "Feed-Back" vs. "Feed-Forward" functionality. With the UnFairchild, UTA has made this extraordinary circuit flexible enough to handle pretty much every compression task on any style of music.
Specifications
- Input Impedance: 2.5KΩ
- Output Impedance: 200Ω
- Output Level: +4dB @ 0Vu (+28dBm clipping point)
- Gain: 20dB (in 1dB steps)
- Frequency Response: 20hz - 20Khz (+0/-.5dB)
- Noise Level: -83dB
- Harmonic Distortion: Better than 1% at +18dB
Please note that universal power supplies manufactured in the USA may be delivered in 110V. Make sure that the fuse is set to 220V (for European countries only) and not 110V before plugging in the unit, otherwise it may be damaged. It may be necessary to use an IEC13 cord suitable for your country, not supplied.
What’s diferent about the UnFairchild 670M II from an original Fairchild?
We are using Cinemag recreations of the original transformers used in the audio path. They are extremely close to the originals with only small adjustments made to accommodate a more desirable gain structure. The side chain circuit has been simplifed to improve reliability and afordability and because the original design was totally insane. It’s still a tube circuit..it still preserves the important sonic characteristics of the original...the only diference is that it’s not insane.
The original Fairchild runs at a very high plate voltage. So high, in fact, that the original Fairchild manual recommends that you should change the tubes every 6 months. UTA lowered the plate voltage going to the 6386 tubes to help extend their life and reliability. 6386 tubes can cost anywhere from $120 -$500 each and the unit uses 8 of them! Best case you’re looking at $1,000 every 6 months to be sure an original Fairchild is running up to spec. This is one of the reasons so many of them sound so diferent from one another...and why some sound so bad. With the lower plate voltage and a good set of tubes, the UnFairchild will run reliably for years.
MORE CONTROL: UTA added a wider range of controls. As cool as the original Fairchild is to own, it’s cooler to have that sound with modern fexibility. The UnFairchild ofers the legacy of the Fairchild; with much more of what one would expect from a compressor built in 2018.
Time Constant Presets
PRESET # | ATTACK | RELEASE |
1 | 0.2 ms | 0.3 Sec. |
2 | 0.2 ms | 0.8 Sec. |
3 | 0.4 ms | 2 Sec. |
4 | 0.8 ms | 5 Sec. |
5 | 0.4 ms | 2 Sec. for individual peaks, 10 Sec. for multiple peaks |
6 | 0.2 ms | 0.3 Sec. for individual peaks and 25 Sec. for multiple peaks |
VAR1 | 0.1 ms - 4.5 ms | 30 ms - 1.2 Sec. |
VAR2 | 0.2 ms - 9 ms | 50 ms - 2.4 Sec. |
VAR3 | 0.4 ms - 18 ms | 110 ms - 4.8 Sec. |
VAR4 | 0.8 ms - 36 ms | 200 ms - 9.6 Sec. |
In addition to the original time constant presets there are:
- Independent control over the Attack and Release
- User control over the DC Ofset (functions similar to a ratio control)
- Access to processing or EQing the side chain signal
- Fine-trim adjustments for precise matching of the L/R balance
- True stereo linking
- Multiple M/S processing modes
- Options for feed-forward compression
- Calibration for meter level accuracy and channel compression matching
- True bypass
- Output metering
Data sheet
- Condition
- New
- Type
- Vari-Mu Compressor
- Application
- Tracking, Mixing & Mastering
- Channels
- Dual Mono
- Circuit
- Tube
- Format
- 19"
- Chassis
- 7U
- Quantity
- 1