API 235L Discrete Channel Noise Gate / Expander

Reduce Noise Fast With the API 235L Discrete Channel Noise Gate / Expander

The API 235L Noise Gate/Expander has the ability to reduce noise in any type of program. The 235L can open unusually fast, without losing any part of the sound. Its extreme flexibility, repeatable settings, and superb sound make it ideal for all studio, live sound, and broadcast applications.

• Threshold control from -45 to +25 dBu
• Variable Fine Adjustable Depth to -80 dB
• Adjustable Release/Hold Time, 50mS to 3 sec
• 2:1 Expander or Noise Gate Selection
• Release or Hold Switch for Release control knob
• Always at Unity Gain, Regardless of settings
• LED Gain Reduction Meter
• Uses the API 2510 and API 2520 Op-Amps
• Transformer Output, to +28 dBu

Delivering Noise Reduction As Fast As Can Be

The 235L is one of the fastest noise gates manufactured today. When an engineer is faced with program material with a high level of background noise, the 235L can either Gate the signal at a preset Threshold, or with the use of the Expander function, can reduce the background noise to an almost undetectable level. This can be achieved without the typical loss of the program material caused by slow triggering of the signal, or "pinging" caused by false triggering.

With a wide range of adjustment, the 235L can operate from -45 to +25 dBu, fitting into any audio situation regardless of program level. Once the Threshold level is set, the Attack time can be selected to react faster than 100uS or slightly slower than 25mS to reduce false triggering. Although the Depth control has a full range of -80 dB, the scale is expanded in the first half of rotation so 0 to 9 dB is available for fine tuning of subtle, undetectable gating. The second half of rotation is from 10 to 80 dB for more drastic noise reduction.

SPECIFICATIONS

• Threshold Range: -45 dBu to +25 dBu
• Depth Range: 0 to -80 dB, Fine adjust control, -9 at 50% rotation
• Attack Time: Fast = 100 u/S, Normal = 25 mS gate at 90% open
• Release Time / Hold Time: 50 mS to 3 s
• Input Impedance: greater than 10 K Ohms, Un-Balanced
• Output Impedance: 85 Ohms, Transformer coupled, Balanced
• Nominal Levels: -45 dBu to +20 dBu
• Clipping Level: +28 dBu
• Frequency Response: 0, -.3, 30 to 20 kHz
• Noise
• Gate Closed: -102 dBu, Unweighted
• Gate Open: -90 dBu Unweighted
• Distortion, Gate Open
• 0.3% THD: -40 dBu
• 0.1% THD: -30 dBu
• 0.03% THD: -20 dBu
• 0.01% THD: -10 dBu
• 0.008% THD: +4 dBu
• 0.01% THD: +12 dBu
• 0.1% THD: +28 dBu
• Connectors: .100 spaced ELCO
• Power Consumption: ±16 VDC, 100 mA max @ +24 dBu
• Size (W x H x D): 1.25 x 2.65 x 6.5 inches / 32 x 67 x 165 mm
• Shipping Size (W x H x D): 4.5 x 6.25 x 10 inches / 114 x 159 x 254 mm
• Actual Weight: 0.61 lb / 277 g
• Shipping Weight: 0.98 lb / 445 g

We are Chuck Levin's Washington Music Center

Since 1958, Chuck Levin’s Washington Music Center has been the trusted destination for musicians and audio professionals across Maryland, Virginia, and Washington, D.C. Family-owned and operated, our legendary music store delivers Everything in Music®—from instruments and recording gear to pro audio, rentals, and repair services.

Our team of musicians and industry experts lives and breathes gear, helping you build the perfect setup for your next performance, studio session, or installation. As an authorized dealer for top brands, we also offer our award-winning CHUCKSCLUSIVE line—exclusive, limited-edition instruments and collaborations recognized with the NAMM Top 100 Dealer Innovation Award for redefining what a music retail experience can be.

Chuck Levin’s isn’t just a store—it’s a community built by players, engineers, and creators who share a lifelong passion for sound. Stop by our legendary Wheaton, MD showroom or contact us anytime for expert advice, product questions, or the best possible deal on your next piece of gear.