IGS AUDIO

One Leveling Amplifier

Optical tube compressor with T4Bx photocell, 30 dB gain, 36 dB reduction, custom IGS transformers, stepped Elma switches, stereo link via RCA, rich vintage tone

Shipping calculated at checkout.
Talk to our experts
Our team of experts is here to support you.

Delivery & Shipping

Free Shipping in Canada with orders over $200. Conditions apply. View details here.

Financing

Affirm

Break your purchase into easy monthly payments, quick approval and no hidden fees.
Click here for more info.

Equilease

Ideal for larger purchases, Equilease offers customized leasing solutions to fit your business needs.
Click here for more info.

Returns & Policy

You can review our terms and conditions here

Description

The IGS One LA is a high-quality optical tube compressor inspired by the classic leveling amplifiers of the 1960s. Known for its warm, musical compression and ease of use, it delivers the smooth dynamics control favored by recording engineers across genres. With only a few intuitive controls like Peak Reduction, Gain, and a Compress/Limit switch, the One LA allows users to quickly dial in rich, analog compression that flatters vocals, bass, guitars, and more.

At the heart of its sonic character is IGS Audio’s custom T4Bx photocell, a modern equivalent of the original T4B, carefully hand-matched for consistency across units. The fully balanced tube circuit features custom IGS input and output transformers, two 6N1P-EW dual triodes for the audio path, and a combination of 6N2P-EW and 6AQ5 tubes in the control section. With up to 36 dB of gain reduction and a dynamic range exceeding 110 dBA, the One LA combines vintage-inspired compression with modern precision and reliability.

Housed in a rugged 2U rackmount chassis with stepped Elma switches, the One LA also supports stereo linking via rear-panel RCA jacks which is ideal for mastering or mix bus applications. Whether used as a single channel or in a matched stereo pair, the One LA adds a signature sonic polish that brings recordings to life with smooth, controlled warmth and presence.

Features

Classic Optical Compression Sound
Inspired by legendary '60s designs for smooth, musical gain control on vocals, bass, and more.

Simple and Intuitive Controls
Easily dial in compression with just Gain, Peak Reduction, and a Limit/Compress switch.

Custom T4Bx Optical Cell
IGS-developed T4Bx photocell delivers consistent, vintage-style opto compression response.

Fully Tube-Based Signal Path
Uses hand-selected tubes in both audio and compression circuits for rich, analog tone.

Transformer-Balanced I/O
Equipped with custom IGS transformers for balanced, warm signal transfer in and out.

Stereo Linking Capabilityy
Link two units with a standard RCA cable for precise stereo tracking.

Built for Consistency
All-stepped controls with Elma switches ensure repeatability and easy session recall.

Specifications

General Specifications
Device Type: Optical Tube Compressor
Compressor Type: T4Bx Photocell-Based Optical Compressor
Channel Configuration: Mono (Stereo Link via RCA)
Construction: Full Tube Circuit with Custom Transformers
Transformer Input: IGS Audio 2510
Transformer Output: IGS Audio 15k/600
Tubes: 2 × 6N1P-EW (Audio), 1 × 6N2P-EW (Sidechain), 1 × 6AQ5 (Sidechain)
Photocell: T4Bx (IGS Audio Custom Equivalent of T4B)
Controls: Peak Reduction, Gain, Limit/Compress Switch, Meter Mode Switch
Meter Functions: Output Level / Gain Reduction
Manipulators: All Stepped (24-Step Elma Switches)
Stereo Link: Yes (via Rear RCA Connector)

Input & Output
Input Impedance: 600 Ω Balanced
Output Impedance: 600 Ω Balanced
Input Level (Max): +16 dBu
Output Level (Max): +18 dBu
Operating Level: +4 dBu
Max Gain: 30 dB
Max Gain Reduction: 36 dB

Performance Specifications
Frequency Response: 20 Hz – 20 kHz
Total Harmonic Distortion + Noise (THD+N): 85 dB (A)
Dynamic Range: >110 dBA (@ 1 kHz, +24 dBu)

Time Constants
Attack Time: 10 ms
Release Time: 0.5 – 5 s (50% @ 60 ms)

Power & Dimensions
Power Supply: Internal
Voltage: 115/230 V AC, 50–60 Hz
Power Consumption: 40 W
Packing Dimensions: 70 × 50 × 30 cm
Shipping Weight: 7 kg

Payment & Security

  • American Express
  • Apple Pay
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Back to top