IGS Audio 825EQ Stereo Tube Mastering Equalizer ±12 dBU Version

Product Description

The IGS Audio 825EQ is a two-channel, five-band tube mastering equalizer with premium inductors, transformers, and tubes that add rich harmonic character to your sound. This ±12 dB version of the IGS Audio 825EQ features Elma stepped controls for fast recalls, plus UTM transformer-balanced I/O with six audio transformers and six tubes for amplification, all in a streamlined 3U 19" rack-mount chassis. Designed for studio professionals who want rich analog tone and repeatable results, the IGS 825EQ stereo equalizer blends intuitive control of a mastering EQ with the harmonic depth of tubes. Here's how the IGS Audio 825EQ takes professional recordings to the next level.

STEPPED CONTROLS FOR MASTERING-GRADE PRECISION

The IGS Audio 825EQ features Elma stepped controls with 24-pole detented switches for quick and easy recall of frequency, gain, and Q settings. The ±12 dB version gives you more boost and cut range per band, while the proportional Q factor tightens from 0.3 to 6 as you push a band harder, keeping broad moves musical and narrow moves surgical. The IGS Audio 825EQ's stepped controls offer mastering-grade precision with intuitive control so you can focus on sounds, not knobs.

PREMIUM COMPONENTS FOR SUPERIOR SOUND QUALITY

The IGS Audio 825EQ's superior sound quality comes from what's under the hood. Inductors set the filter shapes, transformers balance the I/O, and tubes provide the gain, so the signal path stays passive and valve-based rather than IC-driven. Distortion remains low at normal working levels, with THD+N under 0.049% at +24 dBu, yet the same transformers and tubes saturate beautifully when driven hard. From the Elma switch controls to the smallest resistors, the IGS Audio 825EQ's premium components guarantee reliability so you can enjoy decades of rich tube equalizer tone with minimal maintenance.

UTM TRANSFORMER-BALANCED INPUTS AND OUTPUTS

The IGS Audio 825EQ features three audio transformers per channel, all wound in-house for maximum quality and consistency. A UTM2546 input transformer delivers a balanced 10k ohm XLR load, a gapped UTM3525 interstage transformer sits between tube stages, and a second UTM3525 drives the 600 ohm XLR output. The IGS Audio 825EQ's UTM transformer-balanced inputs and outputs anchor both ends of the signal path so that the signal stays fully balanced from connector to connector, rejecting interference and common-mode noise. From transparent, uncolored sound to rich, colorful saturation, the IGS Audio 825EQ can do it all.

LINEAR POWER SUPPLY FOR CLEAN ENERGY

A tube mastering EQ is only as quiet as its power section. The IGS Audio 825EQ uses an internal linear power supply rather than a switching design, so the tubes and transformers receive smooth, regulated voltage. Drawing 45 W from 115/230 V mains, this high-quality linear power supply supports a signal-to-noise ratio of 102 dB at +24 dBu and a dynamic range above 112 dB. Headroom on the IGS Audio 825EQ is generous, with a maximum input level of +22 dBu and a maximum output level of +26 dBu. Frequency response spans 10 Hz to 50 kHz within ±0.4 dB, so this mastering EQ stays open at both frequency extremes.

THREE ECC88 TUBES PER CHANNEL FOR CLASSIC TUBE WARMTH

Each channel of the IGS Audio 825EQ boasts three ECC88 tubes, providing authentic tube warmth from even-order harmonics that thickens low-mids and rounds off transient edges. The IGS Audio 825EQ ships with a stock tube set of 6xECC88 or 6xE88CC, and it also accepts 6x6N23P or 6x6N1P-EV tubes. Swapping in a different set is simple, and each type gives its own sound signature. Whichever tubes you choose, the IGS Audio 825EQ's unmatched sound quality delivers the tone that only a real tube EQ can provide.

MORE ABOUT IGS AUDIO

IGS Audio is a Polish manufacturer founded in 2003 by engineer Igor Sobczyk to provide fully analog, hand-built studio hardware tailored for studio professionals. The company winds its own UTM transformers, which is why the IGS 825EQ stereo equalizer can specify exact transformer models at every stage instead of relying on generic parts. IGS Audio is known for the Tubecore 3U mastering compressor, the Rubber Bands passive EQ, and the One LA 500 opto compressor. The IGS Audio 825EQ tube equalizer follows the same philosophy: heavy iron, real tubes, stepped controls, and no digital layer between you and the audio. Tailored for studio professionals who expect gear to last, every IGS Audio unit ships with a three-year warranty (excluding the tubes themselves).