ITA Specification

ITA inline impedance transformer

The ITA inline impedance transformer is an adaptor available in several impedance ratios and connector options.

The 200kΩ:1kΩ ITA inline impedance transformer matches instrument input to microphone level output. Balanced or unbalanced ¼” TRS input (according to connected cable) to balanced XLR output.

The 10kΩ:500Ω or 10kΩ:10kΩ XLR-F or ¼” TRS to ¼” TRS inline impedance transformers provide line to instrument level matching (10kΩ:500Ω) or line level balun (10kΩ:10kΩ) applications.  ¼” TRS input and output are balanced or unbalanced, according to connected cables.

The XLR-F to ¼” TRS inline impedance transformers are also recommended as balun transformers for microphones (following a phantom power supply, if needed for condenser microphones) to connect with an unbalanced input recorder.  These are available in 10kΩ:10kΩ matching or 600Ω:10kΩ step-up versions.  The step-up version provides +11dB of gain across the stated impedances.

For transformer isolation of unbalanced connections, a special cable assembly is required for the ITA’s TRS input.  The ITA’s chassis is connected to the TRS shield pin by the design of the connector, thus an isolating unbalanced input cable (TS to TRS) should be wired as TS tip to TRS tip, TS shield to TRS ring, and TRS shield unconnected.

The ITA has no internal connection from its transformer leads to its chassis or ground pins (shield or pin 1).  If chassis termination to pin 1 is desired, that may be indicated on order or accomplished via pin 1 to chassis termination in a mating XLR cable.

ITA Specification:

Type: inline impedance transformer adaptor

General:

Weight: 56g (2oz)
Dimensions:  80mm x 19mmø (3 1/8″ x 3/4″ø)

Instrument/microphone 200kΩ:1kΩ:

  • Total Harmonic Distortion, 1kHz @ -10dBV input: <0.01%
  • Total Harmonic Distortion, 1kHz @ +16dBV input: 0.3%
  • Total Harmonic Distortion, 100Hz @ -10dBV input: 1%
  • Frequency Response (5KΩ source): 40Hz to 20kHz
  • Attenuation: -22dB

Line/instrument 10kΩ:500Ω:

  • Total Harmonic Distortion, 1kHz @ -10dBV input: <0.01%
  • Total Harmonic Distortion, 1kHz @ +16dBV input: 0.3%
  • Total Harmonic Distortion, 100Hz @ -10dBV input: 1%
  • Frequency Response (150Ω source): 30Hz to 20kHz
  • Attenuation: -14dB

Line/line 10kΩ:10kΩ:

  • Total Harmonic Distortion, 1kHz @ -10dBV input: <0.01%
  • Total Harmonic Distortion, 1kHz @ +16dBV input: 0.3%
  • Total Harmonic Distortion, 100Hz @ -10dBV input: 1%
  • Frequency Response (150Ω source): 30Hz to 20kHz
  • Attenuation: -1dB

Mic/line 600Ω:10kΩ:

  • Total Harmonic Distortion, 1kHz @ -10dBV input: <0.01%
  • Total Harmonic Distortion, 1kHz @ +16dBV input: 0.3%
  • Total Harmonic Distortion, 100Hz @ -10dBV input: 0.1%
  • Frequency Response (150Ω source): 30Hz to 20kHz
  • Gain: +11dB
  • Weight: 69g (2.4oz)
  • Dimensions:  90mm x 32mm x 26mm (3 1/2″ x 1 1/4″ x 1″)