Stereo Transformer Coupled Buffer with Variable Output Impedance and Stereo/Mono/Split Control



  • Transformer Coupled Inputs and Outputs
  • Two Channels, Configurable as:
    • True Left/Right Stereo
    • L/R Summed to Mono
    • Left Split to Both Outputs
  • Stereo Output Level Control
  • 1/4” Balanced Input and Output on Front Panel
  • Left Channel Input and Output Also Accessible Via 500-Rack XLR on Back Panel
  • Input Impedance: 1.5 MΩ
  • Output Impedance Selectable: 50, 150 or 600 Ω

The BZ10 is a two channel buffer and impedance controller. It was designed as laboratory test equipment for our product development, but proved so valuable in general studio use that it is now being made available on a made-to-order basis. This double-wide 500-series piece weighs in at over 3 pounds due to the use of input and output transformers by Jensen and Lundahl on each channel. Ultra-high input impedance realizes virtually zero signal loading, making the unit excellent for direct input applications.

Output impedance is switchable between 50, 150, and 600 Ohms. The impedance choices come from common microphone output impedances. Since the impedance interactions between microphone and preamp influence the sound so much, we always do careful tuning of our preamp designs so that they work well with all different mic types and their different impedances, and the BZ10 is used for these evaluations. This same interactive effect on sound quality applies to any two pieces of gear that are interfaced together (particularly transformer coupled gear). We found that the BZ10, with its transformer in/out and variable output impedance can also be used as a subtle tone shaper when used in direct box or line level applications.

The unit can be operated in true stereo mode, the left and right channels can be summed together, or the left channel can be split to both left and right output. A stereo volume control affects left and right outputs for all configurations. As with all our gear, it is finely tuned for superb transient response, low noise and smooth, pleasing sound quality. Contact Ingram Engineering for pricing and lead-time.