I had expected the red thing on the rear of this Amperite RB ribbon mic to be a simple on-off switch:
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| Amperite RB – switch on rear |
In fact the knob is connected to a cloth-covered metal plate which slides up and down, blocking the rear of the mic. This is a mechanical method of altering both the pickup pattern and the frequency response.
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| Inside the Amperite – sliding plate, blurry photo 🙁 |
When open, the mic will be a normal figure-8 pattern. Closing the vent will reduce pickup at the rear, and also make the mic sound brighter by reducing the proximity effect.
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| Open and…. |
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| … closed |
The mechanism is not as sophisticated as, for example, an RCA 77DX, but at least they made an early effort to offer engineers a new flavour.
Well done Amperite!