Original, rare AEA TRP.

This is the 2-channel preamplifier amp that defined low-noise, high-gain ribbon microphone preamps.

The TRP's Very High input impedance (33,000 Ohms!) allows ribbon mics to perform at their best. Why?
The ribbon gets magnetically trapped in the gap at lower impedances:

Modern preamps in consoles and recording devices are designed for dynamic and condenser microphones. Usually around 1.5k to 3k input impedance. However, with Ribbon Microphones, a low impedance input causes the passive ribbon to become part of the electron flow of the circuit, and those electrons can cause the foil to get trapped or "damped" in the magnetic gap, preventing its motion at low SPL's and high frequencies. A ribbon mic will sound relatively dull through a modern input. Taking "low impedance" to the extreme, most ribbon microphones are shipped with a short-circuit "Ribbon Lock" on pins 2 and 3 (zero impedance) that self-damps and restricts movement of the foil in the gap during shiping.
A Very High input impedance stops the ribbon from becoming damped or trapped, and it can deliver those low-energy, high-frequency sounds to the amplifier.

Stored in a climate-controlled mic locker for the past 10 years.
FREE SHIPPING to any USA Address or APO/FPO Military location at the asking price.

OR - Free Local Pickup in San Diego, CA 92129

OR - Send me an offer based on your location, and shipping from San Diego.

I have several other microphones and preamplifiers in my other listings. Please send an offer for one or more of them, and I will consider it.