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Glam Journal

Is the Ampex 351 a good mic preamp?

Author

Elijah King

Updated on March 19, 2026

Is the Ampex 351 a good mic preamp?

The Ampex 351 is also highly thought of for use as a mic preamp. It uses miniature noval tubes like the venerable 12AX7, printed circuit boards and lots of negative feedback. The input transformer was made for Ampex by several companies.

Where is the line termination switch on an Ampex 351?

Another MONITOR AMPLIFIER phone jack and a line termination (LINE TERM) OFF-ON switch are located on the back of the amplifier-chassis. Foundational text courtesy of the AMPEX Model 351 operation and service literature.

What is the record calibration on an Ampex 350 tube preamp?

In all the Ampex tube preamps, the record calibration control is very important. It serves as the master gain control when using these units as preamps. If it is dirty, the sound can be trashed. It is labeled “rec cal” or “record calib.” The Ampex 350 and 351 are classic American tape recorders from the 1950’s.

What is a 351 magnetic tape recorder/reproducer?

The AMPEX Series 351 Magnetic Tape Recorder/Reproducers are high quality precision instruments designed for the professional user who requires the finest and most faithful recording and reproduction.

Can I use a tube mic preamp with a Beyer 354?

If a recordist wanted to use mikes directly with the 354, Ampex made octal plug-in mic preamp modules. These mic preamps are not very good. They use very simple transistor circuits with the Beyer mic transformers. This is not the sound you are after if you are here reading about tube mic preamps.

Can a tube preamp be used as a mic preamp?

One would be much better off building a dedicated tube preamp from scratch if that is what one wanted. When these units are used as mic preamps, the signal goes through the mic preamp section and the output section of the tape deck electronics.