Ampex actually made some lovely tube microphone mixers, back in the day along with their 351, not 350, series recorder, which had a microphone input. The 354 was very similar to the 351 but was stereo.

However, make no mistake, there was the AG350/354 which utilized an early transistor design with the same transport and really were not great sounding like the 12AX7/AY/AT/AU7's and similar miniature glass envelope tubes of the 351/354 series.

So I would find out if it was tube or transistor? If its transistors, offer him $20. If its tubes, offer him $200.

If you want a good an interesting sounding transistorized microphone preamp, from an analog tape recorder, look into the original Scully 260/280 White/Silver face electronics with the metal envelope germanium transistors, not the silicon black epoxy transistors, of the later Dictaphone series. Those germanium transistors had a really nice sound.

I also have numerous old manuals to numerous different Ampex/MCI/Scully analog recorders, which also include the Ampex 306 analog FM data recorders. That's right! Analog FM data recorders, for analog computers and satellite data transmissions, based upon the original Ampex 300 series transport. Oh yes, I've got them all.

Former Ampex and MCI certified technician. And former quality control manager and final test technician for Scully/AMPRO. Circa 1978-1981
Ms. Remy Ann David

wow! you are a wealth of knowledge. It is the tube version that he is selling. I am going to borrow it for a while and try it in as many configurations as possible. I do appreciate you taking the time to share your info with me.

Thanks!!!