This is for an Ampex 350 tube amp (as shown in the picture). No tape recorder is attached to this unit. However, it does come with its original power supply which is rare. Its design includes a microphone amplifier which has lots of gain.That's what these units are good for these days. I only ever used the mic preamp to line out function. I don't see how you could use any other parts of its circuitry without the tape machine attached. And I have no way of testing the elements that aren't part of the microphone amp.
The mic amp works well. Don't expect it to be clean and super quiet. This is not what this is, it's an old 1950's tube amp. It's all there in its original form. Some people have been taking out the playback parts of the circuit to make the unit less noisy, but this one is all original.
You are welcome to come and view the unit and test it. It's located in London.
I will include a transformer 220/240 to 110/120 Volts as seen in the pictures. This item is in the category "Musical Instruments & DJ Equipment\Pro Audio Equipment\Preamps".
The seller is "mohoo" and is located in this country: GB. This item can be shipped to United Kingdom, European Union.