Type: mic pre
These used to be the audio electronics for Ampex 351 series recorders.
Steve heard the 351\'s mic preamp at some point and liked it. Next thing we did was get 10 of them for just that use. We started reconditioning them in 1996.
This really pissed-off some Ampex collector snobs.
We completely stripped the circuit boards of all electronics unrelated to the micí pre (bias, record amps, etc.). Then we replaced all the resistors, caps, tube sockets and defective wiring in the preamp path with premium components.
We gave it these options -
- polarity reverse switch
- phantom power (from external power supply)
- -20 dB pad (Gold plated Grayhill switch located where \"input\" switch was)
- Output attenuator (in/out switchable)
- meter defeat
They have a lot of gain and are quiet. You can use ribbon mics with them on quiet acoustic passages with no problem. There is a bit of color to them. At roughly 15kHz there is a 1 to 1.5dB rise in response. From 10 Hz to 14kHz, and 17kHz to 35kHz the response is flat.
The output atenuator is a great feature in that it allows you to overdrive the preamp for a desired effect and maintain a usable output level. If you like having an extremely high output for some reason, you can kill the meter, keeping the needle from pinning all day (meter defeat switch).
They are used mostly on bass, guitar, vocals, and strings.
There are 6 of these in Studio B, and 2 in Studio A.
This is a link to the 351 forum topic.
- Jan 15, 01:06