For school I am in an extra curricular type of club where one particular thing we will be working on is purchasing a kit and assembling a Great River preamp. Something used more for studio stuff so nothing field worthy.
Here is some info on this preamp:
The preamp is, essentially, the microphone circuitry and power supply from the Great River Electronics Mixmaster 20 (
http://www.greweb.com/product.cfm?ID=32&type=0 ), a great product with a strong reputation for audio quality and value. Dan has custom designed this half-rack preamp kit using the components used in his products, including the ME-1NV chassis, transformers, and other components for educational use. The preamp is expected to have 70dB of variable gain, a polarity switch, phantom power, and a 20dB pad. It has XLR and 1/4" TRS inputs and outputs, a line-in circuit, and an instrument input.
A couple pictures can be found here
http://imageshack.us/g/1/9822468/ A prototype of this unit was put through several tests and here are the results:
Frequency Response: -0.3dB @ 20Hz and -1.0dsB @ 34kHz.
Distortion: 20-20kHz at no worse than 0.020% THD, IMD distortion was less than .1%
Input Impedance: >2150 ohms 20-20kHz. The 20dB input pad drops input impedance to >1500 ohms 20-20kHz.
Max Gain: 69.4dB (50dB with input pad on)
Phase Response: -3.6 @20Hz and +48 degrees at 20kHz
Max Output: +29dBu @ 0.003% THD @ 1kHz
I know next to nothing about any of the specs information above, but is anyone knowledgeable about the Great River line of preamps?