The Normaphone MXPre LC1 is a low noise, low distortion preamp to be used in the Sony MXP 3000 series console. It is built around the Lundahl 1538XL transformer, features a low distortion fet op amp gain stage, DC servo, and output amp capable of driving 600Ω loads with ease.
I started this project to replace the noisier and not-so-awesome sounding transformerless Sony preamps in my board.
If you are interested, they are $400 a piece (plus shipping), with a price break for higher quantities.
Preliminary Technical Specs:
Input Impedance - 1400Ω
Output Impedance - 25Ω
Maximum Gain - 65dB
Maximum Output Level - 23dBu w/ 10kΩ Load,
22dBu w/ 600Ω Load
E.I.N. (150Ω Source,
non-weighted) - -127dB @ 41dB Gain
THD+N (1kHz) - %0.0015 (10kΩ load, 23dBu out)
Deviation From Linear Phase = < .5º (BW 10-20kHz)
Power Consumption ≤ 20mA (10mA per 18v rail)