The Realios A9033 is an all discrete transistor design microphone preamplifier, for the 500 series racks. Extremely open and uncolored preamp.
A clipping problem arose one day while recording a really loud vocalist singing through a U47 microphone. The problem was assumed to be the clipping of the microphone since every mic preamp in the studio also was clipping in this signal chain.
Upon further measurement it was determined that the U47 output was not clipping, it was outputing a signal of -15 dBm. Too much output for most mic preamps.
The solution was the A9033. This microphone preamp was designed for this situation. However, the added benefit of passive voltage gain possibly makes this the most transparent and open sounding microphone preamp ever.
Passive transformer gain
Switch for phantom power
Phase reverse switch
20 dB mic preamp
All voltage gain from transformers
All discrete / class A
Input and output transformers
No negative feedback
Extremely open and uncolored
Single-space 500 series rack format
Microphone Input Impedance: 1.2K, balanced
Output Impedance: less than 50
Max. Output Level: +32dBu, transformer balanced
Gain: 5 to 20 dB in 3 dB steps
Frequency Response: +/- 1 dB from 7Hz to 85kHz
Noise Level: better than 86dB below +4dBu, 0-30kHz