The 500 series version of our low noise dicrete microphone preamp, inspired by the famous German V series preamps of the 40's and 50's.

switchable transfomer ratio / input impedance

By selecting the transformer ratio swich a selection between a 1:2.5 or 1:5 transformation ratio can be made. Besides setting voltage gain, this also switches the input impedance of the amplifier between 2.25KOhm and 9 KOhm.

selectable feedback ratio sets gain and character

The feedback ratio switch determines D2O's open loop amplification, besides amplification factor it also influences the preamps character. Less feedback (70dB position) means less supression of even order harmonics which is percieved by the human ear as a richer tone. when recording harmonically rich sources more feedback (50dB position) can be applied to achieve a more analytical sound.

Features:

• switchable transfomer ratio / input impedance
• selectable feedback ratio sets gain and character
• Low noise / dc-dc converter
• stepped attenuator
• phase reverse switch
• phantom power
• Gain D2O Fet: 75 dB
• EIN: -130dB
• Headroom: 34 dB
• Input impedance: 2,25KOhm / 9KOhm
• Output impedance: 50Ohm