The LaChapell Audio 500DT is a 500 series microphone preamp that features two separate topologies or amplification paths. When the blend knob is fully to the TUBE side, the signal will pass through a transformer before being amplified by a TrueTube™ powered 12AX7 vacuum tube. TrueTube is LaChapell Audio’s proprietary method of supplying a full 250V to the vacuum tube so you get loads of clean tube gain.
When the blend knob is turned fully to the OPAMP side, the signal passes directly to a solid state preamplifier. This input is transformer-less and will provide clean gain with exceptionally low noise Placing the blend control anywhere between the two extremes will “blend” the two topologies for a wide variety of tonal options.
Tube Path THD+N 0.08% Frequency Response 20 Hz to 20 kHz Maximum Output 12 dBu Typical EIN 121
Solid State Path THD+N 0.01% Frequency Response 20 Hz to 46 kHz Maximum Output 28 dBu Typical EIN 129 Internal Gain 67 dBu Input Impedance 1.5 KΩ Mic / 10 KΩ Hi-Z Tube Complement/Type 1x 12AX7 (ECC83)