D.W. Fearn VT-1 Operating instructions manual - page 5
D.W. FEARN
VT-1 & VT-2 Microphone Preamplifers
5
VT-1 / VT-2 Vacuum Tube Microphone Preamplifier
Final Test Report
Model _______________ Serial Number_______________Mains Voltage ______________
Date ___________________ Tested by ________ VU Calibrated to _______________ dBm
Test Equipment ____________________________ Microphone ________________________
Channel A
Frequency Response:
20 cps to 20 kc/s +/- ___________ dB
THD+Noise:
20 cps ______________ %
200 cps _____________ %
2 kc/s _______________ %
20 kc/s ______________ %
Noise:
______________ dB below +4 dBm out
Equivalent Input Noise _______ dB
Operational Tests:
-20 pad ________________
Lo-Z input ______________
Phase Reverse __________
+48V ___________________
Listening Test ____________
Channel b
Frequency Response:
20 cps to 20 kc/s +/- ___________ dB
THD+Noise:
20 cps ______________ %
200 cps _____________ %
2 kc/s _______________ %
20 kc/s ______________ %
Noise:
______________ dB below +4 dBm out
Equivalent Input Noise _______ dB
Operational Tests:
-20 pad ________________
Lo-Z input ______________
Phase Reverse __________
+48V ___________________
Listening Test ____________