D.W. FEARN
VT-12 Microphone Preamplifer
5
VT-12 Vacuum Tube Microphone Preamplifier
Final Test Report
Model _______________ Serial Number_______________Mains Voltage: 100 120 240
Date ___________________ Tested by ________ Assembled by _____________________
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
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 ____________
Summary of Contents for VT-12
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