Owner's manual

Gain Calibration:
Due to the fact that no negative feedback is used in the audio circuitry, the actual gain is
dependent of the state of tubes, therefore the 0dB gain level can be adjusted. Apply a 1kHz
test tone at 0db level at the main input and adjust the AC calibration for 0dB gain on the
output. The range is -3dB to +3dB in 0.5dB steps.
Reduction Calibration:
To calibrate the gain reduction meter, apply a 1kHz test tone at 0db level at the main input
and adjust the threshold control until the output Level is -10dB. Then modify the Reduction
Calibration until the gain reduction meter reads 10 dB.
Main Menu:
Push main menu to get back to the root menu.
Specifications:
Frequency Response: 20Hz – 20Khz +- 0.5dB
Distortion: < 0.1% (no compression)
Signal-to-Noise Ratio: >85db at 0db gain
Gain Range: -14dB to +11dB minimum
Threshold: -24dBu to + 16.5dBu
Mains Voltage 110V to 120V in the 115V range
or 220V to 240V in the 230V range
(user selectable)
Power Consumption: < 100W
Dimension (LxHxD): 480mm x 135mm x 250mm
Net Weight: 7.5kg
Fredenstein F660 Manual Release 2.1 July 18, 2014 Page 7