F660A
Limiting Amplifier
Operating Manual
Page 1: ...F660A Limiting Amplifier Operating Manual ...
Page 2: ...n is almost quadratic causing the anode currents to be very small at high compression rate As with all Variable Mu is not advised to go beyond 10dB of compression since audible distortion will be present Setting compression to around 5 dB yields the best results Installation Located on he front panel there are the output level meter the gain reduction meter the quick access buttons for Gain Thresh...
Page 3: ...y and the tubes are still powered off the unit is in bypass mode but the output meter is connected to the main output This allows the user to measure the level even in bypass mode To turn the F660 on please push the rotary control The F660 will power up and go through a tube calibration cycle During this cycle you will see the anode currents in both halves of the push pull Class A amplifier Freden...
Page 4: ...uction can be adjusted in 0 5dB steps in the range of 11db and 11 dB To adjust the gain move the cursor with the rotary control to the gain field and then press the rotary control The cursor will move from the left to the right and the rotary control becomes the level pot The change is applied immediately therefore the engineer can hear the changes right away When Fredenstein F660A Manual Release ...
Page 5: ...ast Attack The attack time can be changed in all 6 time constants by selecting faster attack times Since the Fairchild time constants are more than simple integrating filters it is impossible to set a value for this parameters The actual attack is a combination of the selected time constant and the selected fast attack mode DC Threshold The Fairchild 660 670 has a fixed DC threshold of 2 volts The...
Page 6: ... Recall Parameters Calibration etc Meter Sub Menu After selecting the meter menu on the main menu page the screen below will be displayed Meter Range The meter range of the peak meter can be switched between 60dB one LED per dB and 30dB one LED per 0 5dB In the 60dB setting the overall range is from 39dB to 20dB in the 30dB setting from 24 5dB to 5dB Meter Hold The peak hold time can be selected b...
Page 7: ...was previously used it is indicated but you can overwrite it Recall Configuration You can recall the store configurations Only previously stored configurations will be displayed and allowed to recall Factory Default The F660 can be reset to factory defaults First select Factory default and then turn the rotary control to enable then press the control to perform the reset to the factory defaults DC...
Page 8: ... reads 10 dB Main Menu Push main menu to get back to the root menu Quick Access Buttons Independent which part of the menu system is active at the moment the three quick access buttons allow immediate control of the main operating parameters GAIN Changes the input gain in exactly the same way as through the menu system the secondary function if the control is pushed is toggling the BYPASS function...
Page 9: ...20V 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 Contact Info Fredenstein Professional Audio by Orion Communication 7F 1 No 582 Ruei Guang Rd Neihu District Taipei 114 Taiwan Phone 886 2 2657 2618 Email info fredenstein com Web www fredenstein com Fredenstein F660A Manual Release 1 0 Oct 17 2014 Pa...
Page 10: ...Fredenstein F660A Manual Release 1 0 Oct 17 2014 Page 9 ...
