thread: Revox PR99 mk3
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Old 19th September 2018
Deleted 67ae682
I've been wondering if there is not an error in the Revox PR99 MKIII manual, or at least the version I own.

On the face of the machine, in the center below the tape heads, are the two 'Level' potentiometers, with 'Input Ch1' and 'Input Ch2' printed either side of the 'Uncal' button. In the manual, these are listed as parts # 38.

On the base of the machine, below the removable panel that reveals all the calibration pots, you find the two screws to adjust the input level, named 'Input level CH1 & CH2', at the center of the panel

In the very first section of the calibration procedure, we read:
1. Remove the cover protecting the calibration controls (4 screws on the bottom) See picture below. (-> a picture of the calibration controls is printed underneath on this page)
2. Connect AF millivoltmeter etc etc
3. With AF generator, apply signal etc etc
4. Switch on machine
5. Release UNCAL button
6. Set OUTPUT switch to INPUT
7. Adjust monitor output to 0.775v with the corresponding INPUT LEVEL CONTROL (38)

However, a few pages before, we read about the UNCAL switch that 'when this button is released, the line input is switched to the calibrated line level. When pressed down (position UNCAL), the input sensitivity can be adjusted with the INPUT LEVEL control (38).

So which is it? if you follow this procedure as it's described, there's no way you can adjust the input level to read the correct voltage from the monitor using the #38 controls, since they are inactive with the UNCAL button released.
I'm fairly new to all of this, so I'm asking this with humility... but shouldn't the controls you need to adjust during this initial calibration sequence be the INPUT LEVEL CH1 & CH2 at the base of the machine?