Applies to:
Instant Replay models: DR-550/552/554/600
Symptom:
The input level or headphone knobs require replacement or the dot on the top of the knob does not align properly.
Possible Reason(s):
Worn, missing or damaged knobs.
Solution(s):
General:
The input knobs are smaller (11mm), and the headphone is a larger (15mm) knob with internal splines that mate with the splines on the potentiometer shaft.
Installation:
If installing new knobs, it is best to install the knob first without the cap installed.
1. Install the knob so that the internal splines of the knob mate with the splines on the potentiometer shaft. The knob should push on smoothly without much effort. If it feels like there is too much resistance, rotate the knob slightly and then try again.
2. Once the knob is installed, rotate it to the left until it stops.
3. Install the cap so that the dot is positioned in alignment to indicate the "zero" position. Factory installation was to align the dot with the first "tick" mark. Some prefer the 6 o'clock position.
If for some reason the dot on the cap is misaligned or requires repositioning, remove the cap by sliding a sharp object (knife blade, sharp pick or screwdriver) just under the lip of the cap. This will release the cap so it can be repositioned.
Link(s):
None