Those knobs can be found on the following Marantz models: 1152DC, 3250, 3250b. for the selector knob and copy knob (selector knob very hard to find). The small tape copy knob can also be found on other b model receivers: 2238b, 2252b, 2265b, 2285b, 2330b. Marantz knobs have been getting harder to find and prices have gone up quite a bit. Perhaps someone will machine these simple knobs and start selling them.