They changed over at the end of the 1967 run....so 1968 is the first year of the LARGE round knob mufflers.

Was there ever an earlier smaller round knob?

oh and thanks for the good info

Small round knobs were from the WFL era to about 1962.

Small round knobs were from the WFL era into about 1962 but Ludwig must have had them sitting around because they used them again in 1967 as either a bottom muffler or on acrolites. The large round knob seems to appear around March of 1968. I had a July 1968 set with large round knobs up top and small ones on the bottom. I also have a late 60's acro with a small knob.

The thing that totally threw me off was that I saw a July 1967 psych red 22,13,16 at the conn. drum show last year and it had large and small knobs all the way around, club date spurs, telephone dial wheel on the rail mount and was a pretty early date stamp for psych red. Still trying to figure that one out!

Jan. 1969er

Do the round knob mufflers fit the same hole pattern as the baseball bat mufflers?

In other words, if I've got a rack tom currently with a baseball bat style muffler but the "correct" muffler for the drum should be the round knob muffler can I make the switch quite easily?

The baseball bat type has a hole with a flattened side like a "D" , the knob type has a round hole of similar diameter so to swap from bat-to-knob is no issue... but knob-to-bat you'd need to file the side of the hole to make it the right shape...

If you are going to change the muffler from ballbat to knob it will work But just make sure that the mounting screw hole on the knob muffler is on the bottom of knob..ludwig made the knob mufflers both ways with the mounting screw on top of knob and the other way under knob..Mikey