Do you mean the difference being the round knob muffler instead of the baseball bat muffler?

Mike

Yes, it feels like the BBs outnumber the large knobs 1,000 to 1. Pre-serial drums with small knobs even seem more common than the later large knobs.

A lot of it would be the timing/production. Ludwig used the baseball bat muffler from the early 60's(after the small round knob) and through at least mid '68. And Blue Olive badges were present as early as the fall of '69. So that only leaves a year or two at most for the Keystone badge with large round knob muffler combination.

Mike

Do you know how early the large knobs started?

They started in '68. Rick Gier has a drum documented with the large knob muffler and a Feb '68 date stamp.

Mike

According to Gier (p22) this is the summary:

The Baseball Bat continues in use until about Feb 1968 and the 570000 serial number range. The Small Knob (3/4") tone control resurfaces when the Baseball Bat is discontinued in the Feb 1968 time frame. The Small Knob is mainly seen on Acros and marching drums at that time. The 1" Large Knob tone control is also introduced in 1968. It appears on drums with serial numbers as low as 570438 and date stamps as early as FEB 1, 1968.

This was the state of the evidence in 2013 and data collection is ongoing so precise details of earliest and latest date stamps and serial numbers are subject to change.

ref: Gier, Richard E, 2013: Serial Number Based Dating Guides for Vintage Ludwig Drums, Rebeats Publications

There you have it.

Until something new comes to light. :) I went and looked it up while you were posting. I had forgotten about the slight complexity of the Small Knob coming back for a reprise! That's another cautionary tale to put in the "with Ludwig never say never" basket.

And....the small knobs that were used on the Acrolites during that period are different than the original small knob mufflers from the late 50's/early 60's. Same bolt hole patterns. But the knobs are different.

Mike