Question: “When is a block rim not a block rim?”
Answer: “When it is a Tony Pass Block Rim”
During the first weekend in May of 2002, I had a rare chance to see the secret process Tony Pass uses to assemble his rims. I am not in a position to divulge the information that I now have about these rims, but I learned some very interesting things about the process and the finished product. The purpose of this page is to share what I can with you, so you can understand what makes these rims special.
When most people think of a block rim, they think of the kind of banjo rim that is pictured on the front cover of Roger Siminoff's book Constructing a 5 String Banjo. There is a good reason for this. For many years, the Siminoff book has been the “Bible” of banjo builders. Others might think of the decorative block rim that is picture in the instructions for building a banjo that were written by Dr. Burt Brent and published in Earl Scruggs and the 5 String Banjo. These books are the only books that discuss banjo construction that most people are familiar with. Each of these ideas has some merit. However, the only one of them that is really worth considering from a structural and tonal basis is the idea that Roger Siminoff has. The other method leaves the banjo with large areas of end grain showing, and this is particularly undersirable for a number of reasons, not the least of which is the difficulty in finishing it.
Close examination of the rim on the front cover of the Siminoff book will reveal that there are many areas where the blocks forming the rim do not meet properly. This causes thick glue lines between some of the blocks. One outstanding example of such a line is in the center layer of the rim on the cover, in a direct line below the left thumb of the person holding the banjo rim. This line looks to be about 1/16 of an inch thick. Structurally speaking, this is not good. Acoustically speaking, it is also not good.
This is where Tony's rims are radically different from the ones that most of us know about.
When Tony makes the 24 blocks that form the rim, he machines them to their final shape rather than simply cutting and sanding them. The fit is virtually perfect. Each surface is flat and is perfectly mated to the one it fits against. They are then glued together in such a way that the glue joint is no longer a glue joint -- it becomes a “glued joint.”
Well, what's the difference? Interestingly enough, it is a very significant difference. At each glued area, so much of the glue is squeezed out that wood touches wood for the entire joint. All the glue that is left is forced into the pores of the wood. This is also true of the glued joints between the three layers of wood. Basically, the amount of glue that is left in the rim is such an insignificant amount that you could put it into a thimble and still put your little finger into it.
And it is an incredibly strong joint. Tony routinely strength tests the pieces he saws off of the corners of the octagons that become the rim layers. They are strong enough that they are virtually unbreakable.
So what does this mean in terms of a banjo rim? Well, instead of having a rim that is 24 separate pieces, you now have a rim that is, for all intents and purposes a single piece of wood. And this is a very efficient type of rim, acoustically speaking. For all practical purposes, it vibrates as a single unit.
Tony does not claim that these rims will give you a pre-war sound, whatever that is. What he does claim, and these rims back him up, is that a banjo that has one of these rims in it will have a more powerful, cleaner sound that is quite rich.*
The average 3-ply rim has more than 144 square inches of glue in it. The Tony Pass block rim has less than 70 square inches of glue. That's important. Many banjo specialists feel that glue absorbs sound. They may be right. In the Tony Pass rims, there is so little glue and so much direct contact between the surfaces, that the rim becomes a unit.
There is as much difference between a Tony Pass block rim and block rims that are made by other people as there is between a Rolls Royce and a rollerskate.
Tony Pass rims may be obtained for any style banjo and are available in submerged maple or birch. They are also available as retrofits to Stelling instruments, and many of the top players are using them.
*This was borne out at a recent jam at Tony's residence. I had three banjos with his rims in them. One had a flathead maple rim with a McPeake tone ring, a maple neck and a rosewood fingerboard. This banjo had a good, clean powerful sound. A second instrument had an archtop maple rim with a Hopkins-McPeake conversion tone ring, a maple neck and an ebony fingerboard. This banjo had a bit more powerful sound. A third instrument had a flathead birch rim with a Tennessee 20 tone ring, a maple neck and ebony fingerboard. This was a very pleasing, powerful instrument. I would call all of these an "enhanced, contemporary sound."
New developments in the experiments with the Tony Pass rims
I have shuffled some tone rings around on my test banjos. I now have the Crowe ring in the banjo with the maple rim and the Huber ring in the banjo with the birch rim. The maple rim makes the Crowe ring sound a bit brighter than it did on the Carolina Acoustic rim. The Huber ring sounds similar to the way it sounded on the Carolina Acoustic rim. The reasons for this are not apparent, but this shows some consistency that I had expected.
I have now tried the McPeake ring on the Tony Pass block maple rim. This makes for an extremely powerful banjo. Head tension is critical on this setup.
I have tested the submerger birch rim with several tone rings now. The more I test the Tony Pass submerged birch rims, the more I realize that they sound extremely similar to the three-ply submerged maple rims available from other sources.
Addendum About Tony Pass Block Rims
I have a Tony Pass hard rock maple block rim, which is made from hard maple (not submerged). I was so caught up in testing other rims that I let this one slide. I should have tried it earlier. This rim was made before Tony started working with submerged wood. To give it an honest test, I used a Gibson USA tone ring and a maple neck with an ebony fingerboard. This made it functionally the equivalent of my Scruggs model.
The comparison of the two instruments was interesting. The hard rock maple gives the Gibson USA tone ring a more lively sound. It is crystal clear over the entire range of the banjo, with plenty of power -- a kind of "Stelling meets Gibson" sound.
A Special Note Concerning Archtop to Flathead Conversion Tone Rings on Old Wood Rims
I have been conducting some experiments with archtop to flathead conversion tone rings on old wood rims. For the continuing investigation, click here.
Just an FYI
For several months, Tony was using wood that came strictly from the Lost Forest lumber yard. In order to make it possible to keep using strictly the highest quality submerged wood in his rims, Tony has now started purchasing submerged birch and maple from other suppliers of this wood as well. The wood must meet very strict criteria to bear Tony's trademark -- Lost Timbre® -- but it is ALL submerged wood from the Great Lakes region.
Tony Pass no longer selling complete pot assemblies
Tony Pass is no longer selling complete pot assemblies. Check his web site for more information.
For the latest in Tony's new rim designs, click here.