National Guitar’s Revolution Biscuit Bridge: A Modification

In my last posting I discussed the installation of National Guitar’s new machined aluminum biscuit/bridge on my Reso-Rocket WB. You can find that posting here. Just as I was wrapping up that discussion, it came to my attention via a YouTube posting by Steve James that National was now producing a wooden gasket to place between the aluminum biscuit and the resonator cone. Since I had just completed my installation, I was naturally curious as to what purpose the wooden gasket served. To that end, I sent inquiries to Steve James, Mike Dowling and National Guitars. Both James and Dowling are recording artists and they represent/sell National Guitars so they would have the inside scoop. I was interested in their take on the purpose and value of the gasket. I contacted National to see if I could acquire one as the gasket was not yet available for sale on their website.

Biscuit gasket awaiting installation atop the WB…

After receiving a response from all the aforementioned contacts, there were basically two thoughts regarding the gasket. Steve James believed the wooden gasket which was located between the aluminum cone and aluminum biscuit would bring the guitar’s tone back closer to the sound of the older wooden biscuit design, which he thought was important.

On the other hand, Mike Dowling believed the gasket served the purpose of enhancing how the aluminum bridge “seated” onto the resonator cone during installation, particularly when using a “used” cone that had a wooden biscuit removed from it. According to Dowling, the used cone was “dimpled” by the wooden biscuit which prevented a uniform contact with the Revolution biscuit during subsequent installation. The gasket mitigated this problem. In Mike’s opinion the gasket was totally unnecessary when the Revolution biscuit was installed on a new cone. Mike was pretty firm in his recommendation even though he shared that the president of National thought the gasket might “mellow” the guitar’s tonality.

Since I had installed my Revolution biscuit on a new cone, I was inclined to drop the subject, especially after National confirmed, via email to me, Mike Dowling’s same position on the gasket. National Guitars seemed to have more than one opinion regarding the gasket. It is indeed true that two things can be true at the same time!

Almost immediately after hearing from Mike Dowling, I decided not to pursue the wooden gasket any further. Somewhat ironically, I was simultaneously contacted by Steve James and he basically insisted that I give the wooden gasket a try. In fact, he arranged with National Guitars to send me one! Despite the fact that Steve James did not know me at all, he was super nice and exceptionally accommodating during this process. Below you can see Steve’s initial YouTube posting about the wooden gasket:


In just a day or two, the gasket arrived from National… in fact they sent me two! The gaskets were very thin and flexible wooden shim-like contrivances designed to fit snugly into the underside of the Revolution bridge. To the left you can see the resonator cone I disassembled from my guitar with the Revolution biscuit sitting upside down upon it. The gasket is shown fitting snuggly to the underside of the biscuit. You can also see the the gasket is cut away to make space for the center mounting apparatus that is used to screw the biscuit into the cone. In sum, the gasket is sandwiched between the biscuit and the cone. Since it is so thin, it is basically moldable when the biscuit it screwed into the cone, yet it maintains a thin wooden layer between the two.

Revolution biscuit, Maple saddle with gasket…

To the right, you can see the Revolution bridge attached to the cone with the wooden gasket sandwiched between. Also visible is the Maple saddle inserted into the biscuit. Because the gasket raised the height of the saddle, I had to remove it and sand it down to compensate for the gasket’s thickness. Removal of the bridge is quite easy and one of the selling points for the Revolution biscuit. It took a bit of trial and error but I got the saddle sanded down to get the string action that I wanted. If you refer to my earlier posting on the subject you can find the tolerances I was shooting for.

After I reassembled the instrument I made a recording of the guitar with the gasket installed and compared it the an earlier recording that I made after initially installing the biscuit (without the gasket). The clips are shown below. I am playing Muddy Waters’ “I Can’t Be Satisfied.” The first two recordings are “unplugged” and the last one is the guitar plugged into my Mesa Boogie Filmont 50 and through a series of pedals:

Revolution Biscuit Bridge – Initial installation without wooden gasket

Revolution Biscuit Bridge with wooden gasket installed

Revolution Biscuit Bridge with wooden gasket installed and guitar “plugged-in”

The tonality differences between the guitar with and without the wooden gasket are, I think, subtle; however, after repeated listenings, I believe the gasket fattens and lends a woodiness to the tone. I plan to keep the gasket installed. Feel free to comment below what you think.


National Guitar’s New Bridge Installed…


Flipboard Online Magazine Logo

I believe it was on Flipboard, the online, choose your own content magazine, that I first learned that National Guitar Company had redesigned it’s bridge and biscuit, which they referred to as the Revolution Biscuit-Bridge. Having owned 3 National Resonators and still possessing two of them, I was naturally interested in the innovation, but decided at first glance that it looked a bit too complicated to install and it was expensive… still, I remained interested and would occasionally look for a review… when I queried one of the National Guitar Facebook groups about the new bridge all I heard was crickets… So, I pretty much forgot about the subject…

Mike Dowling on Zoom…

Earlier in the Summer of 2020, I had the great, good fortune of spending several Zoom sessions with recording artist and highly accomplished performer, Mike Dowling. Being prevented from doing his usual summer festival and workshop gigs because of the COVID pandemic, he was recruiting guitar enthusiasts to study with him via Zoom from his home in Mexico. So, I spent several hours with him over the course of a month.

My favorite Mike Dowling recording…

If you’re not familiar with Mike Dowling he is a guitar virtuoso and I discovered him because of his particular artistry with National Resonator guitars. He’s made a couple of excellent educational DVD’s for Happy Traum’s Homespun Music Instruction enterprise. That’s how I found him as I was looking for some basics about how to play bottleneck guitar.

After working with his DVD’s, I was delighted to learn that Mike was performing at the Creek House venue in Minneapolis in May 2018 on a Friday Night and the other two days he would host a guitar workshop. Having never done a workshop before, I decided to attend! The concert was sublime and the workshop was great fun though I was in over my head, surrounded by guitarists far more accomplished then me.

Me and Mike Dowling at Creek House Workshop

To the right you can see a shot of me and Mike at the Creek House Workshop. You will also note I am holding, what was at the time, my recently acquired National Reso-Rocket WB (wood body). Mike is holding the metal version of the same guitar.

I involved myself with resonator guitars because of my interest in playing country blues. I tried out an inexpensive Fender resonator at my local guitar shop and really liked it; however, I thought it was a little under-built and decided to go with the gold standard and purchased a National NRP Steel resonator online through Reverb. I liked the NRP but thought a wood bodied guitar might be even more to my liking so I subsequently purchased the WB from Dream Guitars near Asheville, NC via Reverb. I remember sitting at a concert in the balcony of the Englert Theater with my wife in Iowa City, and covertly communicating via text with Dream Guitar’s owner Paul Heumiller. He made me a great offer and we closed the deal right there… I was stoked! The short Youtube segment below gives more detail about the WB and it’s developer Steve James:


Reso-Rocket WB with Hot Plate

On the left, you can see that my WB has two knurled knobs for tone and volume control when the guitar is plugged into an amp. The sound pickup is a single coil design located between the guitar’s bridge and finger board. This whole arrangement is referred to as a Hot Plate and was actually designed by Mike Dowling. In fact, Mike sold me mine. In addition to performing and teaching, Mike also is an agent for National Guitars. You might be interested to know that Mike also worked with National Guitars to resurrect the deeper wooden bodied El Trovador model.

All this brings me to the fact that during our time on Zoom, Mike brought up the new Revolution Biscuit-Bridge, which he had installed on two of his resonators. He enthused about the flexibility of the bridge, particularly that it could be raised or lowered with set screws while the standard one could not. As he described it, he would lower the bridge when playing finger-style and raise it when he planned to play bottleneck. I became interested because the action was very high on my WB and it made playing anything other than bottleneck-style difficult, which was not really a monumental problem because I had plenty of other guitars that would serve for finger-style, but I was intrigued anyway.

Screen shot of Revolution Biscuit from National Guitar website…

Mike also mentioned that the new biscuit was machined aluminum, thus appearing shiny and metallic, which was very different from the black painted wood of traditional National biscuit/bridge combinations. I inferred from his discussion that traditionalists might be put off by the shiny metallic appearance of the new bridge. He informed me that National was considering selling painted black versions of the new bridge in the future and that I might want to wait. I was not particularly bothered by the shiny appearance of the new bridge and actually like it a lot.

Screen shot of National resonator cone…

About a week or so later I ordered a Revolution Biscuit bridge from Mike. He said he would be happy to consult with me during the installation, and strongly recommended that I purchase a new cone along with the bridge. The traditional biscuit is both screwed and glued into the cone and removing it leaves a dimple that can prevent the new bridge from seating properly unless the dimple is sculpted out, which is difficult given the fragility of the cone. Since I wanted to DIY this conversion, I purchased a new cone with the Revolution bridge to avoid sculpting the older cone.

Various Bridge saddle woods available from National Guitars… another website screenshot…

In addition to the newly machined biscuit, National now offers a choice of bridge saddle woods, including, maple, ebony, rosewood, walnut and holly. I was under the impression that I would receive the full set of saddle woods with my order, but only received the traditional maple one, which is just as well because it was a bit of a stressful effort to “fit” it out for the biscuit. I do remember Mike recommending the maple saddle wood and I like the way it eventually came out in both appearance and sound. Just today in a note to me, Mike wrote that in a “blind” sound test he cannot tell much difference in the various woods or between old and new biscuits. To him the real value of the Revolution Biscuit is the ease of string height adjustment.

So, the package arrived from National about a week or so later. Contained therein was the cone, the aluminum biscuit, a single maple bridge saddle, a length of synthetic sandpaper, and two small Allen wrenches… Why the sandpaper? Because the saddle wood must be shaved down to achieve the proper string to fretboard action…

Measuring string height bridge to biscuit…

For starters Mike had me measure the string height off of the original biscuit and from there he recommended that I shave one 1/8th of an inch off of the bottom of the new maple saddle. Below you can see an image sent to me from Mike Dowling illustrating how to mark the saddle wood for trimming. You will note that he angled his where-to- sand-to mark so that the saddle is slanted, which would allow for the treble string to be closer to the fret board than the bass string. He recommended, in the end, for the bass string to be 7/64 of an inch off of the twelfth fret and for the treble string 6/64 of an inch off of the twelfth fret for a good nominal setting. I had to do quite a bit of sanding in stages, fitting the saddle into the bridge and then measuring before the process was completed.

Before (left) and after (right) images of saddle wood as a result of trimming.
Reso-Rocket sound cavity exposed…

To the right you can see the Reso-Rocket with the original cone and bridge removed. To avoid having to restring the guitar, I controlled the strings on the neck with a capo and used electrical tape to hold the string balls within the tail piece. This way after setting the new cone and biscuit in place it was easy to refasten the tailpiece and tune the guitar back up.

As I said earlier, I went through several stages of sanding the saddle, placing it in the biscuit and mounting the biscuit on the cone. Then I would drop the cone into the guitar, replace the coverplate, remount the tailpiece, retune the guitar and then make my string measurements. The bridge guard was also removed and stayed off throughout the fitting process. During one iteration of fitting, I realized I had to make sure that there was more of a slant sanded into the base of the bridge. I think I did this three, maybe four times… it was a tedious process and not for anyone in a hurry.

Above you can see the two cones, side by side with the new one on the left. If you’re not familiar with resonator technology, the string vibration is intercepted by the bridge, then transferred down to the cone via the biscuit. The cone then amplifies the string vibration giving the characteristic resonator sound back outwards to the listener. The original biscuits were wood, so the transition to an aluminum biscuit makes some traditionalists uncomfortable. Some posters on FaceBook do not like the new biscuit, either on face value or after they’ve tried it out. There are others who have adopted the new approach.

To the left you can see a close-up of the new aluminum bridge and maple saddle mounted onto the cone. You will note that there are three holes set into the saddle that are located in between the carve-outs where the guitar strings traverse. The holes allow access to set screws that are located below in the biscuit itself. Adjusting the set screws can raise the height of the saddle and consequently the height of the strings off of the fret board.

The saddle fits very firmly in the biscuit. The biscuit is machined with a slight zig-zag shaped channel and the saddle is shaped to fit snuggly in the aforementioned channel so that there is only one way for the two to combine together. I really had to press firmly to get the saddle into the channel and the only way I could get the saddle back out was to raise it with the set screws and then pry it out with a small flat head screwdriver, being mindful that the Maple bridge was pretty delicate and kind of expensive.

I was not prepared to make a wood vs aluminum biscuit comparison after completion of the project; however, below you can see a quick A/B comparison made by Steve James:

I do have below a couple of short videos of my WB with the new Biscuit installed. Just below is a short clip of me playing Muddy Waters’ I Can’t Be Satisfied in Open G tuning, bottleneck style. I am using a brass Tone Dome slide purchased from National:

I Can’t Be Satisfied… McKinley Morganfield

I am also presenting a brief finger-style tune on the same guitar. Before I installed the new bridge, it was very difficult to play finger-style on this guitar because the action was so high. Here now I am able to do it, but I must admit because I followed Steve James advice on Youtube and installed a heavy set of Newtone Archtop strings, it was more difficult for me than it should have been… those strings are fine for bottleneck playing but a bit heavy for me to play finger-style… another lesson for me in the school of hard knocks and dirty socks! This is a Stef Grossman arrangement of the Rev. Gary Davis’s Cocaine Blues in standard tuning.

In sum, I am pleased with the biscuit conversion… I believe the saddle as currently located is in a sweet spot where I can play it bottleneck or finger-style without adjustment; however I think I will eventually migrate to the lighter string gauge I was using before following Steve James’s advice.

I like the sound of the guitar too; however, I just noticed during this writing that National Guitars is now recommending placing a wooden gasket between the aluminum biscuit and the cone which probably alters the sound somewhat… According to Mike Dowling, in correspondence while writing this blog, the gasket may be most important for people mounting the Revolution biscuit on an older cone… While the folks at National believe the tone may be mellowed out with the wooden gasket, that remains to be assessed… I may explore this wooden gasket further…