Tim McKnight. McKnight Guitars. | 2009 | Luthier Interview
TT – Hi Tim, thanks for taking the time for this interview. I was wondering if you might tell us a little about how you got into lutherie?
TM– Hi Terence, I always wanted to learn to play the guitar since I was a youth. After dropping some hints, early on in our marriage, Mary, my wife, bought a used Yamaha for me with action that was about 14″ high (well maybe not THAT high). I tried to play that thing but it was killing my fingers and I didn’t know how important it was, especially for a beginner, to have the action adjusted.
I almost had her convinced that I HAD to have a Martin guitar [IF] I was going to get any better. She was almost in agreement … until … she found out how much they cost and how little we had in the bank account at the time. She began secretly saving money and somehow she found out that Martin sold kits. Later that year she surprised me with a Martin HD-28 kit as a Christmas gift. It took me several years to complete it but I finally did. It sounds pretty decent but it has a lot of beginner goofs in it. However, it is probably the most cherished guitar that I own because of the obvious sentimental reasons.
I grew up working around wood since my father was a master carpenter and furniture maker. So I guess I may have been genetically destined to walk some of the same paths that he did even though I did go the other direction as a teenager and young adult.
I really enjoyed building the kit guitar and in the interim I began doing lots of repair work for family, friends and the local guitar shop. Since the guitar came with a blueprint and being an engineer, I decided I could build these from scratch and make some design changes that [I] thought needed to be made.
I had a thirst for knowledge and wanted to learn everything that I could about these wonderful wooden stringed boxes that made music. This was at a time where the internet wasn’t a source of knowledge for builders. There weren’t any local builders that I was aware of and the books at the local library were not much help. Therefore I was on basically my own to learn through lots of trial and error.
As I did repair work I was able to learn a lot about how factory guitars were made but I was convinced that there was a LOT more potential there just waiting to be tapped into. So I began modifying braces inside of guitars and was able to learn a lot about voicing in the process. This stage of my career was extremely beneficial to my learning.
I was spending more and more time enthralled with the mechanics of guitars that learning to play skillfully was put on the back burner. I worked in a huge fortune 100 factory as a mechanical engineer to raise and support our family but my mind was constantly thinking about guitars and building the next one and the next one. Soon I was faced with a decision that I had to choose between building or repairing guitars. The extra side income I made from repairs was tempting but my heart and mind was fixed on building so I stopped all future repair work to focus solely on building guitars. I had no clue how I was going to sell them or even [IF] I could sell them but Mary was behind me 110%. She said that if I build them she would sell them and we have both lived up to that bargain..
TT – So you’re pretty much self taught?
TM– I consider John Greven a long distance mentor though I have never worked with him side by side. Early on John encouraged me to build very light and responsive guitars which I still hold to today. John was there for me to answer questions and give instruction when I was stumped. He showed me his bracing patterns and shared his thoughts on his building approach which was quite helpful. He has always been an encouragement to me when I needed it most. Friends like John are a rare gem in this covetous society we live in.
I studied briefly with Ervin Somogyi. Ervin shares John’s philosophy of building light and responsive instruments as well. Ervin taught me a LOT about top voicing, specifically identifying the different modes of the top, how they move and how they affect the tone of the guitar. He taught me how to manipulate each mode to shape the voice for a particular customer’s tonal goals. I consider Ervin another mentor and friend within our community.
Other than these two brethren I do consider myself basically self taught. Being an engineer has brought a lot of other tools to my approach to building. Having worked in a huge production factory has also been a blessing that taught me how to stream line my building approach, identify process waste, build accurate fixtures and jigs which increased efficiency and minimized errors. This has enabled me to build efficiently while greatly reducing labor hours within the process of each instrument.
TT – But speaking of efficiency, you build double tops right? Don’t those take much longer…
TM– Yes, I have built several dozen DTs. They actually do take longer to build and require specialized vacuum clamping and form fixtures. First the rosette is inlaid in the outer top and then the top is thickness sanded down to about the thickness of two playing cards which is around .030″ – .040″. I have actually sanded through some rosettes during this process and then the top is basically firewood at that point. I have gone through an enormous amount of tops during this learning curve. Big deal you might say … but scrapping a $400 top makes you nearly cry when you toss it in the wood stove! –
Once the outer top is thicknessed to the proper dimension and deflection stiffness then the Nomex is glued to it along with the inner pad that supports the back side of the rosette and the bridge. After the adhesive has cured this lay up is then thickness sanded on the Nomex side and then tapered or graduated. Next the inner top is glued to the Nomex in a compound radiused form using vacuum clamping. This process puts the final arch below the sound hole but leaves the upper bout flat.
After this layup comes out of the dished form the braces are then glued to the inner skin using my own Quint-X bracing pattern. After the adhesive cures the top is voiced for the particular player’s target tonal goal. The last step is a thin coat of finish on the [inner] side of the top. This sealer coat acts as a moisture exchange retarder. I perform this step to retard moisture exchange. Nothing will completely stop moisture but this step does greatly reduce it without negatively affecting the tone of the guitar.
DTs are inherently nearly twice as stiff as a solid top therefore they only require half as much brace mass. The end product is a top that weighs almost half of an equivalently braced solid top. A lighter top is much easier to set into motion by the strings but being extremely stiff it has the ability to hold up to an aggressive and heavy string attack without tonal distortion. It can have the responsiveness of Cedar and the headroom of the best Adirondack spruce. These unique tops have the widest dynamic range of any tops I have ever experienced.
Not all DTs are equal though and there is a significant learning curve to gain a good understanding of how they work and how to build them properly. I experienced some distortion on my first couple of DTs during my R&D work because I was building them too thin. They were very loud and responsive but at the expense of more movement and distortion than I was comfortable with. I added some stiffness in key areas by graduating the thickness of the Nomex in the first lay-up phase which eliminated the distortion without adding a significant amount of weight.
It is real easy to add weight to a DT without even trying and weight is your enemy with these tops. If the top becomes too heavy you might as well stick to building solid tops which are far less work. You have to constantly weigh each top skin, the Nomex, the internal pads and especially the adhesive. Weigh the first lay-up before and after graduating it and keep accurate notes to refer back to. It’s not a process for the hobby builder to just dive into.
TT – Thanks for that. But you also build double backs right?
TM– I do build double backs which I call “Hollow Backs”. They are not double backs in the sense like double tops are. The construction is very different and proprietary. I don’t have too many secrets but this invention is mine. In the simplest terms there are two backs, an inner and outer back and both are independent of each other separated by an air space. Therefore if the outer back is dampened by the player’s body the inner back is still free to vibrate. This design has a tremendous amount of forward projection more so than any guitar that I have experienced or heard to date.
Playing a Hollow Backed guitar sounds very much like a conventional guitar from the player’s perspective. However, if someone stands across the room from the guitar they get a tremendous amount of sound blasted at them. The inner back almost acts like a trampoline for the sound produced by the top.
Imagine that the sound that the guitar produced was in the form of a tennis ball. Throw that ball at brick wall (a conventional back design) the sound or tennis ball would travel a given distance. Now throw the tennis ball at a trampoline and the sound (tennis ball) rockets off traveling a far greater distance.
TT – I see- I know you also build with sound ports- would a sound port negate the benefits of a hollow back?
TM– That is a good question but in my opinion, no. A sound port is like a mini-monitor for the player. A small amount of sound, escapes out of the sound port and is directed towards the player’s face. It provides a unique sonic dimension that envelope the player in a sort of surround sound. A sound port is only a means for the sound to escape and it doesn’t really produce any sound like the top and back can.
Early on, during my sound port R&D work, I would attach a “Post-It” note over the sound port so that I could block off the port and then open it by folding the paper. This would allow me to hear what the port sounded like open and closed. It also gave me a better understanding of how large to make the port. I could make the port oversize, on a test guitar and then make the port gradually smaller by cutting paper donuts to put over the port to reduce its size and hear the affect.
Something that I noticed, as I played the guitar, the Post-It would open and close, if it was only attached with the self adhesive backing and anchored on one edge. The Post-It would move in a flapping motion as air would enter and exit the sound port. The side sound port works just like the main sound hole on the top of the guitar only to a lesser degree, due to its reduced size. I believe the sound port and main sound hole work in harmony but 180* out of phase with one another. As air is entering the main sound hole then air exits the side sound port and vice versa. The sound box is just a big air pump in the simplest of terms, moving air that is vibrated first by the top and then the back.
TT – So would double sides help in the sense that the double back system helps?
TM– Double sides or single sides for that matter don’t play a significant role in producing [much] sound. They are nearly an inert structural member that supports and separates the top from the back.
To prove this, take your finger and tap all over the top and back and listen to the tone. Now tap on the bridge (or in the center of the back) and gradually tap your way out towards the perimeter. When you get about 2″ – 3″ away from the perimeter you will notice a significant change in the sound. It will quickly diminish as the sides dampen energy from the top and back vibrating plates.
I have heard some make a claim that the top’s sound is transmitted through the sides or side braces into the back. I have a difficult time believing this is the case. The sides are shaped in such a way that the curves actually increase the side’s strength. The curves could increase dampening too. The waist of the guitar is one of the strongest and stiffest places on the guitar’s sound box. But all this added stiffness and strength don’t mean that they are contributing to the voice of the instrument in a significant way.
I like to think of the guitar sides are similar to the rim of a drum. The drum rim is designed to be very very stiff and rigid to support the paper thin top and bottom heads of the drums. Sure, the material that the drum rim is made from can color the tone of the drum as can the sides of a guitar. However, I think the role of the top and back are the major contributors in producing sound of the instrument.
The benefit of my “Double-Sides” is to appreciably increase stiffness of the rim without increasing the weight. My sides are the thinner and lighter than a standard one piece side. By laminating two very thin pieces of tone-wood together the end product is one that will resist wood movement during humidity cycles and will be much more crack resistant to the rigors of accidents or abuse.
I have made some comparisons of my single side and double sided guitars by using a ToneRite. This is a small vibrator that is mounted on the strings and induces vibration into the instrument, much in the same way when one would play it. By running your fingers all over the guitar, as it is vibrating, you can quickly ascertain where the instrument is vibrating and where it isn’t. There’s no doubt that there is some activity in certain places in the sides but the amplitude is much lower than the major players; i.e. the top, back and neck system.
TT – I read also that you did some research on whether the Tone rite, does it really work? Or should I say does it make enough difference to invest in the device?
TM– Yes, I have used the ToneRite since I was introduced to them by fellow luthier Michael Lewis. He was giddy and excited when he was telling me about it during the winter NAMM show in January of this year. He felt that it made a huge improvement on his Archtops and Mandos.
However, I am as much of a sckeptic as the next guy and was doubtful that it could make any difference in my guitars. Long story shorter, I bought one and stuck it on a R&D guitar that had been setting in the corner for a couple of years. I was not particularly pleased with the guitar’s tone and remembered that it was somewhat compressed sounding.
I had planned to go back and voice it through the sound hole but never found the time to do so. I strung it up with new strings and noodled around on it for a half hour or so to get a mental snapshot of the tone and responsiveness. It was tight just as I had remembered it. I put the ToneRite on it, hung it in a Hamilton stand and forgot about it for 5 days. Went back and played it again and I was floored. The guitar sounded fantastic, open, alive. The guitar responded to all sorts of tunings and string attacks. There was a huge improvement everywhere. Had I not experienced it first hand I would have not believed it.
Since then the ToneRite has gone on every guitar that has left our shop. I don’t have a scientific explanation or data top prove how it works, but it does blossom and transform an instrument in a magical sort of way, period! Is it worth the investment? Well, I paid $300 something for mine in January and now they are about 1/2 that which I can only assume is due to a more efficient manufacturing process.
IMO, they are worth the investment at twice the price I paid for mine. I don’t mind giving some free press to someone who truly deserves help. Shoot, I am a nobody that just happens to believe in their product and what they are doing. ToneRite consists of a young group of college grads with a dream. What impresses me most is they all have proven they are willing to listen to a few of us who has given them some feedback on early models and incorporated the changes. You can also expect some new and exciting products in the near future too 😉 [For what it is worth I have no stock or affiliation in the company but I think they have a very bright future ahead of them]
TT – And I understand you also have a glue testing project going on too?
TM– Yes, I have been testing a lot of glues lately. It may seem like a nerdy thing to do, but hey, I’m an engineer so I have an excuse. Hand built guitars are all about making subtle changes and learning how each subtle change can influence a guitar’s tone.
There has always been some romantic mysticism about the use of Hot Hide Glue on musical instruments. It has been around forever and some say that it is one of the contributing factors in the tone of older instruments. The difficulty lies in separating fact from lore. So I set out to design an experiment to measure each glue’s vibration spectrum and learn how it may correlate to dampening that vibration energy.
I wanted to learn how different glues impacted the vibration traveling through a properly fitted joint in a guitar and if there was a measurable difference of each glue. More about those tests can be read here and here.
TT – Okay, I’ll let our readers head over to your website for further details. Do you have any other research projects in the works? I remember you have quite a stash of tonewoods….
TM– I am constantly in R&D, so it must be the Engineer in my genes. Not satisfied with the norm, I am always exploring different bracing patterns on tops and backs, experimenting with sound board thicknesses, top and back tapers, varying deflection measurements, X-brace splay angles, X-brace intersection locations, bridge plate foot print sizes, bridge plate thicknesses, BP materials and combining different brace wood species to alter the tone of the guitar’s voice. Its a constant learning process for us.
Stash of tone woods”, well that might be an understatement if you asked Mary. I suffer from a similar disease, Guitar Acquisition Syndrome (GAS), that you guitar players get only mine is called Wood Acquisition Syndrome (WAS). If I never bought another stick of lumber till I die I would still have enough wood for two lifetimes. I am a sucker for a beautiful piece of wood and I just can’t help myself sometimes. Though I am more reserved these days only selecting the best of the best to add to my inventory. God created such marvelous wood for us to use and I consider myself extremely blessed to have an opportunity to re-shape it into stringed instruments.
TT – Would you mind letting us in on some of the more unusual domestic and exotic woods you have?
TM– These are some of the woods that we have in stock and currently use on our guitars: Eastern Black Walnut, Wild Black Cherry, Shag Bark Hickory, Ash,
White Curly Burr Oak, Osage Orange (one of my favorites), Machiche, Pau Rosa, Granadillo, African Wenge (another favorite), Paudauk, Jatoba, Honduras & Cuban Mahogany, FL. Mahogany, FL Rosewood, Flamed Gaboon Ebony,
S.E. Asian RW, Black Limba, Makore, African Movingui, African Anigre and Pernambuco.
Osage Orange & Shag Bark Hickory are two of my favorite domestic tone woods (to the USA). My ear is drawn more to the Rosewood family and I love the dark, rich and sustaining sound of low dampening RWs so its not unusual that African Blackwood RW, Cocobolo RW and Brazilian RW are held in high esteem among the imported exotics. Panama RW and SE Asian RW are in the hunt too so it’s hard for me to nail down any one specific tone wood that surfaces to the top.
Osage closely resembles Brazilian RW in tone and mechanical properties while Shag Bark Hickory is very close to the tone of a good Mahogany with an extremely balanced bass to treble frequency range.
I still have a very special set of S.E.Asian RW set back for my personal #100 guitar. I have long surpassed #100 but I have just never found the time to build it. Plus I am much undecided about the top I will use on it too. I have a similar love affair with great sounding tops too so it has added even more confusion to my delay in building that guitar.
TT – How about Pernambuco, it’s a pretty rare wood for back and sides right?
TM– It is a VERY rare tone-wood, especially in sizes large enough for 100% quarter sawn 2 piece backs. As I understand it the trees are very small in diameter, similar in size to Madagascar RW trees. I was extremely fortunate to be able to purchase some sets that are both quarter sawn and very figured. It is a strange looking shade of burnt orange, almost pumpkin in color but the tone and sustain more than makes up for the odd appearance.
TT – And tonally, how does it hold up to say, Brazilian?
TM– Pernambuco is a very low dampening wood but it’s much denser than BRW. It has low frequency response that is stronger than BRW and more similar to African Black Wood but it still has excellent mids and high frequencies. I guess it should be closely compared to ABW rather than to BRW. We have so many wonderful tone woods at our fingertips these days that it opens up a lot more possibilities for the player and builder alike.
TT – Thanks for explaining Tim. I have heard about an all US woods guitars out of your workshop too?
TM– We decided to build our 2009 Healdsburg batch of guitars using mostly US domestic tone woods to open players minds and ears to the great tonal possibilities that we have right here in our own back yard. I personally love the dark, rich & lush tone of exotic rosewoods but I am also wise enough to know that the world’s tone wood supply is dwindling away quickly.
Therefore, we must investigate other alternative tone wood sources that are ecologically friendly and sustainable. If you have ever seen the vast deforestation of some small countries like Madagascar it will break your heart. Not only at the deforestation but the impoverished people are just trying to survive and provide for their families in any way that they can. It really saddens me on both accounts.
TT – And the domestic tonewoods are just as good as exotics?
TM– I believe it was Torres that built a guitar (back & sides) from paper Mache’. Then Bob Taylor built some guitar (back & sides) out of pallet wood. All were reported to sound much like a guitar J Back and sides add tonal color to the main sound producer [the top]. Some backs will dampen and some will be a lot less dampening reflecting nearly as much energy as is imparted to it.
A neighbor of ours had cut down a Shag Bark Hickory tree many years ago and he gave me a section of the log, which I had milled into back and sides. The wood had a decent tap tone and I thought it would make a good guitar. I posted questions on about every guitar forum I could find and asked if anyone was aware of anyone building guitars from Hickory and the response was a resounding no. I figured I would give it a try since the price was right (free). Much to my surprise, the guitar sounded fantastic. We built several more with the same results. Later we built one for the very first Healdsburg Guitar show we exhibited at and it was the first guitar that we sold and it sold a few hours into the show.
In my opinion some domestic tone woods are just as good as some exotic tone woods. The player and builder alike just need to realize that each piece of wood is unique and each one brings its own tonal palette to the table. It is up to the builder to bring out the maximum potential of each piece of wood so the player can experience the greatest benefit possible for their playing enjoyment. -Brazilian Rosewood and Honduran Mahogany will probably always be the two bench mark tone woods that all woods are compared to. We have all experienced stellar guitars built from both woods and we have all experienced some less than stellar guitars of the same woods from the same companies.
Is it the wood or simply the law of averages? In my opinion, both are true. When a large company produces 100 guitars or more a day using the same specs for each piece of wood you will get a few fantastic guitars, the bulk will be the average mean that the company is aiming for and then there will be a few lemons in the batch as well.
Wood is infinitely variable within the same tree, within the same billet and even within the same piece. No two pieces of wood will ever have the same weight, same stiffness, same density, same dampening properties, etc… That is why production guitars are all over the place in terms of responsiveness and tone. Large production companies simply do not have the time to voice each piece of wood to its [maximum] potential. It takes too much time which adds cost to the end product.
Large scale manufacturing is all about volume and quantity if they want to stay competitive in the market place. Anyone who has ever worked in a factory will tell you that this is true regardless if they are producing silicon widgets, automobiles or guitars. Advertising campaigns may paint a different picture to the potential buyers but it’s simply economics 101 in the most basic form
Domestic woods are a viable alternative and I believe you will see more and more use in the near future. We are already seeing Domestic woods used today such as: Maple, Cherry & Walnut. The likes of Birch and Oak were used in turn of the century instruments and have withstood the test of time for over 100 years after the fact. White Oak is a tremendous tone wood but it looks a lot like furniture instead of tone wood so that may hold a potential buyer back. Put a blindfold on them, hand them a domestic wood guitar and their ears will be fooled more often than not.
TT – What a wonderful idea- blindfold guitar testing! Thanks for taking the time to speak to us, Tim. Before we go, I was wondering if you had any advice for aspiring luthiers or players looking to get into handmade guitars?
TM– Thank you Terence for taking the time to learn more us and about McKnight Guitars. If you are a player, may I suggest that you shop with your ears and not just your eyes. It’s easy to be sucked into tradition or corporate advertising spin and be turned into a “head-stock” shopper. We have exhibited at many guitar shows around the world and you would be surprised by how many “head-stock” shoppers are out there. They will glance at the name on the peg-head and if they don’t recognize the name they walk on by. It’s sad to say but they may be missing out on some wonderful musical instruments by being too brand oriented.
If you are a player, you may be considering building a guitar to save a few bucks. Do your homework and you will discover what many have, that you could have purchased a wonderful hand made guitar for far less than the investment they made in tools equipment to build their own guitar. If you are one of the fortunate few who actually completes the build it’s often a quite satisfying experience.
If you are an aspiring builder … remember there are no shortcuts in this business. There are no fast and easy ways to rise to the top tier of master builder status nor are there any shortcuts to building a truly world class instrument. After I built a few guitars that were [shiny] and [sounded decent] I had visions of grandeur to sell my guitars for thousands of dollars just like the “big boys” were doing at the time. Man was I out in left field. Now, I wish I could gather up my first 50 guitars, build a huge bon fire and have a weenie roast.
I have always built guitars with above average tone and response but my skills for fit and finish took a long time to hone. In all honesty, my early guitars could barely compete with a $49.00 imported guitar in terms of fit and finish. I see a lot of new builders in the same situation that I was once engulfed in.
Don’t get into building with hopes of making a quick buck or to be on a skill level that you have not obtained yet. Your instruments will be worth where your skills are at the time. Be humble and willing to take constructive criticism from players and your peers. By swallowing your pride you will learn a LOT and your instruments will be the better for it. The finished instrument is your autobiography of sorts. What does it say about you?
Have a goal to build each guitar better than the last one. Try to build the [perfect] instrument although you will never attain to do so it should be a goal we all aim for. Build guitars because you are passionate about them. It is a wonderful experience to take a unique one of a kind natural resource, which God created and re-shape it into a stringed box that may inspire a player to create music with. In the end, it’s a fulfilling experience when Mary and I are able to set at the feet of someone who makes beautiful music with an instrument that we had a part in creating. Yes, lutheire can be a true blessing if we put our priorities where they belong.
©2009 Terence Tan.
Pictures courtesy of Tim McKnight ©2009 except:
Picture of Tim by Ellie Warmoth at Artisan Guitar, Franklin, TN.
Picture of Diamond Headstock by John Kitchen of Isimon Photography, PA.
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