Forster oddball archtop

[Greg McKnight]

After reading the PDF it would appear that he consciously traded some acoustic volume for extra sustain knowing full well that the instrument was going to be amplified. I'd suggest that eliminating feedback potential was a secondary motivation. I'm a little surprised that the price of this instrument isn't part of this discussion. The original video stumbled over it incoherently but I think I understood the price as being north of $30k. That's Parker territory...

Those things are $30k?!?! I'm sorry but that's as ridiculously overpriced as anything I've seen.

Just to clarify, I was shocked at the price of a Parker archtop, not the Forster.

[michael o'malley]

I've started building a gut-level version of this. Keep in mind I've never built an acoustic guitar. I have a mold built, and am working on bending sides. So far I have one lightly figured maple side bent. The second, with the cutoff, Is proving to be really difficult. Top will be a piece of spruce I bought years ago. Back will likely be cherry.

I've made a neck blank, using figured flatsawn home depot maple. It was very floppy so I added two graphite stiffening rods. It has a truss rod for a bass, running almost the full length of the neck. I had a 25 inch scale ebony fretboard I bought a decade ago and never used that I've glued on. It will use a very flat pickup, probably one of those lace acoustic pickups that are 1/4 deep. I'm thinking of a parker style headstock.

To cover the truss rod beyond the neck I used a piece of a richlite cutting board. I like this stuff a lot and in the future I'll use it whenever I want an ebony like-board. it's dense and uniform but machines really well--it plains easily and glues up readily. We've had three in use as cutting boards in our house for about five years now, and if it can survive daily cycles in the dishwasher and use as a chopping and cutting board I think it will survive as a fingerboard. Whether it works as it's being used here--as a relatively thin cover for a truss rod--we'll see

[michael o'malley]

So if anyone is interested I have the guitar semi finished. The body is roughly carved--no recurve carved yet--and the neck is attached but not carved and the bridge saddles aren't cut, nut finished etc. Since the pick below I've added a binding and shortened the neck. But here is a clip of the raw acoustic sound, recorded with a ribbon mic about four feet away:


http://chnm.gmu.edu/courses/omalley/archie%20raw.mp3

Keep in mind several things

1. It's not done--the recurve and final sanding haven't been done yet
2. I've never built an acoustic guitar before in my life and have no idea what I'm doing
3. the neck is still a rectangle

It's not loud, but I didn't expect it to be. The guitar resonates reasonably well without the bridge inserted under the neck. With the bridge inserted it's variable according to how much pressure is on the top. I'm looking forward to messing around with it some more

[michael o'malley]

I'm surprised there's not more interest in this. Even with my complete lack of skill and experience I think I ended up with a viable sounding archtop. I haven't been able to try it out amplified yet--I'm waiting on the pickup--but this is definitely a interesting and practical way to build a guitar, and it seems like a real innovation to me. I made a recording and posted it to you tube, just the guitar being played on my porch., There's a little bit of tremolo caused by the porch fan, but otherwise this is what it sounds like, played with a pick in this case


https://youtu.be/mHoxGLMyTgE


Since I recorded that I made a slightly larger, thinner bridge, which i think improved the tone some. If I knew what I was doing I'd work the top some more.

The advantages of this kind of design strike me as being mostly in the modularity--I can take the neck off and with the strings at pitch, and finish the body and neck separately.

[Bob Francis]

I really like this one Mike

[Randolph Rhett]

I'm surprised there's not more interest in this.

I'm not. Archtops have a limited market and in my limited experience there is little appetite for anything unusual or innovative. This comes from a guy who makes archtops with a carbon fiber soundboard, so it's not because I'm a traditionalist. Ken Parker makes an archtop with the action adjustable at the neck and he apparently sells them for 30k. Otherwise people seem to want a Gibson ES335, or maybe a Gibson ES175, or if they are really into archtops they want a Gibson L5. "What kind of Gibson did you make?" "Why doesn't it look like a Gibson?" "You want how much for it? I can get an Epiphone for a lot less."

I'm not sure I see an obvious advantage to this guitar, but even if there was one I still think there would be much interest. Don't let that stop you from experimenting and exploring, though. Especially if this technique speaks to you. I wouldn't keep making guitars if I had to make one Martin dreadnought clone after another.

[michael o'malley]

I'm surprised there's not more interest in this.

I'm not. Archtops have a limited market and in my limited experience there is little appetite for anything unusual or innovative. This comes from a guy who makes archtops with a carbon fiber soundboard, so it's not because I'm a traditionalist. Ken Parker makes an archtop with the action adjustable at the neck and he apparently sells them for 30k. Otherwise people seem to want a Gibson ES335, or maybe a Gibson ES175, or if they are really into archtops they want a Gibson L5. "What kind of Gibson did you make?" "Why doesn't it look like a Gibson?" "You want how much for it? I can get an Epiphone for a lot less."

I'm not sure I see an obvious advantage to this guitar, but even if there was one I still think there would be much interest. Don't let that stop you from experimenting and exploring, though. Especially if this technique speaks to you. I wouldn't keep making guitars if I had to make one Martin dreadnought clone after another.

Yes musicians and guitar nerds are incredibly conservative. It's remarkable. I love the idea of a carbon fiber top--every time I see somebody talking about "old growth spruce" I think about deforestation. Do you have any links to your work?

The primary advantage of this design to someone more skilled than me would be the way you could design the top. It doesn't have to bear the pressure of the strings. You could carve/ brace it very lightly, assuming very little pressure, and you can make the pressure adjustable. If you like light strings, for example, you can play with light strings but have the tension on the top you'd get from heavy strings. Or the other way around. I notice significant differences if I move the bridge slightly, and that's interesting.

[Randolph Rhett]

I don't want to highjack your thread, but you can see one of my arch tops at a different forum. Is posting a link to a different forum allowed?

http://luthiersforum.com/forum/viewtopi ... 01&t=45742

In any case, I chose CF because of what you said about clear cutting. However, I also thought it would make acoustic sense. I've played a LOT of guitars over 30 years of playing, so I feel I know what I like in an instrument. My luthier skills are way behind, I've only built about 20. Most of my experiments result in guitars that are OK at best, and probably not much of an improvement over the state of the art. No so with this one. I LOVE the sound, I love the playability, I'm thrilled to death.

I've had some great responses from musician friends, but many were very skeptical until they played it. One very good friend practically refused to play it because it wasn't traditional wood. Now he wants to borrow it for a recording session. I've also had other responses from the general public including, "why did he paint that black?" "Is that a carbon fiber decal?" "Why didn't he make the neck carbon fiber?" "No thanks, I want a real guitar" and, "Can you make a three humbucker version?"

My point being that radical design departures don't elicit the kind of excitement in the archtop world that they do in, say, the electric guitar world. I suppose people interested in archtops tend to be traditionalist in the first place or they wouldn't be interested in an archtop.

[michael o'malley]

Well it's more or less finished except for the pickup I'm waiting to get in the mail.

For skeptics, below is an acoustic sound comparison--my blundering forster style effort and my 1978 Guild Artist Award. Both recorded with a Shure Sm44 about three feet away, with identical amounts of reverb. Both with Thomastik flats, although the strings on the Guild are months old

http://chnm.gmu.edu/courses/magic/guild.mp3

http://chnm.gmu.edu/courses/magic/forster%20style.mp3

[Randolph Rhett]

The Forster sounds very tight and brittle, but I think that may be more of a function of the top than of the unique construction. I am amazed at the volume. Both are recorded with the same levels, I assume?

[michael o'malley]

I might have had the level slightly up on the Forster, but they were within a few db


Here's a short clip of the Forster style with a pickup, recorded direct into the computer, no amp, a little reverb


http://chnm.gmu.edu/courses/magic/archpickup.mp3

[Jason Rodgers]

Your attempt on this design looks good. Good job on finding something you like and going for it.

I won't comment further on the mechanics of this design, but aesthetically, I personally find the sound hole on both the original and yours to be a little odd. I'm all for non-traditional shapes and locations, but this just doesn't work for me.

I dig the headstock, though.

[michael o'malley]

My wife told me she really liked the soundhole! Go figure. This was a first effort for me and there are a number of things I'd change


Here's a clip of the guitar played through a ZT Amps Lunchbox

http://chnm.gmu.edu/courses/magic/archpamp.mp3

Flaws in my playing aside, I feel like this guitar has a really excellent amplified tone, and that its enough like the tone of the guitar in Forster's clips that it confirms the value of his design

[Jim Kirby]

So, I'm wishing I had more CAD drawing skills to illustrate what I'm thinking...

I'm imagining a bridge assembly where the bridge is resting in an insert in the neck that is floating in an opening in the neck and bears directly on the top, and which is free to adjust vertically relative to neck position, but can't rotate due to the fact that it's sticking through a slot in the neck structure. It is, however, resting directly on the top, and transmitting the entire vertical load from the string break over the bridge to the top, and it's doing so regardless of any other adjustments of the neck angle to account for action.

This would eliminate the problem of the bridge saddle resting on the neck assembly which is then, in turn, jacked up on the body some how.

I need to see if I can hand-sketch a picture. Frantically busy these days, though.

[michael o'malley]

If I'm understanding you right I'm not sure what the advantage would be. The strings press on the bridge which then press on the top? It's sort of what this design already does, I think?

[Jim Kirby]

I'm thinking it would be a little more independent, going back to something more like the mechanism of a regular bridge with tailpiece, but with the tailpiece just replaced by the end of neck. But I've never built even a conventional archtop, so I'm just speculating.