Post 25: Temporarily Sidetracked by a new Harmonica!

    I am still working on the bass, but I received a new harmonica from Germany a few days ago that got me into something. Basically, I found out a week or so ago that Seydel, the only old-time harmonica manufacturer left in Germany, and the only maker of steel reed harmonicas had come up with an instrument that could be re-tuned at will from Major to Natural Minor, Harmonic Minor, or even some odd tunings, using magnets:

     Since I prefer the Minor tunings, it seemed like a really interesting design that would allow me to experiment. It wasn't cheap, German-made harmonicas are more expensive than Chinese made harmonicas with a German name like Hohner, but I got excited and ordered it. It came all the way from Germany in two days. Honestly, I was a little disappointed at first, I suppose because I am not used to steel reeds. The sound is colder to my ear than the warm sound of brass reed, and there seem to be fewer harmonics. It's harder to play and take some getting used to. Also, I was not overly impressed with the tuning system. It does work, but the magnets affect the sound quality and are hard to adjust precisely, especially on the draw reeds. The whole thing seemed a little flimsy. I considered sending it back, but there was in the user sheet an interesting footnote saying:

     "The inspiration for designing the ALL MINOR HARMONICA came from Jim Antaki's Turboslide harmonica (>www.turboharp.com) where little magnets were used to alter the pitch of stainless steel reeds for the first time."

     So of course, I checked out the website mentioned:  TURBOHARP.COM

     And that's how I discovered that a guy named Jim Antaki was actually the "inventor" and had patented the magnet idea. I am not sure what the relationship is with Seydel, maybe they pay him a fee to use his idea, or maybe they made a deal since he uses Seydel Harmonica as a base for the "Turboharps" he sells.

    In any case, there are all kinds of interesting things on his website, including detailed drawings of his tuning mechanism, which is different from Seydel's. He mounts his magnets on the plate next to the reed and slides them over towards the reed. The magnets can be adjusted a bit vertically with an X-wrench :

    Seydel on the other hand has the magnets attached to the cover plates, and slides them diagonally over the reed. I felt like I would like to play with the idea too, and decided to keep that harmonica. Of course, I immediately took it apart to see exactly how it worked, and it is actually pretty simple: a magnetic field close to the reed slows down its vibration, and flattens the pitch about a halftone, allowing minor tunings. The magnet slides closer to the tip of the reed diagonally, and the player just tunes to a flat by ear with the sliders:

      As I said above, it does work, but frankly not all that well, especially on the bottom draw reeds, presumably because they are on the same side of the reed plate. Could I possibly take off with the idea and do better? I do like challenges after all! 

   

Post 24: Making the 12 Strings Bass 3

    After some tests on the backside of the 2x4, I gave up the idea of drilling holes larger than 1/2". But I placed them close together and staggered in 3 rows. I cut out most of the back, leaving just 3 crossties. I have a piece of 1/8" padouk that will make a nice lightweight cover plate. 

    I quite like the final result:

      It turned out easier than I thought to drill 6 holes through the body into the neck. I have temporary screws holding the thing together, that will be replaced by 4"+ through threaded rods with brass acorn nuts. 

      I ordered some brass/gold pickup covers, and some steel pick up plates. They were of course way too shiny for my taste. It actually took a lot of sanding to remove multiple layers of gold, nickel, and copper plating. Also, the brass covers were too small for my pickups, so I had to stretch them a bit and sand the plastic on the sides of the pickups to make them fit, but they came out looking great.

      To make the bridge adjustable in height, I made a 1/4" aluminum plate and fitted (barely) two of my 1/4" knurled brass screws. Two rod-piezo pickups will go between the aluminum plate and the brass bridge. 

     Time to assemble things and see if everything fits as planned. Final assembly with the nut in place and the strings tight will tell, but it seems that the bridge will probably need very little adjustment for the strings to be at the proper height above the fingerboard and the big frets I will be using. I might actually make the nut adjustable too. 

      The acoustic guitar PreampEqualizer is a tight fit at the end of the 2x4, which will be cut with the matching curve. The pots will get large knurled aluminum knobs. I am well pleased with the look:

         Now, putting the strings on this thing turned out to be quite a challenge, as both the anchor block for the strings at the head and the tuning system at the bridge gave me problems. I finally got all strings on and tuned to test it, and it works fine, but I am going to have to do some more work on both. 

       At first, I only used two M3 screws to attach the brass strip holding the tuning screws to a slanted aluminum base, and they were pulled by the tension of the 12 strings, so I had to modify it and use four screws with washers and nuts.  After full assembly and stringing, I could see the slanted plate was too narrow and too slanted, and I will replace it with one that supports the 12 small brass string holders.

       At the other end, my hard steel tightening screws ended up breaking a number of strings, and I had to use small pieces of brass rod as fillers and spacers.  They had to be tightened very hard, and some threads stripped. I rethreaded bigger, but that doesn't look so good.  Also, I never managed to get out the small drill bit I broke in there and had to drill another hole next to it. The entire brass anchor block system needs to be redesigned and modified to be gentler on the strings. I should probably add a cover to hide the ends of the strings;  unless of course  I just snip them really short.

Post 23: Making the 12 Strings Bass 2

   Well, I had a (maybe) better idea. I have laying around a couple of long aluminum 2x4's I used in the construction of my house 20 years ago. They are very thick and very rigid, but also very rough from construction use (and abuse). It's OK though, I don't mind a few "scars" left from a hard life after I sand and polish them as best I can. 

    So I cut notches in the neck for the two pickups and bent it. I then cut a piece 20 " or so, and notched it to fit one end of my long neck. It took quite a while to get that properly fitted, as the walls of the 2x4 are 1/4" thick. The neck will be attached with six 4.5" long through 1/4" bolts and brass spacers.

        That chunk of metal is heavy and needs to be tightened while keeping its rigidity. I could drill a bunch of large holes on the side and back, but that would be very time consuming, and I am not sure the result would be satisfactory. So I chose instead to cut most of the backside out leaving just three half-inch wide ties. It can be covered with a lightweight aluminum plate. The top needs a cutout for the pots and jack plate. The sides could still possibly be drilled, but with a bunch of smaller holes. The largest drill I have is 1", and I will just have to try and see if I can drill neat enough holes.