Yamaha BB300

Discussion in 'Hardware, Setup & Repair [BG]' started by Cristo, Oct 20, 2005.

  1. Anyone with one of these old guys replaced the tuning machines? If so, what did you use as a replacement?
  2. Jascal


    Oct 18, 2005
    I am a noob to all this, so don't confuse me with an expert. This is what I chose to do, nothing more.

    I recently replaced everything on a BB300, including the tuning keys. There were 2 different types of machines on the bass, one was a clover type, and the other 3 appear to be original. The original looking keys were pitted with small rust spots and I decided to replace them all.

    After searching around the internet, I chose Hipshot HB-2 machines. When I removed the existing keys, I found 20 holes, none of which could be used with the new tuners, so I filled the holes in before I did anything else. Almost every hole would be covered by the new tuners, but I wanted to fill and seal the holes to minimize humidity and other contamination, including wee tiny spiders who might like to make the holes their home. *chuckle*

    I used some bass wood (left over from RC airplane kits, toothpicks would probably do just fine) and made small pegs which I hammered in each hole. Once seated, I shaved them flush with a sharp XActo and sealed them with a tiny dot of water based polyurethane. I dont know what the existing finish is, and all I wanted to do was seal the wood, so I covered the fill wood and no more.

    When I removed the bushings, I found the new bushings were entirely too loose, and would not work as-is. I read some of the repair sites and the solutions I found were based on adding some kind of material to the holes. Using cyanoacrlate seemed most common, but my experience with CA is that it suffers from being brittle over time. I decided on a novel solution, I used a ring of aluminum tape wrapped around the new bushings. This gave sufficient clearance corection and the new bushings were tapped snugly into place.

    I placed all 4 machines on the head and estimated their placement and tried to anticipate problems. I found that the gap between each machine was a little less than 1/16th inch. Then I attached the first machine, trying to keep the key shaft projecting perpendicular to the edge of the Fender-style head. Once it was in place, I fit the second. I made sure the ~1/16 in gap was made, and tried to get it exactly parallel edged to the first. I recommend drilling one pilot hole, screwing it o tightly, and then drill the 3 remaining holes as this gives the best chance to keep symmetry and position.

    I am really happy with the results, but I may have done things wrong... feedback would be appreciated as I am a raw noob to this stuff. Other things I did include replacing the bridge and electronics, including the pickups. I didnt pour much money into the bridge, it is just a basic P bass type. I chose to install the SB-3 Quarter Pound pickup, and found the pickup hole pattern was identical, but the pickups have a gap around them. The gap is mimimal on the sides, but the ends where the screws are the gap is approximately 1/4". My long term solution is to fabricate a cover to close the gaps until they are barely there. Mainly for looks and keeping crud from accumulating in the cutouts.

    Another change I made for the pickups was replacing the rubber hose tensioners with a slab of high density foam rubber, about 1/4" thick. These gave excellent tension for adjusting pickup height.

    Before I replaced the pots and jack I lined the bays with aluminum as Faraday cage noise isolation is at least good theory, perhaps unnecessary, but with the sea of EMF in my house why not do it while it was easily done. I also followed the Guitar nuts process of eliminating ground loops, paying close attention to the small differences in the S-D pickup circuit from the myriad of "P-Bass circuits".

    The bass plays just fine, and the only sad part is that I don't really know what it sounded like before, and can't appreciate any improvement directly. I read about the Yamaha BB300 and decided it was worth the modest cash spent on better parts. Again, feedback would be appreciated!
  3. Very interesting! You did a lot more than just tuning machines...

    This was my first bass, and although I have moved on to a Fender Jazz as my main bass now, I'd like to keep this as a backup, and maybe it will occasionally make an appearance as a more P-bass style instrument.

    Problem is, one of the tuners completely broke off.

    The main thing - I'm guessing that the center post hole diamter was correct for the HB-2. I'm sure the mounting screws wouoldn't line up, since the Yamaha tuners only have 3 screws.
  4. Jascal


    Oct 18, 2005
    The center post dia was correct, but the O.D. of the bushings themselves was a loose fit in the wood. If your bushings are good, leave them, and simply replace the rest of the machine.