Cabinet Restoration

Nov 22, 2015
Cabinet Restoration

  • Introduction (top)

    To restore or not to restore, that is the question. This is always a troubling question. I ask myself if an amp has survived so many years in its current state, should it be changing it? Restoration means restoration, or does it? How far should a restoration be taken? Should the amp or cabinet be modified? With some amps, deciding what to do is easy. The owner wants the amp to look as great as it sounds. But there are often difficult questions that have to be asked and answered. Should the chassis be modified to add a jack or mount a can Capacitor. Should upgrades be added such as a Speakon connector. What about safety issues, should a three conductor power cord be installed. If the cabinet is being re-tolexed, should the vinyl be applied in the same way as it was originally or is there a better way to do it. Time is also an important consideration. Cleaning an amp cabinet can take a day or two, with a restoration, it can take months to get the amp back in service. There is a lot to consider.

    I think that the answer depends on the amp, the budget, and how much time is available to perform the work. Some collectors want a functioning museum piece. In those cases, even re-flowing a solder joint can upset some people. But amps need a certain amount of maintenance to keep them working. It is better to have an amp that works than one that just sits in a corner and can't be used. In the normal vintage amp market, basic changes that address safety issues such as a three conductor power cord, or changing electrolytic capacitors or other components so that the amp is functional does not affect the value. In fact, it is considered a plus. As long as the amp can be restored to original condition, this will not be an issue. Amps that are museum quality pieces owned by collectors who want them functional are a different story. In these cases, if you change a component such as a Capacitor, you want to source a NOS part that is the same as the original. Some parts such as jacks are still in production and if the quality is the same, that's a plus. Replaced potentiometers and other components with date codes should match the dates of the original ones. Reproduction parts such as knobs are not the same as the originals. They look similar but are made out of different materials. Rebuilding a transformer is labor intensive and can cost hundreds of dollars. If the vinyl has edges that need to be re-glued, the originals used hide glue so that should be done. A restoration to completely original condition can be achieved with NOS parts but it can be very, very, expensive and time consuming to track down the parts. Sometimes it takes years to stumble onto elusive parts.

    Fortunately, most restorations do not call for that level of attention to original detail. Some people want to completely redo the amp, others simply want to Clean it up a bit. A host of good quality reproduction parts are available. Many are from manufacturers that are making reproduction amps. For example, reproduction transformers that meet or exceed the original specifications are more cost effective. Enhancements such as modern speakers are available that can make the amp perform even better. For those that take pride in their amp and want to transform it from road worn and looking as good as it sounds, affordable restorations are very doable. There are still a lot of decisions to make. The journey, the creative thought process, and the technical challenges are what makes this type of work interesting. It never gets stale and there never seems to be an end to new challenges.

    Old cabinets can be a little Funky and tend to come with many challenges. Fortunately, anything can be fixed.

    The list of potential problems include:

    • peeling, torn, or missing vinyl on the cabinet or the amp tray
    • can't pass the smell test, if a cabinets smells musty or of smoke, or a pet has been using it as an outhouse, the vinyl should replaced
    • over Compressed foam gasket around the lid
    • latches that don't pull the cabinet lid down tightly enough allowing Air leaks
    • cabinets that leak Air at the joints and cause vibrations
    • missing rubber seal over the hole where the dolly attaches
    • damaged vibration isolators that attach the amp tray to the cabinet lid
    • rusted, missing, or damaged cabinet hardware
    • internal damage to the cabinet that requires repair or re-staining
    • wavy plywood surfaces
    • finger joint issues
    • missing wood in the form of splinters, dings, chips, and gouges that require filling or patches
    • over Rounded or damaged edges and corners
    • wood rot and mold
    • cabinets that are out of square makes aligning the check vinyl covering difficult
    • Loose internal plywood laminates that will vibrate if they are not stabilized
    • protruding nails that need to be seated and filled
    • screw holes or holes from the metal corner nails that need repairing
    • Damping material on the inside back wall of the cabinet
    • damaged or missing dolly
    • modified speaker connector, wiring issues
    • warped or Loose speaker baffle
    • damaged speaker
    • loose, torn, or Dirty grille cloth
    • disintegrated foam under the grille cloth

    Clearly, a through inspection is required when evaluating what work should be performed on an amp. An amp that was built in the 1960's is around fifty years old. It isn't uncommon to find that most of the items on the list typically need to be addressed.

    Restoration Photo Essays (top)

    It's important to document your work. Photo essays are an invaluable way of keeping a record of not only an amp's original condition but the details of how it was put together. Reviewing how the original tolex was applied, for example, can help when planning how to reapply the new tolex. Even better, have a detailed record can help enormously with future projects. When you look back, you wonder how you managed to do certain things. Reviewing detailed records can make a big difference. I find it very helpful to keep both a written and a visual record of what I've done.

    Clint's (stiles72) 1963 B-15N Restoration (top)

    Clint's 1963 B-15N is the classic double baffle cabinet. This is the design that got everything rolling and is found in Jess' early revisions of the B-15. This is the cabinet design that Loud adopted for the Heritage line of B-15's and is also the one that Mark Gandenberger offers at Vintage Blue.

    Clint's B-15N cabinet restoration photo essay is presented here: 1963 B-15N Restoration

    Roberto's (xoir) 1966 SB-12 Cabinet Restoration(top)