Fishman Loudbox Mini has Defective Tolex from the Factory

This Fishman Loudbox Mini is about a year old. The owner loaned it out, and when she got it back, the covering was in tatters. Could The Unbrokenstring Crew do something?

.

Fishman will give you a Return Authorization to return these little amps back to the factory, at your expense, and another unit would be returned to you. With supply chain issues, no stock at the factory, and not really wanting to be without the amp until a replacement became available, the owner decided to have it recovered locally.

.

What was really irritating was, whenever you picked up the unit, the space under your fingernails would fill with this rubbery ‘stuff’ that was shedding from the original covering. This is particularly annoying for finger-pickers with long fingernails.

.

To make matters worse, the owner would have to vacuum up little bits of covering two or three times a week in her apartment, and her car and the stage at church was always a mess after she used her amp.

.

The first thing we did was remove the feet. The old covering stuck to everything!

.

The handle bolts hold down this wooden stiffener on the top of the unit. Off it goes!

.

This little hex bit is used to remove the bolts that hold the electronics in the chassis.

.

Six bolts hold the chassis in the body of the cabinet. The unusual style of this cabinet will make the job of recovering the unit a little out of the ordinary compared to the usual Tolex job. Along the edges, both sides as well as the edge will need to be covered, with closely-matching seams.

.

I’ll take a few pictures to show where the wire harness connects. These are polarized, but it is possible to swap a couple around and cause who-knows-what havoc.

.

Power to the board comes from a power transformer inside the cabinet. The secondary voltages come through this cable.

.

This is an audio connection from the front panel. We don’t have to remove this, but I snapped a picture just in case it came loose later.

.

The front grille is held in place by three screws, almost hidden inside the electronics compartment.

.

The grille tilts away from the cabinet, but is still held captive at the bottom somewhere.

.

This little tab fits in the slot cut into the cabinet. We need to keep track of this slot lest it be covered with Tolex and forgotten.

.

The inside corners, next to the control panel, are covered with these little plastic corner covers. Naturally, the sticky covering is all over these corners. A neat little feature of these corners is, some of the seams of the original covering come together under these corners, and are hidden from sight and protected from damage.

.

These corners need to be cleaned up. Heat is not an option, as the plastic will probably deform. Most chemicals will likely attack the plastic.

.

A little old-fashioned elbow grease is applied to break the adhesion between the old covering and the plastic. It rolls off slowly, with this electricians’ screwdriver.

.

Once the posts are cleaned, this can be set aside, ready for reassembly later.

.

While we are cleaning up hardware, every item that touches the old covering requires cleaning. Here we are cleaning under the heads of the machine screws that hold the electronics in the cabinet.

.

Little washers under the heads of the screws that held the power transformer are particularly sticky. Here, we are using a sharpened edge of a popsicle stick (excuse me, they are called tongue depressors nowadays) to scrape the goo from the washers.

.

Even the edges of the hardware that holds the handle strap to the unit is messy.

.

We now turn our attention to the cabinet itself. We will remove the loudspeakers and keep them in a safe place while we work on the cabinet itself.

.

As with most Tolex removals, a heat gun is just the thing for speeding the process along. This is a paint stripper, run on the lowest setting.

.

Once an edge is heated, the old covering can be pulled away from the cabinet material. Here we go!

.

The cabinet is sealed particle board, giving us a good surface to support the new Tolex.

.

The old covering is shedding each time we handle the cabinet. What a mess!

.

Now, we’re starting to get somewhere! Note that the aluminum tape shield around the electronics has been peeled back, so that the old covering could be completely removed.

.

To re-Tolex the small panel under the handle, we are arranging to have all the edges meet at the screw holes, so that the pressure of the handle screws can secure all the edges. No over-lapping of Tolex is allowed anywhere, because of the tight tolerances between the existing cabinet and the pieces that fit into it (the electronics, the grille, and this panel.)

.

One side of the cabinet is done. Here, we are opening up the holes before we forget where they were.

.

Once the sides are covered, a simple rectangular strip covers the top, back, and bottom. But rather than get contact adhesive on the new Tolex, we will mask off everything, starting with these inside corners.

.

I don’t think that it will be a deal-killer if adhesive is accidentally smeared on the speaker baffle, but my obsessive/compulsive disorder forces me to do it anyway.

.

The blue tape indicates the start and ends of the last piece of Tolex to be applied. It wraps around the bottom, back, and top of the cabinet.

.

The masking tape must conform to the Tolex already installed to prevent any wicking of the adhesive, so this brush pushes the masking tape into the contour of the new Tolex.

.

This corner, at the bottom, is the fussy-est edge because of the small geometries involved. The contact adhesive on both the Tolex and the cabinet must be completely sticky and dry to hold this thin edge down. Here, more masking helps control the spread of adhesive on the bottom of the cabinet.

.

I took a clear picture of the bottom before the Tolex was applied, because I will need to find those holes again, for the feet as well as the power transformer.

.

And this is why we need to mask off the edges. The disposable brush works well, but it’s a little hard to control near the edges. The white stuff is the contact adhesive.

.

When the adhesive is dry, it turns clear. A little heat will help speed the process along where I put a little thicker layer of adhesive on the cabinet.

.

Here is the top and the right side of the covered cabinet.

.

Here is a view of the back and bottom of the recovered cabinet. This is starting to look nice!

.

The power transformer is bolted to the bottom. Remember those little washers that we were cleaning up earlier? They go here.

.

The clean feet are returned to where they belong. Note the pink eraser; It’s just the thing for cleaning up spots on the new Tolex where adhesive leaked under the masking tape. It rolls right off, without a trace.

.

The tweeter is mounted back where it belongs. The wiring is polarized so that we don’t need to worry about + and – connections on either loudspeaker.

.

The other loudspeaker is reconnected and installed now.

.

Remember the slot that holds the tab on the grille? This is it.

.

This is a better view of the tab/slot system.

.

The tab goes into the slot, and the grille fits tightly against the new Tolex.

.

You have seen this before, from another angle. Three screws hold the grille in place.

.

A grounding lead on the electronics is attached to the aluminum shield inside the cabinet, as shown here.

.

These big screws hold the electronics in place. Recognize that little hex bit I showed you earlier? Here we are again!

.

Two screws hold the handle and the rectangular spacer in place on the top of the cabinet. This project is all done!

Thanks for reading all the way to the bottom!

CONTACT – David Latchaw EE
281-636-8626