Monthly Archives: February 2011

Rehousing a Danelectro Coolcat Vibe

Why bother doing this at all?

Bad knob positioning on the Coolcat Vibe

Bad knob positioning on the Coolcat Vibe. Who thought of that?

Take a look at the picture on the right; that’s the back end of the stock unit. While this device sounds great once you get it dialed in, it’s almost impossible to interact with it while you are playing. While I’ve never thought about it before, it seems that I like to see where my controls are when I’m playing. Perhaps it is akin to driving a car in that even though you might be just cruising along, you still want to be able to glance down and see what speed you are doing. So when you’re tinkering with the vibe’s controls you just can’t see anything because it’s all hidden.

Secondly, the big switch isn’t quite perfect. I’ve become accustomed to the basic switch that every custom builder knows and loves. This one doesn’t seem to switch effectively unless the force you apply is perfectly in line with the axis of travel of the switch.

Thirdly, it’s a really ugly box.

Preparations

I knew I would have to replace a few parts here and there. Here’s what I bought:

  • Potentiometers. I saw from this post that I needed 2 x B50k pots and 1 x C 50k pot. I found 16mm Alphas at Mammoth Electronics, who I had been wanting to try since a recommendation from Shawn over at DIY Effects.
  • DC power connector. The existing one is square and I don’t have an square drill bits.
  • 1/4″ jacks. The existing ones are probably crappy PCB mounted ones.
  • An enclosure. You can get a painted and drilled enclosure from Mammoth for $10. At that price why would I ever do this myself? When I tried it for my first ever pedal build it was messy, time-consuming and ultimately I was not pleased with the results.

Coolcat Vibe - in pieces ready for rehousing

Coolcat Vibe - in pieces ready for rehousing

Disassembly

This part was easy as I could use normal tools, so it only took five minutes. It’s a shame really; this enclosure is really well made, and would probably stand up to a considerable amount of abuse. If only they had located the knobs in a useful place (and it didn’t look like a clam).

The coolest part was finding a ‘real’ 3PDT switch underneath all that cast zinc. It fit the pre-drilled hole in the new enclosure and it seemed I would not have to bother removing the small PCB that it was soldered onto.

Still functioning, sans enclosure.

Still functioning, sans enclosure.

At all stages in disassembly/assemblyI wanted to make sure I didn’t break anything, so I made the effort to plugin and power up the device.

Mounting inside new enclosure

Mounting inside new enclosure

Assembly

The first task was to isolate the power supply jack, and the input/output jacks. You can see that the jacks are PCB mounted, and there are thin shield wires going between this PCB and the switch PCB. I chose to use those wires, and simply solder them to the appropriate replacement parts. At this point I was able to mount the switch and the new signal jacks into the new enclosure, and test once more. So far, so good; I haven’t broken it yet.

One by one the pots get replaced 'off board'

One by one the pots get replaced 'off board'

The next stage was to replace the pots. I had a feeling this was going to be painful, and I was not wrong. Over recent months I’ve replaced many a component in my amplifiers, and other pedals, but I’ve never dealt with PCB mounted potentiometers. What a terrible, terrible nightmare. I fully understand that they are designed this way so that untrained monkeys can assemble the boards, and then they slap some molten solder underneath and its done. After all, I did buy this device for $40 online,so you can imagine that its out-of-factory price is probably closer to $5. But it makes repairs very hard indeed. I managed to cook one leg of the first pot, which meant the PCB trace lifted from the board. Nothing that super-glue couldn’t fix though. My technique of removal was using a solder-sucker. It wasn’t very efficient as the suckers nozzle is quite larger compared to these component legs, and it was hard to keep the sucker ‘focussed’ on the leg AND hold the soldering iron in place. I was more careful with the other 2, so they went more smoothly. And when I say ‘more careful’, I mean I desoldered as much as I could with the sucker and some wick, and then mechanically pulled the pots off the board while trying to keep their solder molten. I know, I know.

The tabs that hold the LDR/Bulb enclosure in place.

The tabs that hold the LDR/Bulb enclosure in place.

Potentially the most treacherous part was rewiring the LED. To get to the soldered legs I had to take off the little metal box that enclosed up the light bulb and LDRs (light dependent resistors). Here’s a great article all about the inner workings of a classic Univibe.

The bulb and LDRs in action!

The bulb and LDRs in action!

You can see in the picture to the left, that there are three metal tabs surrounding the blue LED. All I had to do was gently bend those perpendicular to the board, and the box came right off revealing the bulb. Of course I couldn’t resist powering it up again, just to see the bulb working. In the picture you can see that there are two solder points above the bulb; these are for the LED indicator. Once again I had to carefully de-solder these, so as not to de-laminate the traces. I then attached wires, and connected a bright blue LED in its place.

Enclosure finished

Once I’d mounted the LED in it’s little bezel, I was basically done. I had to make sure I put the metal bulb enclosure back in place, of course, but all that was left was to tighten up any mounting nuts, and close up the box. Here’s a shot of the newly rehoused Coolcat Vibe next to my also-recently-rehoused DIY Effects OD (fantastic Tubescreamer clone).

The finished item...so far

The finished item...so far

An idea

I suddenly had an idea to make this rehouse a little more interesting. In other words, I looked at my vibe and the DIY Effects OD, which I had also rehoused (the green one, duh), and thought they looked somewhat plain. I’m basically proficient with publishing/layout-tools, so I thought I would try and create a decal for the top of the units. I took some basic measurements, and setup grids and guidelines, and just kind of went for it. Sadly I cannot find my decal paper (must buy some more), but I did do a basic printout onto photo paper. This is a work in progress, so updates to follow when I do finally buy some decal paper. The real one would not have the yellow background obviously. I can turn that layer off when I print so that it’ll be transparent, but you get the idea.

A mock-up of the decal

A mock-up of the decal

Advertisements
Tagged , , , , , , ,