Jerry Springer, input amp revisited

One of those small things I’ve been planning to do something about for a good while: the input amp of Jerry Springer, my DIY spring reverb unit.

Say hello to Jerry.

It wasn’t long after I completed the build, that the amp board blew up on me. Since the original build also included a “Direct In” that bypasses the amp (via switching jack), I simply continued using the tank by feeding it directly from one of the outputs of my AD/DA converter (the Behringer ADA8000). Sure, the signal levels weren’t anything good but the setup worked..

Macintosh Plus

A little personal history: Macintosh Plus, commonly referred to as “linnunpönttö” (birdhouse) in finnish, is a computer I got to test hands-on way later than it was released. By the time I did, Amiga 500 had been ruling the home computer hobbyist scene for years. Familiar with A500’s awesome capabilities the Plus (with it’s small gray-scale monitor) simply was, in comparison, a uninteresting relic.

Macintosh Plus. Photo by Wikimedia.

Fast forward ten (or so) years and I found myself looking at one in a second hand store. With a near yours-for-free-if-you-take-it-out-the-shop price tag, the Plus powered on nicely but came only with a keyboard (minus one key cap). The lack of OS disks and mouse made it pretty much a unusable piece-of-shit. Nonetheless, I took it with me and stored it away to wait for closer inspection. Then life had its funny ways, and the Plus sat in the basement waiting.. and waiting, right up until this august when I dug it up thinking “maybe it’s about time..” And here, we start to close in on this post.

There is a lot of info about Mac+ out and about the net. But as it often is with these retro systems, not everything is necessarily applicable or usable, or you’ll simply come across a bunch of dead links. One of my ideas with this post was to compact my findings and provide one usable solution for “how to get that damn can of worms up and running“. If you, like me, acquired a second-hand Plus with just a keyboard, this one is a definite read for you. Maybe you’ll have a little less grandiose mission getting your Plus back in action ;)

JBL C1 woofer foam repair

The woofer elements of my beloved JBL Control One speakers have been badly in need of foam surround replacements for ages and recently, I finally decided to take up the project. The foams started “decaying” many years ago, but by now they had already become almost but dust. Lightly poking any part of the foam, or moreover what little there was left, just made it crumble away!

The situation to boot with.

30€ re-foam kit from Ebay, a few items from the toolbox and the replacement project was a go!

Casio DG-20, fretboard

One last repair for the DG-20 before I can start considering breaking it in some other way! Any electronic instrument from the 80s is very much a excellent candidate for circuit-bending after all.. ;)

When I got it, the DG-20 had serious problems deciding whether a note was held on the fretboard or not. In closer inspection it turned out that a previous owner had attempted some kind of repairs on the fretboard. Like said, it’s too bad that this person had decided to remove the rubber mat by pulling it off from the fretboard instead of doing it properly, in turn tearing the mat into three slices. To illustrate the structure just for you (<3), I made the this fancy mspaint diagram:

Slice diagram of neck / fretboard

So in its original configuration, the rubber mat attaches to the fretboard with the bits wrapping around the PCB edges. Once this combination is installed to the neck (double-sided tape and two screws used on the PCB), the mat will stay nicely put although it’s not actually fastened with anything else than surface contact.

Casio DG-20, headpiece mech

Advancing with the DG-20 repairs..  Against my initial plan of “covering the rest of mech stuff at once”, the focus this time will be entirely on fixing the damaged headpiece mech. It turned out that some previous owner of my DG-20 has been kind enough to remove the fretboard rubber mat by tearing it off and attaching it back with some “hard plastic” type glue. Sooo.. because of this the rubber mat is in three pieces (instead of one) and there’s a neat glue mess waiting to be cleaned off the fretboard, all adding up to a bit of extra repair “fun” for me. Thanks a bunch.

These here are what this post is about, the DG-20 headpiece string tuning mech. A complete original part above and the damaged below it.