I made sure to procure a functional unit and upon plugging in the unit, the volume adjustment was fairly scratchy sounding and needed some new potentiometers. So I figured I'd tear down the unit and see what could be improved while I was in there. The old pots were CTS VRS-100K-70S that also had a power switch built in that activated when initially turning the knob.
|Scratchy old CTS Potentiometer needs to go|
Also on the chopping block were a couple of questionable looking capacitors that had began to bubble.
Unfortunately, while CTS is still in business, they no longer build that particular pot. So, I decided to fit brand new Alps mono Blue Velvet pots. These did not have a built in power switch, so a toggle switch was fitted (at twice the specs of the original) that could be mounted on the back of the unit. I opted to replace all easily reachable capacitors with new ones of the same specs or higher.
|Alps Blue Velvet Pots for volume and tone mounted|
The driver in the unit was a very low-cost oval paper cone speaker that had begun to flake. This prompted me to remove the unit in the interest of replacing it with another. The spec of the original speaker was 12 ohms, so one could fit 2 six ohm speakers in series or a single 12 ohm speaker. I decided to fit a single 12 ohm circular speaker, and settled on the 5" Audio Galaxy S5N-12 Neodymium full range driver. This unit is likely overkill, but it was unlikely that the Town Crier would be opened up again anytime soon, so might as well go with something nice that would last.
|5" Audio Galaxy S5N-12 Neodymium full range driver|
Finally, the power cable was a typical lamp cord that you'd find on just about anything from this period. I opted to use higher quality 16 gauge silver plated copper in teflon wire in a twisted pair configuration which was then covered with black nylon for a vintage look.
|The new 16 gauge power cord|
Here's some photos of the re-assembled unit below:
|Guild Town Crier Front|
|Guild Town Crier Back|
|Guild Town Crier Open|
Now it's ready for a a few more years of service :)
The Fine Print:
Please remember that building circuits and performing circuit modifications can be dangerous to you and/or your surroundings and should only be performed by a certified technician. The owner of this blog and all associated parties can not / will not be held responsible if you attempt a build or modification posted above and cause physical harm to yourself or your surroundings. Many electronics contain high voltages that can kill, and mods, if performed improperly, can be a fire hazard. Please keep this in mind.