Hi there all,
I'm pretty new to circuit bending and modding gear, but thought I'd come on here to ask a quick question before I destroy a classic toy!
I have a Grandstand Major Minor, and was wondering how to install a line out onto it. I've found a few schematics of this in various places, but am not too sure how to implement them (i.e. which wire to the speaker is the speaker ground? is there a way of wiring up to a jack socket so that when a jack is inserted, the internal speaker is deactivated?)
If anyone could give me a solution to this, I'd be very grateful - I'll make sure I post a quick sample pack when I get it all sorted out!
Cheers,
mouldi101
The easiest way is to just wire a jack socket to the speaker terminals. The speaker probably has a + and - embossed on it next to were the wires are soldered on. Ideally + should go to the jack tip and - to the sleeve / ground but it doesn't matter that much in most cases. If the output level is just too loud use this circuit to calm it down.
(http://www.epanorama.net/circuits/speaker_to_line.gif)
You can make the speaker cut off when you use the line output by using a switched mono jack socket in line with the speaker wires. When theres nothing plugged into the socket the signal goes straight to the speaker but when you plug in a jack the speaker is disconnected and the output switches to the jack output.
In some rare cases you might have to put a dummy load across the speaker wires when using the jack output if the speaker is disconnected, at which point things get a little more complicated, but this is unlikely.