How to turn my line out into an external speaker out?

August 30, 2008 6:06 AM

Wiring/music equipment question: I have a fairly cheap 30WVox guitar amplifier with a phone/line out jack on the back. When I plug something into the jack, sounds stops coming from the amp's speaker and starts coming out of whatever I plugged in instead. However, I would like it if the sound would come out of both at the same time. How easy or difficult would it be to rewire the amp so that it works this way? I'm good with a soldering iron, but not too great with circuit analysis.
posted by donkeymon to technology (4 answers total)

I know nothing about rewiring an amp like this, so what I'd do if I were in your situation is I'd ask the guys down at my trusted guitar shop to do it for me. In your case maybe you could even just ask them for advice about how to do it yourself if you it's going to cost too much or you want to do it yourself. Hopefully someone else can give you a better answer so you can do it yourself though.
posted by atmosphere at 6:20 AM on August 30, 2008

You could direct mic the amp, a la Bluesbreaker era Clapton.
posted by the cuban at 7:25 AM on August 30, 2008

I'm unsue what jack you are talking about. Line out is normally RCA connectors but they will not shut of the internal speaker. Is it an headphone jack like THIS then it has an internal breaker in the connector on the amp side and you can very simply disable it by either bridging it or move the wires (soldering required for both).
posted by Ferrari328 at 8:33 AM on August 30, 2008

I think Ferrari328 has it, just adding a little bit of clarity. When you open up the amp, you will likely see the back side of the headphone socket look like this picture from the Wikipedia page Ferrari linked to. The tip of the 1/4" plug is pressing against that bent connector on top, and pushing it away from the shorter flange that's running parallel to it. When it's not plugged in, those two pieces are spring-loaded against each other (in the photo, you can see a little bulge in the short arm where the contact happens).

What you need to do is trace those two pieces of metal to the contacts on the socket, and permanently solder those two points together, so the amp thinks the line-out is always unplugged. Both will probably work fine after that. If you're feeling fancy, you could connect the two points with a switch you add to the case, so you can choose whether it's in normal (either/or) mode or in both-at-once mode.
posted by range at 1:19 PM on August 30, 2008