making an amp from junk?

hey yall.

i have this old JVC RX-150 AM/FM tuner, and i was wondering if i could make a deacy amp sorta thing with it.

you know, queen's bassist (deacon) made brian may an amp out of a car's radio. how and what it was made of gave the amp that signature tone.

so i was looking at the wiring inside of this tuner. it looks all anolog- i can see two tubes in it, not sure what they're for. i could manipulate the audio in's in the back and put in a guitar input.

but the only problem is, once i take it apart, i dont really know where to start. im not a mechanical genious. and also, if i make this amp, i really want it to sound different. i dont want it to just sound all muddy or whatnot. so if yall have any ideas for experimenting with tones, that would be cool.



does anyone know where to find a wiring diagram for the deacy amp? ive been through pages of google. im thinking about using these wirings as sort of a guide.

anyways, any help with this project would be very much appreciated. :D

This is one of those things where, if you gotta ask, you probably shouldn't go there.

Unless that box has an audio power amp to drive speakers with, you're wasting your time.

Originally Posted by: LordathestringsThis is one of those things where, if you gotta ask, you probably shouldn't go there.

Unless that box has an audio power amp to drive speakers with, you're wasting your time.

If it didn't could he make a pre-amp out of it?

Originally Posted by: magicninjaIf it didn't could he make a pre-amp out of it?

A tuner won't have any tone control circuits.

Originally Posted by: LordathestringsA tuner won't have any tone control circuits.

Could it be modified to include some ( easily of course)?

Edit--> Sorry I joined in but every time I walk into Radioshack the component boards and what not seem to be calling to me. :D

Someone who has sufficient resources and expertise to achieve what rockonn91 was asking about, would not have asked the question in the first place. Which syllables of "wasting your time" have escaped your comprehension???

Ouch, Sorry LATS I just thought humans were beings capable of learning. My mistake.

Of course people can learn! My point is that a tuner is not a good candidate for conversion to a guitar preamp. I you really want to DIY, then dig up some schematics, spend some quality time with some reference material on tube specs and circuit design, and either build from scratch or pick something more suitable to modify.

rockonn91 obviously has some clear ideas of what he wants to achieve, and I told him not to waste his time on a tuner.

Radio Shack (now called "The Source"?) proto boards represent a step or two up from what I got my start on. I would recommend the audio output of an old tube table-top radio as a much better place to start. If you have the interest, go with it. Just do some research first, and be very careful playing with those lethal voltages!

Originally Posted by: LordathestringsOf course people can learn! My point is that a tuner is not a good candidate for conversion to a guitar preamp. I you really want to DIY, then dig up some schematics, spend some quality time with some reference material on tube specs and circuit design, and either build from scratch or pick something more suitable to modify.

rockonn91 obviously has some clear ideas of what he wants to achieve, and I told him not to waste his time on a tuner.

Radio Shack (now called "The Source"?) proto boards represent a step or two up from what I got my start on. I would recommend the audio output of an old tube table-top radio as a much better place to start. If you have the interest, go with it. Just do some research first, and be very careful playing with those lethal voltages!

Ok Well I got this old fender frontman 15watt amp. Should I gut it then replace the board it has or should I add to it. It would be nice to be able to add some tubes somehow. Would I be able to even add tubes to a solid state? I'd be up for using the Fender board as a jumping off place then putting a finished product in a bigger box or using it as a preamp setup. I know a little about electronics so I'm not flying blind here. If you say I have a decent chance I'll do all my homework. If there's some info that is unclear or something could you give me a hand?

Transistor amps are not very friendly places for the inquisitive. The beauty of old tube amps is that they were built by point-to-point stringing a few components together on turret boards. This makes for untidy assemblies, but they're so easy to modify. I have no idea what's in a Frontman, but I'm pretty sure it's all built on printed circuit boards. A lot harder to do anything with.

Start out small. A one-tube, single-sided Class A output. That's where an old tube radio comes in. Pick one up from a flea market for a few bucks. Find a schematic for it. If you're lucky, there's one in the cabinet. Get some tube amp books from the library, or buy a couple from StewMac. Look up the data sheets for the tube(s). Figure out how to separate the radio section from the audio section and feed your guitar into the amp instead of the radio. Study the biasing circuit, and see what effect different component values have. Look up some tone control circuits and add them to your system. Get a thorough understanding of the one-tube, single-sided Class A output circuit, and then move on to a two-tube, push-pull circuit. See how biasing can change it from Class A to Class A-B. Understand what the difference is, and how that affects the sound. Keep pushing, keep learning.