Introduction: Convert Any Radio Into a Guitar Amp

Picture of Convert Any Radio Into a Guitar Amp

Turn any radio into a guitar amp.

This is probably one of my favourite hacks that I have ever stumbled across! It’s so simple that anyone with a soldering iron and screwdriver can do it.

All radios have an amplifier built into them – it’s how your able to increase the volume. What this hack allows you to do is to tap into the radio’s amplifier so you can play guitar through it.

You may be thinking why in hell would I want to do that!

Well hacking a radio (especially a vintage radio) gives you the most amazing vintage tone. The distinct “Lo-fidelity” sounds that come out of these vintage radio’s will really surprise you. It’s a real raw and dirty sound which is perfect for playing some bluesy riffs. There is also the added bonus of creating your very own sound as no 2 radios are ever alike.

When you get your hands on a radio that you want to hack, there is a good change that it would have seen some miles. You’ll probably find that the speaker hisses or rattles, the volume jumps around or it has some other left-of-centre feature which is what makes these amps so cool.

So if you have a vintage radio lying about gathering dust, it’s time to crack it open and turn it into something beautiful.

Check out this website - it has some wicked ideas on how to convert radio's into amps and is a great source of information

Step 1: Check Out the Video

Picture of Check Out the Video

Here's the amp in action. Excuse my lame playing - its been awhile since I picked-up the axe...

I have also recently hacked another radio I found and made a video of it. This is the second clip I go through how I repaired and added a jack to the radio. So if you can't be asked reading the ible' then just watch the clip!

I'm having issues with posting clips so if you don't see the right one then try either of the 2 links below

Link 1

Link 2

Step 2: Things to Gather

Picture of Things to Gather

Parts

1. Vintage radio - check out your local thrift store or op shop. If you have no luck at these places, then there is always eBay!

2. 1/4 mono, input jack - eBay

3. Wire - any old lengths

Tools:

1. Soldering Iron

2. Guitar

3. Guitar cord

4. Drill

5. Screwdriver / Phillips head

Step 3: What Type of Radio Is Best?

Picture of What Type of Radio Is Best?

I'm no expert on this hack, but after some research and a little experimentation, there are some radio's that will work better than others. Below I have included some notes on what to look for when your out searching for a vintage radio to convert.

The radio that I hacked isn't anything too vintage, but I wanted to start on something that didn't matter if I messed it up or not. The second radio was a little more older but I found that this was even easier to hack! The back just clipped off and there as some cardboard hiding all of the electronics!

Types of radio's

There isn't really many radio's that can't be modified into an amp. The trick is to find one that has some style and is large enough to pump out some decent sound. You can modify small transistor radios but you'll probably find that they aren't very loud or have any distortion. Reason being that they are too compact. If the radio has no handle and a wrist strap or is in a little leather case it will be a bit too small to waste you time with. This is due to the small, crappy speaker that they come with. Look for a radio that's at least 5 by 5 inches or so with at least a 3 inch speaker that will ensure the speaker is big enough to have an effect on the tone.

Batteries

The size and quantity of the batteries that the radio takes will effect the tone!! The bigger the size of battery the fuller the tone and the more volume the radio will have. Try and find a radio which takes "C" or "D" batteries as these will give you the best result. Radios which take a 9v or AA batteries won't give you the best sound. It is definitely worth though experimenting and seeing what type of sound you can get out of the small "transistor" type radio's. You never know...

Step 4: Pull Apart Your Radio

Picture of Pull Apart Your Radio

The first radio that I did the mod on was more of a recent one. I didn't want to screw-up a vintage one on my first go. Turns out it's really quite a simple hack, especially if you have AM and FM, but more on that later. It also turned out that this modern radio has amazing tones and overdrive!

Steps:

1. First un-screw all of the screws holing the radio together.

2. With a screwdriver, lever off the knobs and switches. They should pop off with some jiggling.

3. Gently remove the cover making sure that no wires are pulled out.

4. Lastly un-screw the circuit board.

Step 5: Wiring the Jack and Identifying the Volume Pot

Picture of Wiring the Jack and Identifying the Volume Pot

When deciding on where to add the positive wire on the voltage pot, you need to do a little bit of testing. There are usually about 5 solder points that the voltage pot has, and the wire from the jack will need to be soldered to the right one for the amp to work. Don't worry, it's really simple. I promise anyone can do this, even if you know absolutely nothing about electronics.

What is a volume pot? Damn good question! The simple answer is it's the thing that you turn to increase or decrease the volume. You can see from the pictures that the solder points are easily recognisable. Locate this on the circuit board.

Steps:

1. Solder 2 wires onto the solder points on the female jack. make sure that there is a bit of length on each one. You can trim them later

2. Plug in a guitar jack, making sure that the other end is plugged into your guitar.

Step 6: Testing and Soldering

Picture of Testing and Soldering

The next steps involve attaching the wires from the jack to the inside of the radio. On my first radio I followed the below steps. On my second however I accidentally messed the wiring up and everything still worked! I'll go through how I wired this one up first and then let you know what I did on the second.

Steps:

1. One of the wires needs to be soldered to a negative point on the radio. The easiest place to solder the wire is on the negative terminal inside the battery case. There's already solder there (you'll have to add more though) and it's easy to identify.

2. So which wire on the input jack do you solder on to the negative terminal? Well on a jack the tip is the "hot" section meaning its positive and the side is the negative section. In the pictures I have attached a yellow wire to the negative solder point on the jack. Just solder the end of the wire to the negative battery terminal.

3. Now with your guitar plugged into the input jack, test each of the solder pads on the volume pot. Place the wire on one, strum the guitar and if nothing happens try the next until you can hear the guitar come out of the radio.

4. solder the wire into place and your done with the wiring.

Notes on my second attempt.

On my second attempt on making one of these (documented inthe Youtube clip below) I messed-up the wiring. Throughout the video I kept on calling the positive terminal the negative (very silly mistake!) Because of this I actually added the negative wire from the input jack to the positive terminal on the radio. Surprisingly everything still worked perfectly! Just goes to show how easy this hack really is – you can mess-up the wiring and it still works!

Step 7: Adding the Mono Input Jack to the Case

Picture of Adding the Mono Input Jack to the Case

Steps:

1. Work out the best place to add the ¼ inch jack. The reason why I chose the top was there was a lot of empty space there in the radio. Also, I didn’t want any interference from the circuitry. Probably would have been better to add it to the side but it works either way.

2. Drill a hole big enough for the jack to screw into.

3. Add the jack, test and if everything is working, screw the radio back together.

4. Done! Now go and upset the neighbours.

Step 8: Notes.

Picture of Notes.

his is a really fun and simple hack and I would recommend anyone who has a guitar to try it out. This type of amp is supposed to be perfect for a cigar box guitar so I’m going to have to make one of these next!

If you’re worried about defacing a vintage radio then don’t. You are actually enhancing these things and making them useful again. Think about it, when was the last time you listened to AM? The only time I listen to it is when I can’t get FM on my radio. Oh and my dad sometimes inflicts it on me when his listening to the horse races.

The great thing is you can keep the radio working! The hack doesn’t have to affect it at all. As soon as you take out the lead from the input jack, the radio come straight back on. I bet if you showed someone the radio after the hack they wouldn’t even know what you did.

In Australia it is quite hard to find real vintage radio’s. Virtually all of the second hand and thrift stores I visited had nothing. My first was found down the tip and the second one was purchased at a small county op shop. It seems that one brand really dominated in Australia in the 50’s and 60’s and this was AWA. Other brands like Silvertone or Motorola seem to have not really been distributed here.

The US on the other hand has an abundance of very cool vintage radio’s available. A quick look on eBay will show a huge variety available. The great thing is, most are available to anyone in the world as long as they are willing to pay the shipment costs which can be more than the actual radio.

For anyone interested in going further with their hacks or want more credible info then my ramblings, then check out the below websites

Radio-Guitar-Amps

Cigar Box Nation

Lonesoulsurfer

Comments

TheStrayCreature made it! (author)2016-04-11

This is great! I had an old stereo that I never used anymore and can play it through the tape deck without a tape in to avoid all the static.

ThisGuyLovesToBuild (author)2016-03-23

I did it anyway and it turned out great. Although the volume control is bypassed so you have to control the volume on the divice

ThisGuyLovesToBuild (author)2016-03-23

can I use this as a speaker for my MP3 and just use a 3.5 female jack ins

You could try but I think you'll find the sound is crackly.

ThisGuyLovesToBuild (author)2016-03-23

sorry it kept auto correcting me weirdly

ThisGuyLovesToBuild (author)2016-03-23

instead

ThisGuyLovesToBuild (author)2016-03-23

ins

darrenhall (author)2016-03-12

Nicely done - again!!!
I have just ordered a lap steel guitar and would like to be able to practice when I am on the move - ya just saved me a load of cash and gave me the ability to get more bluesy soul for my money.
Cheers for the post.

anytime man - did you get your hands on a nice vintage radio?

I am looking around for two - one small one as a portable plug in direct practice amp and another either vintage or a big ole boom box.
This INST has gotta go on the F/B page as a COOL HACK - - practical and a fun little project.

Handyman SWL (author)2016-03-10

Would that work in the same way with old tube amps? If so I guess it would be good to have the radio receiver disable in otder to avoid white noise and static. Any one have done this mod with vintage tube radio?

Hey there,
Yes the mod would work with valves. You can disable the radio crystal and that should stop it receiving.
The problem you usually run into with valve type radios is they use AC so you are dealing with high voltage. If your comfortable with dealing with AC then I think using a valve radio would be ideal for this project

CoryH made it! (author)2016-03-08

I made one in my classroom. Had some issue with the solder and sound but it works and is easy!

lonesoulsurfer (author)CoryH2016-03-08

good work. Def agree that it's an easy hack (and fun)

PhillipLeRoss made it! (author)2015-12-19

Really appreciate your instructable! I read through some of the radio-guitar-amps site a while back and made a mental note to keep my eyes out for a suitable radio...found this portable one in a local antique store. One thing I've noticed so far, is the radio function isn't disabled when I plug in the guitar - and there's a fair amount of buzz that gets better or worse as I tune the radio. Is there an extra trick to getting the radio function to quit when the guitar's plugged in? Cheers!

Hey Mate - Nice looking radio!

You can get rid of the radio function by removing the radio crystal. Jump on the net and you should be able to fiund out where it is located on your radio.

Try and have it on AM as well and find a spot between stations. Lastly, with the buzzing, I would play around with the positive wire which is attached top the volume jack. Try and attach it to a different lug on the jack and see if that helps. each radio is different so you might not be able to get rid of the buzzing sound at all. I've done this a few times now and each one sounds different!

ahh, that makes sense. I'll look around and see what I can come up with for the crystal. This one's AM only, so no trouble keeping it there. I'll have another look at the connection but I'm pretty sure there was only one lug I could get a guitar signal with. That said, the best signal I could get from the radio was pretty dismal, so if I got rid of the radio function all together it wouldn't be a huge loss. Thanks again for the advice!

jack37255 made it! (author)2015-05-23

this is sooo cool. i made from an an alarm clock radio thing and the clock and radio still work.

robertrader (author)2015-04-30

looks good

monster_mash (author)2015-03-30

Is it aletrect ?????

Gizah (author)2014-11-06

Haha, this reminds me I never replied back to you in your "vintage radio guitar amp" ible. Anyways, excellent instructable!

Jack Moran (author)2014-10-06

Ampsome!

See your your pun and raise you - Tuneiffic!

Stop your pun-ishing me!

That's Major sharp of you

wobbler (author)lonesoulsurfer2014-10-07

Can we all stop picking on him?

Jack Moran (author)wobbler2014-10-10

Don't fret I'm sure he's fine!

wobbler (author)Jack Moran2014-10-11

I'm fully in a chord with that statement.

Don't B Flat, B natural, but don't B Sharp!

efabric (author)2014-10-07

This is a very dangerous hack, and not optimised for guitar signal. You need some sort of impedance matching and electrical hazard protection. This is not overly difficult to do : Just need a small tree-legged transistor, a condensator and some resistors to do the trick. The hardest part is to find with a multimeter the voltage source to power your transistor ; then read the reference of the existing chips inside your radio to find the best pin where you can plug your guitar one-transistor preamp. You can find all those parts in a salvaged electronic garbage.

AnTennA13 (author)efabric2014-10-09

What are you trying to say? You can't be serious. First, it's a called a condenser or if you are living in the 21st century - a capacitor. But really man, do you think building a preamp is about the multimeter? Allow me to use a big technical engineering term that I learned in the laboratory and say: Huh? In the battery powered radio he shows there is NO DANGER AT ALL of either harming yourself or the radio. Unless the radio has ebola or you don't know which end of the soldering iron to hold. It's just a cheap, dumb, fun and easy hack. Just don't try it with AC mains powered radios. (from an electronics engineer)

lonesoulsurfer (author)efabric2014-10-07

Only danger here is rocking out too much!

it runs off 4 x C batteries so i don't think that there is too much danger in that. In saying that, I wouldn't recommend anyone using AC unless they are extreamly confident in what they are doing.

wobbler (author)efabric2014-10-07

There is no inherent danger in doing this and certainly no need for any electrical hazard protection. You won't get a shock or anything because the radio is battery powered. It wouldn't even be dangerous even if the radio had a mains adapter, assuming the radio itself was ok.

The only issue is that you can blow up the speaker as it is possible to put in a pure signal in which will overpower the speaker or you can generate harmonics by overloading the amp. This is why they don't recommend putting a raw guitar signal through a hifi amp and speakers as you could blow the tweeters (the high frequency speakers). However, these radios usually don't have a tweeter. The amp itself however won't blow up by feeding in a guitar signal any more than turning the volume up full would blow it.

Regarding the need for preamp you are talking about, then why do they recommend using that? There are several reasons:

1) it that it conditions the sounds somewhat, either for mellowness or distortion.

2) It matches the impedances correctly. This means the guitar pickup signal is better matched to the am,p, resulting in a better sound.

3) It amplifies the output from the pickup to the levels needed by an amp.

4) In the case of piezo pickups, it compensates for the non-linear frequency response of a piezo pickup and makes them sound better. Piezos have an inflated higher frequency response which is why a piezo put straight to an amp sounds so tinny.

In this Instructable it's not really needed.

agis68 (author)efabric2014-10-07

i agree, another reason is these kind of "portable" radios are low amp class. You need a IC to control the signal for the quitar. Else you may burn all the radio

jimvandamme (author)2014-10-08

I've used all kinds of gadgets as guitar amps, almost all AC powered. But I know what I'm doing (MSEE degree). My favorite is a set of computer speakers that I use with my Boss effects pedal. It's stereo so the chorus & reverb sounds nice. The gain is pretty low on computer speakers, they really could use a 10X gain stage but I'm lazy.

Too bad you modify all those nice old radios. That probably ruins their value as collectibles. (I've collected - and thrown out - lots of them.) Better to use a 90's boom box; same idea, and they have tone controls. Disconnect the tape head preamp output to the volume control and you'll get more volume.

tauhid (author)2014-10-08

Since 40 years ago I've used a dynamic mike or an earphone or to add the radio function as an amplifier; I don't play guitar.

Kurt E. Clothier (author)2014-10-07

This is one of the first things I ever did in electronics. I had a "homemade" multi-stage stereo system made up of old radios by soldering input leads across the volume potentiometers. It worked fairly well for a few years... until it stopped working and caught on fire, but that was probably more to do with my inexperience than anything. Don't get me wrong, these things are fun to mess with, but are high unstable and can result in severe oscillations. In my case, an input signal went into an an infinite feedback loop until it blew the connected speakers, shorted the drive transistors outputs, and started smoking. Had I not been around to unplug the system (yes, I used A/C power) it could have burned the house down (but not in the music related good way, in the fire related bad way).

Keep on rockin, man, but be careful!

Hey Kurt,

That's kind of the reason why I have stayed away from AC. Too easy for something to go wrong (esp with my skills!).

I did a lot of research on the net before I went ahead with the hack and didn't come across any blown speakers. maybe no-one is admitting to it!

if I do manage though to blow the speaker playing some stella riffs, then at least the radio was sent off in style.

For sure man. Here I am a decade and a half later, designing complex circuitry for robotics... so maybe you will build upon your initial concepts and design some new class of amplifier in the future. And I can promise you there are plenty of blown speakers out there; it's just that very few people will admit to their failures.

Dyemor (author)2014-10-07

Very cool, will have to find a nice old radio to do this on. I've a digital one with an existing aux input which might be fun, especially if I can get it so I can play along with tracks at the same time from an MP3 source.

Was the audio you're getting from a direct source without any effects? It sound really good and dirty.

BadPuns (author)2014-10-06

This is pretty cool. I have been looking into a battery powered amp, but the good ones are $150+ and I don't get much money... I usually never get around to trying the stuff on Instructables, but I have to do this one. :)

lonesoulsurfer (author)BadPuns2014-10-06

Nice one - I promise you won't be disappointed.

MsSweetSatisfaction (author)2014-10-06

Dude that's an awesome hack! Sounds really nice! Thanks for sharing!

Cheers. Yeah I was really surprised by the sound I could get out of a simple radio.

tomatoskins (author)2014-10-06

I love vintage hacks!

yep - so do I. As long as i don't destroy the item too much though!

pfred2 (author)2014-10-06

I did something similar to this with a cassette recorder a long time ago. I found the preamplifier input inside it and fed a signal into the circuit there. Today I'd rather make my own amplifier, then I can set the bias hot, so an instrument sounds decent. Amplifiers for reproduction do not make very good musical instrument amplifiers, they're biased too flat.

I've run guitars through audio stereos too, and that sucks too compared to what a real instrument amplifier sounds like.

AAAHan (author)2014-10-06

WOW! GREAT!

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Bio: I've always liked pulling things apart - it's the putting back together again that I have some issues with.
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