Very cool. Hacking old transistor radios works great to make an amp. I did one with an old Philips trans radio...love it. Total cost to hack, including radio from Salvation Army store, one jack, a switch, and a couple bits of wire...about $7.00
Yeah, I took the battery holder out to expose the two circuits (one for am/fm tuner and the other the amplifier). I could have hacked into the on/off volume pot, but was a bit tight to do that, so I found the wire leading from tuner circuit to the volume pot and cut there. Spliced a lead onto each, attached the lead from tuner to one side of a three prong on/on switch, the lead to the volume to the middle prong, and the lead to the newly installed 1/4" jack for the guitar to the other outside switch prong. Nice part of this radio is that there was already an additional headphone jack, which allows for quiet amped playing and/or radio listening.
In the end, the radio still functions, and with the flick of the switch, it can be used as an amplifier. Was a fun project.
Here's a link to the Convert Old Radios to Amps group that shows how I did it:
You are welcome
Ok, made some progress on hacking this little radio into a practice amp....
Above you will see circles that show the points that I will solder the needed wires to the board to make it work as an amp. I will install a switch that will let me select between the radio and the guitar amp modes.
Green: the cut circuit trace.
Red: the points to connect the tuner back up.
Yellow: the points to hook up the 1/4" guitar jack
( lower yellow the tip connection, upper yellow barrow connection)
I love this Arvin! possibly my total fav!!!!
such a cool look too!
The one thing I noticed when I did a test to see if it was working was the volume didn't seem to be that high... I'm thinking I need to use a preamp so I don't get any impedance issues between the magnetic pickup and the amp input... What have some of you run into when you used an old radio for this?
Here is an upload of my Arvin 8 Transistor radio practice amp hack, hooked up to 2 piezo pickups from Radio Scrap (Shack) sold as buzzers.