I understand that mains valve radios are not to be messed with because of the high voltages but are battery valve radios ok for converting to guitar amps.  Some guidance would be helpful before I fry myself!



Views: 297

Replies to This Discussion

Valve radio circuits are not the same as a valve guitar amp. Some of the valves in a radio (tubes, for those reading west of the Atlantic) are designated as signal detectors (radio waves), while others are there to invert the signal to a usable wavelength for continuing through the circuit. Of course there are valves present to boost the signal (pre-amp), and at least one valve to drive the speaker.

It may be possible to convert the radio. But unless you have a schematic for the radio circuit, you will be working blind.

Perhaps if you had the schematic and posted it here, more help could be offered.

I build guitar valve amplifiers. And personally, I would not take on converting a valve radio to an amp. But that's only my take on the idea.

If you're looking for something small, like a 1 or 2 watt valve amp, there are online resources to help you out too.

Hey Bird,

I've done numerous high voltage tube radio amps to guitar amps. The easy way to do this is to tap into the volume pot with the hot lead from your jack, your ground goes to a good chassis ground. Use test leads or a built input jack & leads, Install your ground, strum your guitar and touch volume pot leads till you hear your guitar. Test again to see if you have control of the volume and the correct contact and you should be good to go.

Hope this helps.

Hi Lemon,

I realize this is a slightly dated thread. But after reading your reply I noticed something that should be mentioned regarding safety. You said to "tap into the volume pot with the hot lead from your jack"...no worries there.

But you then said "your ground goes to a good chassis ground".

This would seem a normal process if the power cord on old valve radios were 3-prong grounded ones, with the green ground wire soldered/star grounded to the chassis. But old valve radios have 2-prong units without the larger neutral prong to ensure the plug is inserted correctly.

So what can happen is that the plug can be inserted into an electrical outlet with the "hot" mains current running either through the direct circuit path as it should. Or if the cord is inserted in reverse (which can happen), the current can go to the chassis.

If this potential situation is not averted and a guitar is plugged into the converted amp, the moment the player touches a string/bridge, etc, smoke and sparks...

Hey Scott, I meant the ground for the 1/4" guitar jack. I mention the jack in the thread, so I assume the reader would understand there are 2 connections for the guitar jack. (+ & -)

Yes, I saw that. But power cords on vintage tube radios can be plugged in right side up or down, which could result with the ac wall power going to the chassis, and send the 120v ac through the guitar jack negative, through the patch cord negative and up to the strings, if bridge is grounded, or through the ground on guitar pots, resonator metal, license plates.

Was only concerned about safety.


I appreciate your input guys but I have a battery powered valve radio that I fancy converting to a guitar / CBG amp by tapping into the amplifier circuit just as if it were a battery transistor radio. I think I understand the safety issues associated with mains valve radios but I have no idea if there are similar issues with the battery variety.

Oh, and I do have the schematic Farmer Ted!

Thanks again



The Essential Pages

New to Cigar Box Nation? How to Play Cigar Box GuitarsFree Plans & How to Build Cigar Box GuitarsCigar Box Guitar Building Basics

Site Sponsor

Recommended Links & Resources

Discussion Forum

Sony not working

Started by Carlo Apr 16, 2021. 0 Replies

Zenith C845

Started by James Pobog. Last reply by James Pobog Nov 22, 2019. 1 Reply

Just got a radio/cassette player--My next move--HELP!!

Started by Andy Busch. Last reply by Tim Pannabecker Aug 25, 2019. 3 Replies

Sweet Norwegian Transistor Radio - any tips?

Started by Elliott Fisher. Last reply by GARY KNIGHT Mar 25, 2018. 4 Replies

Battery valve radios

Started by Bird. Last reply by Bird Nov 22, 2016. 6 Replies

3 tube 8 watter Valco style amp with swamp sound

Started by Doug Christensen. Last reply by Doug Christensen Oct 17, 2016. 66 Replies

hey guys just alittle info please

Started by gregory lazorchak. Last reply by Denis U Jul 23, 2016. 3 Replies

Hitachi Transistor Radio with Tape.

Started by David Wilson. Last reply by GARY KNIGHT Jul 4, 2016. 9 Replies

Mini Amp - Where Do I make Connections? What is missing?

Started by Brian Revels. Last reply by daniel clarke May 13, 2016. 1 Reply

Car radio Amp

Started by Orcabait. Last reply by GARY KNIGHT May 10, 2016. 1 Reply

1962 Silvertone Medalist 3217

Started by Monterey. Last reply by Scott aka Farmer Ted Apr 3, 2015. 11 Replies

New jack in an old radio

Started by White Raven. Last reply by Scott aka Farmer Ted Mar 30, 2015. 3 Replies

Suitcase Amp

Started by Gary Ross. Last reply by Gary Ross Jan 26, 2015. 4 Replies

Arvin 8 Transistor AM radio...

Started by Corbin. Last reply by Corbin Jan 15, 2015. 11 Replies

Low volume with your Hacked Radio --- Amp

Started by Corbin. Last reply by Corbin Jan 12, 2015. 4 Replies

DIY amp question

Started by Greg Thompson. Last reply by Greg Thompson Jan 10, 2015. 2 Replies

1964 Philips AM/FM Radio to guitar amp project

Started by Scott aka Farmer Ted. Last reply by Scott aka Farmer Ted Jan 8, 2015. 4 Replies

Thank you beetle juice!

Started by Greg Thompson. Last reply by Jim Quinlan Nov 6, 2014. 5 Replies


Started by John Newman. Last reply by 3 String Blues Aug 21, 2014. 3 Replies

Latest Activity

Robert Vance Jr. liked Robert Vance Jr.'s profile
4 hours ago
Robert Vance Jr. liked Aaron Green's photo
4 hours ago
Southern Ray commented on Southern Ray's photo

First Chugger

" Thank you Doug. You certainly know your way around the chuggers and make them sing. I've…"
8 hours ago
Southern Ray commented on Southern Ray's photo

Getting there...

" Thank you for the "Like" AGP #"
9 hours ago
Southern Ray commented on Southern Ray's photo

Getting there...

" Thank you Uncle John! It's actually closed-cell foam of some sort. Pretty tough stuff…"
9 hours ago
Uncle John commented on Aaron Green's photo

First Build

"Hi Aaron Green,  I like this quite a lot.  The vintage looking box and that clean white…"
12 hours ago
Uncle John commented on Southern Ray's photo

Getting there...

"That styrofoam resting block is a good eye deer!"
12 hours ago
Uncle John commented on Poorness Studios's video

CD Player (an original rap about my CD collection)

"Ha, a wrap with an old country talking feeling.  I liked it.  CW McCall and Kale Poorness."
12 hours ago
Uncle John commented on A.D.EKER's video

Waiting at the Station BCB 2024

"Very cool listen and look, Andries.  Hey if you can do it without two much trouble - please…"
13 hours ago
AGP # commented on Aaron Green's photo

First Build

"Nice Clean & Simple 1st Build, probably the start of an CBG Building Addiction ?? :-) "
14 hours ago
AGP # liked Aaron Green's photo
14 hours ago
AGP # liked Southern Ray's photo
14 hours ago



© 2024   Created by Ben "C. B. Gitty" Baker.   Powered by

Badges  |  Report an Issue  |  Terms of Service

\uastyle>\ud/** Scrollup **/\ud.scrollup {\ud background: url("https://storage.ning.com/topology/rest/1.0/file/get/963882636?profile=original") no-repeat scroll 0 0 transparent;\ud bottom: 25px;\ud display: inline !important;\ud height: 40px;\ud opacity: 0.3 !important;\ud position: fixed;\ud right: 30px;\ud text-indent: -9999px;\ud width: 40px;\ud z-index: 999;\ud}\ud.scrollup:hover {\ud opacity:0.99!important;\ud}\ud \uascript type="text/javascript">\ud x$(document).ready(function(){\ud x$(window).scroll(function(){\ud if (x$(this).scrollTop() > 100) {\ud x$('.scrollup').fadeIn();\ud } else {\ud x$('.scrollup').fadeOut();\ud }\ud });\ud x$('.scrollup').click(function(){\ud x$("html, body").animate({ scrollTop: 0 }, 600);\ud return false;\ud });\ud });\ud \ua!-- End Scroll Up -->