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!

Dave 

UK

Views: 225

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.

Cheers

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

Dave

RSS

The Essential Pages

New to Cigar Box Nation? How to Play Cigar Box GuitarsFree Plans & How to Build Cigar Box GuitarsCigar Box Guitar Building BasicsCigar Box Guitar Parts Store

Site Sponsor

Recommended Links & Resources

Discussion Forum

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

Question

Started by BILL GRONER. Last reply by Wayne Bigler Apr 9, 2016. 2 Replies

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 16, 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

Preamps

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

Grundig Yacht Boy Radio

Started by Keith 66. Last reply by 3 String Guitars Aug 2, 2014. 1 Reply

Having problems with a 1959 Silvertone 9014

Started by Darren Addy. Last reply by 3 String Guitars Jul 30, 2014. 1 Reply

Blog Posts

Tab for Ry Cooder

Posted by Keith Gibson on September 30, 2019 at 12:44pm 2 Comments

Ducktail Run in James Dean Country

Posted by Rick Tish on September 29, 2019 at 9:57pm 1 Comment

Tiki mask guitar

Posted by Phil Stickings on September 27, 2019 at 12:39pm 5 Comments

Festival in the land that time forgot

Posted by Rick Tish on September 23, 2019 at 10:09am 2 Comments

Latest Activity

Lonman replied to James Pobog's discussion couple more pix
"really nice.  I built a bass for a client, but am thinking I'd like something for my own…"
30 minutes ago
Dave Lynas commented on Dave Lynas's video
Thumbnail

Let that Boy Boggie

"Thanks Tony. Thanks Uncle John. Being on the road for our tour is tiring but gotta happen if you…"
58 minutes ago
BrianQ. commented on David Hopkins's photo
Thumbnail

Hopkins "Anti-Body" builds 3 and 4

"Looks like you might ride them into the beyond when you’re done playing them :) thanx for…"
1 hour ago
BrianQ. liked David Hopkins's photo
1 hour ago
BrianQ. replied to White Raven's discussion Preping boxes
"Sand them out with super extra fine sandpaper & recoat, no worries :)"
1 hour ago
the anonymous pick replied to Will "KOOL DOG HOOCH" Bonner's discussion This month's installment of "WHAT THE HECK IS IT?"
"looks like a Sheet Metal Notcher to me "
1 hour ago
White Raven posted a discussion

Preping boxes

OI ran in to a problem on a custom order. I received a black cohiba box that looked perfect. While…See More
2 hours ago
Uncle John commented on Jeff 'Bones' Reilly's photo
Thumbnail

Fret Rocking not so shocking

"Jeff,  we moved to a new town and house 6 months ago.  I left behind a B- shop for a D…"
2 hours ago
Uncle John commented on Taffy Evans's video
Thumbnail

The Queen of Hearts Guitar build

"Taffy, those hearts and heart sound hole are nice touches,   The rosette is fine work,…"
2 hours ago
James Pobog posted discussions
2 hours ago
Andrew Connors posted discussions
2 hours ago
Timothy Hunter replied to Taffy Evans's discussion Video.. Building an Evans full acoustic guitar
"i meant a link in this thread. looks like Davic L posted one."
4 hours ago

Music

Loading…

© 2019   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 -->