Looking for Assistance with reviewing Schematic for my Transistor Radio to Amp Conversion.

I have an old 1960's GE AM radio that I've had trouble converting over to a Cigar Box Amp.  Tried the usual ways.  Anyone here good with Electronic Schematics that can advise?

Here's the Schematic:  http://oi47.tinypic.com/14btdue.jpg

Here's the diagrams of the insides:  http://oi46.tinypic.com/108eahd.jpg

She worked okay when tapping into the volume knob... but played at a very low volume.  The radio itself is very loud so I must need to tap into the preamp or something???

Here's what she looks like:  

Views: 444

Replies are closed for this discussion.

Replies to This Discussion

I would try tapping into the + side of C3  (desolder or cut the trace and don't forget the guitar cable ground) just after the volume control but I suspect there is just a level difference between the output of the pickup and the audio output from the tuner.  If so the solution is to add gain to the guitar.  A op amp chip on a small breadboard using the volume control from the radio would do.  Plenty of standard 8 pin chips and circuits on the web.  Do a quick google search for Op Amp guitar pre

Thanks Don.  An Ipod worked fine, so that would make sense that none of my guitars were loud.. but I would have thought my acoustic with the LR Baggs preamp would jam... but it was barely louder than the piezo coming from the CBG.

I'm sorry, but I'm a rookie at electronics mods... Can I just measure the voltage on each side of C3 by reading between C3 and ground to find the + side?

The Baggs pre is mainly a buffer amp and not intended as a gain stage.  The piezo is really high impedance and the pre helps with the relatively low input impedance of the amps.  Even if the output was doubled of what a mag pickup was, you are still in a low level situation.  The guys in the Mod section can likely help you out with resources and ideas.

Here is a simple circuit I found using a common op amp chip.  Change the value of the two input resistors, you change the gain.

Guitar Wiring Blog PreAmp

If u look @ the Cap(C3) there's a bold stripe going down the side w/ some -  - (Dashes) right? That's - neg other side is + pos just remember the opposite side of the stripe is + Positive.

U should join dis Group:

http://www.cigarboxnation.com/group/vintage-radios-converted-into-g...

lots of conversion videos there

Thanks Brian!

Thanks again Brian and Don!

Moved discussion to:  http://www.cigarboxnation.com/xn/detail/2592684:Topic:1467634?xg_so...

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

Forum

Lid thickness question.

Started by Will "KOOL DOG HOOCH" Bonner in Building Secrets, Tips, Advice, Discussion. Last reply by Rick Tish 5 hours ago. 15 Replies

67% Les Paul Tribute

Started by Tom T in Building Secrets, Tips, Advice, Discussion. Last reply by Will "KOOL DOG HOOCH" Bonner 11 hours ago. 7 Replies

built-in reverb

Started by JOHN POMEROY in Building Secrets, Tips, Advice, Discussion. Last reply by JOHN POMEROY 20 hours ago. 7 Replies

Screw Inlays

Started by Brent Kasl in Building Secrets, Tips, Advice, Discussion. Last reply by Titch the Clown yesterday. 4 Replies

Peloton Bike

Started by Grace Acebedo in Performances, How to Play, Lessons, Concerts. Last reply by Grace Acebedo on Friday. 6 Replies

Holding the CBG

Started by Jack Brady in Performances, How to Play, Lessons, Concerts. Last reply by Will "KOOL DOG HOOCH" Bonner on Thursday. 4 Replies

Logo using tracing paper

Started by Titch the Clown in Building Secrets, Tips, Advice, Discussion. Last reply by Will "KOOL DOG HOOCH" Bonner on Wednesday. 1 Reply

Blog Posts

My mistake at the markets

Posted by Rick Tish on August 22, 2019 at 9:27am 5 Comments

Indiana State Fair

Posted by Rick Tish on August 19, 2019 at 7:46pm 1 Comment

Buying in bulk

Posted by Rick Tish on August 17, 2019 at 6:31pm 3 Comments

Shellac

Posted by Rick Tish on August 15, 2019 at 7:00pm 1 Comment

Latest Activity

MadGomer replied to Warren Williams's discussion A simple tuning peg question in the group Building a Cigar Box Guitar 101
"I'm not able to measure mine right now but I make my headstock 5/8" thick and always have…"
17 minutes ago
Art Prior replied to Warren Williams's discussion A simple tuning peg question in the group Building a Cigar Box Guitar 101
"I usually go about 1/2 inch above the headstock, or the ferrule if one is used. Art"
27 minutes ago
Tom T replied to Taffy Evans's discussion Its a CBG but not cigar box guitar. new build
"That is just TOO COOL for words. The bat is a perfect body for a guitar and anyone familiar with…"
44 minutes ago
Christopher G Daniels liked Warren Williams's discussion A simple tuning peg question
1 hour ago
Uncle John commented on Kevin Sprague (Knotlenny)'s video
Thumbnail

Knotlenny's 3-String CBG 101

"Oh no!   I can't either.  I will ask Kevin to repost."
1 hour ago
Warren Williams commented on Kevin Sprague (Knotlenny)'s video
Thumbnail

Knotlenny's 3-String CBG 101

"Is the video still available? I can't see it."
2 hours ago
AGP # liked Doug Krantz's photo
2 hours ago
Warren Williams added a discussion to the group Building a Cigar Box Guitar 101
Thumbnail

A simple tuning peg question

How much of the capstan should protrude above the headstock once the tuning peg is installed? I've…See More
2 hours ago
AGP # commented on Uncle John's photo
Thumbnail

Swag and Booty.

""Sweet"  :-)"
2 hours ago
AGP # liked Uncle John's photo
2 hours ago
AGP # liked Dave Lynas's video
2 hours ago
AGP # commented on Dennis "Denbo" Goodinson's video
Thumbnail

Jimmy Jam 3

""Ditto Uncle John", "BB" certainly has a lovely voice all of its own! :-)"
2 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 -->