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: 429

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

aluminium bobbins

Started by micky rooney in Building Secrets, Tips, Advice, Discussion. Last reply by micky rooney 2 hours ago. 6 Replies

LMM GDG strings.

Started by Bruce Young in Building Secrets, Tips, Advice, Discussion. Last reply by Bruce Young 3 hours ago. 6 Replies

Build puzzle

Started by cbgnewbie in Building Secrets, Tips, Advice, Discussion. Last reply by Paul Craig on Friday. 7 Replies

Playing Slide with a Pocketknife - Mance Lipscomb Captured on Film

Started by Shane Speal shanespeal.com in Feature Articles. Last reply by Jeffrey Warren Park on Wednesday. 6 Replies

Video search for specific cbg build!

Started by Will "KOOLDOG HOOCH" Bonner in Building Secrets, Tips, Advice, Discussion. Last reply by Will "KOOLDOG HOOCH" Bonner Apr 10. 2 Replies

Bridge questions

Started by Will "KOOLDOG HOOCH" Bonner in Building Secrets, Tips, Advice, Discussion. Last reply by BrianQ. Apr 9. 12 Replies

Fret width / depth

Started by Jeffrey Blessing in Building Secrets, Tips, Advice, Discussion. Last reply by Jerry Jordan Apr 5. 2 Replies

Latest Activity

Dennis "Denbo" Goodinson commented on Jim Morris's video
Thumbnail

Cookie Tin Banjo - Magpie

"Very nice I love the Banjo which is a superb build but the star element here is your playing of it,…"
46 minutes ago
Dennis "Denbo" Goodinson liked Jim Morris's video
50 minutes ago
Dennis "Denbo" Goodinson liked Jim Morris's photo
52 minutes ago
Dennis "Denbo" Goodinson liked Jim Morris's photo
52 minutes ago
Denny liked Jim Morris's video
1 hour ago
Uncle John commented on Jim Morris's video
Thumbnail

Cookie Tin Banjo - Magpie

"Sounding great, Jim."
1 hour ago
Chris Lyons commented on Chris Lyons's photo
Thumbnail

Shiny

"Thinking about putting a chrome 3 string bridge on this one."
2 hours ago
Chris Lyons commented on Chris Lyons's photo
Thumbnail

Fretless Face

"The wood ruler on this one actually made it sound fuller so I put one on Shiny Top."
2 hours ago
Chris Lyons commented on Chris Lyons's photo
Thumbnail

Different but same

"Thanks bud. I lost count at 40 hours. I got a few more pre build pics too. Thanks again for the…"
2 hours ago
Bruce Young posted photos
2 hours ago
micky rooney replied to micky rooney's discussion aluminium bobbins
"Thank you,JL.I think I will stick with making bobbins from plastic or wood..."
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 -->