I built a nasty little dual chip-dual stage op amp based on the Ruby amp that turned out very good.

Here's a schematic if anyone is interested in building their own.

Views: 1783

Replies to This Discussion

Thanks again. I really appreciate all your help with this. I'm very excited about this amplifier project. A LM386 amp with guts!

No Problem. 

I love my Ruby amp's sound and really wanted something louder with a little more balls. This fit the bill.

I tend to play my acoustic CBG through the regular Ruby most of the time because it just sounds so good through it's 6" speaker The dual chip amp is hooked up to a old Jensen 15" speaker that I pulled from an old Motorola phonograph that was powered by a tube amp. Going to build a Fender Bassman/Tweed circuit out of that when Get around to it.

Any updates Erik?

nice and simple circuit.. what gain is set on the J-FET input do you know? do you play with a wound pickup or a piezeo? with the 1M5 input resistor i am guessing a piezeo?

No Gain setting on the J-FET, each 386 chip has a 2k Gain pot.

This is a great little amp for Magnetic pickups or piezo's.

The 1M5 resistor in question is just that - a 1/4watt resistor. The J-FET circuit is the same circuit found in the Ruby amp which was my initial inspiration in making this dual chip circuit.

However, lately I made a change to the schematic and thought that I had posted that change here. The new version deletes 1 of the volume pots because both stayed all the way up in all scenarios. I also added a B100k tone pot . 

thanks. i will have to look up the circuit for the Ruby amp.

are the two gain pots ganged? that is two pots but one shaft? because if they are different pots i can see asymetric gain possible. because you are using one as an inverting amp and the other as a non inverting amp and stringing the speaker between them you can get a a full 9v swing on both positive and negative parts of the wave.a single amp is internally biased to 1/2 the supply voltage giving a 4.5V swing positive or negative. with this setup you can make the negative part of the wave less gain/quieter ot the positive. or even vice versa.... must have an interesting sound...

2 separate gain pots. When I use it the volume stays all the way up and the 1st gain at about 75%, then I can dial up the 2nd gain for what ever level of nastiness I want.

I prefer using big speakers over the small ones. My current speaker is a 8ohm-15watt WGS 10" Veteran(American Voiced) speaker, but would like to try out a British Voiced speaker some time.


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

Ruby Amp

Started by BrianQ.. Last reply by BrianQ. May 19, 2020. 6 Replies

Smokin' amp (literally)

Started by James Conder. Last reply by James Conder Aug 27, 2019. 4 Replies

Simple Headphone/Practice Amp

Started by BrianQ. May 17, 2019. 0 Replies

Problem with second-hand amp.

Started by Arthur Payne Apr 1, 2019. 0 Replies

Artec Amp Help!

Started by Jesse Lively Sep 10, 2017. 0 Replies

LM386 N-4

Started by Denis U. Last reply by Richard Haas Dec 3, 2016. 4 Replies

History Mystery--Orrtronic Tube Amplifier project

Started by Scott aka Farmer Ted Nov 17, 2016. 0 Replies

Dual IM386 Chip amp

Started by Paul Craig. Last reply by Paul Craig Nov 3, 2016. 31 Replies

Amp Speakers

Started by Primitive Acoustics. Last reply by Primitive Acoustics Mar 9, 2016. 3 Replies

Grounding for Cigar Box Amps: Chassis Ground?

Started by Erik Bell. Last reply by Scott aka Farmer Ted Dec 20, 2015. 4 Replies

Neat amp components

Started by Surly. Last reply by Alan Steeg Oct 27, 2015. 1 Reply

can a dab radio be turned into an amp

Started by Coventry Halfpenny guitars. Last reply by Pickedmoor Jon Oct 20, 2015. 3 Replies

SDA-T Questions

Started by alectron. Last reply by Zac Ray Sep 2, 2015. 10 Replies

HI - New guy & And speaker question

Started by Henry S. Last reply by Henry S Mar 25, 2015. 4 Replies

Are Pre-fabbed LM386 Moduals Worth Trying?

Started by Scott W. Last reply by Henry S Mar 24, 2015. 6 Replies

Powered sub to amp ??

Started by wormil. Last reply by wormil Sep 3, 2014. 2 Replies

Amp and speaker INSIDE the guitar?

Started by Greg Potts. Last reply by Ron "Oily" Sprague Jul 1, 2014. 1 Reply

trying to hack an old valve radio, into a guitar amp,

Started by GARAGE HERMIT. Last reply by GARAGE HERMIT Apr 29, 2014. 108 Replies

Best mini amp KITS

Started by MichaelS Country Boy Guitars. Last reply by Henrik Johansson Mar 10, 2014. 34 Replies

amp wiring help

Started by HarleyTodd. Last reply by Bernie Mango Feb 26, 2014. 18 Replies

Latest Activity

A.D.EKER commented on A.D.EKER's video

New Born Dream A D Eker 2022

"Thanks for the vote of confidence Keith appriciated!"
1 hour ago
A.D.EKER commented on A.D.EKER's video

New Born Dream A D Eker 2022

"Hello John! sins i play the four string and use the four sting tunings i listen more to schottich…"
1 hour ago
W.M. Peterson liked Gary O'slide's video
1 hour ago
W.M. Peterson liked Miku's video
1 hour ago
W.M. Peterson liked Poorness Studios's video
1 hour ago
W.M. Peterson liked Poorness Studios's video
1 hour ago
Engblom posted a discussion

String attachment place

All "normal" guitars have the strings attached at the saddle, right behind the bridge while most…See More
2 hours ago
Keith Rearick liked A.D.EKER's video
3 hours ago
Keith Rearick liked A.D.EKER's photo
3 hours ago
BrianQ. liked Randy S. Bretz's photo
3 hours ago
Keith Rearick liked Randy S. Bretz's photo
3 hours ago
A.D.EKER commented on A.D.EKER's photo

cbg Hall of Fame clean

"Thank you Uncle John ! i did resurve a spot for your relic builds aswell ,as Pick ,Randy B,…"
5 hours ago


© 2022   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 -->