Making Of Double D ..

[kaushik]

Hi all ,

here i wil be putting my construction journey for my DIY Distortion padel for guitar .

The goal is to make a DOUBLE D clone given by the original author here :

http://www.runoffgroove.com/doubled.html
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The Idea :javascript:smilie('')

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I wanted to make a decent distortion pedal for my guitar , at a lesser expense .
Also wanted some thing of small foot print.
Online i got good reviews for the Double D . The simple design looked great ,
component count was less and .only 1 chip! CD 4049 ... power javascript:smilie('')packed with six
inverters .





some pics here
http://www.flickr.com/photos/kaushik...ags/mydoubled/

[kaushik]

The construction started some time back ...however ...the early days are logged here

DAY1: Making of 'MY Double D' guitar distortion

12:46 PM 6/26/2008>
[Thursday]

-today is the first day
i just did the purchasing part [at sp road,bangalore,india]

tools and components costedd roughlt 4$ .[ 160 INR ]..

-getting the J-FETs was a pain ..i replaced the J209 with J 112


I Have one doubt : Wheather J112 J-FET (similar specs.) will serve as a equivalent for J209 ????

-taken the pictures
-read the runoffgroove.com author's page on my laptop ......today just got time to plan the component placements
-prepared some wires such as HOOKUP wires [1 solid wire strand type] and flexible connecting wires


note i will use a verro/General Purpose Board for the prototype ..after modifications ... i will order PCBs




DAY2: the placing components and soldering
9:38 AM 6/27/2008 >


yesterday the following were purchased
-Capacitor box , all the reqd pfs (they call the ceramic disc cps as pfs here ) , it was lacking some of the required values
so extra capacitors also purchased
still some are missing line 47kpf etc ,plan to purchase today ...
-IC CD 4049 ,2 J -FETs j112 [as a replace ment for the J109 ] ,vendor told it should match the
actual one upto 90%
-Ribbon wire 6 core , 1 mtr , for the pots ,
-Mic jack and socket , for testing phase i am using a cheap mic jack 10 Rs and Mic socket
-Electorlytics 10uf and 4.7uf ,diodes 1N4007 [for reducing mains supply to the soldering iron ..heh not part of original double d]
-A cutter and Stripper , to be used wire and leg cutter,twizer ..may be helpful to hold hot parts,small parts
-A soap box ...wait its a temporary cabinet to hold the SIX POTS ,and the mic jack ..battery etc what so-ever

- also a thin soap box is . easy to drill ... with some heated iron ..my new trick



The already exiting parts
- resistor box , still some missing values like 1 M , 2.2 M , 220K etc
soo i have to add today
-solder materials
-hook up wire , wires with one solid strand
-favicol,all knows its a famous adhesive here ..has to be used for a special purpose see below
-Added the components to the board [yellow verro board for a test run]


The disaster ..
My cheap [25 INR] soldering iron died !
- so just the components are added to the verro board as per the plan in the website ,
This saves time !

- and i used *favicol* to hold them in place as i could not solder the components
[usually after the legs are bent and shortened ,normally i put it on the board
thru-holes ...they tend to fall out if not soldered immediately ..afvicol saves from this trouble ]
-finally i was able to visualize how the assembled circuit will look after it is done

to do:
-Buy a good soldering iron , missing parts ,extra solder wires , shielded wires
-then the solder the board
-solder the ribbons to the pots ,fit in the soap box
-test by connecting to the pocket AMP
(...my secret tiny amp ..runs on 9V battery )

-Add a killer looking final cabinet ..keep watching

[kaushik]

---past logs :MY DOUBLE D----

Day3: Making of 'MY Double D' guitar distortion
9:34 AM 6/29/2008 SUNDAY

-Bought SOLDRON make soldering iron

About:
The iron is of good quality , uses ceramic heater element ,
it is very fast heating approx 6 seconds all ti take to reach a peak
temperature remains steady at that temperature




- Today I finished partially assembled the thing
- Just 2 Pots are conncted as I planned to test JIGGLE section
- A MIC Jack as input and output through a MIC socket

1 st test
- I have connected the unit to the 9v battery
- connected my guitar and MINI AMP from the out put
- "No sounds" !!! meaning 1 st test failed

I am not worried as i buit 200+ small circuit projects :


suspects >

1. DRY JOINTS , i bought good quality soldering wire
2.MAY BE THE IC DIED : IC CD 4049 is a CMOS device..sensitive to temperature ... as i did lott of soldering in the past
i avoided to use a IC base ... may be during the asembly the IC died


Diagnosis

- Tested the FETs by isolating and applying +ve gate voltage using 100K resistor ,a test LED comnected between Source and Gnd.
As i apply the +ve bias the LED glows bright ... soo FETs are alive !

- Visually checked the IC connections ....all ok ..

-Next I will do some electrical continuity test ,all seems fine ......

next plan ---FRESH REASSEMBLY-- :

i think better i will re assemble the board with 1 IC base , that will save lott of time ... later i will diagnose the not -working board
-Done the reassembly halfway ...