A beginner Needs help builing MXR distortion plus.

[Izzy]

Ok sir I will try to get 4.7 k Resistor when I go to radio shack.


I didnt quite get this, can you explain

With your meter, measure 9v at your power in...connect black lead to power supply ground, probe with the red lead.  Set meter for "DC volts".   You oughtta get 9v on the other power supply lead.   

I do have this small multimeter. But I dont know how to use it.hehe
I think I should learn it.

http://www.radioshack.com/product/index.jsp?productId=2103174&cp=&origkw=multimeter&kw=multimeter&parentPage=search

See if you can find if it has connectivity test.



And I am thinking of using plactic enclosure box that I bought from radio shack
http://www.radioshack.com/product/index.jsp?productId=2062281&cp=&pg=3&origkw=enclosure&kw=enclosure&parentPage=search

It is safe to use this box for enclosure? COz one of my friend was telling me that I need to use Metal box for enclosore so that it will have ground and it can also shield the circuit. Is it true?

[Mark Hammer]

And I am thinking of using plactic enclosure box that I bought from radio shack
http://www.radioshack.com/product/index.jsp?productId=2062281&cp=&pg=3&origkw=enclosure&kw=enclosure&parentPage=search
It is safe to use this box for enclosure? COz one of my friend was telling me that I need to use Metal box for enclosore so that it will have ground and it can also shield the circuit. Is it true?

Many companies use plastic enclosures successfully.  Sometimes even "big names".  Keep the following guidelines in mind:

1) Plastic works best when it is small.  That increases its rigidity.

2) Many people like to use the stompswitch to snuggle the battery against the end of the box.  With plastic, you need to swing that around so that the switch is as close to the edge/wall of the box as you can comfortably manage.  That will provide the added stability so that the case doesn't crack when you step on it.

3) Plastic is fine for experiments and home-playing, but not really for gigging.

4) Metal chassis DO provide helpful shielding, but the shielding can be provided by additions to the box (I buy sheets of copper shim and cut out cover plates the size of the top, secured to the chassis by the pots.)  Buzz and other interference can be reduced by having short, well-planned leads to your pots, switches, and jacks, and by using shielded wire at least from the input jack to the circuit board.

[Izzy]

Hmm so that means its better to use Metal box rather than plastic box for making it less noisy?

So which one you think will be better?
One of them is  Plastic box(black) from radio shack. Another one is Tin box .

http://img107.imageshack.us/img107/9209/dsc000073gt2.jpg

I want this pedal to be very less noisy As I need this pedal for Home recording purpose.

[Izzy]

One more question.

Which one of these board will be easier for this project?

I guess the second one right?


http://www.radioshack.com/product/index.jsp?productId=2102845&cp=&pg=2&origkw=breadboard&kw=breadboard&parentPage=search

http://www.radioshack.com/product/index.jsp?productId=2103799&cp=&pg=2&origkw=breadboard&kw=breadboard&parentPage=search

[GibsonGM]

Your best bet is to get a metal box thru Smallbear Electronics, link on the link page here. $10, you get a real effect box that'll last forever!!  I get the 2nd smallest size metal (NOT Hammond 1590 or whatever size).  Read up on it!  You will not be disappointed.  Metal is easier and quieter for SURE.

  Watch out for Radio Shack, my man...resistors & parts are fine to get there ( a little expensive).  Meters etc. aren't very good.  I can't even find any specs for the meter you have from the web site!  I have a nice Extech DMM I got online, for like $50.  Does a lot, incl. measuring frequency & temp, and auto-ranges.  And I have an old RS meter that measures transistor gain.   

Click each function on your meter, and touch the probes together.  If you find a setting that goes "BEEP" when you do that, that is the continuity test ;o) 
If you don't have that, use the ohm function (the Omega-sign "horseshoe", I'm sure you know)....when you touch 2 connected items, it will read "0" or ".1" or something incredibly small.  Try it with a piece of wire to see when 2 things are definitely connected )

----get the 417 holes multi purpose, NOT THE IC BOARD!!!!  I always use the 1st one you posted; it resembles the breadboard and is easier by far.   ANd get a 2-pack of 8-pin DIP sockets, so you don't have to solder the LM741...

[$uperpuma]

did anyone catch that Izzy called Mark Hammer "METAL HAMMER" on page 1? Just thought that was awesome....
and Izzy, you'll find that RS is not super-useful for what we do... but the DIST + was my very first project as well and I still use it! very flexible circuit, and I tried a lot of different clipping options... make sure you do that

[Izzy]

@ GibsonGM

Thanks once again sir.
Actually i have already bought 417 Multipurpose board yesterday. Just want too sure that is the right one.Thanks for clearing things up.
And yes I already got IC sockets.

Now that Multimeter doesnot has connectivity thing. How sad!
No BEEPS..haha I think I should Return this multimeter.


The reason I didnt want to buy hammond is I will have to buy driller and Bits for it which will cost and extra  box($10)+driller ($30-40) + bit($5)
haha So i was trying to go cheaper way.



Anyway sir do you mind giving some idea how to connect dpdt swicth with LED?

[Izzy]

which one you think will be better?
One of them is  Plastic box(black) from radio shack. Another one is Tin box .

http://img107.imageshack.us/img107/9209/dsc000073gt2.jpg

I want this pedal to be very less noisy As I need this pedal for Home recording purpose.

[aron]

Anyway sir do you mind giving some idea how to connect dpdt swicth with LED?

The beginner project, the FAQ and the WIKI have info on how to connect circuits to a DPDT switch with LED.

[Jay Doyle]

Izzy,

I really mean no offense here, but you need to do some of this for yourself. All of this has been done before and is available in the FAQ, the search function, on GEOFEX, AMZ and a lot of other places. If you have people hold your hand through out the whole project you aren't going to ever learn it for yourself.

Good luck,

Jay Doyle

[Izzy]

Thanks for your sugegstion sir.
Yes I did checked in FAQ. But I still had confusion, so I was looking for help.
I am still learning so please ignore my stupidity.

And Yes I will try as you said Sir.

But I need one rroe help, before I return this Radio shack plastic project box.

which of these box will be better for pedal?

http://img107.imageshack.us/img107/9209/dsc000073gt2.jpg

The black plastic one(Radio shack) or the Tin one?

[$uperpuma]

pedal parts plus dot com has reasonable boxes... $5 for a box that would be perfect for that... shipping is cheap. a metal would be better...

[aron]

Go for the metal since you want to use it for studio work.

[Izzy]

Thanks

I will check it. But still not sure whether I am going to spend more$ in this pedal or not. Already spend $110+ for a 80$ pedal. Sounds crazy..haha

And finally I figured out how to use dpdt using LED.
But there is a significant amount of Hum?noise. How to get rid of this?
Yes I will definately go through other threads but if you have any suggestion please POst it.

[GibsonGM]

Take my advice, Izzy, LOL...get a metal box from Small Bear or another suggested site.  You could get the pre-drilled one, but most everyone finds it easier to get one with no holes yet, and put the jacks above the volume/gain pots (top side), not on left & right sides.  To drill them, you just need a set of cheapo bits and a hand drill.  You start by punching where you want the center to be with a nail, and use 1/8" bit.  Then something a little larger, and so on.  It's soft aluminum and I always get GREAT results using them. You're putting a lot of effort into this project...you should build it to last!   I wouldn't use plastic or tin.  Plastic can work, as M.Hammer said, but that's a more advanced subject (shielding).  Tin will fail...takes us to #2...

2.  You're likely getting some hum from lights in your house, a tv or monitor nearby...when the ckt is on the breadboard it's not shielded (just like if it was in an improperly shielded plastic box     It picks up any interference in the air (RF, 60Hz power hum...).   Provided it is built properly, when you get it in an enclosure, the box provides all the shielding from that that you'll need.

3. You'll need a 3PDT switch (again, Small Bear) to have the LED, or a DPDT for no LED.  I made mine without - I know when it's on, and it's almost always on      You COULD make a millenium bypass, but at this stage, a bit much to try to tackle (let's get it in the box and working!).

4.  The idea with these DIY things is to get bulk parts...not just 1 cap, but a package of them, maybe even 100 to 500 assorted values.  Buying individual stuff costs a lot.  Same with the resistors - get a whole package, $12 at RS, instead of just a rack of 5.  Get some opamps and transistors (npn small switching/amplifier type, even RS has those), pots, small tools etc.  Start up cost is like $100 - $150 including a new, awesome $50 meter (Extech).  That way you can build things at will, and they only cost about $10 in actual parts. Add in the box & switch, comes to like $40 per pedal.  After you have made 5 of them or so, the initial $100 seems like nothing!  Plus you'll use the stuff to fix your guitar, etc etc.  Save your cash and buy stock!

Listen to the advice of the others on here, you can learn TONS!!!!  I've made about 8 or 9 effects, and there are veterans like Mark Hammer et al. that have designed and built many more.  They've learned the hard way, so we don't have to!   

[Izzy]

Once again Salute to you Sir!
Thanks for another very helpfull post.

I will see what I can do with this low budget.
As per your suggestion I will try to return this chepo multimeter to Radio shack tomorrow, and most probably the plastic enclosure too. And I will see if I can get things in bulk.

And about the hum/ Noise , Is it because I am using an AC adapter through 9v batetry connector? I dont have tube light, No Tv around, One LCD monitor (Which I think doesnot cause hum). One thing I noticed was when I bring my hand nearrrr to bread board the hum/noise increased!

Yeah and I did get LED On with DPDT, even though its not true bypass it will work fine for me coz I never play guitar without distortion.


Anyway here's my near final Pic, before I mesh things up with Solder.       

[Izzy]

One more thing to Gibson GM or anyone.

When I rotate the drive knob untill 80% the drive is pretty low and the drive start to increase after around 80% it increases really fast.
Why is that?

Is it because  of this mistake? The resister circled near Opamp was supposed to be 4.7 k instead I put 0.47 k.
Could that be the reason? That is the resistor which comes before Drive Pot.
I tried with 2.2k but still it didnt changed much.

[aron]

1. For absolute authenticity, a 1meg reverse-log pot is needed.  Most of what that pot does, though, is not of any great use.  If you are not interested in "authenticity" but primarily are interested in cranking it up and rocking ASAP, buy either a log OR linear 100k pot and use it in place of the 1meg unit shown.  I guarantee it will work just fine and give you 90% of what the original will.

It's probably the taper of your drive pot. That's what Mark Hammer was getting at.

Oh no! Another article to check out!  Look at the graph of the pot tapers in the article.

http://geofex.com/Article_Folders/potsecrets/potscret.htm

[Izzy]

Thanks Sir.

I was thinking Log's graph as Reverse log's graph, so I was comparing the increasement according to it. haha
My bad.
But still the distortion sounded sudden around 80%.I will check it again.
So is LOG what most of the pedal use for Drive?
I dont know why I feel reverse log was better Option.  May be I am wrong.

[GibsonGM]

The pot needs to be a Log taper just for this project. Usually the schematic will be labeled what kind you need, but the MXR only says 1M.  You don't see them very often.  Mine does exactly the same thing, but I got used to it and can dial it in ok.  I usually just leave it about 90% or so.    If you put the 2.2K resistor in the place that needs the 4.7K, things should be just fine - in fact, if you use 2  of them in series, you don't have to get a 4.7K resistor (2.2+2.2=4.4, close enough!!). 

Hum when you bring your hand near suggests a floating ground.  Check everything that should go to ground to be sure it's all connected properly.  It's easy to make mistakes, esp. when it does work, but just not working perfectly!   A distortion pedal IS noisy, tho.  Over time you'll learn what noise level is normal and what = a problem. The AC adapter may have something to do with it, yes...try a battery.

You'd do well to find someone with a credit card that will help you, Izzy, he he.  That way you can order up stuff online - saves $ and you can research what you need, find out if people liked their purchases.