A beginner Needs help builing MXR distortion plus.

[Izzy]

Hmmm No body answered my question

I have one more question. What type of capacitors are needed for MXR distortion plus. That radioshack guy gave me all ceramic capacitors (Beside one was taltanum). Is that what I am supposed to use? Or is it electrolytic Capacitor?

Anyone?

[aron]

Well, you need know how to identify the different types of capacitors in the circuit. The DIY FAQ has a lot on this and the beginner forum has a schematic and how to identify parts/connections etc...

Any 1M pot will do as Mark pointed out. If you must have a 1M audio taper pot, you might need to order away from Mouser.com or Small Bear.

Please take the time to read the DIY FAQ (also linked above). It will help you A LOT with your project.

[aron]

No one has said this, but the MXR distortion plus is NOT what I would recommend as a beginner project at all. You really would do much better trying the beginner project or a really, really simple booster.

[Izzy]

Hey Aron thanks a lot for helping me to clear some confusion.
I went through beginners guide that helped me a lot.
But after going through Few pages of FAQ pages, few confusion still arouse.

1>
In this MXR distortion schematic can you explain how does dpdt works? In the FAQ page it says at one position it routes from input>fx> output and in another position input wired staight to output. But this mXR had led so can you explain in few line how does connection happen in either position. If possible please draw small diagram of dpdt connection in paint brush.


http://www.freeinfosociety.com/electronics/schematics/audio/pictures/mxrdistp.gif
2>
It is necessary to get stereo jack for input? or can I still work with mono.
According to FAQ page Stereo jack allows to turn power on/off with input jack. What will happenif I use mono? What would be a remedy here?

3>
According to FAQ pages capacitor from 1 uf and above should use Electrolytic caps. But I bought ceramic caps for all the caps that I needed. WIll it be a problem (beside one was taltanum).


4>
just wanted to make sure Audio taper pots  = Logarithmic Pots?  right?


5> I am going to buy few more things that I needed for this project from small bear electrnics . Can you please check  they are the right ones

Qty SKU Description Price Total
2205 Diode 1N4148
$0.15  $0.30


1300 Capacitor Silver Mica 500V 10 pf. - 150 pf.
(10 pf.) $0.55  $0.55

2201 Diode 1N270
$0.75  $1.50

0203 Switch - Alpha 107-SF12020-L DPDT
$4.95  $4.95

1006 Pot Alpha Single-Gang Audio Taper 16mm
(50K) $1.25  $1.25 .

1006 Pot Alpha Single-Gang Audio Taper 16mm
(100K) $1.25  $1.25

0602A Jack, 1/4 in. Stereo Neutrik #NYS230 




I would really appreciate if anyone would answer these questions.

[Barcode80]

new to building, but want to help where i can...  i believe there are 3 types of pots, log, audio, and linear. ALL can be interchanged, but the results of how smoothly you can control whatever you are trying to control will be afftected by which type you use. check out geofex.com's tutorial called "the secret life of pots" for more info.

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

as for the LED, you can't have true bypasswith an LED without either a 3pdt switch or a millenium bypass circuit with a DPDT. I believe with the MXR you should use a 3pdt switch if you have on available, especially if you are gong to mount this in a box similar to the original MXR boxes (which if you are like a gajillion other people, you will be using the Hammond box that almost exactly replicates the MXR box). The extra bypass circuit would take up a little more space in an already cramped enclosure.

http://www.geofex.com/FX_images/stompsw.gif
http://www.geofex.com/Article_Folders/Millenium/millen.htm

for more info, check out geofex.com, lots of info on creating bypasses and using LED's. other than these two options, I know  of no other way to incorporate an LED and still have true bypass.

[Izzy]

Hey firstly thanks for your help.
I went through those pics before but was bit confusing to em as I am a begginer. I am not looking for True bypass so I think i will go with dpdt.
And in that Pot article it says "Log or Audio" and Linear. So I though Log and Audio are the same type. Isnt that right?

I just now found out that for one of the 1mf capacitor with polarity shown that roadio shack guy gave me tantalum capacitor will that be fine?

And also please answer my Previous post. I am waiting for it.
Thanks

[Izzy]

I am still waiting hoping for some one to answer 

[Barcode80]

The skinny on capacitors is this:

Although the type of capacitor used will usually affect what type of sound you get, as i understand capacitors you can interchange any type for any type.

for example, if you get a polyester film .01uF cap, it will functionally operate the same as a ceramic disc version of the same value. However, some people prefer the sound one gets from particular types. the different materials used have different responses to the voltages, resulting in differences in sound to some ears.

be careful though. if you ever substitute an electro;ytic capacitor in place of a non-polarized cap (polyester film, metal film, ceramic disc, etc.), you have to make sure that the pos. and neg. of the electrolytic caps are facing the right way. bad things happen otherwise....

[Izzy]

Thanks once again that helped to clearify one question.
I appreciate

here are the remaining question Once again.

1>
In this MXR distortion schematic can you explain how does dpdt works? In the FAQ page it says at one position it routes from input>fx> output and in another position input wired staight to output. But this mXR had led so can you explain in few line how does connection happen in either position. If possible please draw small diagram of dpdt connection in paint brush.


http://www.freeinfosociety.com/electronics/schematics/audio/pictures/mxrdistp.gif
2>
It is necessary to get stereo jack for input? or can I still work with mono.
According to FAQ page Stereo jack allows to turn power on/off with input jack. What will happenif I use mono? What would be a remedy here?


4>
just wanted to make sure Audio taper pots  = Logarithmic Pots?  right?


5> I am going to buy few more things that I needed for this project from small bear electrnics . Can you please check  they are the right ones

Qty SKU Description Price Total
2205 Diode 1N4148
$0.15  $0.30


1300 Capacitor Silver Mica 500V 10 pf. - 150 pf.
(10 pf.) $0.55  $0.55

2201 Diode 1N270
$0.75  $1.50

0203 Switch - Alpha 107-SF12020-L DPDT
$4.95  $4.95

1006 Pot Alpha Single-Gang Audio Taper 16mm
(50K) $1.25  $1.25 .

1006 Pot Alpha Single-Gang Audio Taper 16mm
(100K) $1.25  $1.25

0602A Jack, 1/4 in. Stereo Neutrik #NYS230 

[Barcode80]

heh, sorry. I think (here is my novice showing through) that if you aren't after true bypass, you can wire the + LED lead to a 9v+ point on the board and vice versa for the ground lead, that way whenever there is power to the board the LED would light up. however, I also think this could affect the operation of your circuit, as the voltage drain might mean necessary adjustments in the values of the other components. once i again, i recommend building a true bypass. Other board contributors, tell me if this is correct, I'm sort of guessing here. not taking into account the LED, the FAQ is dead on.

You can use a mono jack instead of a stereo on the input, but you will not get the functionality of the effect only being on when you have a plug inserted. All this means is that the effect powered on will stay on (and drain battery) whether the guitar is plugged in or not. However, it won't affect the circuit one bit otherwise. Just connect the mono jack in the same way the other jack is wired, only to the input stuff instead of output stuff.

I'm still not sure myself about the log s. audio pots thing, but i DO know that the effect will work either way. It seems like I remember seeing 3 different descriptions of pots, but maybe I'm wrong. Only been building circuits for about a week.

at a glance the parts list looks fine.

[Izzy]

Guys Is this wire or heat shrink tube?
http://www.smallbearelec.com/Categories.bok?category=Wire+And+Cable

I was going to buy it but I am confused. I needed cable for connecting pots, jacks  and other parts.
Please some one answer.

[petemoore]

  I see many products on that page including shrink tubing and wire.
 

[Izzy]

I mean the first few ones.

Like


Heat Shrink Black 1/16 [.063] diam. - 1 ft.



Heat Shrink Black 3/32 [.093] diam. - 1 ft.



Heat Shrink 1/8 [.125] diam. - 1 ft.



Heat Shrink Black 1/4 [.250] diam. - 1 ft. 

[petemoore]

Heat Shrink Black 1/16 [.063] diam. - 1 ft.
  1/16'' for little wires, 1ft. length black heat shrink...

Heat Shrink Black 3/32 [.093] diam. - 1 ft.
  Smaller Diameter for skinnier wires

Heat Shrink 1/8 [.125] diam. - 1 ft.
  Thicker

Heat Shrink Black 1/4 [.250] diam. - 1 ft.
  Would be used for like guitar cable wire, you could get 6 x 2'' pieces.

[Izzy]

So they are wires? Not heat shrink tubes?


Few more questions

1>>
How do you wire a pot. Accoring to FAQ page it says they will be numbered in schematic but in mxr dist + is not numbered . Can anyone help?

2>>
This guy has Op amp attached to the board which has parallel connection .Isnt he shorting the Opamp here?
http://img227.imageshack.us/img227/3121/mxrdistplussizedba3.jpg

[Mark Hammer]

The little red squares signify a cut on the copper strip so that the pins on the left and right sides of the chip are not connected together.  That is the principle behind vero-board: they give some common connections by virtue of the thin isolated rows, and you the user further specify what you do and don't want connected by cutting those rows.

I don't mean to be discouraging, but from your questions it is starting to sound like you need to start simpler.  That is not to suggest for one minute that you WON'T master all this stuff in a couple of months' time, but the general strategy is to point people towards projects that they can successfully build in a short time period, with a minimum of troubleshooting.  Presumably, there WILL be problems along the way, regardless of how simple the project is, but they ought to be easily solvable ones, and the builder shouldn't find themselves thinking "Why on earth did I get myself into this?", while they stare at the $60 worth of stuff they purchased from here and there that isn't doing anything at all for them.  During an era when you can stroll into a music store and buy a Danelectro chorus, echo, flanger and distortion pedal for about the same amount of money as what you have to lay out for your first full pedal, every extra week you wait until you get all your troubleshooting questions answered and the pedal working will make you wonder even more if it was such a good idea to leap into the deeper end of the pool.

Again, a VERY big welcome to this hobby.  Just don't get yourself into anything that makes you regret that decision.

[Izzy]

Thanks Mark , I appreciate your suggestion.
Probably that was my mistake I choose harder one than I supposed to.

But since I have bougght everything for this pedal. I will finish it. I sure am not going to be disspointed, even if it takes month to complete it.
I want to get into pedal designing seriously, thats the reason I choosed E . Engineerng. Ofcourse I am just a sophomore now.hehe

But still I hope guys here will help me to complete this project.
Once again cheers to everybody who has helped me till now.
Thanks.

[Izzy]

Thi is what I am exaclty confused about.

In this picture it relates  dpdt switch either connects top 4 terminal or bottom 4 terminal.
http://www.diystompboxes.com/pedals/articles/elbypass.html

and I followed how the signal flows.


But now I look in this pic. DPDT switch seems to be different. Does it conenct top 4  in one position and botttom 4 in another position?
http://www.generalguitargadgets.com/diagrams/switch_lo_dpdt_led_out.gif

Can some body explain?

[GibsonGM]

Hi Izzy, welcome again    Like R.G. was saying, going simple at first will really save a lot of headaches!  Plus, you'll more fully understand why things are done the way they are!

What I suggest for you is this:

Build the MXR on a breadboard.  Don't worry about the switch or LED right now...just get it on there working, to test that you understand HOW it works.  That means all you need is 1 wire in, and 1 wire out (to your jack tips)...the other side of the jack (sleeve) goes to ground on the board.  The +9v goes to the op amp power pin.  This way, you can plug your guitar and amp in, and play with things!     I've found that the switch and enclosure are the hardest parts of the whole thing, where most mistakes happen.  Doing it all at once increases chances of it not working, and you not knowing why!  And if you solder it up right away, you can't play with caps and diodes as easily.     I build each new effect this way, so I am sure of it before I make it permanent.

After THAT, then you can get a PCB or build it on perfboard or vero...and add that nice switch and LED, and get it in a box....which are challenges again!

If you have a multimeter, you can play with any of these switches to see how they work....just test for continuity on the pins, throw the switch, and note how it changed.  Some bypass schems use a different way of hooking it all up, but they all work.   Paying close attention to the fundamentals of audio electronics will pay off big-time later on...you certainly have the motivation!  Reading electronics books and doing breadboard work is where I (and many of us) started, and is a GREAT way to learn!
Good luck!
Mike

[Mark Hammer]

They are two different ways of accomplishing the same thing. There are certain advantages to using the second one under certain conditions, but for most uses there is no sonic difference between them.   Since you are starting out, I would say to use the first method rather than the second, simply because it is visually easier to follow, especially if you use a 3PDT and want to wire up a status LED..