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hi I had this one weird idea, but I wanted to make sure with you guys.

How much of  change does a diode makes in distortion?
I wanted to make a pedal with 6 diodes selection in each diode position. So that I can select any diode out of 6 diodes in using rotary 3 rotary switch.

I havent shown diodes in the pic below, but just wanted to show what I mean.

with 6 changable diodes in 3 position there will 216 possible  outcome of distortion sound.
What do you think?


(http://img242.imageshack.us/img242/1466/creameryg3.jpg)

Not a weird idea at all
http://www.diystompboxes.com/pedals/shaka.JPG

I'm not sure how you'de wire up the switch. I suppose it would just take a little thought as to how the connections are made.  Don' know

Scott

No, probably I couldnt explain it well.
I mean you can select 6 diodes in each diodes shown up there. I didnt mean 6 diode at once.
there will be only 3 diodes as shown above but i will be able to change any diodes with a rotary switch.

what do you guys think? how much of variety of distortion am I gonna get?

I am planning to use
1n4148
1n270,
1n4001
1n4007
LED
1n34


Which LED is better? 3mm or 5 mm? and what color  is best?

Quote from: Izzy on October 21, 2006, 11:23:32 PM
Which LED is better? 3mm or 5 mm? and what color  is best?

i think people like 5mm red.  i don't know, just wire a bunch of different ones in the switch.  test test test.

Well, my recommendation is sort through those and remove those you don't like the sound of.
Different colour LEDs have different threshold voltages, so what is 'best' is subject to your taste, so you should try a few.
I would personally narrow it down to 1 diode type that sounds the best.

Thanks

how does the connection on this one work?

http://www.smallbearelec.com/Detail.bok?no=117

anyone? :-X

Changing the number of diodes in series on each side can be just as drastic as changing the diodes themselves, if not more so. As long as you're modding the bejeezus out of your pedal, try switching diodes in and out of the circuit altogether.

As for the switch, just order it and figure it out with the beep mode on your meter  ;) shouldn't take ya five minutes.

haha Nice one.
Yeah I was gonna order them but I wanted to make sure whether I can make then 2p6t or not.

I wanted switching like this.

x x o o o o o
x o x o o o o
x o o x o o o
x o o o x o o
x o o o o x o
x o o o o o x


So I wanted to make sure. Doesnot adding more diodes in series decrease the distortion and increase the the level?

yes, but you can experiment with asymmetrical clipping (one side has more diodes than the other). Some people hear a huge difference, some don't. It depends on what characteristics of distortion you tend to hear more.

yes I am trying to make assymtrical clipping too.

This is what I have been trying to make in Boss DS-1 circuit, with
1n4148
1n4001
1n4007
1n271
1n34a
LED

here will be huge possible of outcomes but I dont know how much of each out come is gonna differ. There is also an option for hard clipping for soft clipping using dpdt.


(http://img233.imageshack.us/img233/3655/megaishtortionkk3.jpg)

Any help?
which diodes should be the best options?

1N4007 is almost exactly the same as 1N4001. A different/better option would be to use a MOSFET as a clipping diode. And aren't 1N271 and 1N34as both germs?

Thanks a lot.
That would help.
So Instead of 4001 and 4001 I will only use 4001.
Hmm and I dont know how to attach transsistor there. Can you help a  bit?

And yes 34's and 271 are both germs, so are they the same too? If yes then I will have to remove one of them

Thanks!

So any other better option?

Enjoy the clipping experience  ;D

I have a DS1 which I modified and added clipping options via a 2 5 way rotary switches.

Gives me any combination of the following:
Germanium
Stock Silicon
LED
Tube
Open (no clipper)

(http://i21.photobucket.com/albums/b290/theblueark/Image005.jpg)

You could also try putting a few of them in series, it will increase the headroom while keeping most of the characteristics. Especially useful for the low head room germaniums.

To wire MOSFETs as clippers, scroll down to the bottom of this page.

http://www.diystompboxes.com/wb/pages/build-your-own-stompboxes/stuff-to-read/simple-modstips.php

Quote from: theblueark on October 23, 2006, 12:24:27 AM
Enjoy the clipping experience  ;D

I have a DS1 which I modified and added clipping options via a 2 5 way rotary switches.

Gives me any combination of the following:
Germanium
Stock Silicon
LED
Tube
Open (no clipper)

(http://i21.photobucket.com/albums/b290/theblueark/Image005.jpg)

You could also try putting a few of them in series, it will increase the headroom while keeping most of the characteristics. Especially useful for the low head room germaniums.

WOW you had a tube too?? I wanted to try with a tube but I am kinda scare of its high voltage!  ;D

Hi Izzy,

For this kind of application, one uses a preamp tube, such as a12AX7....they run on 12V (yes, the first part of the name = voltage; the AX=gain factor, and the 7 = # of elements inside the tube).

If your pedal is already assembled, you could put wires where the diodes go in the board, run them out to a breadboard, and switch all kinds around.  When you find winning combinations, write them down.  Then you can set up your switch and install that part of the ckt ;o)
One way to tell diodes are going to be "different" from each other is to measure their forward voltage.  That, I believe, has MUCH more to do with their sound than diodes from within each "family".  Another thing to think about is that if you change diodes radically, you may also want to change input/output caps at the same time, or that filtering cap on the MXR to the right of the clip section - the character of the distortion can change a lot between diodes.  That means another knob, or toggle, or some really fancy wiring!  Worth looking into, tho.

Thanks GibsonGM.!

So that mean 12ax7 only needs 12v? I heard they needed 110 v??
So If I use tube wouldnt it be a hassle to bring 12 v just for the tube?

And for the mosfet transistor can I use any one? Or can you tell me some good ones?

So then I have narrowed down my options to
1 -4148
2 - 4001
3 - 271 or 34's (which one is better?)
4 - Led
5 - Mosfets
6 - ? (Any suggestion?)



And do I always need to attach a diode with Mosfets?

Attach a diode????

Sorry I mean putting diode in  series with mosfet.

I don't think so...I've never done it myself, but I've heard clips and seen other people do it   :icon_biggrin:. It uses the diodes inside the MOSFET to clip already.

Thanks again salty beans!

Can any one give me some idea of how to put tube (12ax7)? I eman do they need separete setup or can they just go in feedback looop?

whoa whoa Izzy, LOL!   You'd have to look up "tube preamps" on the net, or look in the links...there is a tube amp site (AX84, maybe?).   What you'd be doing with a 12AX7 is making a small preamp...the tube is driven into clipping, resulting in distortion (just like the front end of an amp).  If you're already using a tube amp, this might be a pain in the ass for no good benefit  ;)  They operate just like transistors in theory, but sound a lot better in my opinion.

If I recall correctly, you use a Fender Hot Rod Deluxe? I do too...just replaced V1 and V2 with 12AT7's. It tamed the fizzle distortion, warmed the amp up, and my MXR sounds GREAT thru it now!!  Making a pedal with one may in fact just duplicate what the amp is already doing.

To get you started, the first number with preamp tubes refers to the voltage it operates at (12 in 12AX7, for example).  The letters = gain, and the last number is the number of elements in the tube.  There are 7 in many, this is a dual triode.  3 elements each, and 1 for the heater which is common to both.   Power tubes are entirely different, I don't know much about them except that they DO take 100's of volts to operate. 

Start searching the net...maybe you'll create something new!  lol  Now you're opening up amplifier construction  8)

haha thanks GibsonGM!

So it does take 100 voltage...hmm..I guess I am not at that level to play with 100v now. ;D

But I will sure do look it up.

And No I dont have fender deluxe hotrod. I have this crappy 15w marshall which I use to use for headphones As I never get to play it because I live in apartment.hehe
I dont want cops knocking at my door.
I have been a headphone guy for a long time.And now after I bought Line6 toneport Ux2, it gave me the tone that I was looking for...haha now I have been using that computer generated effect with headphone.

While I  look up tube preamp does someone know any good diodes for clipping beside these :

4148
4001
led
mosfet
1n271 or 34 (can anyone tell me the difference between these two?)

I am still waiting for some one to fill the 6th  space for Diodes option :D

Actually the tubes can run on 6V or 12V too. It's called starve plate or something. For mine, I'm actually using them as clippers, not as a preamp.

Check out this thread for more info: http://www.diystompboxes.com/smfforum/index.php?topic=41416.0

I asked a lot of questions near the end, which should help you with understanding it.

Your other option for the 6th position, I reccommend leaving it open, so you can hear how it sounds without any clippers too.

Thanks!
But looks like people say it aint worth the effort for using Tubes as clipper. I guess tube alone costs like $20 in ebay. :D
I guess using tube inside the pedal as a preamp wuld be cool but looks like I need to do lot of research before I start ;D

Well I was about to but parts from smallbear, but I need someone to fill in this 6th diode option spot.
I dont want to leave it empty  :-X

1.4148
2.4001
3.LED (red 3mm)
4.Mosfet
5.Germanium diode (271 or 31's? which one is better?)
6. _ _ _ _ _  can anyone suggest? :-\

Quote from: Izzy on October 22, 2006, 09:20:12 AM
how does the connection on this one work?
http://www.smallbearelec.com/Detail.bok?no=117

like that!  :icon_mrgreen:

(http://i11.photobucket.com/albums/a192/alderbody/Temp/Cap_switch.jpg)

If you want to find out, just short the two "output" leads and run a continuity test on every pin.
You'll discover that the pairs are formed every sixth pin. That is, the first you'll test will match with the seventh, and so on...

Mark them, so you won't lose what you found.

[tip] You may need to fit a knob in order to rotate that shaft.
It's kinda hard to do it with your fingertips. At least my switch was really tight...

Quote from: Izzy on October 24, 2006, 12:18:31 AM
I am still waiting for some one to fill the 6th  space for Diodes option :D

Assymetrical clipping?   
Let's say, Ge on one side and Si on the other.
Or two Ge on one and one on the other...

your options are countless... 
Just listen before you solder... ;)

btw, mosfets need a Ge diode in order to produce the "mosfet" clipping.
Otherwise they should sound like Si.  (oversimplified approach)

More info can be found here:
http://www.elixant.com/~stompbox/smfforum/index.php?topic=38581.0

Quote from: Izzy on October 24, 2006, 02:33:22 AM
Germanium diode (271 or 31's? which one is better?)

It's not a matter of diode part number, but mostly a matter of material/turn-on voltage.

So the categories are generally: LED, Si, mosfet_as_diode, Ge or Schottky (similar thresholds).
It's just that in the real world, even some parts of the same type might have some minor (or major?) differences.

Also read: http://www.muzique.com/lab/warp.htm  and all the similar articles.

Once again: listen before soldering!... 

good luck!

Thanks man I appreciate.

And yes here I can choose between symmetrical clipping and assymetrical clipping. If you see on the pic, one of diode selection has empty option which lets  me to make  ayyemtrical into symmetrical. hehe


And thanks for explaining switch. So it means there are 12 connections? each one connects to the one on the opposite side right?
So If I short 6 connector in one side I  guess I can make this switch a 1p6t switch, I guess.?

Quote from: Izzy on October 22, 2006, 10:31:00 PM
yes I am trying to make assymtrical clipping too.

This is what I have been trying to make in Boss DS-1 circuit, with
1n4148
1n4001
1n4007
1n271
1n34a
LED

here will be huge possible of outcomes but I dont know how much of each out come is gonna differ. There is also an option for hard clipping for soft clipping using dpdt.


(http://img233.imageshack.us/img233/3655/megaishtortionkk3.jpg)

Can anyone recommend best MOSFET trannies for heavy metal kinda distortion, or closer to that? ???

To get a metal distortion, you need a super-high-gain circuit. Changing diodes alone won't get you radically new tones. They affect the distortion clipping only. Changing diodes is something subtle. Don't expect to go from a light bluesy tone to heavy-metal crunch with one diode switch.

hmmm Can you show me any super high gain circuit?
Are they the one with 4 opamps? :-X

can any one suggest me some good transistors for higher distortion?

no one? :-\

Good MOSfets would be the BS170 (of course) and the 2N7000 (probably would recommend this one for your circuit).

QuoteChanging diodes alone won't get you radically new tones. They affect the distortion clipping only. Changing diodes is something subtle. Don't expect to go from a light bluesy tone to heavy-metal crunch with one diode switch.

This is the truth. It could be argued that a single turn of a tone control could have a more radical effect than diode changes. OTOH, diode changes do change the "feel" of the effect.

Hi-gain transistors  - look for high hFE readings. The 2N5088/2N5089 are pretty high hFE.

Check out:

http://www.diystompboxes.com/analogalchemy/

Obsidian and Vulcan. You will love them.

Thanks Aron!

But this circuit is weird!
http://www.diystompboxes.com/analogalchemy/sch/vulcan.html

How will the current go from cathode to anode of those 1n914 diodes?  :o?

Looks like the transistors are used as gain in those circuits. I was specifically looking for Transistors as diode.

But your advices are valuable as always. I might add trannies in DS-1 as gain stage (is it possible)?

I think DS-1 already uses 2 trannies, one as Input buffer and another as Gain stage right?, so adding another gain stage after the one in ds-1 would help?

Kinda confused here :D

If you look at the "Clipboard" or "FlexiClip" by Dano12, you can see this idea of using singular and multiple diodes and transistors as diodes from input to output with cathode to anode, and anode to cathode idea.  This clips one side of the sound going through it, and gives it a nice boost depending on what diodes you use.  The MOSfet to Germanium Diode arrangement gives a warmer tone.  The Germanium Diode alone gives the loudest and nicest warm and smooth boost.  The LEDs and Silicon diodes (1N914/1N4148s) are very loose and wild.  They dont sound great by themselves.

Hope this helps.

EDIT: Links:
Clipboard Topic: http://www.diystompboxes.com/smfforum/index.php?topic=49318.0
Banika's Article: http://storm-software.co.yu/diy/index.php?project=flexi_clip

QuoteI was specifically looking for Transistors as diode.

I see. Well, you can try any Si or FET as clipping diodes as mentioned here:

http://www.diystompboxes.com/wiki/index.php?title=Simplemods#Simple.2C_Easy_Mods.2FTips_.26_Techniques

Look for FETs as diodes.

Hmm Thanks man, I appreciate. I have already read that article  a week ago. That article was helpful.
Looks like skotchy (spelling?) diodes are what I am looking for. Diodes that clips fast! hehe
I guess they clip at 280mv? I hope they are different than germanium ones.
So that means any mosfet trannies will do for clipper right?

So is it possible to add one more gain stage in DS-1 using transistor?

There's a simple gain stage posted somewhere, I don't know where...but I have the schem on my comp. 4 resistors, two caps, a high-gain tranny and a pot. PM me and I'll send it to you so I don't offend anyone's posting requests.

One final quitestion regarding this.

So the type of diodes doesnot really matter as clipper? Its only the diode voltage that matter?

If a germanium diode has .3mv across and a scotchy  diode also has same voltage across , does that mean I am going to get the same kinda clipping  with each one?
So no change  at all then?

anyone? ???

I guess I should Drop this IDea. Instead I will try to make this pedal a Super High gain circuit  ;D (Atleast I will try)

Where can I find High gain , quiet Transistors at?

2N5088s and 2N5089s are commonly used.

Oh cool. Then I dont really have to look for Hfe?

It would be wise to order a good amount of them and measure the hfe is each for the highest gain ones. You can mix and match 5088s and 5089s without a problem.