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Projects => How Do I? Beginner's Paradise. => Topic started by: JackSkellington on March 01, 2016, 11:57:25 AM

Title: The "Multi" Rat and the switches
Post by: JackSkellington on March 01, 2016, 11:57:25 AM
Hi guys.
One of my next projects is The Rat, a kind of multi rat version.
I chose this:
http://www.sabrotone.com/?attachment_id=2127 (http://www.sabrotone.com/?attachment_id=2127)

So, that should be a sort of three version in one, cause the several clipping.
I wanted to use for the first time a rotary switch and I bought this 2P6T:
http://www.musikding.de/Rotary-switch-2P6T-open (http://www.musikding.de/Rotary-switch-2P6T-open)

I bought it for a more complex version, but then I change my mind for an easier version, in the first link.

My question:
1. Can I use a 2P6T rotary switch in that layout? I was thinking to use the three clipping modes and a fourth position for a no clipping mode.
2. I would like to know if that rotary switch has the chance to set only four positions. (I wish because it will be Very useful.)

Thank you!
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 01, 2016, 01:28:16 PM
Hey there,
1.) You should be able to use a 2P6T rotary switch with that layout just fine
2.) This particular rotary switch doesn't have a way to set to only 4 positions. You'll just have to remember that. There are alpha 2P6T rotary switches out there which have a washer with a knib which allows you to adjust if you want it to only go to a certain number of positions, they aren't as beefy as the one you've got, but in my experience I've never had an issue with them.
Hope this helps.
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 01, 2016, 06:44:35 PM
Thanks for your help. ;)
Problem solved, more or less.

I could decide to solder this 6 position rotary, that I have already, and use 4 position ignoring other 2 :(, but I don't like too much the idea. Or I could buy this kind of DPDT On/On/On http://www.sabrotone.com/wp-content/uploads/2013/01/DPDT_on_on_on.png (http://www.sabrotone.com/wp-content/uploads/2013/01/DPDT_on_on_on.png) and use it like this: http://www.sabrotone.com/wp-content/uploads/2013/01/DPDT_on_on_on_as_SP3T.png (http://www.sabrotone.com/wp-content/uploads/2013/01/DPDT_on_on_on_as_SP3T.png).

Too bad, I would had a rotary switch, most of my pedals have toggle switch.
I'll see.
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 02, 2016, 04:08:54 PM
yeah on-on-on is probably a better solution for this situation
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 02, 2016, 04:58:30 PM
I really wanted to use in this project a rotary switch in this project. :(
The "special" on-on-on switch I found is more expensive than regular. Have to be "Z". And more expensive even than any rotary switch I found. ::)

So probably I have to buy again the right (or better) component.
Which rotary switch should be perfect for this project? I would like a 4 position and having a no clipping mode further the 3 modes included in the layout.
I'm looking this page: http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch.html (http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch.html).
A good four posistion for this project should be a "ROTARY SWITCH 2 POLE 4 POSITION". Right?

I have some doubts about the size of the shaft, 15mm or 17mm? I want it about the same of a normal potentiometer alpha with base diameter of 16mm. I assume I have to buy the 15mm shaft. But... just to be sure...

Thanks!
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 02, 2016, 09:55:23 PM
Heh if you really wanted to use a rotary switch on this project, then the one below should work.
http://smallbear-electronics.mybigcommerce.com/26mm-enclosed-1p2-12t/
you only need 1 pole, since you are using the point after the opamp to ground to select diodes/(no diodes).
These are nice because as you'll see (if you buy it) that you can use the washer they provide to limit the number of throws being used.  that way you can limit it to just 4 positions.  The shaft is a little bit tall, i have just recently started cutting a little bit off the top so that the height of all the knobs outside of the enclosure are the same.
One pole should work, the only other reasons you'd want other poles is if you are going to be making "Switching" changes in other parts of the circuit.

Hope this helps.
  Lubdar
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 03, 2016, 11:28:41 AM
Well, thanks, again. :)
I used to place my order by Tayda, and seems to me the rotary switch you have linked should be this http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch/rotary-switch-1-pole-12-position-alpha-sr2611f.html (http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch/rotary-switch-1-pole-12-position-alpha-sr2611f.html) I can see it also from the datasheet, where I can read One Lockwasher Piece. So it could be that the right rotary switch.
It's a bit more expensive, but still less than toggle switch "Z", (if I have buy the rotary switch from Tayda).
Never mind how position it has, I can setting just 4, somehow.

Now I have to know what means "Non-Shorting (break-before-make)" and "Shorting (Make-Before-Break)".
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 03, 2016, 01:36:06 PM
Sounds like it should work out well.
taken from Beavis Audio:
"Non-shorting" means that when you switch the positions, the switch breaks the connection with the current position before engaging the next
"Shorting" means that when you switch positions, the switch the leaves the current connection intact while switching to the new position and then disconnects the current connection.

I'd go with the "shorting" option.

You would need to connect the pole on the rotary switch to ground, and then have the connections for diode clipping wired to the different throws of the switch.

You can read up more about switches here:
https://web.archive.org/web/20130225164157/http://www.beavisaudio.com/techpages/Switches/ (https://web.archive.org/web/20130225164157/http://www.beavisaudio.com/techpages/Switches/)
Hope this helps,
   Lubdar
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 03, 2016, 03:49:43 PM
Thank you for the link. I visit Beavis Audio rarely since that have change address.

I'm sorry, but more answers I got, more question I have! ???

Ok the thing about shorting an non-shorting.

But on Tayda web site, where I have to buy, the rotary switch with positions setting, those black (plastic I assume), are non-shorting, while the shorting (with knurled metal shaft) could have not the lock washer to set the number of position. I could write to Tayda to be sure.

Or rather maybe, I can buy a 2 pole 4 position ignoring the second useless pole, it has metal shaft, it is shorting and with the right number of positions. It is a problem ignoring the second pole? Because this seems to me the easy and cheap solution. I'm messing myself with this rotary! ::)
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 03, 2016, 07:07:48 PM
There's no problem if you ignore the other pole, its just a waste of a pole that's all.
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 03, 2016, 09:17:08 PM
Ok, Lubdar. I guess I can use a shorting 2P4T. ;)

Quote from: JackSkeletron on March 02, 2016, 04:58:30 PM
I have some doubts about the size of the shaft, 15mm or 17mm? I want it about the same of a normal potentiometer alpha with base diameter of 16mm. I assume I have to buy the 15mm shaft. But... just to be sure...

15mm or 17mm? This is the last info I need.
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 04, 2016, 02:55:14 AM
Without seeing the data sheet I would assume they're talking about the footprint. The main issue is making sure the diameter of the shafts willwork with your knobs. I'd personally go with the 17mm just since it might be a little bigger and have slightly larger spacing of terminals. But if you have enough space i'd go for the larger size.
Glad I could be of help  :)
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 04, 2016, 09:38:40 AM
This is the Specifications:

ALPHA 25mm (I think this is the base diameter)
15mm Shaft (This is the lenght, but just of the knurled part? Or the whole part included the thread?) My question.
6mm shaft diameter (This should be ok with the knobs of the regular pots)
Spline Shaft (No problem with it)
2 Pole (OK)
4 Position (OK)
Shorting (Make-Before-Break) (OK)
Solder Lugs (OK)

I don't want to risk to have a shaft too much long and set his knob higher than other.
Unfortunately I can't find the datasheet of this exact rotary switch.

This is my really last question. :P

Thanks.
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 04, 2016, 01:36:34 PM
Heh i don't mind the questions :)

If its a metal shaft then you might have knobs sticking up higher than others, but only a slight bit, if its plastic then you can trim it down.  (I do that with the alpha 2p6t knobs) The 15 mm should include the threads.
can you paste the link to the switch?
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 04, 2016, 02:18:37 PM
Sure! :)
This is the shaft lenght of 15mm:
http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch/rotary-switch-2-pole-4-position-alpha-sr2511-3583.html (http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch/rotary-switch-2-pole-4-position-alpha-sr2511-3583.html).

This 17mm:
http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch/rotary-switch-2-pole-4-position-alpha-sr2511.html (http://www.taydaelectronics.com/electromechanical/switches-key-pad/rotary-switch/rotary-switch-2-pole-4-position-alpha-sr2511.html).
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on March 04, 2016, 06:34:11 PM
ahh ok, in that case it looks like it is indeed the length of the shaft.  I would measure the length of the shafts on the other potentiometers you're using on that build and got with whatever is similar.  In this case, erring on the side of caution you might consider the 15mm shaft, just because it's highest point is ever so slightly lower and less likely to cause the knob to be above the others.
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 05, 2016, 03:25:08 PM
Usually I buy this kind of pots:
http://www.taydaelectronics.com/potentiometer-variable-resistors/rotary-potentiometer/linear/1k-ohm-linear-taper-potentiometer-round-shaft-solder-lugs-3588.html (http://www.taydaelectronics.com/potentiometer-variable-resistors/rotary-potentiometer/linear/1k-ohm-linear-taper-potentiometer-round-shaft-solder-lugs-3588.html)
10.5mm shaft length + 4.5mm thread length = 15mm

So I'll buy the rotary switch with 15mm shaft length.

Thanks for the reasoning. ;D
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 23, 2016, 11:14:42 AM
I'm back.
I have to wait a lot for order the rotary switch, and meanwhile, I'm looking the layout. Is this:
(http://www.sabrotone.com/wp-content/uploads/2011/10/ProCo-Rat-vero.gif)
I want to add the Lube/Ruetz mod. I got I have to switch the R7 47R resistor with a 1k linear pot.
So I should to replace R7 with two wires connected to the two center poles of a DPDT switch.
So, one side I have to solder the 47R, to the other side I have to connect with a wire 1&2 lugs of the pot together on a pole (the one headed to the 2.2uF cap), and the lug 3 connected to the other pole (the one headed to the IC).
It's hard to explain, and I'm famous for complicate the things, but it should be ok.

Thanks for repling! ;)
Title: Re: The "Multi" Rat and the switches
Post by: jimilee on March 23, 2016, 02:35:10 PM
That's pretty cool


Sent from my iPhone using Tapatalk
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 23, 2016, 03:10:23 PM
Good! Thanks! ;)

A question about the rotary switch I have to get, with 4 positions instead 3.
According the layout I have the input of the switch from the lug 1 of the Filter pot. On the board I have the connection fromthree poles of the rotary with the stripes for the three modes, getting silicons, leds and germaniums (+mosfet) clipping.
With the fourth position I would get a "no clipping" mode. Should I connect a fourth pole of the rotary switch with the ground stripe?
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on March 30, 2016, 09:30:34 AM
Need a bit help, please. :(
Thank you.
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on April 04, 2016, 07:52:49 AM
Quote from: JackSkeletron on March 23, 2016, 03:10:23 PM
Good! Thanks! ;)

A question about the rotary switch I have to get, with 4 positions instead 3.
According the layout I have the input of the switch from the lug 1 of the Filter pot. On the board I have the connection fromthree poles of the rotary with the stripes for the three modes, getting silicons, leds and germaniums (+mosfet) clipping.
With the fourth position I would get a "no clipping" mode. Should I connect a fourth pole of the rotary switch with the ground stripe?

I need just a little confirm. I would cut the board. :)
Thanks!
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on July 27, 2016, 09:45:45 AM
My pedal is here!
Stock control for Distortion, Filter and Volume, the Ruetz pot with a switch On/Off beside it, and a 4 position rotary switch.
And I think one of my best look.

Thank you!
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on September 14, 2019, 03:21:44 PM
Hi guys!
I built this Multi Rat a pair of time.
I want to build this again, but in a 1590B enclosure (or 125B at max), using a toggle  3-way switch DPDT with Z connection for three clipping and the stock three pots, without any Ruetz mod with extra toggle switch or pot.
I want save some room inside the box, and I ask if I have necessary to use the IRF520 mosfet or I can use the normal size BS170. Reading the datasheet or the specification I can't say if that is a good replacement with no difference.

I read the Fat Rat use BS170 with a pair 1N270 (the layout says 1N34A), or the BS170 with BATxx. But I have no proof.
Who knows what mosfet use the original Fat Rat? Does someone find some picture?

Thanks! :)
Title: Re: The "Multi" Rat and the switches
Post by: Lubdar on October 21, 2019, 02:11:37 AM
Hey there, it has been a while for both of us.  I've never compared the IRF520 vs BS170 sound. But I would let your ears be the judge; if it sounds good, it is good.
Title: Re: The "Multi" Rat and the switches
Post by: JackSkellington on October 21, 2019, 07:00:31 AM
Probably I'm going to try a pair of BS170 next time I will buy them. :) Just I wanted know if somebody else already do it. :)
It's just a guess, but I find hard to think that in the Fat Rat, the version with the Mosfet clipping mode, there are the IRF520.
Maybe the 2n7000?