The "Multi" Rat and the switches

[Lubdar]

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.

[JackSkellington]

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
10.5mm shaft length + 4.5mm thread length = 15mm

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

Thanks for the reasoning.

[JackSkellington]

I'm back.
I have to wait a lot for order the rotary switch, and meanwhile, I'm looking the layout. Is this:

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!

[jimilee]

That's pretty cool


Sent from my iPhone using Tapatalk

[JackSkellington]

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?

[JackSkellington]

Need a bit help, please.
Thank you.

[JackSkellington]

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!

[JackSkellington]

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!

[JackSkellington]

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!

[Lubdar]

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.

[JackSkellington]

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?