Tonepad Tubescreamer Resistor Switching Mods?

[boogietube]

I want to build the Tubescreamer posted at Tonepad, but I'd like to wire up a switch to switch between the two 808 resistors and the two ts9 resistors. How would I do this and what kind of switch do I need? Diagrams are appreciated as I am a relative noob.
Thanks
Sean

[bancika]

you need DPTD switch (ON/ON). Each pole (with three lugs) will switch one resistor. For each pole one lead goes from first hole on board to center lug on switch. Two resistors are mounted on lugs 1 and 3 and both of the are connected to second hole on board. Do the same for other pole and you're set.

[darron]

drew this up quickly. can people think of a better way?



cut back one end of the resistors so that it's pretty short, about 1cm (1/3") or so, and solder them directly to the switch. on the other side trim it down a bit and connect it to some wire that's the right length to go the the board, and melt some shrink wrap over the connection so that it doesn't short out in the future.

my tubescreamer has 3 external switches sticking out of it hehe.

[smank]

My default is the 808 resistors.
What difference can you hear switching between TS9 and TS808 positions?

[bancika]

I've got one more idea...two leads go from board to outer lugs and switchable resistors go from lug 1 to lug 2 and from lug 2 to lug 3. When switch is in first position first resistor is bypassed which leaves only second resistor. Do the same with second pole of switch. I don't have time to draw it now, bu tI think it's better than previous because you don't have any "floating" joints or something, all connections are on switch.
Cheers

[cab42]

I soldered my resistors on a piece of perf and used a sticky pad??? to attach it to the switch

My default is the 808 resistors.
What difference can you hear switching between TS9 and TS808 positions?

Not much However I experience a volume drop in one position. I was planning to install fixed resistors and replacing the switcable resistors with switchable diodes.

my tubescreamer has 3 external switches sticking out of it hehe.

Whats the third switch for? Assuming that the other two are switchable resistors and switcable diodes?

Regards

Carsten

[darron]

I'm not sure I understand you bancika, you could solder the two resistors together, but maybe this is what you have in mind:



it requires a 4pdt switch however. it's the same method i used to switch my diodes in my tube screamer. id still go the dpdt for space conservation and to have less lugs in the switch.

Whats the third switch for? Assuming that the other two are switchable resistors and switcable diodes?

Regards

Carsten

hmm. one switch does the simple bass boost from geofex (which i never use), the other switches a diode to a 1n4004 for asymetric clipping. and, with a VERY tight squeeze i managed to get a 3pdt foot switch in there for true bypass. other than that i have the ts808 resistors, and a jrc4558d opamp in there.

[bancika]

Here's sketch of idea I have:

I don't know if it would work with diodes though

[darron]

a ha! that's a pretty good idea.

looks like it might be fiddly to wire, but, nice.

[cab42]

Bancika:

This is most likely a public display of ignorance! Normally I would try it before asking, but i'm on work and I'm curious

As I see this you will always have resistance of R1a + R1b for R1 and R2a + R2b for R2 not matter the position of the swich??

Or have I missed something?

Regards

Carsten

[darron]

Bancika:

This is most likely a public display of ignorance! Normally I would try it before asking, but i'm on work and I'm curious

As I see this you will always have resistance of R1a + R1b for R1 and R2a + R2b for R2 not matter the position of the swich??

Or have I missed something?

Regards

Carsten

maybe i'm wrong. i think that bancika's idea should work. while the switch is in a position, there will be a connection between the middle pole to one of the throws. this will short out one of the resistors as the signal should take the path of lesser resistance, via the switch.

can this method be confirmed by anyone?

[bancika]

you should think before insulting, man.
those resistors are in series all the time BUT one of them is bypassed because there's connection between center lug and one of outer lugs depending on switch position. When you parallel resistor with jumper you get ZERO resistance. Put zero resistance in series with other resistor on that pole and you get....gues what, only other resistor

[suicidalmoose]

man i don't think he was insulting you i think he was referring to himself as maybe making of an ass of himself by asking that question.

[cab42]

you should think before insulting, man.

Bancika, You must have misunderstood my post. I was referring to my own ignorance, not yours. I would never dream of insulting anyone on this board. Reading my post again I can se how it could be misunderstood. I'm very sorry.

BTW - Thanks for the explanation.

Carsten

[bancika]

Oh, totally missunderstood. No harm done 
Hope that little idea might help someone.
Cheers

[darron]

i'm glad that was sorted.

there you go though. three different methods for switching two resistors!
i guarantee them all or your money back.

[cab42]

No harm done 

Thanks

When you parallel resistor with jumper you get ZERO resistance.

This was the point I was missing!

Regards

Carsten

[boogietube]

Again - the forum comes to the rescue!! You guys rock!!
Thanks
Sean

[d95err]

...getting back to a previous question - is there actually any audible difference between the "808" and "9" resistors? Would it really (*really*) be worth it to have a switch?

[darron]

...getting back to a previous question - is there actually any audible difference between the "808" and "9" resistors? Would it really (*really*) be worth it to have a switch?

it's not worth it to have a switch i don't think. yes, there is a difference, and the better one is the ts808. still, it makes me wonder why they made the move to the ts9 style ones when the ts9 is a newer model. i'd just hard solder the resistors in and have a listen, chances are that you will leave them there.