Tube screamer ... help

[JebemMajke]

Here is the schematic



I've made my own pcb in eagle ... and for some reason, unknown even to myself, for C2 i've made used the size of a tantalum cap. No biggie, I have a dozen of those. Just one question, how to orient it? Where does the plus side goes?

[Govmnt_Lacky]

In a pinch, you could always use (2) 470nF caps wired in parallel 

I believe the film cap is preferred here. You might not want to go with a polarized cap.

[JebemMajke]

Thing is there is no physical space for two 470n.

I have a couple of 1uf non polarized ... but there is no physical place for it on the board

[armdnrdy]

Tack the cap to the trace side of the board, bent over.

You should have plenty of room there. 

[Govmnt_Lacky]

This is a valid question based on the answers thus far....

Is this an SMD build? 

If not, then armdnrdy's response would be your best bet with the 1uF NP

[JebemMajke]

Tack the cap to the trace side of the board, bent over.

You should have plenty of room there. 

I thought of that as well ... i would like to use it as a backup plan if everything else fails.

Not an SMD build.

[Govmnt_Lacky]

Well... it look like you will need to experiment then....

I really do not think you will damage anything by trying the tant cap both ways to see which works or works better. Its not part of the power feed circuit so the risk is minimal.

I say give it a shot. 

BTW... Did you do the same thing for C8?

[Ice-9]

I can't see the schematic, If you can post a picture of the schematic with the cap numbered  I can tell you which way to put the tant.

[armdnrdy]

If you are using this schematic....then C2 is a non polar 1µf cap.

http://www.generalguitargadgets.com/pdf/ggg_its8_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

I believe that you can use the tant with the positive side facing toward the input.

(connected to Q1 emitter and R3)

[Ice-9]

If you are using this schematic....then C2 is a non polar 1µf cap.

http://www.generalguitargadgets.com/pdf/ggg_its8_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

I believe that you can use the tant with the positive side facing toward the input.

(connected to Q1 emitter and R3)

+1 with Armdnrdy, if that is the schematic you are using the + side of the tant to R3-Q1 and the negative - side to the op amp .

[MrStab]

probably not too helpful, but iirc, i used polarised electrolytics for both the input to the clipping section and the output of the tone section back when i did my first Tube Screamer, and it's worked fine through many a gig. i didn't know you could get 1uF film caps for cheap back then!

ofc, the stakes are higher here, with potential tantalum explosion.

[duck_arse]

tack in any greencap, value not important. measure volts either side of cap. which is more positive? replace greencap.

[ashcat_lt]

tack in any greencap, value not important. measure volts either side of cap. which is more positive? replace greencap.

This works.  Shouldn't it be pretty close to 0V difference there?  Couldn't you just jumper the damn thing and be done?

[slacker]

ON the schemo Larry linked to replace R5 with 100k and use a 100n for C2, end result should be the same, and may be easier than finding 1uF non polarised caps.