Fulltone 70: Mid pot not working [SOLVED]

[warioblast]

Hi,
I've just finished building the FT70 using Torchy's layout.



Everything's fine except for the mid pot that does nothing. 
Before building the FT70, I made a fuzz face clone with some '70s mods to it, minus the  diodes. The fuzz was self oscillating when controls were set to the max, but the mid pot was effective.
Looking now at Torchy's layout I can see some differences between the couple schematics that are floating around.



Have anyone successfully built the FT70 using Torchy's layout ? Or Should I start messing with my board.
All suggestions are welcome.
Thx, Fabrice

[cd]

The "mid" pot doesn't do much in the first place.  It's doesn't really affect the mids, it's more of an overall tone shaper that makes a small difference.

Besides that, the layout looks wrong to me.  R3, the 33k resistor, should be connected to 9V.  R3 shouldn't be touching TP1 either.  R2 and R6 should not be touching R3, and R6 should not go to +9V either.  Looks like the two 1k resistors (R2 and R6) were confused with each other.  The layout does not appear to be easily salvageable.

[cd]

If you want to try to salvage things, try this:

On the third strip from the top, cut in between R2 and R6

Remove R6

Run a jumper from +9V to MID - 3

Run a new 1k resistor from TP1 (third strip from top) to the junction of C5 and R5

[warioblast]

I've just done some tweakings to make the layout looks like the schematic and... it works like a charm. 

Next time I'll ask if the layout is verified 

[mojotron]

I've just done some tweakings to make the layout looks like the schematic and... it works like a charm. 
Next time I'll ask if the layout is verified 

Please edit layout and post it with your fixes if you can.

[warioblast]

I've just done some tweakings to make the layout looks like the schematic and... it works like a charm. 
Next time I'll ask if the layout is verified 

Please edit layout and post it with your fixes if you can.

My fixes


For now, it's loaded with BC 109B. I'll try BC 108 B & C, 2N2219, BC 548B and 2N3904
I also put sockets for C3.
I'll let you know how it goes.

[Melanhead]

Yup, I had to mod the layout as well to make it work ... I think I posted something about it a long time ago somewhere 

[Thomas3D]

Maybe i am not seeing it, but What are the values of the pots? anyone know?

[Thomas3D]

i found the answer after alot of searching,

from this thread...http://www.diystompboxes.com/smfforum/index.php?topic=36801.0

Going to build it soon ... Pot values are: Vol A100k, mids B1k, Fuzz C1K ( reverse log is what I'm gonna use for the fuzz ... )