Radio interference in Highway 89 finally solved !

[alfafalfa]

Hi all,

Just wanted you to tell that I finally succeeded in getting rid of the radio interfence I have had in my Highway 89 build.
Could be that because I designed a pcb for it myself and this caused the problem.
Sometimes radio reception came drifting in and noise with it.
Have been trying to solve it with ferrite cores , making the wires as short as possible , small caps from drain to gate : this seemed to work first.
Now I have just added, after having a look at the schem , a 68 k resistor at the input and voila !
Just like in regular amps , very sensitive stages can't do without.

Regards , Alf   

[Paul Marossy]

Cool. When all else fails, you can also solder a 47pF cap from the input to ground to kill RFI.

[oldrocker]

I agree with Paul.  The small size cap at the input to ground usually helps with RFI.  I had success with a .001 (102) but it sounds like you found something that works for you.  Congrats on this build.  It's definitely one of my favorite distortion pedals which I gave to the guitarist in my band.  Now I have to build me one.

[alfafalfa]

Oldrocker,

I'll bear that in mind the next time I have this problem , could work for me then !
I absolutely agree with this design being one of the best for a  terrific crunch and rock sound and  when you open up your volumepot on the guitar , a marvellous leadsound .
What I like most about it is , it sounds more open than your regular fetbased distortion and then I mean in particular all the J102 based designs , including the BSIAb's which I also like alot.
This distortion has a different character, it's tighter imho .
A pity is however that the gain pot scratches but I understand there's no way to avoid this , being where it is   . 
For my taste there's a bit too much treble so I rolled it off a bit with a few filters.
Boy do I love this contraption .

Alf