Danelectro French Friese Autowah

[boratto]

This is a GREAT sounding Autowah, the best of all.
BUT: there´s a pop switch when the effect is on.
Help wanted! I trued the following without success:

1) It´s not from the led. The led was disconnected and the pop still there.

2) Tried a buffer at the input, the pop still there.

2) Tried a buffer at the output, the pop still there.

4) Inserted several pulldown 1M resistor.
At the efx input and output.
At the IC outputs.

 the pop still there.

Please help!!!

[Frank_NH]

Remove the 100K resistor next to the input.  It's connected to Vref, and I don't know why it's there!  The 1 uF cap is just going remove the DC voltage anyway, so why have that resistor providing some sort of "bias" voltage?

Let me know if that works.

[induction]

This circuit, as drawn, has pulldown issues at both the input and output.

Input: The 100k pulldown resistor goes to Vref instead of ground. (This arrangement probably has to do with the switching in the original pedal. With the original switching, it probably works fine, but adapted for true bypass, the resistor has to be moved.) Adding a second pulldown to ground will still leave DC on the input, unless the original pulldown is removed. The 100k resistor can be rerouted to ground on the board (it will probably have to stand up), or simply removed and another pulldown added on the switch or somesuch. 100k seems kind of low, and since many people recommend a buffer in front of this circuit, I would consider bumping the input pulldown up to 1M or so.

Output: No output pulldown at all.

It sounds like you already tried pulling down the output, so I would try properly pulling down the input first. If it still pops, try pulling down the output as well (leave the new input pulldown in place). If it still pops after that, post pictures.

[boratto]

guys here comes the entire project.
It is verified and works like a charm (it´s voiced for bass) , only problem the pop still there.
I am using a buffer splitter to blend the signal (dry wet) and a recovery stage at the end.

1) I get rid off the 100k resistor

[induction]

Layout looks fine to me. You don't need the input cap for the french fries if you keep the output cap from the splitter. And you don't need a pulldown on the input of the french fries either. But those shouldn't cause any pops.

Could be a bad switch or a build error. If you post some photos, I'll take a look.

[boratto]

I can´t shoot good pics enough in details by now.
It´s verified (just the pop issue), the effect is so tasteful, i suggest you try to build one.

Does you mean substitute 1 uf for a jumper?

[Frank_NH]

So it still pops without the 100K?  If so, then check your off-board wiring.  Are the input and output grounded when the effect is off?  A 1M antipop should do that, but maybe there is something going on with the switch or your off-board grounding.

I may try to build this thing - I liked the demo and it would be something I might actually use in my live rig!

[induction]

boratto wrote

Does you mean substitute 1 uf for a jumper?

Yes, or just remove it and move Res3 up two rows. Also remove the 1M connected to pin 4 of the 4558.

Have you tried another switch?

[boratto]

thanks, tommorow i´ll put new switch and jacks... let´s see what happens.

[boratto]

1) get rid off 1M at French Fries input

2) get rid off 1UF at French Fries input.

3) Replaced new jacks and new 3pdt

Results: Still pops.

Hope you guys build this effect (1 or 2 caps was changed  for bass, if you want for guitar must come back with old values).
It works great, Verified (just the hell POP issue).

I am certain one of you will come with the solution and we will have a great effect for contribution.

[Frank_NH]

Can you show us your off-board wiring?

[boratto]

hi Frank, i don´t have a cam by now, but it´s exactly the same used on this site, and all the pots ground, going into the output jack.
On the french fries page of this site, comments section, people are telling about the pop too.

[Frank_NH]

OK.  Here's the schematic from FSB (I think the last one, on which the vero layout is based).



There is a switch in this effect for a "high" or "low" setting.  Does the popping depend on the position of this switch?

Also, after looking at the off-board wiring, try the following.  Temporarily connect the output from the board to your output jack so they are always connected even in the bypass mode.  So you won't get a bypass signal, but I'm curious to see if the popping is coming from the output rather than the input.

If all else fails, then try Mr. Black's last option on this link:

http://www.mrblackpedals.com/blogs/straight-jive/6629778-what-really-causes-switch-pop

That is, put a current-limiting resistor in series with the input and output and see if that reduces the popping.  Good luck!

[EDIT:  Here is a similar thread about popping.  Read 11 Gauge's  response about the current limiting resistor at the input.  I would try that as a quick experiment, maybe use a 10K resistor.

http://www.tdpri.com/forum/stomp-box/414984-getting-rid-joyo-popping-noise.html
]

[boratto]

Frank,

1, the pop is the same, in any switch position.



2. No pop , when direct connected on output jack!

[Frank_NH]

OK.  Try the Mr. Black current limiting series resistor at the output trick along with a pulldown resistor.

[boratto]

Ok,

Mr Black get rid about half of the pop level, using

10R, 56R, 100R  and 1M, 2M2 (pulldown) combinations

the  circuit start to high pitched whistle, louder when the blend pot is near 0 (full effect).

the trimmer position make the whistle louder or quieter, but the effect dessapear when set to end the whistle.

Then added 1 uf and 22uf  before the resistors. No changes.

[Frank_NH]

Thanks for trying these options out, Boratto.  I guess I'll have to build this and find out for myself.  

[boratto]

Many thanks Frank. I am certain you will find the solution very fast.
 Keep in mind it´s voiced for bass! It will be great!