Flintlock Flanger build problems hum

[Spenzerleehorton]

Hi All,

Have completed build of this pedal, voltages looking good and getting flinging but awful hum present with effect engaged or not?
Also not entirely sure how to wire the foot switch, as wired it as per other pedals with led but could get it to switch off led?
Have scope and multimeter just need to trace audio path to see why I'm getting hum?
Any help would be good as I've seen a lot of problems with this pedal!!

[Scruffie]

No special wiring needed for the foot switch, no LED and hum, probably a problem with your off board wiring in the power and ground department.

[Haberdasher]

If you're testing it before it's boxed, make sure both in and out jacks are grounded.
AFAIK, there is no problem with the Flintlock pcb.  I've built 3 or 4 of them and they all worked fine.

[Spenzerleehorton]

Is there an IC voltage chart for correct voltages on this build, might help find my problem a bit quicker.

[Spenzerleehorton]

corrected the mistake i've made with the footswitch and also found that the PSU unit i was using was the hum problem.
have twiddled the pedal into chaos now so need to go back and setup again!!
got some great sounds in it, just need to tame this beast!!

[Scruffie]

Congrats on getting it going! I hate debugging outside issues, they're always the last thing to occur to you.

[Spenzerleehorton]

I've found some other issues with it.
When range fully on I get a hum sound at about 1.9Meg in the sweep?
Don't know why?
Also there is some high pitched interference which seems to be part of the seeep as well?
The flange part of the sound, sound distorted as well so I'm not out of the woods with this pedal.
Some of this maybe due to using some alternative caps?
Again a full voltage chart would help me trace any issues if anyone has one please?

[Scruffie]

I haven't got a full voltage chart I'm afraid but if you post yours I can see what I can spot.

What cap changes did you make?

[Haberdasher]

I think there used to be some voltages posted in the lectric-fx section, but we lost that in when the forum lost data, and I can't find them on my drive.
I grabbed an older flintlock and took these real quick, so hopefully these are on.  Let me know if you see anything off with these, Scruff.

Flintlock Flanger Voltages

[Spenzerleehorton]

I have several caps which should be poly rather than ceramic, so i will change them first.
Not sure if i've got my 2n5457 in correctly so will check this along with voltages, thank you for the voltage chart.

[Spenzerleehorton]

just getting distortion no flange now!!
changed 2n5457 for 2n3819, aaargggg!!!!!

[Scruffie]

Woah there Nelly, take a step back.

Did you change any cap values? Composition isn't important, just that they're the right values.

Putting in the J-FET wrong would kill the flange so break out a datasheet.

Posting up your voltages and photos of your board so another set of eyes can look at them and taking a breather before you want to throw it out the window is the best course of action now.

[Spenzerleehorton]

all cap values are the same, just i've used a few ceramic caps in parallel to get values, i've ordered some more so can change.
i'll post up some pictures and voltages.

[Spenzerleehorton]

IC1
1 - 7.2v
2 - 7.2v
3 - 6.5v
4 - 0v
5 - 14.33v
6 - 13v
7 - 13.68v
8 - 14.25v

IC2

1 - 4.8v
2 - 4.8v
3 - 4.8v
4 - 0v
5 - 7.2v
6 - 7.2v
7 - 7.7v
8 - 14.4v

IC3 looks pretty close to your voltages

IC4

1 - 2.2v
2 - 7.2v
3 - up&down
4 - 0v
5 - 7.2v
6 - 7.2v
7 - up&down
8 - 14.91v

IC6 voltages look close to yours
IC7 is getting 9v and 15v
IC10

1 - 15.01v
2 - 7.55v
3 - 13.72v
4 - 1.1v
5 - 0V
6 - 7.5v
7 - 9.28v
8 - 9.28

IC11 voltages look good very close
IC12 voltages look good very close
IC13 pin 1 is only 2.2v all other voltages look close

Q1 (2N3819)
D - 6.8v
S - 7.2v
G - 6.8v

IC8 and IC9 will follow

no sign of flanging now, just works as distortion effect, when adjusting speed can slightly hear that it is working but too much distortion and fuzz to make out.

[Scruffie]

IC1.2 is way out, that'd explain the distortion, either your bias trim is set wrong or there's a problem there.