How do you use a scope to calibrate flangers?

[blearyeyes]

I have a  Colosulous (however you spell it) and a Flintlock flanger that I calibrated by ear but they both have sweep issues I would like to fix.

Would somebody school me on this topic?

TYIA

[dont-tase-me-bro]

This is for something different, may or may not be useful

https://www.diystompboxes.com/smfforum/index.php?topic=107427.0

[Bio77]

I was searching for similar information awhile back here's a link to that:
https://www.madbeanpedals.com/forum/index.php?topic=27925.msg270453#msg270453

My process these days: 1.  I set the clock to the factory setting using the frequency setting on my DMM.  2.  I use the scope to set the bias of the BBD.  3.  I set the feedback max trim by ear.  4.  I go back and make small adjustments to the clock trim by ear (this will remove the sweep artifacts you are mentioning).

[blearyeyes]

On the Flintlock it’s not artifacts, the top of the sweep goes too far up into nowhere land and stays there for too long (several seconds) before sweeping back down into the effect area. Just want to set the sweep to be consistent. You can hear it hit low bottom and start back up. I would like to set it so you can hear it go over the top and head back down. 4 seconds of no movement at the top.

[Bio77]

Hmm, that is a weird one.  Have you checked that the LFO is working properly?  Scope would be perfect for that.

[thomasha]

Not sure how it works for the collosalus, but you want to adjust the voltage around which the LFO sweeps.

There is a "manual" potentiometer for that. There is a spot where you are right between a chorus sound and a normal sound, and sweeping from one to the other makes the jet sound.

The width (amplitude) of the LFO sets how deep you go into each region. Too much width and nothing happens for a large part of the sweep. The problem is, that the amplitude of the sine wave depends on the rate. Faster waves have larger amplitudes than slower ones. I guess this is one of the problems with LFOs. They have a defined range where this drop in amplitude is negligible. This range, however, is way shorter than the range available from the potentiometer.

Check the voltage at the input of your VCO (CD4013). The LFO should sweep around the input voltage.

[blearyeyes]

Hmm, that is a weird one.  Have you checked that the LFO is working properly?  Scope would be perfect for that.

Where would I attempt to probe with the scope to check?

It's been a while and I have a Cullasulusiusumusius (I can never remember how to spell Collosalus) and a flintlock flanger and now that I think about it.. might be the flintlock. I could never get the LFO adjusted to the numbers in the docs with the frequency counter on my meter.

[thomasha]

Pins 1 and 7 of the LFO. You can check the frequency of the square. Try changing the rate potentiometer to see what is the frequency range of the LFO.

[blearyeyes]

Thanks Thomas, I'll give that a try. I need to finalize the Flintlock and box it. Going build crazy after a 5-6 year break I'm finding a ton of projects that need finishing... Of course I want to buy all the new projects as well..

[blearyeyes]

Hmm, that is a weird one.  Have you checked that the LFO is working properly?  Scope would be perfect for that.

Probably a component mistake.. I'll go through it and double check the components around clock.