Loophole - Detune not working

[jbgron]

Hi guys,

I just built the Loophole project, everything is working perfectly except the Detune switch does not work.  I've eliminated solder bridges and I've replaced the switch but I still cannot get it to work.  Does anyone have any pointers?

Cheers

Mike

[juansolo]

Mine sort of worked, but not as much as I'd expected. I decided I'd never use it anyhow so if you haven't boxed it up already, I'd just omit it.

[jbgron]

Thanks for the reply.  Unfortunately I've already boxed this up and the detune function was untested because I didn't have a switch at the time.  Are you saying the Detune effect is meant to be very subtle?  I thought it was meant to sound like in this video, toward the end;

[jbgron]

Has it got something to do with my CD4001, mine is a CD4001BP.  I've seen issues with 4049's buffered and unbuffered, are we looking at the same thing here?

[sprayfe]

Good lord my feet are ugly!
It's not subtle at all!

[jbgron]

Ugly feet but nice clip, thanks man.  Can you confirm what type/brand of CD4001 you used?  I could be on the wrong track but I can't see what else could be wrong with my build.

[jbgron]

BUMP!

I'm getting no joy with this, I tried a CD4001BE and the problem still persists.  It's definitely not a solder bridge or cold joint, all signs are pointing to something actually wrong with my ISD1020AP IC.  

Anyone? Bueller?

[petesz]

I had the same problem with my loophole build, couldn't figure out the problem so I just gave up on the detune feature!

[juansolo]

Ah, in which case I suspect I have the same problem Odd.

[jbgron]

Thanks for the replies guys, it's good to know I'm not the only one.  I bought my IC from Small Bear, did everyone else with the problem buy from there too?

[sprayfe]

It's got to be something with your chips I would imagine. You guys are much better on the iron than myself and mine fired right up. Hmmm....

[jbgron]

Can I ask where you bought your IC from?

[sprayfe]

The answering machine IC i got from smallbear (as soon as the documentation dropped) and the rest I got from ole mousy.

[jbgron]

Thanks, I was hoping you'd say you got it elsewhere though 

As a last desperate attempt to get this working I'm going to buy another IC from eBay.

[madbean]

If everything else is working as it should except for the detune thing, then it's simply a matter of finding the right value resistor. 22R 1/4W is consistently worked for me, but as little as a few ohms +/- will alter how quickly it works or if at all.

Here is an idea for a hack: take a spare 22R resistor you have and use an Xacto knife to shave off material from the body of the resistor. Try and drop it an ohm or two and see if it works better.

Note that the resistor will get quite hot when used in the circuit so be careful when handling it.