ADA flanger callibration help?

[daverdave]

Hi everyone. I built an ADA flanger some time ago and as far as I can tell it works, but I never callibrated it as I didn't have the equipment and found it hard to do it without. Well I've started a degree in electronics and music tech now and I have access to plenty of stuff at uni, so today I took it in to see if I could get it working, I printed off the callibration sheet and parts layout from moosapotamous. The build I made was rev 3, using the sad1024.

Anyhow, when I came to trying to set the frequency of the clock I found that when manual was CCW (I'm assuming that CCW and CW stand for counter clockwise and clockwise) the frequeny was HIGHER than when the manual pot was CW. I'm pretty sure I have the pot wired correctly, could anyone point me in the right direction? Cheers.
Dave

[oldschoolanalog]

Are you 100% certain that the Man. pot isn't wired backwards? That's what it sounds like from your description.
Does it function properly otherwise?

Dave

[daverdave]

Yeah positive, I've just double checked. everything else is working properly as far as I can tell, it needs callibrating, I don't think the sweep is symmetrical. I just wanted to figure out what was wrong with this before hand.

[oldschoolanalog]

Yeah positive, I've just double checked.

Well, you could always switch the wires from lugs 1 & 3 if you want the longer delay times (lower clock f's) at the CCW end of the pots rotation.

...everything else is working properly as far as I can tell, it needs calibrating...

Calibration should be the priority; especially now that you have access to proper test equipment.

I don't think the sweep is symmetrical. I just wanted to figure out what was wrong with this before hand.

This is something one would need to hear to comment on. That being said, first get the clock f range "dialed in". Going too high or too low will have an affect on how "symmetrical" you perceive the sweep to be. Also, one of the things that contributes to the A/DA's unique character is (when properly set up) the sweep lingers at the bottom a bit longer than your "average" flanger.
Take the time to set this up nicely. You will be very glad you did.
All the Best!
Dave

[daverdave]

Cheers for the replies mate, I'll take it to uni and follow your advice.

[daverdave]

Right, I took it back to uni today and tried doing the bbd bias callibration. I put the 1kHz at 2V signal in and made sure it was coming in at the input of the board, but when I measured it at pin 8 of ic 2 (as it says in the notes) I was getting an 8V dc signal roughly. Is this normal or is it likely that there is a problem with the circuit?