Current Lover 2015 Feedback Calibration

[Davefx]

Just completed the Current Lover and it sounds great but when I tried calibrating the T1/Feedback limit, with T1 at minimum I cant turn the feedback pot past 10 o'clock no matter where the clock /bias is set...

I'm doing something wrong or screwed up somewhere, please help!
Thanks!

[selfdestroyer]

I have not built this project but, to make it easy for people to help I have posted the calibration notes from Brian's build doc:

Calibrating

The Current Lover must be correctly calibrated to function properly. This is done with the Clock and Bias trimmers. These
work independently from one another but require some re-adjustments as you work through calibration. The Clock
trimmer is very sensitive to fine adjustment so be prepared to spend a few minutes getting the right setting.
Before powering up the board and connecting your guitar and amp, set the Clock and Bias trimmers to their middle
position. Set the T1 trimmer and Rate pot fully counter-clockwise. Finally, set the Range, Volume and Feedback pots to
approximately their middle positions and the Filter switch to the right position. Now connect the board between your guitar
and amp and power it up. You should get signal through the effect, although you may not hear any flanging yet. If you do
not have any signal, double check your connections and ensure that there are no bugs in your build.
First adjust the Bias trimpot until you get some flanging. You don't have to be precise, just get the BBD working. Next
adjust the Clock trimpot to the point where you achieve a wide sweep with minimum noise. If the flange starts to whine or
"chirp" at the extremes of its sweep you will need to do a little more adjustment. Go back and tweak the Bias trimpot
further clockwise until you get smooth up and down flange without distortion. Set the Feedback control fully clockwise and
gently adjust T1 clockwise until you get the maximum feedback desired (T1 acts as a limit to the maximum allowed
feedback). Continue making minor adjustments to the trimmers while testing the limits of the Rate, Range and Feedback
controls. Describing this process makes it seem more complicated than it actually is: your ear will be the guide in
achieving the best sound across the widest range of control settings.
The most important thing to balance here is the Clock trimmer. You need to make sure you get no "chirpping" at the
extremes of flanging when you set the Range, Fdbk and Rate pots fully up. Like I said before...very minute adjustments to
the Clock trimmer make a big difference. Most of the adjustment will occur in the first 1⁄4 turn of the trimmer.

Cody

[Davefx]

I've read those thanks..     As I said I get a decent flange with no clock noise, but to follow the feedback cal. instructions, it will not allow me to set the feedback control all the way clockwise without horrible whine.  Only about 10 o'clock.. That's with the T1 trimmer at minimum.  Turn that up and it goes crazy! 

Any experienced builders on the latest 2015 edition?  Of course if Brian would chime in that would be great!

[Davefx]

No takers?

[jowskua]

having problems with the calibration in general, I can not get rid of the noise, also, Its hard to find the sweet spot on the bias pot, the flanging only works in a very small spot, it will cut in and out if I even barely adjust it, and I just cant seem to get rid of the noise no matter how much I mess with the clock trimmer, anyone have advice here?  Also, the clock trimmer is changed from 100k on the old version to 10k on the new version, does 10k give enough range for calibration?

[Davefx]

Good point, I wonder if meeting half way with a 50k trimmer may help? But having built one of these years ago with the original SAD1024 which chirped with clock noise even in the factory units I'd  played, I will say this unit doesn't have that kind of problem no doubt due to its well buffered clock signal. At the same time it's still having this feedback whine past 10 o clock on the feed back knob.. I may try changing that 100 to 50k and see what happens. . Brian said it was lowered to ease biasing. But I may try anything because it seems we're on our own  with this one I'm afraid.

[JC103]

I don't want to stray too far off topic... but, can someone explain the chirping sound? I have 2 CL/2014's running at 12v with the 3007 chip. They are noisier than the 3207 at 9v. I can't seem to eliminate the chirping noise. Is this bleed over from the clock?

[Davefx]

Yes chirping is caused by the clock signal. . Referring to this circuit, the addition of the buffers provided by the 4049 chip pretty much eliminates the chirping ..At least I have not noticed it with mine..But I'm no engineer.. I just wish someone would chime in with the knowledge to help out my problem!  Lol... Brian, Jacob. .Someone!

[JC103]

Thanks for the confirmation Davefx. Out of curiosity, what voltage are you using while attempting to bias the 2015 version?

PS: Maybe send this dude a PM http://www.madbeanpedals.com/forum/index.php?topic=21634.0
I think it's the only 2015 in the build section at the moment.

[Scruffie]

I might be able to lend a hand...

First things first, have you checked all your values? A wrong one could certainly cause excessive feedback.

The chirp of the originals being cured has nothing to do with the buffer, the buffer is to help the clock overcome the 3007s higher clock pin capacitance so the square wave doesn't get rounded off. It's actually because of that 1nF cap in the feedback loop of the inverting opamp that was added in the 9V version of the Electric Mistress but wasn't found in the earlier 18V models as it acts as a low pass filter to the BBDs input.