Animato help

[Giglawyer]

I just finished an Animato build.  I will post pics in the build thread.  It sounds AWESOME...but...

Internally, the effect has a trimpot that controls the treble boost.  If you crank up the boost, you get awesome, grindy distortion.  However, it makes the Volume and Distortion knobs unusable past 2:00 or 3:00.  Unusable might not be the right word.  You can still jam out, but when you stop playing, the pedal emits a terrible squeal.  You can elimate that altogether by turning down the trimpot, but then you lose a lot of the grind. 

Is this just a tradeoff that goes with the effect, or does it sound like I am doing something wrong.  I can post pics, but I would have to unbox it to get to the underside of the vero (which I am happy to do). 

Any advice would be appreciated.

[Giglawyer]

FWIW - here is the link to the vero:  http://tagboardeffects.blogspot.com/2015/11/human-gear-animato.html

[robthequiet]

I was reading Crowella's thread over here: http://www.diystompboxes.com/smfforum/index.php?topic=108850.20

I'd like to try one of these sometime -- which transistors did you use for Q4/Q5?

[Giglawyer]

I used NTE 102 and NTE 103 for Q4 and Q5. 

I think I may have discovered my problem. I think the Distortion pot wiring is coming into contact with something .  I am going to unbox it all and have a look see.

[robthequiet]

Please post back with what you find, GL

[Giglawyer]

I really could use some other thoughts.  I can't seem to figure this out.  Here are some pics of the guts:




Presently, the problem that I am having is that the Tone and Distortion knobs cause the effect to squeal loudly if they are dimed.  Now, I can control this with the trimpot.  If I tun the trimmer down almost all the way, the squeal goes away.  But, the effect then sounds like crap.  If I keep the trimpot somewhere in the middle, the effect sounds awesome, but you can't dime the distortion or tone knobs. 

Am I doing something wrong, or is this just the nature of the effect. Also, I added a blend knob that has a built in buffer.  Is the buffer causing this? 

Any thoughts?  Here is the link fore the Animato Vero - http://tagboardeffects.blogspot.com/2015/11/human-gear-animato.html. 
Here is the link for the Buff-n-Blend I used - http://www.guitarpcb.com/apps/webstore/products/show/6178745

[robthequiet]

Great photos. Since the effect works well except for the squeal and it has to do with gain levels, my first check would be checking that all the component leads are nicely trimmed. Also check that  the jumpers are nice and straight and not accidentally touching or even nearly touching another component.

One thing that can happen if you have all your cables nicely tied together is that sometimes you get crosstalk. Some folks might disagree, but maybe try separating the cables a bit instead. Not a sure thing but something to try. Layout in gain circuits can be tricky.

Is there a chance we could get photos from the solder side also?

[Giglawyer]

It would be easy enough to separate the wiring.  I will do that and report the results.  Here is the solder side. 




Again, the trimpot can be turned up to eliminate the squeal, but it tames the effect wayyy too much. 

Anything you see that stands out?

[robthequiet]

I don't see anything that stands out. Everything looks nicely routed. I wouldn't expect to see major shorts or anything because it's not totally failing, but it would still be worth checking for a hairline strand of solder coming into contact with part of the trace. Looks like a textbook job to me. A bit generous with solder here and there but nice trimmed joints. Also curious about whether separating the wires and leaving them random makes the problem better or worse.

Other threads have mentioned that squealing circuits can sometimes be tamed by placing a buffer ahead of them in the effect chain. I'm looking at the B and B board and wondering if it helps in that regard. If all else fails, it may be worth trying to run the Animato without the B and B to see if it changes the squealing, but of course that means taking things apart ,so that would be a choice to be made. You didn't by any chance try the Animato by itself?

There is a thread that talks about this, over at http://www.diystompboxes.com/smfforum/index.php?topic=114048.0

Hope this heads you in the right direction.

[Giglawyer]

After looking through the build notes of one of the guys who helped get this schematic finished, he says that the trimpot is used to tame the gain.  I am assuming that, since I can set the trimpot low enough to eliminate the squeal, the circuit is as it should be.  I have experimented with increasing the value of the 33k resistor that leads into the Distortion knob.  It has helped a little. So, I think form here I am going to box it up and just accept that the trimpot is either going to be turned down to eliminate the squeal OR that I can't dime the distortion pot.  Either way, this thing still CRUSHES.  I will post a finished pic.

Rob - thanks for your help.

[thermionix]

My suggestion would be to snip off the zip ties, fire it up to get the squeal going, and then see if moving wires around affects it in any way.  More or less squeal, change in frequency, something like that.  Maybe best to use something other than your fingers to move the wires, I always recommend a chopstick.