Silicon Tone Bender MKII Professional Switching Question

[pgorey]

Been a little while but now that Fall is here, it's pedal building season again and I've got 4 builds going.  Two Ross compressors and two Tone Benders.

1st Ross build worked first time plugging it in.  Was proud and excited and I had some extra confidence and buttoned up the enclosure of my first Bender build without testing - it unfortunately has some super goofy things going on - all of the knobs seem to adjust volume, eq or distortion amount in small amounts - adjusting the fuzz pot to far CC, the power LED pulses with the dynamics of playing so there's a short or connection happening that I can't see after cleaning the strip board.  It sounds great in one particular configuration of settings but obviously not working as designed.

https://imgur.com/fSXWjiw

https://www.instagram.com/p/Bo7bBNGApUeBBwdIt2daKp2hiA4oJrNVzEEGeM0/?taken-by=pgorey


I'll post photos of the circuits once home but long story short, I'm not sure what to do with the SW1 and SW2 connection points from the circuit board - using a 9 lug foot-switch and the wiring I'm following for the off board switching is this - i have the ground of the foot-switch tied to the bottom left lug as well.

https://imgur.com/K9vCfKN

In searching other stripboard layouts on the tagboard site, there are other designs with the SW1 / SW2 connections and the info there is to tie it to lugs 1 and 2 of the switch but what will that do to the current connections / LED / I/O if I just add those two points to lugs 1 and 2?

Thanks in advance for the help everyone!

[pokus]

As far as I understand is one misunderstanding of yours that sw1 and sw2 don't belong to the footswitch. You need another SPST switch like the graphic mentioned. So that one time there's a connection between them and the other time not.

[pgorey]

I had a feeling that may be the case after looking up what the modded version of the MKII professional typically included - a fat / sustain switch.  That would be it!  I'll wire em up and hope everything else is looking good.  Thank you for the quick response - sometimes even with the obvious stuff, having another set of fresh eyes makes ALL the difference between pulling out your hair and moving forward.

[pgorey]

  I re-flowed the board and installed the spst switch for the sustain / punch mod.  Have sound and all controls do something but it seems really strange.  I'm going to unbox again tonight and look at the pot values again to make sure I didn't switch them by accident.  Volume kind of works but has a noticeable jump after the halfway mark.  Attack increases volume and fuzz and in the last quarter turn has crazy noise and thinner sounding fuzz.  The fuzz control goes from fat sounding on the fully CC end and then thin fuzz on the CW end.  The CC end also has a big volume boost.

Here's a Facebook link to a short vid so you can hear what I'm hearing.  I'll post pics of the circuit board once home but I have checked all solder joints and layout of components and it looks pretty clean.  I recut all lines between strips on the strip board but there's always a chance of some flux joint causing an inadvertent short.  I'll start tracing signal too based off of the design but since there is both bypassed and effected signal, I'm not sure which components to start with based off of the results I'm getting.

https://www.facebook.com/20800958/posts/10101159278753089/

Edited to fix typos from cell phone

[pgorey]

I built two of these side by side and just closed up the enclosure of the second and tested.

I did verify pot values
Volume - A100k
Fuzz - B5k
Attack - B1k

Both pedals have the same sound and results from adjustments of controls.  Perhaps I'm just not into the sound of this kind of dirt.   Don't get me wrong, there's a big range of sounds, but the sputtery / gated sound is just not for me.  Glad I built these as one is going to my guitar teacher from 20 years ago so that's fun, but I don't see this sound ever becoming a staple on my pedalboard.  Give me a double tube screamer after ross compressor and I'm golden.  To each their own I suppose. 

That said, I get a decent pop on the foot-switch on one and not on the other.  Anyone have an idea as to what went wrong there?  I have gone over the wiring and they both match.

[pokus]

Ok I took a look at the vero and as far as I understand your attack pot controls the feedback path (which is controlled by the fuzz pot in a common fuzz face), so a increase in fuzz and volume should be normal here.
Your fuzz pot controls the gain of the last transistor stage and it's also normal going from thin to fat sounding fuzz, but I watched your video an also don't really like what the fuzz pot is doing unless it sounds pretty cool when you switch the modes

So I guess there's nothing really wrong with your build unless the fact you don't like the tone of it. Maybe a Big Muff would do the trick for you 

[pgorey]

Thank you for your response and for taking the time to dig in!  I think this circuit works fine -  just not going to take up real estate on my board.  There  are a lot of cool tones that can be found with this design and I've owned a couple Muffs, but really not super into those either.  I guess i'm a tube screamer / overdrive fan more so than fuzz fan.  Thanks again! 

[pgorey]

Circling back to this.  Of the two builds I did side by side, one ended up working great and sounding like the circuit should.  The other, after more thorough testing and listening has a few interesting issues. 

1.  There is a considerable hiss / noise when the circuit is engaged even at low volume / attack / fuzz settings.
2.  Turning the volume control from fully counterclockwise to fully clockwise, the status LED goes from very bright to almost completely dim.  It's a bright white with a 5.6k current-resistor. 
3.   Volume control does not allow volume to go to zero or very quiet.  Though it's the same value pot used in the other build, it's lowest point produces a volume output similar to around noon on the working build.

I'm thinking that I may have blown a cap or have a bad cap.  There is a huge pop on this build vs the working so that seems to point to the input cap? 

Here's the strip-board layout used for reference:

https://imgur.com/fSXWjiw

Could the 10nf cap be the culprit? 

[pokus]

Can you tell/show how you connected the LED and Volume pot? When the pot is connected GND-Out-IN, there's almost no way  it could act like this.(unless it's a 4 pin one) Also the LED seems to be in or at least interacting with your signal path if it reacts to your playing and the volume.
The broken 10nF cap could cause some hiss, but should have nothing to do with the other problems you've mentioned.

[duck_arse]

sounds like a wiring error, possibly putting DC on the input or output. can we see photos of your build, please?

[pgorey]

Here's some pics  -

Build pics toward bottom of album

https://imgur.com/a/WYiqXR1


sorry for the spaghetti.  Wires looked nice when they were managed and I use standoffs for the board so it doesn't just float in there.

Some more info.  If I unplug the output to amp, the LED goes off and volume does not change LED brightness.  On / Off shows a quick flash of light on the LED.

Also, i know the solder now looks sloppy - I re-cut/flowed this a couple times.

[pokus]

Ok, I think I've found a problem. It seems like your board gnd is connected to the middle pot pin 2(attack pot?). So it's kind of a loop with the 3.3uF in it. And I guess there's something other connected to gnd then, but I can't see where every wire is lead to.
You've got 2 wires on your DC V- jack, where do they go?

[pgorey]

Thanks for the quick response! 

Two wires from DC- go to ground strip on circuit and then sleeve of input jack.  The sleeve of the input jack goes to sleeve on output jack and then ground on the foot-switch - pin 7 that also has jumpers to connect ground to pin 4 and 8. 

Sorry about the wires and good job seeing all of that!  I must have switched attack pot pins 1 and 2 as 1 should go to ground.  I'll switch the attack pot wires when I get home from work tonight.  Thanks again!

[pokus]

Alright, but as far as I can see it your main ground wire on the board is only connected to attack 2. So switching attack 2 and 1 is good, but you also need to ground the board correctly. When the attack 1 wire from your board goes to DC gnd then it's ok, because it's the same stripe. I think you mixed up the gnd and attack 1 wires.

To make it clear, the last gnd stripe of your board must be directly connected to DC-

[pgorey]

Turns out the wires for DC to ground, all Attack legs etc are already soldered in the right places.  I went back through and looked at each pot's connections.  They connect just as shown in the diagram.  DC ground to lowest strip.  On the other side, Leg 1 of the Attack pot to the other side of the ground strip.
Leg one goes to ground, 3 to the strip right above and 2 above that.  Then Fuzz 2+3 two spaces above and then finally Volume 3.  That's on the right side.  Everything on left looking right as well.  I'm tempted to admit defeat an move on to the next pedal and maybe return to this but everything seems right!  I've gone over the board I don't know how many times to make sure component placement and jumpers / cuts are good.  Recut between all strips again today just to be sure there's not cross strip shorts.