n00b vero grounding question

[alphadog808]

Hey guys,
  So I'm working on a pinnacle and in my attempts to stop the squeal when the boost is on, I've been doing some research and reading to see how people got around their problems.  Unfortunately, it seemed most people ended up living with it.

That being said, I did run across a poster on another forum who was mentioning that the pinnacle vero from here actually doesn't need to have vol1, contour3, and Gain1 on board.  He said I should be able to simply ground those lugs to the casing of the pot(assuming the pot is grounded).

I do see that those 3 lugs DO go to ground, so it makes sense to me, I think...

If that solution will work(even if doesn't stop the squeal), why does the vero not just have the user simply send those lugs to ground?  I'd think it'd be less work and less wires, and hopefully less noise.  

Just wondering if this might be a nice shortcut in wiring up veros...

[IvIark]

I often make ground connections to the board if there is a free hole on any of the ground rails.  You don't have to of course, but based on personal preference I would much prefer to make the connections to a solid hole on the board than have to make multiple connections to the same place offboard, such as one of the socket sleeve lugs.

It won't stop the squeal though.  A connection to the board will be a much more solid ground connection than soldering to the back of a pot which may not be connected adequately because of dirt, grease etc on the box or pot threading.

[alphadog808]

Thanks for the reply, Mark.  I got your message after I had made the change.  Strangely, I could be wrong, but it seems that the squeal might be worse!  It's definitely not any better, as you suggested.  In fact, my ears might be deceiving me, but I kinda wonder if I lost some gain as well...could be my fatigued ears or me jacking with the board to much.  

Oh well, back to the drawing board!  

[IvIark]

Try increasing the 10R resistor where the 9V supply connects (try 100R maybe), or the 470R at the input (try 1K maybe).  Also you could try putting a resistor (maybe 10K or 22K) in series with Gain 3 and the board connection for Gain 3 and see how that affects things.  The top end gain may be affected but hopefully will help remove the squeal

[alphadog808]

Thanks Mark.  Do you think lowering the 1M pulldown resistor(to maybe 100k?) might help as well/instead?

I don't know if this helps, but if I have boss pedal(powered but off) in front of the pinnacle, all the squealing goes away.  I guess if I carry around my boss pedal with the pinnacle, all would be good...but weird...especially as it's an AC2!  

[IvIark]

That happens a lot, I'd just make a little transistor buffer and put it in the box somewhere.  Impedance can be a bitch but buffers cure a lot of ills.

[alphadog808]

Would this be a good buffer?  I will say, the layout software you use is much nicer...

http://www.muzique.com/news/jfet-buffer-on-stripboard/

[IvIark]

Yes, or try the Cornish Buffer on the blog

[alphadog808]

wow, that cornish buffer has alot more components!  Normally, it shouldn't matter, but I don't have much/any spare components, so I need to order them as I make stuff(I'm working to change this).  Thanks for the info, I just PRAY that the buffer will save the day.

[IvIark]

If it's fine with an off Boss pedal in front of, then a buffer will sort it.  If you put the buffer right before the effect board input (and so after the switch) then you can keep the pedal true bypass as well if that is your preference.

[alphadog808]

well, I think I figured out the problem.  I'll update the squeal/wampler thread to close it out, and hopefully be of help to someone in the future.  Thanks so much!!

[alphadog808]

So, I ended up making this buffer...


I still get squealing.  If I put a boss pedal in front, the problem goes away.  Any ideas on components I could tweak on my buffer to help?  Or does anyone have another buffer layout that might work better?  I figure a boss one would be best, but maybe it has to be outside the enclosure to work best?  Not sure.  Thoughts?  

Oh, one thing I noticed..if I turn the volume down on the guitar a bit, the squeal goes away...