ReVibe Grounding Scheme

[alathIN]

This was suggested to me by others who had good luck with it, and it worked for me too, so I wanted to share.
Regarding the issue of ground loops between the ReVibe and the amp - Merlin (the Valve Wizard) has a "ground lift" circuit that seems to eliminate this problem.
http://www.valvewizard.co.uk/Grounding.html

Main points:
There is a "safety earth" that goes from the ground lead of the power cable and anchors to the chassis. Nothing else grounds at this spot.
All of the circuit grounds are segregated by the power node they are associated with. So for instance, all of the grounds in the reverb driver circuit feed into one ground wire. Same for the reverb recovery circuit. Etc. ALL of the circuit grounds, grounds on the pots, and grounds on the input and output jacks are insulated from the chassis EXCEPT through a circuit called the "ground lift."
All the input and output jacks themselves have to be insulated from the chassis (drill the hole bigger and use insulating washers).

The ground lift consists of two diodes and a resistor and looks like this:


All of the circuit grounds and the ground bus from the filter caps all connect to one side of the ground lift.
The other side of the ground lift connects to a single chassis ground (not the safety earth chassis ground).
Some folks put a cap on the ground lift to filter out radio frequencies.
You can also put this cap between the tip of the input jack and ground the other side to the chassis.

Voila: no ground loop hum.

[alathIN]

Someone smarter than me can explain how this works.
All I can testify is that it does work.

[kagliostro]

Someone smarter than me can explain how this works.

The explanation on the Merlin's pdf didn't satisfy you ?

Franco

[alathIN]

Someone smarter than me can explain how this works.

The explanation on the Merlin's pdf didn't satisfy you ?

Franco

Well, I'm sure it's a very satisfying answer for those who can understand it 
I will admit that some of Merlin's stuff goes over head.

[d95err]

Is the resistor in that picture 15k ohms? I think you’d want a very small value such as 10 ohms.

[sluckey]

Is the resistor in that picture 15k ohms? I think you’d want a very small value such as 10 ohms.

+1

Merlin used a 10Ω in his example found in the above link.

[alathIN]

Is the resistor in that picture 15k ohms? I think you’d want a very small value such as 10 ohms.

Sharp eye, and thank you!
The layout I used had a 15 ohms resistor in that spot - and I'm imagining 15 ohms vs. 10 ohms is probably good either way.
15 K ohms however... might not be ideal.
I have heard that little "k" makes a difference 

It's actually working fine and quite low noise... but just for fun I will put in the correct value and see what it does.
Thank you gentlemen for the free Quality Control consult.
I knew I come here for a reason!

[alathIN]

OK this looks like I'm closer to the correct order of magnitude.


The only 5W 10 ohm resistor I had was pulled from something else and I had to solder new leads on it - but there was enough to wrap around and get a solid mechanical connection.
Still I am tempted to replace this with a new resistor eventually.

[shooter]

Still I am tempted

move on, your solder skills are good.

I've used that lift a few times, worked well.  it's not a cure-all, but easy enough to try

[alathIN]

Still I am tempted

move on, your solder skills are good.

Now I can die and go to heaven. This is where the Soldering Kings come to hold court. I know I'm not up to the highest standards here but just being "not totally horrible" on el34world makes my day.

Here is a sound sample of what I got.
I have heard/read of people needing to do some tweaking, trim-potting, even oscilliscoping, to get the full "harmonic" effect.
This does not sound exactly like regular bias tremolo to me, but I don't think it's totally there yet either.
https://soundcloud.com/anthony-lathrop-821707426/vibe-demo-2