Huminator II - Power Filtering

[Neil mcNasty]

Since many people are requesting information about power supply noise issues and wiring 2 effect in the same enclosure.
I've decided to add this here, so that it is easier for people to find it without searching trough multiple discussions.

This is my slightly upgraded version of the original Huminator with a half wave rectifier at the input to remove any additional ripple current. (a 1N4001 can be used if you do not have the 1N5817)

First a single effect version + one for multiple effects with a schematic of the single version to give an idea how it works:


And here's one for dual effects in one enclosure:

[Addy Bart]

Nice one, Neil! I really like adding this to every build.

[traktop]

You mean every build? Single effects as well? Does it makes so much difference?
Cheers, Gilberto.

[Addy Bart]

Obviously just the first layout. It's perfect for eliminating psu whine but I'm using a cheap old 1spot so my power isn't all that clean.

[Kinski]

I can't believe I just tried this little circuit for the first time today. The Foxx Tone Machine I just built had a huge amount of white noise when using a OneSpot power supply. Not anymore! Thanks!

[doxasound]

Hi, I recently built myself an isolated powersupply and am thinking of adding a huminator to each 9v output.

I'm curious how the Huminator II will affect the 9v output current, if at all. The 9v outputs provide up to 400ma each and it would be great to retain that current as much as I can.

I'm not sure, but a 100r resistor inline with my 9v supply would decrease my current, no?

[doxasound]

May have answered my own question... ohm's law... haha

So looks like replacing the 100r resistor with a 22r will get me 410ma with a 9v supply for 3.7 watts. That's going to be a huge resistor....

[Neil mcNasty]

WARNING! doxasound
You might be thinking about this in the wrong way!!!

Do not add a Huminator between a single outlet and a daisy chain, or in any way feed power to several pedals at the same time by going via a single Huminator!
If you do that... It not only defeats it's whole purpose of the circuit, but you will also get a huge voltage drop (the higher the current draw, the higer the voltage drop will be) + it adds a high load on the resistor (as you note)!!!

The Huminator is originally meant to be added inside a pedal with power related noise issues.

But you could do like me: make a breakout box that has a Huminator for each of the DC outlets and where each DC outlet only feeds one pedal, and not several...
Therefore a giant resistor should not be needed when used correctly!

[doxasound]

Thanks for the warning!

I made an isolated power supply and was thinking of fitting it as such:

MAINS Power to DC 9v to Huminator II to 2.1mm Out Jack. Each power outlet has it's own transformer (as opposed to having 1 transformer with multiple secondaries, etc.), as I mentioned it's an isolated power supply.

Sounds like the only pedals that would draw a lot of current are those digital 300ma+ pedals, so I was thinking I could add a toggle switch for each outlet to engage the huminator IIs or bypass them. That way I can easily just "Fix" a noisy pedal.

What do you think?

[Neil mcNasty]

The switching idea sounds neat!
Did not think about that option...

Personally I have built several breakout boxes that gets it's +9v from a powerful main supply that has 6 x 1 Amp Outlets, and then the breakout box splits it to 8 outlets with each their own Huminator, wired piont-to-point inside the box.
I've been using 22R or 33R resistors instead of the 100R you find in my layout above, in order to avoid large voltage drops when using pedals that draws a lot.
100R is ok when you add it to dirt-boxes that has a low draw, but not so suitable for 100mA or more...

Note that in the breakout boxes, I only use 2 diodes and a large cap at the input, and then I run 8x resistors followed by a Cap, going to each of the 8 outlets.
No need to add the diodes for each output in this case...
In the layouts above, there is a 4 way version of this, that can easily be expanded...

By doing it in sections, I can scale the power supply depending on my needs.
At the moment it feeds a pedalboard with over 30 pedals on it
A typical DIY builder scenario that I guess many of you recognise, adding what you want, instead of what you actually need

[doxasound]

hahaha 30 pedals?! That's awesome!

I guess it would make sense that the noisy pedals are usually the higher gain, dirt pedals, and not so much the digital (aside from ground loop noise and what not). Hmm...

I really like that 4 in 1 layout you did, so expanding that layout might be a good option too haha

Thanks!

[GrooveChampion]

Well, I just built one and I have an issue, when the effect is bypassed there is unbearable white noise and when its engaged its even more unbearable. The effect in question is a DBA Reverberation Machine and I am sure that I wired something wrong. I wired the mains from the DC jack as instructed, I wired the 9v out into the DBA RM board and the ground from the board, the jack and the LED into the Ground Out. I tried disconnecting the 9V for the LED from the DC jack but no affect.

[Travis]

Are you using insulated (plastic) or open frame metal jacks?

I’ve had that problem from not connecting ground to the enclosure

[GrooveChampion]

They are metal jacks, so I use the chassis as ground.

[aelling]

Did you remove the 1N4001 diode from the RM circuit?

[GrooveChampion]

No

[GrooveChampion]

So you're saying the built in polarity protection of the RM in causing the problems?

[aelling]

No, but it's a place to start since it looks like the huminator has a polarity protection as well.

[Addy Bart]

When using the Huminator with PT2399 chips (there’s three PT2399 in a Belton brick), and the voltage drops too much, it creates all manner of noise. Changing the resistor in the Huminator can often help - Take some alligator clips and piggyback a resistor (start with 10 ohms for example) on the back of that 100 ohm. You can find the best value that will remove the noise from the PSU, and still play nice with the effect.