Two effets in the same box. Voltage, ground recomendation

[nonost]

 Hi! I'm going to box a delay with a booster at the output and with another booster. So it will be two footswitches and three circuits. All in the same box.

Are there any tricks regarding dealing with voltage or ground in order to avoid noise or whatever?

Cheers.

[alltrax74]

You could use this small board for the DC
https://www.pedalpcb.com/product/dcbreakout/

[Mulekicker]

I put multiple circuits in one box all the time. Sometimes your dc jack gets crowded so I usually just strip off a little extra insulation from one of the wires that's going to the jack. I'll then attach any other wires connecting to the jack to the extra little piece of wire that's sticking out. Make sure I solder a solid connection. Does that make sense? Probably not, ha! Otherwise, just follow standard protocol. No ground loops, keep in/out wires separated...

[nonost]

I was thinking in a small piece of vero with a protection diode and a filtering cap near to de DC jack. And the run all the +ve wires to circuits from it. And I would keep the filtering cap of each circuit as well.

Thanks!

[induction]

Sounds like a good idea. Separate filtering for each circuit is highly recommended, especially since there's a delay in there. Digital circuits put lots of noise on the rails.

[Mulekicker]

Just as a side note pertaining to your project. I just finished an EP pre into a Keeley Mag Echo into an EQD Space Spiral. I was expecting some noisy gremlins I'd have to troubleshoot but it actually is quiet as a mouse. Good luck!

[SeaWitch]

Mulekicker wrote

I just finished an EP pre into a Keeley Mag Echo into an EQD Space Spiral...

Mulekicker,

Any chance I can hear this thing?  Sounds very interesting...I also accidentally sent you an email instead of reply to the post...

[nonost]

That's great Mulekicker! How did you deal with voltage & ground?

I'm building a DeProfundis with a LPB1 booster at the output and another footswitch for the MXR Microamp. I'm keeping each power filter cap at its board and then use a decoupling aux. board near the DC jack. Something like this:



Cheers!

[ξεναγος νεκροπολης]

maybe an overkill but i would probably go this way.
those small resistors might save you regarding noise in some circuits.


 

[nonost]

A little bit overkill yes :)

"Matar moscas a cañonazos" we will say here in Spain. But it's great! I did the board this morning but the next time I'll do this way in case there's enough space.

I ended up doing something quite similar. I used 100R and 100uf.  I only omitted the tiny 100nf caps.

 Thank you very much for taking your time! I think this will be helpful to many others

 Cheers!

 pd: the only thing I would change is the 1n4001. I'm used to 1n5817 in series.

[Travis]

I’m trying to learn spanish. Without translating I’m thinking that means killing a fly with a cannon.

[Travis]

I wonder if the small parallel caps are really effective on the main PS rail.

Op amp datasheets usually recommend a ~100nf ceramic cap close to power pins for decoupling, but it is usually stipulated that the cap must be physically very close to the pin to be effective.

In a case where you have the filter caps then a wire to the board I think that wire technically starts to defeat the purpose because you want the filtering to be right where the current is being drawn

But I’m sorta just thinking out loud because it is beyond me

[nonost]

Ey Travis! That makes sense. I saw that cap in some scenarios, like 7660 voltage stuff.

Yes, you are right about the translation! :)  

Feel free to ask me anything related to spanish, here's my mail:

[e-mail]

It can be tricky grammatically and I'm happy to help.

[induction]

Noise filtering close to the source certainly won't hurt, especially if you add more filtering on each individual circuit. The advice of filtering as close to the op-amp as possible is good, but is done to avoid oscillation in certain designs, and sometimes to avoid ticking in some time-based circuits (like the repeat percussion, where the issue is keeping current pulses routed into sections of the ground path that are not directly connected to components in the audio path). For simple noise reduction, the suggested approach will probably be good.

The only thing I can think of to watch out for is the total series resistance between the adapter and the circuit. If you have multiple low-pass filters in the path, the multiple resistors in series will drop voltage of the V+ rail seen by the circuit. Usually it's not a problem, but some circuits (delays and reverbs come to mind) have chips with fairly tight limits on supply voltage. For example, too much series resistance can turn a Belton reverb brick into a white noise generator. The best way to know if it will work is to try it and see, keeping these issues in mind.

[nonost]

Ey! The voltage drop is just a bit. I'm using a 1n5817 (180mVf) and the battety dropped from 8.8v to 8.5v. So no problem.

But I had a problem with the DeProfundis. You can't use a resistor in series with the v+ before it hits the board. I suspect the regulator being the problem. Was really weird. The voltage dropped 2v!!! I isolated the DeProfundis from the rest of the circuits and decoupling board and double check that a series resistors with the v+ was the cause.

Weird stuff...

Thanks induction! ;)