OFF-BOARD WIRING: Positive Ground

A short guide to off-board wiring for positive ground effects.  It's not as complicated as it's sometimes made out, but I do get that it's confusing.  If you want all the details, head over to the tech section of Amplified Parts - it may hurt your brain by the end, as it's very detailed.

Note #1:   Positive ground effects are not the same as positive centre DC power jacks.  People often confuse the two.  

However, I have heard that some people do reverse the DC jack polarity for their positive ground effects, as they prefer the switching when a battery is involved.  For me, this is just one more complication that should be avoided.  

Note #2:   Apart from the battery-only option, these all need a good quality isolated power supply to work (no daisy chaining with negative ground effects).  

I use a Voodoo Labs Pedal Power 2 Plus that I picked up second-hand.  It's great, but it's not the most lightweight or modern supply - if you travel internationally, you'll probably want a lighter fast switching supply that can automatically handle variations in supply voltage (220-240v vs 110-120 etc).

POSITIVE GROUND GUITAR EFFECTS - DC ONLY

Often just a DC jack on its own is fine - there are a lot of benefits with this approach.  No batteries for one (obviously), mono jacks are fine and you gain space in the enclosure.  

This is my preferred approach for anything that will live on my board.  Note that the DC jack is wired in the normal manner and the polarity of the LED is reversed.  Simple right?

DC WITH BATTERY

Sometimes people want both options, which is understandable, but I'm not really into it.  

It's not obvious, but two switches are now working in the circuit above.  One in the DC jack, and the stereo input jack.  

DC switch:  When the DC jack is plugged in, it breaks a connection between the two positive terminals, so the battery is now out of the circuit.

Input jack switch:  V+ is connected to the ring of the stereo jack.  The circuit can only be powered up once a jack is inserted, connecting the ring (V+) to the sleeve (ground).

JUST BATTERY - OLD SCHOOL, NO LED

Possibly the easiest option, if you don't mind changing batteries occasionally and can remember to unplug a guitar lead.  There is no cleaner power supply than a battery, although they are kind of an environmental disaster.  Without an LED, they will last about a year or so in fuzz pedal.   Some folks also swear that batteries sound better and only use carbon types.  

WHAT ABOUT DC INVERTERS?

Yes, you could just add a DC inverter, but then it's no longer a positive ground effect, is it?  As far as the rest of your pedal chain is concerned, it's a regular negative ground effect.

I rarely do this, as I mostly use 0.15" vero board for vintage-style circuits.  The hole spacing doesn't match the inverter IC and being a bit of a purist at times, I don't like the look of it.  I've also had issues with dodgy ICs and high-pitched noise at times.  It can work well and heaps of people do it, it's just not for me.