I am wondering why Guitar Amps never have a 9V output on the back for pedals ?
It would be really easy to include on a new build, and not very expensive.
How easy to run a few pedals with a 9V output already there.
Is there a reason I have never seen it done?
For $10 you could have 4 x 9V 1.5A outlets on the back of an Amp.
Most existing amps can probably have one added with the current transformer.
I would love to know what others think of this.
Is there a valid reason not to do it ?
Michael.
My first thought is "polarity".
2nd is current draw.
Probably more constraints but that is what comes to mind.
Quote from: Jazz P Bass on January 31, 2022, 12:09:55 PM
My first thought is "polarity".
2nd is current draw.
Probably more constraints but that is what comes to mind.
Pedals are (almost entirely) 9v center negative. I see no reason not to do this and have actually thought about doing it as well. The only issue I can think of is that many times your pedal board isn't right next to your amp and you would need a really long 9v power cable to go from your amp to your board - could be done though, just using larger gauge wire to carry the load over the required distance.
I think this is a great idea, do it up!
There ^^^ is my concern. Your 9v output now needs a 20-30 foot power cable down to your pedals. Besides, they already make little power supply pedals to throw in your floor toy collection.
Quote from: Enzo on January 31, 2022, 05:49:04 PM
There ^^^ is my concern. Your 9v output now needs a 20-30 foot power cable down to your pedals. Besides, they already make little power supply pedals to throw in your floor toy collection.
It makes more sense for practice amps where you're probably right next to it, on stage it's a hard sell.
I guess I was thinking more for home use or practice.
But if you consider that old style pedals only used around 4mA - 30mA each.
That's about 30 pedals at under 1 Amp if you are using overdrives, wahs, chorus, phasers, big muffs etc.
The 20ft cable going to my car trailer lights is smaller then a guitar cable, and brake light alone use 3.5 Amps.
Speakers carry more amps then pedal boards, cable is not thick as a fire hose.
Modern pedals can use a lot more, loopers and multi digital pedals can get close to 500mA, but how many use them ?
I am just guessing as I just tinker with playing, and making pedals and amps for my daughter.
I feel that 2 x 1.5A 9V outlets would be of use to a lot of people, but I know bugger all.
I was mainly wondering what others thought, before I add it to my next amp.
I feel that a 20 - 30 foot run should be ok if you start with 9.5V at the amp, good for 1 Amp with little loss with speaker cable.
https://stinkfoot.se/power-list
I am not concerned over losses in the DC cable. I am concerned a whole extra cable is needed trailing across the stage. Electrically it can be tiny, you are right, not a lot of current. But practically, the cable needs to be sturdy enough you can step on it, so it needs to be jacketed.
That is a very good point Enzo
Since I am not a musician, only a casual string plucker I would not know that.
I guess if the stage has mains power at the front so you can power a pedal board from somewhere in front of you then you don't want any extra cables to trip on.
I have only had a close view of people playing in clubs and pubs where the stage is very small.
I have seen The Angels, Midnight Oil, AC/DC and many other acts on small stages where they hardly moved around.
I guess I'm showing my age if I saw them on small stages early in their careers.
I have seen ABBA busking in a park in Stockholm before they got famous too, (I was really young)
I still think it would be feasible in small clubs and venues, or practice and home use.
I brought it up mainly because the expense would be minimal if incorporated in the build, and good for beginners at least.
It would also be one less item needed to buy, drag around etc.
I like all the answers so far, informative.
Michael
AC/DC rig
https://www.youtube.com/watch?v=x2bXLaQX2rw