Amp Tech Thread / Ask a tech Q

[mortlock]

so having said that..how many mAs do i need..how do you know..

[Hemisaurus]

It's often printed on the pedal, else guesstimate about 300mA per.

[mortlock]

if you are in the ballpark of that number will my device be ok..?? by ballpark i mean + or - 400mA

[moose23]

You can never have too much current/mA on your power supply only too little as each pedal will only draw as much current as it needs. Me I'd only buy 500mA and over regulated supplies but even that's overkill for the seven pedals I run which I'd guess add up to under 200mA with my Boss DD3 being the biggest at 45-60mA.

[Hemisaurus]

Probably. Most pedals take a little overvoltage.

I have a Boss pedal that only works with a Boss adaptor I assume bevause it needs 9.6V to run, I imagine they stuck a protection diode in on the power jack, and my regulated 9V supply is too low for it.

[Hemisaurus]

You can never have too much current/mA on your power supply only too little as each pedal will only draw as much current as it needs. Me I'd only buy 500mA and over regulated supplies but even that's overkill for the seven pedals I run which I'd guess add up to under 200mA with my Boss DD3 being the biggest at 45-60mA.

The problem with too much current capability is on unregulated supplies, having over the spec'd 9V when they are not fully loaded down.

A 1.5A regulator can be built, for the nervous, from a 7809 regulator and a couple of caps, see the 7809 spec sheet.

[mortlock]

would this work.. 

[mortlock]

i could power everything with that..

[Hemisaurus]

Most likely. You haven't said what you are powering though.

[mortlock]

i am powering 3 synths..the infection 2 and 3 as well as the dementia synth..also a few standard guitar fx pedals that i run the synths through..boss and dod pedals..

[Hemisaurus]

The synth's if properly built should hopefully have a nice big resevoir capacitor and maybe protection diodes on the power input, and probably would be just as happy running of 12V as 9, so I imagine your safe. The Boss pedals, if they are analog, I imagine you'll be OK, if they are digital, it was a half analog, half digital Boss pedal I had the problems with using a bog standard 9V adaptor, so be warned, and the DOD will require the funky mini-jack (2.5mm or 3.5mm I forget) earplug style, rather than a Boss style, looks like a couple are included in your hairy harry kit.

According to Visual Sound, they're 1-Spot will handle 1700mA so that should be plenty, but those synth's might be big drinkers, so if you have problems, try adding one pedal at a time to the chain, until things start to go wrong, start with the guitar pedals I guess

Or you could email Audible Disease and ask them the power requirements of their synths.

[mortlock]

would i be better off just getting individual power supplies for each synth..??
fuck the pedals..i can just keep sticking batteries in them if need be..although it would be nice to have everything run off one or two power supplies.

thanks for the advice..

[inductorguitars]

would i be better off just getting individual power supplies for each synth..??
fuck the pedals..i can just keep sticking batteries in them if need be..although it would be nice to have everything run off one or two power supplies.

thanks for the advice..

In the long run one of these would be cheaper than batteries. http://www.voodoolab.com/pedalpower_2.htm


I have a Extention cord/ reg. power supply on the drawing board.

[Hemisaurus]

Erik, Weber do a xfmr for that, though it's not a toroid, 8 individual. 11V AC 300mA windings and a 9V AC 2A winding for your Alesis gear

Mortlock, I'd try it and see, see how much you can run from one wart first.

[inductorguitars]

Yep. I'm going to use one of the weber trannies. I got into a discussion about pedal power with my brother. He wants batteries, saying there is never an outlet for pedals. Which got me thinking....

[Hemisaurus]

There's a couple of options there. There's the rechargeable pedal power block (is that Voodoo), there's some company makes a Li-on battery back with a DC-DC converter to power 9V pedals (it was in a Tape-Op), you could also grab a couple of 6V wet cells or gel cells and make your own.

With a rechargeable block, you need to figure out a cigar lighter attachment charger, for charging it in the van between shows.

[dunwichamps]

solar cells + DC/DC converter hahaha j/k

[VOLVO)))]

Green Power!

[Hemisaurus]

My car charger is green, the car runs on corn.

[fallen]

How can there be power for amps and no power for pedals?

I run a power supply into a power plug on the back of my board. Plug one 18' extension cord onto the back of my board and everything's powered up. Way easier than when I used to mess around with a bunch of batteries.

[inductorguitars]

How can there be power for amps and no power for pedals?

I run a power supply into a power plug on the back of my board. Plug one 18' extension cord onto the back of my board and everything's powered up. Way easier than when I used to mess around with a bunch of batteries.

That was my thought. While a rechargeable pedal power is interesting, I was thinking of a power strip/extension cord/power supply. Easy enough to do and eliminates ground loops from different circuits.

[Mr. Foxen]

Anyone got a source for impedance plugs like this:


Pretty sure I'm going to have to make some, since I've got about half as many as I need. Making sure there isn't somewhere I can jsut get them. Anyone want any if I do?

[inductorguitars]

Looking for a book or a link to download this book. I owned this book but was lost in one of my moves - it's still in a box along with my copy of Radiotron Designer's handbook volume 4.
I can't remember the author or the title of the book, but it's was shall I say "different".
Here are the details the author was Australian and was a huge fan of Tektronic "Our father who art in Beaverton". He may of even worked for them. This book was all about designing the "perfect" tube preamp. The preamp was fully differential and used 6dj8 tubes in a cascode circuit with jfet's (i think) as a constant current source for the tubes. (Totem pole design?)
Alot of the book was about his journey as a tube circuit designer, he had very "odd" ideas. It had lots of theory but put in a easy way to understand - very little mafs IIRC.

Way long shot - I bought this book back in 94 or 95 off of Compuserve or Usenet posts. It came as a flimsy photo copy and was about $35 plus shipping! But the info was AWESOME.

[inductorguitars]

Aha!

Typing out that request jogged the last remaining brain cells I have left.

I figured out the book and author.
Author: Allen Wright
Book: The Tube Preamp Cookbook

I guess he died last year. Couldn't find a copy to download tho.

[VOLVO)))]

Ill search for yas, E.