LoadBox

[TonyS.]

Im seachring for a cheap loadbox which allows me to kill the poweramp signal.
I dont want one of these expensive things with DI-Out etc. Just a resistor.

SO...whats on the market?

 

[006]

Weber used to sell just a 150w 8ohm resistor but I can't seem to find it any more on the site, it was rather cheap too like less than $30 or so. You just need to find a resistor with at least the same wattage rating as your amp and the correct ohm rating that you will be using (4, 8 or 16). You can then wire a normal 1/4" jack to it, plug your head into that, with a speaker cable, and you are good to go.

 

[Wolfeman]

These are what I use. Cheap and do the job fine. http://www.mcmelectronics.com/product/28-048

 

[006]

^^ There ya go. Bookmarked, thanks for that Wolfe

 

[TheUnknown]

These are what I use. Cheap and do the job fine. http://www.mcmelectronics.com/product/28-048

Ive been reading the "Home-Made Dummy Load Tutorial - Save Money!!!" thread for the last few days as Im looking to record with my head silently, after reading it back an forth I got the feeling that it wasnt really safe. Theres many posts saying dont follow the original schematic its incorrect you'll fry your head etc, etc.

So if you are indeed "the" Mr. Wolf... you must know if this is in fact...Safe...or Not?

And if so, could please point me in the right direction of a Correct schematic?

 

[Wolfeman]

For that resistor, you simply wire it to a mono jack. One side goes to +, one side goes to -. No schematic needed.

The only thing you need to watch out for is heat, but just mounting it properly will take care of that.

If you want something a little more 'complete', Parts Express sells the same resistor mounted into a nice heat-sink for a buck more. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=019-020

If you are still worried about heat, then get a 200 watt resistor. It will not get as hot, and probably last a lot longer.

 

[TonyS.]

Thank you very much for the informations!!!!

I was looking for a german shop and just found this one: http://cgi.ebay.de/Lastwiderstand-8-Ohm-250-Watt-Hochlastwiderstand-/220765711659
any german guys with better offers?

Edit: a cheaper one --> 8,2Ohm and 100W http://www.conrad.de/ce/de/product/423122/WIDERSTAND-DRAHT-100-W-5-8R2/0241360&ref=list

So I just have to wire a speaker cable with +and - to the pins and I'm done?

 

[Wolfeman]

So I just have to wire a speaker cable with +and - to the pins and I'm done?

Yep that's all there is to it. If you go with that second one, I would mount it on a piece of metal and allow air to flow over it to keep it cool.

 

[TonyS.]

Cool...but I think a poweramp with a apparent power of 100W, cranked up to 50% or something, is just around 30W ( real power) ?!
What are your experiences?

EDIT: I decide to buy 2x 4Ohm 100W resistors and wire them parallel.--> Much cheaper than a 250W 8Ohm one.

 

[Wolfeman]

It's good practice to build it to cover anything you can plug in to it.

 

[SavageDoom]

EDIT: I decide to buy 2x 4Ohm 100W resistors and wire them parallel.--> Much cheaper than a 250W 8Ohm one.

For 8 Ohms you will want to connect them in series. 2 x 4 Ohm resistors in parallel will give you a total of 2 Ohms.

 

[TonyS.]

For 8 Ohms you will want to connect them in series. 2 x 4 Ohm resistors in parallel will give you a total of 2 Ohms.

Yepp, just scribal error.

 

[Trevoire520]

Just make sure you read the whole dummy load tutorial and you'll be fine dude. The first couple of diagrams are wrong but the one with 3 rows of 3 is ok.

I just grabbed two 100w 4 ohm resistors and wired them in series. So I've got a 200w 8 ohm load (though because of tolerances it's more like 9 ohms)

These things do get pretty hot though, I really need to drill some holes in my case to let it breathe a little.