DIY Attenuators

[vroomery]

I've been doing some recent research online into building an attenuator for my fender hrd. There's a pretty cheap kit through the guys over at Bitmo, but its a 30w version. I've also found a couple of sites that show an extremely simple build featuring a 50w RMS fader.

http://www.guitarpug.com/2008/07/diy-wattage-attenuator-box/

I know there are many different styles and designs for attenuators, but how can it be this simple? Are the super expensive versions really worth the money? I would be more than excited if i could build my own for this cheap.

 

[Ch0jin]

Well as the guy on that linked site explains, yeah it -can- be that simple.

The problem is, as he states, when you wind up the attenuation and your tone fades away.

The big dollar units have more circuitry inside (and in a few cases radically different designs using speaker cones etc) and usually a few switches and such for -trying- to let some of the tone through when you have it attenuated. A lot of the discussion around attenuators seems to be by guys wanting to get power tube distortion/compression at apartment volume and even with a 15W tube amp thats gunna require bucket loads of attenuation, and therefore, tone suck if you don't have some electronic means of restoring frequencies to the signal. (meaning a more complex kit, or commercial product)

The main thing though is power. He suggests a 50W fader would be OK for up to 30W of amp and that sounds fair enough to me, but it really depends what amp you intend to use. If your packing a 100W head or something, well, good luck

Of course this is all just stuff I've read My Ultra goes well at low volume and I get to wail in proper rehearsal space from time to time so I haven't tried one personally...

 

[jim p]

need inductance and resistance

If you build an attenuator you want to use both a resistor and an inductor as a load on the amplifier. The reason you will lose brightness if you just use a resistive load is the impedance will not increase with frequency which is what a speaker will do. Look at post #310 and #314 on this page http://www.thefret.net/showthread.php?t=9379&page=17