This is equivalent to a fixed-setting power attenuator and single-speaker cab, but is less expensive and more portable.
For repair and test of tube amps while monitoring result quietly. Not just dummy load (which can't monitor).
At local electronics store can buy the cheapest speaker - a single 6" driver - or a $20 WeberVST.com speaker.
Mount in a little open-back particle board box, about 9" x 9" x 4". (do you build this? can you buy it?)
Mount eight 25W load resistors inside.
Put a couple of 1/4" jacks and a dual banana connector on the top.
Forms a 200W 8-ohm cab that weighs about a pound, and only puts out a couple of watts when cranked.
Can build a 16 ohm and 2 ohm version.
Can build a 900W 4 ohm cab for testing bass heads.
Cheap, light, easy to build, and really useful.
Drawings available.
Affordable, lightweight piece of test gear.
Mini-cab that sounds pretty cool. You can totally dime out a Marshall 100W head and just wail away.
This is a type of DIY circuit and construction that is right for the amptone site. Not covered by other sites such as schematic sites. Soaks, iso boxes, and custom low-wattage cabs aren't covered. This is an attenuating cab, related to the Folded Space: Micro Room speaker isolation cab. ( )
Layout is one of the gotchas with DIY.
Is there a switch or another way to adjust how much attenuation (how loud the speaker is)?
How do you route the wires from the resistors or spk to the 1/4" jack?
What do you connect to the banana jacks - scope?
How are the power resistors secured? Do they float? Metal heatsink?
Are the wires bare?
Do the power resistors get hot and ignite the particleboard?
Did you cut and build the cab yourself?
How did you cut the speaker hole?
Amptone.com ultra gear-search page