Attenuator Schematic/Layout

[surfsup]

Well I saw ApexJR had the Ohmite Dividohm 50R 50W resistors for $1, so I ordered two and worked them into an attenuator layout in parallel. Here it is, I'm going to build this over the next week. Any tips on:

1) How to hold the ceramic resistor?

2) Painting/Decal tips? I don't want to go crazy so will probably use primer, rustoleum, and clearcoat.

[Structo]

Usually those type of ceramic resistors have spring clips that insert into each end, then are fastened to the enclosure.

Look up the Airbrake type attenuator that the Trainwreck guys use.

Also, resistive type attenuators tend to get real hot, so maybe some type of heatsink fins or ventilation scheme is in order.

I'm not sure if these are the same clips but it's what was used for the Airbrake resistors.
Here is a data sheet about resistor mounts.
http://www.ohmite.com/catalog/pdf/resistor_hardware.pdf

The spring clips used in the Airbrake.
Mouser# 588-12-E
http://www.mouser.com/ProductDetail/Ohm ... 252b6aQ%3d


Can you describe what your switching options give you?

[surfsup]

I already ordered and received all the parts, including the mounts, etc. The drillplan is to size, including the clips. I got the rest of the stuff I needed from Mouser, so I'm ready to go. Here's a spreadsheet of the attenuation levels if my math is right, and to be honest I am making a somewhat educated guess so any input from you guys would be appreciated.

Also, the ceramic resistor, any clever ideas how to mount that? its 25W but by my calcs it dissipates 12W at one setting. Maybe I'll fashion my own little strip with two holes on the end to secure it...

[surfsup]

Well this project turned out nicely. The attenuator doesn't seem to affect the tone much at all. Though maybe on the lower setting(s) there might be a bit darker tone. Also, I think I want more attenuation since this seems to only affect the volume about 1/2 or 1/3 of full power but it does give me more options with the amp for sure.

[Herec]

What amp are you using it with?

[surfsup]

Tried it with three amps i built so far. two single ended EL34, and one 2xEL84