Crawls Backward (When Alarmed)

IconProjects, musings about guitar builds, guitar repairs, vintage tube amplifiers, old radios, travel, home renovation, and other stuff.

Building a Baffle Step Compensation Box, Pt.2

All of the grounds need to be tied together, so I figured I'd try an actual buss (aka 'bus') instead of daisy-chaining them all together.  I got the idea of using a piece of solid copper wire to make the buss.

Problem was I didn't have a ready piece of solid wire laying around, but then it hit me that I had some leftover pieces of 12 gauge 3-conductor cable from the sunroom project.  So I just cut one open and took the ground wire out of it.

Here's most of the circuit for one channel - minus the pot - assembled.  Looks pretty much like the schematic, imagine that!

Those PIO caps are beautiful.  I want to look at them for hours.  But, alas, I cannot.  I have to finish this project.

Here's the whole enchilada wired up.

You can see the ground buss running through the ground tabs of the input and output connectors.  The resistor-cap-cap circuit also goes to the buss (on the right side).

I used a bit of that crazy (in a good way) Swedish silver stranded speaker wire for the input and output wiring.  I figure all of my signal is going through it, so I should use the best stuff I have.

The assembled box works (I tested it on my 'lab' system).  I am getting a bit forgetful so I labelled which end is IN and which point on the rotation is zero cut. 

I'm going to try yet another way of finishing off the box. 

I found a lettering stencil at my local art supply store and used it as a guide (of sorts...)  for the labels.

It won't win any awards for Beauty-In-Labelling, but it's functional, and anyway, it will be stashed away with the components and will rarely be seen.

The "dB cut" numbers probably aren't too accurate (i.e., "3 dB" may not be exactly 3 dB), but they're really there as a reference point.

The box goes inline between the output of the preamp and the power amp.  The thinking behind the design was that there would be less efficiency loss there than in the speaker line, which is where most baffle step compensation usually is applied.

I now have it connected in the stereo and it works fine.  Pretty much set-and-forget.


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