Part IV – CTH Casework, Finishing Top & Bottom Lids, Case Feet, and Final Dry Fit
(Continued from Part III
This is Part IV of my CTH little case project. It’s nearing the home stretch so this will probably be the build log’s last portion.
Picking up where I left off, I took the top lid to the drill press and cut a 1” hole for the tube, plus four additional holes (5/32”) on each corner for the fastener screws. I placed a scrap wood block underneath the top lid to avoid tear-out.Note:
I find using a fence on the drill press table really helps support the piece and I get more accurate results when drilling several holes in series.
I fitted the top lid to the poplar wood chassis then pencil-marked the 4 holes I drilled previously. I then drilled 4 smaller holes on each corner of the poplar case, and tapped them for the fasteners to mount onto.(Note: I can't seem to find those fancy hex nuts you pros use for your metal front or top plates. Instead I have to settle for some shoddy looking canvass fasteners from the local hardware store )
Next thing is I worked on the bottom cover for the case (i.e. the bottom lid). I used another piece of MDF and sized it accordingly.
I find that ¾” is a bit too thick for a bottom lid, so I turned to my portable planer to shave it down to about ½” thick. I could’ve gone thinner, but not so thin as I wanted the PCB (with standoffs) to sit a little higher inside so that the tube sticks further out from the top.
After I got the MDF piece thickness down to ½”, took it back to the router table and rabbeted the edges, sized just right to fit the bottom of the case.
I checked out the aisles of my local hardware store to see if I could find some cheap ‘alternate’ for case feet. I found these nail-on chair gliders and they look simple enough to install (used the same ones for my SOHA II but larger diameter). I thought they disguised themselves well after they’re installed – the beauty is a set only cost $2.50!
Before I can mount them to the base, I needed to pre-drill small holes in each corner for the nail to stick into (see red arrows). I didn’t want to just hammer them in since the nail could split the wood. After I drilled the small holes, I also needed to cut out small notches for each corner of the bottom lid to make space for the “feet” (see yellow arrows). The bottom lid and case feet all will be permanently epoxied to the base of the case.
Next step, I marked and pre-drilled the location where the standoffs will rest (and to be epoxied permanently to). I also added 3 large holes for additional vents (1.5” diameter each, I hope it’s more than enough to keep the amp well ventilated inside)
And so that is it -- the case is virtually complete, however there are still some things that need done. The entire project needs sanding before I can apply stain and paint the top/bottom lids. At any rate, I thought it has come a long way from a piece of poplar stock and few small pieces of MDF.
Overall I thought it turned out okay and here is what it looks like now (note: no pot/shaft installed):
So that is it for this edition of zk’s build log
Just want to take this opportunity to say that I’m really pleased to see some of you take some interest on this little CTH case project. The fact that I have very little electronics experience, it has been a struggle to find some way to contribute back to this forum. I thought by sharing this little project that you might find it worthwhile and offered some inspiration/give a few ideas even to just a couple of individuals in this great DIY community. Even if only one person finds this of value I’ll be more than happy
Once again, thank you all for reading – cheers.