Tuesday, January 01, 2008

The TNH Amp, 1.3

After a two-month hiatus, the amp project is back in progress. The two 1/2" thick pieces here serve to strengthen the amp as well as provide a kick plate (the bottom one). The top plate will house the jack to plug in from the amplifier. If you look closely, you can see that these pieces are sitting in a dado for a tight fit. My goal is to use no fasteners (screws or bolts) to keep this together. Integrating things like this help make it strong enough to never worry about. The speaker cabinet could get more messed up than the chassis cabinet, because it is bigger and heavier. So, using dado slots ensures a strong tight fit. If you look even closer, you can see the dado on the front of the cabinet. This is for the speaker baffle.

I learned the hard way that you should cut out the speaker holes from the baffle before you assemble the whole cabinet. Well, it seems obvious now. Here is Tyler cutting out the first hole. This is an 11" diameter hole, to house a 12" speaker. The hole speaker diameter thing is a bit of a ripoff, because there is only 11" of cone diameter, the extra inch is for the speaker cage. This is Tyler's first time with the jig saw. He seemed to figure that out pretty quick.



We ended up putting so many marks on that speaker baffle before cutting it to size and popping this hole out. We spent some extra time with the sander taking those marks off before gluing it up. That's another lesson that I learned - sand off any marks or rough spots on interior pieces before you assemble the cabinet. It is so hard to get inside something like that later on. I hope things go smooth on the next step - because it's gone pretty well so far. I'm proud of myself for having him wear shop glasses in these pictures. It's a good habit. When we were sanding, he even learned that sawdust can still get in your eyes, even with the glasses on - so I think he understands how important that is now.


Here is the cabinet all glued up. I drilled out the holes for that will hold the speakers in before putting this together (yeah, another lesson I learned from other builds). Even from this horrible little phone camera picture, I can see my glaring mistake. One of the holes is too close to the speaker hole. It really bugs me looking at it, even though I don't think it will even show later on. The mounting holes are all counter sunk (forstner bit) because I will put t-nuts in there to receive the bolts that hold the speaker in. The speaker will be loaded in from the back, which is easy because it is an open-back cabinet. The other cabinet that I am building, a closed-back design, will have to have the speakers mounted on the front.

The next stage will be sanding, conditioning, staining, and finishing. Should be fun.

--gh