Good day to all!
I have completed building the preamp and amplifier modules, and have a proven – though simple- power supply design.
Now I need an enclosure to house all the electronics and speakers! In this first of a two part post on the enclosure, I'll be putting together the basic enclosure from stock lumber.
Since I want it to be a compliment to my existing "Classy Lassie" combo (as seen elsewhere in this forum – and shown in earlier posts), I took the time to measure the "Lassie"'s dimensions once again.
Found on the wall of an old Babylonian carpenter shop were these words (post translation) "Measure Once, cut Twice. Measure Twice, cut Once". Never so true as with this. Originally I measured the Classie Lassie "footprint" at 17 inches by 11 inches. I used the old "trick" of starting the measurement at the 1" mark on my measuring device when I took these – but, apparently I forgot to subtract 1 from the measurements. For when I measured again, I found the "Lassie" footprint to be 16 inches by 10 inches. The width was a combination of a 9 ½ inch board and a ½ inch back plate. 9 ½ inches wide is the width of a "1x10", so to facilitate the main body I went down to the local lumber yard and picked up an 8 ft 1x10.
I decided to match the "Lassie" in footprint, which means the new amplifier had to be 16 inches long by 10 inches wide total. Because the "Lassie" has no controls on the front panel, I decided to match that look with this outboard amplifier. This means that I must put the control panel upon the back plate, if I am going to have the "Lassie" sitting on top of the outboard amplifier. Thus, front panel will be speakers only, top is plain wood and controls and inputs are to be mounted on the ½ inch thick back plate – should work out well.
Please see the drawing "concept1.jpg" for a visualization of this.
We interrupt this thread entry for an "Aside" or "Sidebar":
Now, before I go any farther, I want to dispel the myth that you need a professional woodshop to make a nice enclosure. The tools I use to manufacture my enclosures are simple handheld power tools and hand tools. Specifically: A circular saw, a saber saw, a cordless drill/driver, drill bits, countersink bit, screwdriver bits, ¼ sheet palm sander, small handsaw, hammer, tape measure, and carpenter's square. With these common handheld power tools, some careful measuring, wood glue and screw hardware, I have built the enclosures for all the amplifiers I have posted schematics for elsewhere in this forum. Every permanent wood to wood joint is glued, then screwed down – usually with a drywall screw.
Now we take you back to our regularly scheduled thread entry:
I determined to use a 1x10 (8 ft) as the base wood for my enclosure. Actual measurements of the 1x10 board are 9 ½ inches by ¾ inches. The total length of the "Lassie" is 16 inches, and subtracting two board widths from that gives me a front (speaker) panel width of 14.5 inches. The question was then, could my speakers I want to use fit within this size board? I laid the speakers out on a board, and found that I could fit all three speakers in a 12 inch square, with 1 inch boarder on all sides – 13 inch square: perfect!
I cut a 14.5 inch square board, marked off an offset boarder of 1 inch, and laid the speakers out on it. You can see a picture of the speaker plate labeled "spkrpnl1.jpg".
My back plate board will then be 16 inches by 16 inches. I cut this from a scrap piece of ½ inch thick OSB I had around the house at the time.
With this speaker panel, and the ½ inch back plate, the final dimensions of the "outboard amplifier" will be 16 inches long, 16 inches high and 10 inches deep.
The speaker plate can be attached via screws into the front plate, or sandwiched between a border wood and an interior wedge. Since the Classie Lassie is set up in the latter method, I will follow suit with this unit to visually match.
The pieces of 1x10 needed for the enclosure are 2 – 14.5" long and 2- 16" long. To create the wood frame that keeps the speaker panel from falling out the front, I took a furring strip ( 1 ½" x ¾") and rip cut it down the middle for 48 inches of the board. This gave me 8 feet of approximately ¾" x ¾" "trim board".
I carefully attached the "trim" pieces the full length of the 14.5" boards and centered a 13 inch piece of trim onto the "front" edge of both 16" pieces of 2x10. This allows the trim pieces to form a "frame" for the speaker panel to rest against. (check Assy1.jpg for how this fits together).
Examine "initwood.jpg" to see all of the pieces for the enclosure as described laid out.
Next, I took one of the 1x10 pieces and scribed a line on the end of each 16" board, on the "inside" showing how thick the 1x10 was. Then I drilled two holes from the "inside" to the "outside" on each end, and used the countersink bit on the "outside" for the mounting screw head. See "drilled.jpg" for this step. This is a critical step to insure a clean and accurate assembly.
I put a bead of wood glue on the end of one of the 14.5" pieces, laid the 16" piece on it and ran screws through the pre drilled holes into the end of the "side" piece. Attached the other side, and then affixed the bottom in a like manner. The screws provide the clamping action for the glue, and assist in keeping it all together. Careful examination of "concept1.jpg" below will give you the manner in which the box is assembled.
In "Assy1.jpg" below, you can see how the speaker panel is butted up on the inside of the frame, and the main box is now ready for sanding – once the glue is dry!.
In my next post, I'll be cutting out the speaker panel and prepping it for assembly, as well as preparing the back panel with control and I/O locations. :tu:
http://img111.imageshack.us/img111/6017/concept1ba4.jpg
http://img111.imageshack.us/img111/348/spkpnl1xk6.jpg
http://img253.imageshack.us/img253/555/initwoodfq4.jpg
http://img253.imageshack.us/img253/9066/drilledwz6.jpg
http://img253.imageshack.us/img253/7812/assy1ow2.jpg
I have completed building the preamp and amplifier modules, and have a proven – though simple- power supply design.
Now I need an enclosure to house all the electronics and speakers! In this first of a two part post on the enclosure, I'll be putting together the basic enclosure from stock lumber.
Since I want it to be a compliment to my existing "Classy Lassie" combo (as seen elsewhere in this forum – and shown in earlier posts), I took the time to measure the "Lassie"'s dimensions once again.
Found on the wall of an old Babylonian carpenter shop were these words (post translation) "Measure Once, cut Twice. Measure Twice, cut Once". Never so true as with this. Originally I measured the Classie Lassie "footprint" at 17 inches by 11 inches. I used the old "trick" of starting the measurement at the 1" mark on my measuring device when I took these – but, apparently I forgot to subtract 1 from the measurements. For when I measured again, I found the "Lassie" footprint to be 16 inches by 10 inches. The width was a combination of a 9 ½ inch board and a ½ inch back plate. 9 ½ inches wide is the width of a "1x10", so to facilitate the main body I went down to the local lumber yard and picked up an 8 ft 1x10.
I decided to match the "Lassie" in footprint, which means the new amplifier had to be 16 inches long by 10 inches wide total. Because the "Lassie" has no controls on the front panel, I decided to match that look with this outboard amplifier. This means that I must put the control panel upon the back plate, if I am going to have the "Lassie" sitting on top of the outboard amplifier. Thus, front panel will be speakers only, top is plain wood and controls and inputs are to be mounted on the ½ inch thick back plate – should work out well.
Please see the drawing "concept1.jpg" for a visualization of this.
We interrupt this thread entry for an "Aside" or "Sidebar":
Now, before I go any farther, I want to dispel the myth that you need a professional woodshop to make a nice enclosure. The tools I use to manufacture my enclosures are simple handheld power tools and hand tools. Specifically: A circular saw, a saber saw, a cordless drill/driver, drill bits, countersink bit, screwdriver bits, ¼ sheet palm sander, small handsaw, hammer, tape measure, and carpenter's square. With these common handheld power tools, some careful measuring, wood glue and screw hardware, I have built the enclosures for all the amplifiers I have posted schematics for elsewhere in this forum. Every permanent wood to wood joint is glued, then screwed down – usually with a drywall screw.
Now we take you back to our regularly scheduled thread entry:
I determined to use a 1x10 (8 ft) as the base wood for my enclosure. Actual measurements of the 1x10 board are 9 ½ inches by ¾ inches. The total length of the "Lassie" is 16 inches, and subtracting two board widths from that gives me a front (speaker) panel width of 14.5 inches. The question was then, could my speakers I want to use fit within this size board? I laid the speakers out on a board, and found that I could fit all three speakers in a 12 inch square, with 1 inch boarder on all sides – 13 inch square: perfect!
I cut a 14.5 inch square board, marked off an offset boarder of 1 inch, and laid the speakers out on it. You can see a picture of the speaker plate labeled "spkrpnl1.jpg".
My back plate board will then be 16 inches by 16 inches. I cut this from a scrap piece of ½ inch thick OSB I had around the house at the time.
With this speaker panel, and the ½ inch back plate, the final dimensions of the "outboard amplifier" will be 16 inches long, 16 inches high and 10 inches deep.
The speaker plate can be attached via screws into the front plate, or sandwiched between a border wood and an interior wedge. Since the Classie Lassie is set up in the latter method, I will follow suit with this unit to visually match.
The pieces of 1x10 needed for the enclosure are 2 – 14.5" long and 2- 16" long. To create the wood frame that keeps the speaker panel from falling out the front, I took a furring strip ( 1 ½" x ¾") and rip cut it down the middle for 48 inches of the board. This gave me 8 feet of approximately ¾" x ¾" "trim board".
I carefully attached the "trim" pieces the full length of the 14.5" boards and centered a 13 inch piece of trim onto the "front" edge of both 16" pieces of 2x10. This allows the trim pieces to form a "frame" for the speaker panel to rest against. (check Assy1.jpg for how this fits together).
Examine "initwood.jpg" to see all of the pieces for the enclosure as described laid out.
Next, I took one of the 1x10 pieces and scribed a line on the end of each 16" board, on the "inside" showing how thick the 1x10 was. Then I drilled two holes from the "inside" to the "outside" on each end, and used the countersink bit on the "outside" for the mounting screw head. See "drilled.jpg" for this step. This is a critical step to insure a clean and accurate assembly.
I put a bead of wood glue on the end of one of the 14.5" pieces, laid the 16" piece on it and ran screws through the pre drilled holes into the end of the "side" piece. Attached the other side, and then affixed the bottom in a like manner. The screws provide the clamping action for the glue, and assist in keeping it all together. Careful examination of "concept1.jpg" below will give you the manner in which the box is assembled.
In "Assy1.jpg" below, you can see how the speaker panel is butted up on the inside of the frame, and the main box is now ready for sanding – once the glue is dry!.
In my next post, I'll be cutting out the speaker panel and prepping it for assembly, as well as preparing the back panel with control and I/O locations. :tu:
http://img111.imageshack.us/img111/6017/concept1ba4.jpg
http://img111.imageshack.us/img111/348/spkpnl1xk6.jpg
http://img253.imageshack.us/img253/555/initwoodfq4.jpg
http://img253.imageshack.us/img253/9066/drilledwz6.jpg
http://img253.imageshack.us/img253/7812/assy1ow2.jpg