2021 Super Single-Ended Amp 17
Drilling S.S.E.
Top Panel
Chassis to cabinet holes 5/8” from ends of metal. Use 13/64” drill bit to finish but start with a 3/32” pilot hole for safety.
On-Off Switch 1&1/2” measured from the left side. Start with a smaller pilot holes until you can use a small stepped Versa Bit to get to finished hole size of approximately .493”.
Fuse Assembly 2&1/2” measured from the left side. Same size as On-Off switch.
Pilot Light 3&1/2” measured from the left side. I used a real Fender assembly so a .684” (11/16”) was made with pilots and Versa Bit.
Cathode Bypass switch 5&1/4 measured from the left side. Use a 1/4” bit to finish but start with smaller pilot holes.
Tone Pot 6&1/2” measured from the left side. 3/8” hole.
Volume Pot 7&3/4” measured from the left side. 3/8” hole.
Deep/Bright Switch 10” measured from the left side. 1/4” hole.
Input Jack 11&1/4” measured from the left side. 3/8” hole.
Hole For Power Transformer
Mark the center line of the 7” deep chassis at 3&1/2” .
Make sure that you locate the power transformer on the opposite side from the input jack!
Mark a line 1/2” from the edge of the chassis.
Take the end bell off and use it as a marking and drilling guide. Easy!
Position the short end of the end bell on the 1/2” line.
Mark the four mounting holes and also trace around the edge of the entire end bell.
The raised portion of the bell is 1/2” from the flat portion with the mounting holes.
So, you’ll need to cut out a rectangle slightly larger than that so it will fit smoothly through the hole, right?
Draw your cutting lines accordingly.
Now drill a 1/8” hole just inside each corner of your drawn rectangle.
Drill a 1/8” also in the center of the drawn rectangle and also four more 1/8” holes about an inch away from each of your corner holes. Now enlarge all but the four corner holes up to 3/8” gradually! These are you access holes for your fine tooth cutting saber saw blade. Start cutting metal from access hole to access hole. Once you’ve removed some metal you can start cutting along your straight lines very carefully. Remember, the straighter your cuts the less filing you’ll need to do later to straighten up the rectangular cut. Finish up with 100 grit abrasive paper so there’s no chance of a sharp edge cutting any of your wires or fingers!
I ended up with a rectangular hole cutout that measured 2.842” X 2.169”. The end bell now fits very nicely.
Now drill the four 3/16” screw mounting holes.
Reassemble the power transformer and check for fit.
Mount Output Transformer.
Mark a line along the long side 2” from the edge where the sockets will be mounted. The first hole will be located 3&1/4” from the side of the chassis opposite the power transformer. The second hole will be around 7&1/4” in from the edge. Actually, when you drill the first hole you can just plop down the 125ESE and you’ll know where the second hole should be drilled. I used an 11/64” bit.
Mount Choke.
I ‘eyeballed” this mount. I wanted to get it close to the rectifier tubes but not bump into the power transformer.
Mount Board On Standoffs
Mark a line 3/4” from the edge of the chassis opposite from the power transformer side. This is the 7” deep portion of the chassis. The first of the four holes you’ll need to drill to mount the board on its standoffs will be 2” in from the side of the chassis where the sockets will be mounted, dig? Mark a line 2” in from that long edge; this is where you’ll drill the second of the four holes. Once you have those two holes drilled use a couple of drill bits or metal rods to hold the board in base so you can use it as a drilling jig to mark the location of the last two hole. I used a 9/64” bit and that works out really nice with the 6-32 machine screws I use to hold the board in place. If you buy the orange board like I’m using here you’ll need to open up the four mounting holes as well with the 9/64” bit.
Drilling The Tube Socket And AC Cord Holes
Draw a center line on the tube socket side of the chassis box. It’s 2” deep so 1” in is the center. Measure 3/4” in from the side where power transformer goes and that’s where you drill out box for the AC cord with push-in strain relief. For the first tube socket measure 2& 3/8” from the side where the power transformer goes. The other sockets are all 2” apart so also mark the line at 4&3/8”, 6&3/8”, 8&3/8” and 10&3/8”. Center punch each hole ant then drill a 3/32” pilot hole. Keep opening up the holes with progressively larger bits until the #4 Unibit fits through. When you get to the hole for the 12AX7A socket be very careful not to open it up too much. Check your work as you go. The socket I chose fit a .749” (almost 3/4”) hole very nicely. With the Unitbit spinning we’re talking Torque City so put the chassis down flat on your padded bench top and drill from the side. Hold down the chassis with the palm of your hand or clamp it carefully with blocks of wood. When I tried to finish the holes with the larger Unibit I found that I needed a drill with a 1/2” chuck that I no longer owned! It was Christmas Eve but I found an open ACE Hardware and bought one. The battery in the box was uncharged so I went home and stole one from my Craftsman mower! The final octal socket holes are about 1” diameter. I eyeballed the screw holes and punched ‘em with the General. Finish drilling size for the mounting holes is 1/8”. I’m using 4-40 machine screws and kep nuts to keep them in place. Thats a vintage HEYCO 7P-2 strain relief same as I used on the OG SSE. Hole size here is 3/4”.
Drilling The Holes For The Choke And Output Transformer
I decided to open up the mounting holes on the choke with a 13/64” bit. I also opened up the mounting holes in the chassis with the same bit. I drilled a pilot hole for the rubber grommet to protect the choke wires where they enter the chassis with a 5/64” bit. I then opened up the hole with a 13/64” bit. It’s tricky getting the exact size right for those little rubber grommets so I worked with a tapered reamer and opened the hole up until the fit felt right. Deburr the hole with a small round file. I didn’t have much room to work with between the edge of the choke and the edge of the chassis so I used a really small .4” grommet. Be csreful not to stress the choke wires when you put them through the hole in the center of the grommet.
Process for drilling the access hole for the output transformer wires is about the same. I positioned the hole between the two output tubes around 1/2” from the lip of the chassis. Be sure to deburr the hole with a file before you install the rubber grommet.
Hole For The Star Ground Lugs
Drill an 11/64” hole 2” in from the edge of the chassis and 1&1/2” in from the control panel side edge. I used an 11/64” bit so it would fit a 6-32 brass machine screw. I can’t get any more of the really cool six arm star ground lugs anymore so I used three doubles. When you install these parts clean the chassis surface with acetone and alcohol before you tighten everything down.
2021 Super Single-Ended Amp 17
Drilling S.S.E.
Top Panel
Chassis to cabinet holes 5/8” from ends of metal. Use 13/64” drill bit to finish but start with a 3/32” pilot hole for safety.
On-Off Switch 1&1/2” measured from the left side. Start with a smaller pilot holes until you can use a small stepped Versa Bit to get to finished hole size of approximately .493”.
Fuse Assembly 2&1/2” measured from the left side. Same size as On-Off switch.
Pilot Light 3&1/2” measured from the left side. I used a real Fender assembly so a .684” (11/16”) was made with pilots and Versa Bit.
Cathode Bypass switch 5&1/4 measured from the left side. Use a 1/4” bit to finish but start with smaller pilot holes.
Tone Pot 6&1/2” measured from the left side. 3/8” hole.
Volume Pot 7&3/4” measured from the left side. 3/8” hole.
Deep/Bright Switch 10” measured from the left side. 1/4” hole.
Input Jack 11&1/4” measured from the left side. 3/8” hole.
Hole For Power Transformer
Mark the center line of the 7” deep chassis at 3&1/2” .
Make sure that you locate the power transformer on the opposite side from the input jack!
Mark a line 1/2” from the edge of the chassis.
Take the end bell off and use it as a marking and drilling guide. Easy!
Position the short end of the end bell on the 1/2” line.
Mark the four mounting holes and also trace around the edge of the entire end bell.
The raised portion of the bell is 1/2” from the flat portion with the mounting holes.
So, you’ll need to cut out a rectangle slightly larger than that so it will fit smoothly through the hole, right?
Draw your cutting lines accordingly.
Now drill a 1/8” hole just inside each corner of your drawn rectangle.
Drill a 1/8” also in the center of the drawn rectangle and also four more 1/8” holes about an inch away from each of your corner holes. Now enlarge all but the four corner holes up to 3/8” gradually! These are you access holes for your fine tooth cutting saber saw blade. Start cutting metal from access hole to access hole. Once you’ve removed some metal you can start cutting along your straight lines very carefully. Remember, the straighter your cuts the less filing you’ll need to do later to straighten up the rectangular cut. Finish up with 100 grit abrasive paper so there’s no chance of a sharp edge cutting any of your wires or fingers!
I ended up with a rectangular hole cutout that measured 2.842” X 2.169”. The end bell now fits very nicely.
Now drill the four 3/16” screw mounting holes.
Reassemble the power transformer and check for fit.
Mount Output Transformer.
Mark a line along the long side 2” from the edge where the sockets will be mounted. The first hole will be located 3&1/4” from the side of the chassis opposite the power transformer. The second hole will be around 7&1/4” in from the edge. Actually, when you drill the first hole you can just plop down the 125ESE and you’ll know where the second hole should be drilled. I used an 11/64” bit.
Mount Choke.
I ‘eyeballed” this mount. I wanted to get it close to the rectifier tubes but not bump into the power transformer.
Mount Board On Standoffs
Mark a line 3/4” from the edge of the chassis opposite from the power transformer side. This is the 7” deep portion of the chassis. The first of the four holes you’ll need to drill to mount the board on its standoffs will be 2” in from the side of the chassis where the sockets will be mounted, dig? Mark a line 2” in from that long edge; this is where you’ll drill the second of the four holes. Once you have those two holes drilled use a couple of drill bits or metal rods to hold the board in base so you can use it as a drilling jig to mark the location of the last two hole. I used a 9/64” bit and that works out really nice with the 6-32 machine screws I use to hold the board in place. If you buy the orange board like I’m using here you’ll need to open up the four mounting holes as well with the 9/64” bit.
Drilling The Tube Socket And AC Cord Holes
Draw a center line on the tube socket side of the chassis box. It’s 2” deep so 1” in is the center. Measure 3/4” in from the side where power transformer goes and that’s where you drill out box for the AC cord with push-in strain relief. For the first tube socket measure 2& 3/8” from the side where the power transformer goes. The other sockets are all 2” apart so also mark the line at 4&3/8”, 6&3/8”, 8&3/8” and 10&3/8”. Center punch each hole ant then drill a 3/32” pilot hole. Keep opening up the holes with progressively larger bits until the #4 Unibit fits through. When you get to the hole for the 12AX7A socket be very careful not to open it up too much. Check your work as you go. The socket I chose fit a .749” (almost 3/4”) hole very nicely. With the Unitbit spinning we’re talking Torque City so put the chassis down flat on your padded bench top and drill from the side. Hold down the chassis with the palm of your hand or clamp it carefully with blocks of wood. When I tried to finish the holes with the larger Unibit I found that I needed a drill with a 1/2” chuck that I no longer owned! It was Christmas Eve but I found an open ACE Hardware and bought one. The battery in the box was uncharged so I went home and stole one from my Craftsman mower! The final octal socket holes are about 1” diameter. I eyeballed the screw holes and punched ‘em with the General. Finish drilling size for the mounting holes is 1/8”. I’m using 4-40 machine screws and kep nuts to keep them in place. Thats a vintage HEYCO 7P-2 strain relief same as I used on the OG SSE. Hole size here is 3/4”.
Drilling The Holes For The Choke And Output Transformer
I decided to open up the mounting holes on the choke with a 13/64” bit. I also opened up the mounting holes in the chassis with the same bit. I drilled a pilot hole for the rubber grommet to protect the choke wires where they enter the chassis with a 5/64” bit. I then opened up the hole with a 13/64” bit. It’s tricky getting the exact size right for those little rubber grommets so I worked with a tapered reamer and opened the hole up until the fit felt right. Deburr the hole with a small round file. I didn’t have much room to work with between the edge of the choke and the edge of the chassis so I used a really small .4” grommet. Be csreful not to stress the choke wires when you put them through the hole in the center of the grommet.
Process for drilling the access hole for the output transformer wires is about the same. I positioned the hole between the two output tubes around 1/2” from the lip of the chassis. Be sure to deburr the hole with a file before you install the rubber grommet.
Hole For The Star Ground Lugs
Drill an 11/64” hole 2” in from the edge of the chassis and 1&1/2” in from the control panel side edge. I used an 11/64” bit so it would fit a 6-32 brass machine screw. I can’t get any more of the really cool six arm star ground lugs anymore so I used three doubles. When you install these parts clean the chassis surface with acetone and alcohol before you tighten everything down.