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Build notes specific to this amp from Mitch.

This amp has a single ended power amp operating Class A. It has a KT77 made by JJ in the Slovak Republic for the output tube. It sounds warm and strong. The bias for the output tube is adjustable so a variety tubes can be used, such as EL34, 6L6 or 6V6. The KT77 works well with the bias set for around 45mA of cathode current. I also tried a 6V6. I didn't notice a big difference except there is a bit less volume and it gets crunchy earlier.

The preamp has two gain stages and bass, mid and treble controls. It uses a 12AX7 tube also made by JJ.

The amp has Alpha pots, Cliff Jacks and Hammond transformers.

It has a 16 gauge aluminum chassis. It's very easy to drill, I just used a step bit for the large holes for the tube sockets rather than a chasis punch.

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The first step after the hole drilling was mounting the transformers, tube sockets, pots, switches and jacks.

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The eyelet board assembly was next. The board is 1/8" fiberglass. I roughly measured all the flyoff wires that will go to the tubes and the pots and attached them to the underside of the board. They could go on the top too. That makes tracing the wires easier but it looks neater to run them on the bottom.

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I wired the AC, the heaters, the jacks, the pots and the output transformer secondary. The transformers and the AC power use stranded wire. This tends not to stay where you put it so I bundle these with cable lacing. It's an old school way to do it but it looks a lot better than using nylon zip ties.

Shielded cable is used for sensitive areas of the preamp. All other wiring is done using solid 22 gauge hookup wire. I twisted the heater wires using a power drill.

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I installed the eyelet board and attached its wires to the tubes, pots and switches.

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This completed the wiring. I checked everyting thoroughly a couple of times and applied power. No tubes in yet. There was no smoke and all the voltages read good. I shut it off, waited for the capacitors to discharge, then I plugged in the tubes and a dummy load. I applied power again. Still no smoke, the tubes glowed nicely and all the voltages still read good. All that was left now was to plug in a guitar and a speaker. It sounded fantastic for such a small amp.

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I built a fairly standard combo cabinet for the amp and a 10" speaker. The plywood is 3/4" Baltic birch. I'll be covering it with Tolex.

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Here's the cabinet with its front and back panels. The grill cloth panel came from a small speaker cabinet I made several years ago.

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I installed the Tolex. Rounded Tolex corners can be tricky. It just takes time and careful trimming to get them perfect. The indented part at the top of the cabinet took a while.

The other corners were done fairly quickly because I plan to use metal corner protectors on this cabinet. They might look good in the picture but there are a few flaws that will be hidden by the corner protectors.

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Here's the amp after I painted the front and back panels with black textured lacquer, installed the corner protectors and mounted the chassis.

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The speaker is a well broken in 10" Eminence Ramrod.

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I mounted the chassis upside down so I'll have to install a retainig clip on the power tube.

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The blue Tolex didn't go with the red speaker grill as well as I thought. I changed the grill cloth and painted the interior of the cabinet black.

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I had a suggestion of using a Union Jack on the grill cloth because of the amp's British sound. I Photoshopped a Union Jack onto a picture of the amp to see how it would look. I like it and will keep it in mind for future builds.

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With the installation of a faceplate and backplate the amp is finally finished. I had the plates made at a local laser engraving facility.

They used a material called lamicoid. It's white acryllic with a thin black layer on top. It's usually used for signs and name tags. It's similar to the traffolyte material that Hiwatt used for their faceplates and emblems.

The laser burns off the black layer where you want the lettering. This produces white letters on a black background. Mechanical engraving tools can be used, too. Also there are lots of other color combinations available.

I did the layout using Inkscape (free software similar to CorelDraw) which can output the artwork as a vector graphics file in EPS format. The engravers used this file to run their laser. The laser cut the holes for the switches, jacks and pots, too.

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This amp has more than enough power for practicing and recording. It can go from clean to crunch all at living room or bedroom levels. It can go pretty loud too, so it's good for gigging or jamming as long as the rest of the band isn't playing at hearing protection levels!

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