Let's build an amp! Greg's journey to electrocution

[Greg_L]

It is officially underway.

I peeled all the protective film off the chassis and it's mirror finished. Lol. Wasn't expecting that. I knew it was a little shiny, but damn. I didn't do anything too heavy duty today. I wanted to get the faceplate on it so I installed the pilot light and all the pots and jacks and shit. The pilot light was a motherfucker. It was the first thing I did and it got us off to a rough start. The bulb would not push in and turn and lock. I had to tweak the housing a bit...but it's good to go now. Also, the fucking bright switches. They're fine, but the little screws are countersink heads and the faceplate is not countersunk so they stick out a tiny bit. No big deal. I can just leave it or find some flat screws later.






Installed all the tube sockets and numbered the pins with sharpie because they're pretty much impossible to read on the sockets themselves. From left to right we have the rectifier, power tube, power tube, phase inverter, tremolo, reverb recovery/vibrato channel 3rd stage, reverb driver, vibrato channel 1&2 stage, normal channel 1&2 stage. Whew. Check out that mirror finish!



And this is where it's at right now. I might start the heater wiring later tonight. Baby steps.

[Greg_L]

P.S. - this is how I'm twisting my heater wire. Nice and tight and even! We'll see how it turns out.

[muttley]

P.S. - this is how I'm twisting my heater wire. Nice and tight and even! We'll see how it turns out.

You should have disposed of the dead body round the corner before you did that. You're nicked....

[muttley]

Is this similar to what you're building? I played though it this evening. Really nice. 20180430_191923.jpg

Possibly one of the best amps ever....

[Greg_L]

So I've tackled a little bit of heater wiring. Holy shit, this is really hard. I've come off the pilot light and gotten the two power tubes done. Only six more smaller tube sockets to go!

I'm running my heater wires the Marshall way - tucked in the corner of the chassis. Fenders usually have the heater wires flying high above everything...and I see why. There's shit for room in that chassis corner with switches and shit installed. My wiring just barely fits under the power/standby switches. But I'm staying the course and gonna keep it Marshall-style. If I do it right, it will be less susceptible to "heater hum" noise.

[rayc]

Neat & petite.

[Lt. Bob]

.... the little screws are countersink heads and the faceplate is not countersunk so they stick out a tiny bit. No big deal. I can just leave it or find some flat screws later.

or countersink 'em ...... that's not hard as you know.

That's beautiful man ..... that mirror finished chassis ..... that's a surprise .... really nice.

[Greg_L]

or countersink 'em ...... that's not hard as you know.

That's beautiful man ..... that mirror finished chassis ..... that's a surprise .... really nice.

The edges aint no joke though. That's one complaint I have - they left every edge razor sharp. I'm gonna have to do a little deburring before I go any further.

[WhiskeyJack]

Outstanding.

[einstein magoo]

Looking good! Are your fingers bleeding yet? all that small, precise, meticulous work with fingertips can get to you after a while.

Have a ball man, stay the course and you'll be blasting sweet tones before you know it! Fingertip puncture wounds and all.

[Greg_L]

Looking good! Are your fingers bleeding yet? all that small, precise, meticulous work with fingertips can get to you after a while.

Have a ball man, stay the course and you'll be blasting sweet tones before you know it! Fingertip puncture wounds and all.

Ya know, my fingers do hurt, but it's from twisting those goddamn wires. No punctures, no burns, just constant twisting and twisting and keeping it tight.

So...right now, I've redone some of my heater wiring and I'm about halfway through to the preamp tubes. This is a real, serious, bitch. I'm trying to do it neatly and correctly so it's an excruciatingly slow process for a hack like me. I switched to slightly lighter gauge wire and it is much easier to deal with. I made a mistake by starting too heavy duty. Lesson learned. Pics later....

[Greg_L]

Wow, what a task. Heaters are done! And I must say....I feel pretty good about it. That was tough and I think I did a pretty good job for a n00b.

I implemented the "valve wizard" method. This wiring scheme keeps the heater wires totally out of the way of the signal wires when they go on later.

The power tubes were pretty basic.



The preamp tubes needed some tricks. First, jumper pins 4 and 5 with a tiny little "U" made of scrap leads or buss wire.



Then, just start daisy-chaining. Reds to 4 and 5, blacks up and over the tube socket to pin 9. The chain ends at the first preamp tube.





It's kind of almost already starting to look like an amp!


So now I need to go through and check for continuity and isolation where necessary. Hopefully this passes the test.

[Greg_L]

Nice work.

With skills like that there's a career for you braiding hair if the whole music thing doesn't work out.

Well, I know that braids take three strands, these wires are just two twisted together. So that's probably not going to work.

[Lt. Bob]

I can see ya' with some woman's hair fastened to your electric drill!

[Greg_L]

I can see ya' with some woman's hair fastened to your electric drill!

Now that might be a good business idea!

[Bubba]

Looking marvellous so far. Very tidy, well-planned and executed.

[Greg_L]

Looking marvellous so far. Very tidy, well-planned and executed.

Thanks. There is a LOT more wire to cram in there, so I'm thinking that doing it in layers from the bottom up might yield the best results. And can you imagine having to run those heater wires with a bunch of other stuff already in there? No way.

I have a different project to work on today - my fishing truck. The A/C took a shit and it's getting warm in Texas. I gotta put a compressor and all of it's related parts on that thing today.

[Tadpui]

Looking good, man. You're a brave soul! I like the mirror finish. Is that on the outside of the chassis too, or just inside?

[Greg_L]

Looking good, man. You're a brave soul! I like the mirror finish. Is that on the outside of the chassis too, or just inside?

Thanks. The mirror is everywhere...and it's pretty much going to be completely covered, so I don't really understand why they did it that way. And honestly it makes soldering much more difficult and confusing. I'm shining a light in there, trying to solder tiny little things, and I'm getting weird shadows and reflections and light blasting back at my eyes. The mirror looks nice, but a dull finish on the chassis would be much easier to deal with.

[Greg_L]

Not too much to report today. I worked on my truck, A/C blows ice cubes now, so back to the amp for a little bit.

More than meets the eye! Transformers!

No, they are pretty much exactly what meets the eye. I just bolted the transformers to the chassis. It was a little confusing at first because I have nothing to go on. The Power Transformer's location is obvious - a gaping hole. The rest....who knows? This chassis is full of tiny pre-drilled holes. I used a little process of elimination. I knew the reverb transformer wedged in between the preamp tubes. Found some holes that match. I knew the choke sat next to the Power Transformer...found some holes that match. And as some of you know, my mailbox looks like a brick dick. Check out my dining room light in the chassis reflection. It's a boob. My house is very sexy.



The Output Transformer, being a beefier upgrade, had no matching mounting holes in this chassis. So I figured out which grommet locations the wires need to pass through, found a pre-drilled hole to use as a guide for one of the mounting holes, and marked the opposing spot and drilled it. So that was that. All mounted up. From left to right - power transformer, choke, output transformer, reverb transformer.



Now we're getting somewhere. Miles of colorful wire. I actually braided the OT primary wires (brown/red/blue) for Armistice.



So I'm pretty much all set now to start wiring the power section. Power cord, pilot light, rectifier, power/standby switches, fuse, some grounds, etc. I would start tonight, but I want to get some cable eyelets that will mount to the various transformer bolts. That will help keep things routed neatly and out of the way. So that's for tomorrow.