Electric Kool-Aid Amp Test: Day 118—It's ALIVE!

It's Alive!Some of you who’ve been reading this blog for a while might recall I’ve been playing Dr. Frankenstein in my basement, building a replica of the legendary Marshall 18-watt amplifier. You can catch up on the story here:

Day 1 – The start of the project.

Day 23 – Loopy from solder smoke, I have a mystical vision.

In February, with the wiring completed, Al “Igor” Scott and I tickled the beast to see if it’d twitch. Well, it twitched.

I’ll let Al tell the story. This is an excerpt from a post in response to people asking how the amp project was going:

Hey everyone, Rob DID finish it. And I took pictures when he switched it on. The thing smoked, caught fire and then burned the house down. It’s all on film. How come you don’t post it, Rob?

No….. That’s not what happened.

There was a loud piercing squeal. Like a smoke alarm going off. So we turned it off and looked at it. Hmmm. All the knobs were turned down. So we put them half-way up. Turned it on, squeal gone! Could it really be that simple? Seems it only squealed if the tone pots were all the way down. So we centered them. Pure silence. Blissfully hum free.

Rob got the Les Paul.

He turned the volume up full.

And the most gorgeous sustained distortion poured out. Rich, detailed, articulate, phat. Like that first taste of beer on Friday. Like butter on pancakes. Like sex with everyone you’ve ever dreamed of. At once.

And when wild man Rob held the guitar to the speaker (the way you know he likes to) the feedback careened out just like it does on TV!

We were in Rob’s basement, and just then his girlfriend arrived and said she heard it from the street. “You guys having a party?”

Who, us?

It was at this point that I noticed the 18 Watt has no gain knob. Just volume.

“Right,” Rob said. “You want distortion, you gotta play loud. Like our forefathers did.”

So we kinda did burn the house down after all.

Now Rob seems to be in the midst of figuring out the cabinet issue. I’ll let him post about that.


Uh, Rob? Can you stop singing and finish the amp?

Here are some videos of the Moment of Truth:

Baby’s First Scream – It turns out the 18-watt design I used sometimes has a “ground loop” problem when the tone or volume pot is turned all the way off. I solved the problem by grounding the volume knob to the chassis.

Baby’s First Power Chord – After months of soldering in silence, this was a sweet, sweet moment.

Since that evening, the amp has sat cold and silent on my workbench while I mulled over the question of the cabinet. Hardwood or tolex? Handmade or profe$$ionally built? On 4/27, I finally ordered a cherry cabinet from Weber Speakers, which has an 8-10 week wait for all hardwood cabinets.

Every time a UPS truck passes my house, I jump…

Comments 12

  1. well…FINALLY!!!!
    I was wondering when you would get that done!

    You are gonna love it when you get that cab. I would have gone with an Avitar 2×12 loaded with a V30 and a G12H instead of the Weber…but either way, it’ll sound good.

    Now, what are you building next? 🙂

    oh, yes. There will be a “next”. Trust me.

  2. Hey there Rob, I just want to say that I have scoured the internet for informed and intelligent guitar reference sites, and yours is by far the best. That is saying A LOT, trust me. I found a boatload of sites offering scales (pentatonic seems to be the scale of choice) and basic theory, but none of these sites dig into the technicalities of effective practice the way your site does (let alone even recognize that there IS an optimal way to practice).

    I consider myself a singer first and foremost (bass, primarily country-western flavored music); however, I’ve decided that, after a few years of “stubbornly dicking around,” I figure I ought to finally and truly learn to play the guitar in a presentable way. I’ve found some great foundational material on your site to help me begin this (e.g., the muscle memory article – brilliant, man! – I’ve made a bad habit of playing “quick ‘n sloppy,” you know, buzzing barre chords, choppy transitions, and all that – practicing slowly should put a stop to this).

    Great site!

  3. Rob,

    I just want to drop a line a say thanks for the great site. Out of all the guitar sites I have found, none are as personable as your blog. It seems that no one running guitar sites is interested in expressing their experiences without it being a lesson or guide.

    Part of what makes a person a great musician, no matter the instrument, is the experience of playing, of feeling, of doing. Your enthusiasm for you passion shines through and that is what makes this a great site. I’m trying to be honest and do the same thing on my own site.

    That amp sounds awesome, and thank you for sharing the process with us, and letting the world in on your guitar life.

  4. dude i love your les paul, i have an sg myself how long have you been playing? and what kind of pickups you using? im thinking about getting rid of my stock 490R and 490T alnico magnet humbuckers for something better. are they the 57 classic humbuckers? anyway love that tone.

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