AMI 'Dumb Luck' (what is this?) UPDATE

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andrewsrea
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Gearlist: 28 Guitars: (2) basses, (2) acoustics, (3) hollow bodies, (3) Semi hollow, (1) Double-neck, (17) Solid-bodies

Introducing my big project, by request of a long-time client from Fairfax, VA: The AMI 'Dumb Luck'. The name is an amalgamation of 'Dumble' and 'Vibrolux.' Basically a reliable amp that sounds like it is 120dB loud, at 90dB and fits easily in a car with other gear.

My friend gigs heavy in the summer, playing pedal or lap steel & guitar. Equally adept on both. He prefers Fender amps, has about 10 different amps and sends them to me in St. Louis for all repairs and set ups. He has often left me artistic freedom, gives me his desires, we chat and I design. he also has pedals and most of his pickups from me.

He requested the ability to have two inputs that can be used simultaneously (guitar and steel), with the steel side more midrange, a 20w amp with a high headroom, sweet clean channel and a dirt channel that blooms (foot switchable). Both channels having shared reverb and separate tone. He had this Virbrolux chassis and cabinet as the starting point. Even though this is 2x10", he wanted a sound more akin to an EVM-12L. So I am going for two of the 1980's Pyle 10" 100w speakers, which Derek Trucks favors. The transformers are being custom built to my specs by Musicalpowersupplies in Tennessee.

For those who are tech oriented, this will some of my new and old innovations: soft (subtle) limiter / high headroom FET buffer / mixer on the input, separating the steel and the guitar inputs (so the controls and pickups of both instruments don't interfere with each other). A separate B+ power for each of the 2 channels. Solid-state, fast acting rectification with large caps to make the amp responsive and articulate. KT-66 power tubes and cascading preamps based on my AMI Lil Giant. Silent channel switching.

Definitely channeling Leo Fender and Howard Dumble on this one.

A very expensive build, to which I already have two other players who desperately want one. I'll try and keep updating here for progress.
AMI Dumb Luck 1.jpg
Live life to the fullest! - Rob
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tonebender
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Gearlist: Fav: Gibson LP and Gibson Goldtone Amp. Other gear: Gretsch, Peavey, Taylor and more.

Awesome and a serious undertaking.
"Will follow through with a transaction when the terms are agreed upon" almightybunghole
golem
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I've heard about this. I'm looking forward to seeing it come together.
From Mesa I've learned I just slightly favor SS rectification when there's a switch available to go between the two. I only yesterday learned that my Filmore uses SS in that spot (no switch).
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Partscaster
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wow. how many might you make ?
"The man that hath no music in himself, nor is not moved with concord of sweet sounds, is fit for treasons, stratagems, and spoils. The motions of his spirit are dull as night, and his affections dark as Erebus. Let no such man be trusted."
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andrewsrea
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Gearlist: 28 Guitars: (2) basses, (2) acoustics, (3) hollow bodies, (3) Semi hollow, (1) Double-neck, (17) Solid-bodies

Partscaster wrote: Wed Jun 14, 2023 5:22 pm wow. how many might you make ?
Made to order. Right now 1 order and 2 seriously interested. I am fairly sure that the 2 will want one after they play it.
Live life to the fullest! - Rob
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andrewsrea
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Location: Lake Saint Louis, MO
Gearlist: 28 Guitars: (2) basses, (2) acoustics, (3) hollow bodies, (3) Semi hollow, (1) Double-neck, (17) Solid-bodies

I am still working on this one. Sounds spectacular. The clean channel is uber clean and the gain channel sounds like a Two Rock.

I just figured out the source of a nasty hum in the reverb. It has taken me three days to figure it out, but it ended up being eddy currents in the chassis messing with the panel mount RCA connectors. Isolated the jacks from the chassis and it works like a charm!
Live life to the fullest! - Rob
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andrewsrea
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Joined: Wed May 27, 2020 4:43 pm
Location: Lake Saint Louis, MO
Gearlist: 28 Guitars: (2) basses, (2) acoustics, (3) hollow bodies, (3) Semi hollow, (1) Double-neck, (17) Solid-bodies

Well this was my last big challenge to the AMI Dumb Luck amplifier I am building.

It is the interface/ channel control pedal, which is phantom powered by the amp. it inputs and tweaks two instruments and switches the amp's between the clean and overdriven channels. Pictured are the schematic, component layout and enclosure, all prepared from my feeble mind which started with a concept provided by my client. I start construction later today.
AMI Dumb Luck Interface and FS.jpg
Live life to the fullest! - Rob
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andrewsrea
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Joined: Wed May 27, 2020 4:43 pm
Location: Lake Saint Louis, MO
Gearlist: 28 Guitars: (2) basses, (2) acoustics, (3) hollow bodies, (3) Semi hollow, (1) Double-neck, (17) Solid-bodies

My good friend TJ Clark and I finished the amp's front panel. Sandblasted & repaired a dent, painted with Cerakote (high-temp baked-on paint used to paint guns) which we blended to a color which went with the oxblood grille cloth and then laser etched my graphics onto it. The laser is super cool and allowed for some really cool effects.
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Live life to the fullest! - Rob
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tonebender
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Gearlist: Fav: Gibson LP and Gibson Goldtone Amp. Other gear: Gretsch, Peavey, Taylor and more.

Man oh man.....nice amp.
"Will follow through with a transaction when the terms are agreed upon" almightybunghole
Buddha Pickups
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This is not an easy job by any means
Looks great 👍
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