Design & fabrication of highly acclaimed guitar/bass amplifiers and electronic audio equipment that offers superior musical context for the discerning musician, audiophile, and music lover.
“It’s like your favorite amp, only better”
www.dumblekiller.com
JCA Circuits “Vibe” Amplifier
“This strikes us as an unreal studio amp, or something that would be amazing for around home sitting right in front of it and pouring your heart out to after midnight. What a perfect little amp that can do it all. Hot damn…” Tone Quest Report
“For life, is all about the sweet spot, isn’t it? You know it when you find it. The amp has a beautiful and absolutely WIDE GLIDE, pure Fender tone, all while cranking out far more clean headroom than we thought possible from a small amp, and the use of the Jupiter ceramic 8-inch speaker was superb. It was definitively surprising how much sweet and stout low end each note has, and the clarity of the top and mids are also pristine.” Tone Quest Report
“Once we cranked it past about 8 it really sang, but still, maintained a gorgeous fidelity of signal with zero graininess or harsh frequencies. It loved Strats, Les Pauls, and the Junior, and we even put a Gibson J-200 through it to hear it acoustically. This amp is all about the pristine and stunning clean tones, and what you do from there is up to each player.” Tone Quest Report
JCA Circuits GR1.6 “Golden Ratio” Amplifier
“To us, it is among the best 1X12 20 Watt amplifiers we have ever reviewed” Tone Quest Report
“Well, I finally cranked this baby up…OMG! Like Riding a Wild Horse, WOW…Woman Tone X5, Yikes….I think a 100 Watt version would be a useful military weapon (:” Huey Redwine
“JCA GR1.6 Golden Ratio Amp. “Dumble Killer”. Best 1×12 boutique combo ever built.” The Black Lodge
“If a Trainwreck was the sound of the 90’s, then this amp is the sound of the future” Harmony Central Review
“Purring look, roaring sound!” Vintage Guitar Magazine
“A buddy said the Golden Ratio is an amalgamation of many classic medium/small amps, with a level of refinement similar to what the Trainwreck Rocket was to the AC30. I’m paraphrasing and I hope it makes sense but it’s quite the compliment. Your amps are remembered as being at that level.” Elijah Robinson
I was fortunate enough to make JCA’s acquaintance, and he invited me over to the shop to have a look at his gear. I got a sneak peak of what he was building for you, the Dumble Killer. It’s not only going to sound great, it’s going to look great too. Exquisite attention to detail through and through.” Jae H.
“Jason, Just letting you know how completely thrilled I am with your fantastic amp! With the right pedal, I can finally accurately recreate Alex Lifeson’s unique and elusive tone on Limelight. I don’t know whether or not your amp has any similarities to the Marshall Club and Country (different tubes and power rating of course), but I am so happy with it, all around. It can do almost anything. My tech noted the high build quality and he’s not easily impressed.. Thanks so much!” J.H.
“Okay, Jason, I got the amp home and unpacked it…I’ve got one word for you. RIDICULOUS. Holy shit, man this thing sounds GREAT! It sound EXACTLY how you described it which, to be honest, is usually not the case. I mean I obviously expected it to sound really good or I wouldn’t have sold stuff at a loss and scrambled to buy it. But WOW. Super great cleans, Marshall roar, and that Trainwreck feedback hanging on the ends of the notes when it’s cranked up. And it cleans up with my guitar volume. I still haven’t touched the EQ, cut or trim, just the switches and volume knob. Thank you. THANK YOU.” J.P.
“I just got a JCA Circuits GR (Golden Ratio) 1.6. It’s the best low wattage combo amp I have ever had, played or heard! A truly magical piece of gear!” N. Bessie
“If you relish the prospect of jumping from the sound of a blackface Deluxe (without reverb) to a high gain Marshall short stack with all the dimensional bloom and harmonic character of a hand-wired tube amplifier, the GR 1.6 performs this nifty trick better than just about any amp we have reviewed. A Marshall PA20 can’t do it… the reissue 1974X 1×12 combo can’t do it… and the AC15 won’t do it. The DR. Z MAZ18 comes close, as does the Balls M18, but both lack a bit of the Fender DNA we hear in the GR 1.6. This is an extraordinarily toneful amplifier, created with an equally extraordinary voice, feel and attitude.” Tone Quest Report
“Given its laid-back appearance, we were expecting the amp to purr like kitten, but what we got was a roar! The 6V6s didn’t produce that sedate, scooped Fender-like clean tone; rather it more closely resembled a blackface or tweed on steroids, with an abundance of natural overtones and overdrive and very present upper midrange.” Vintage Guitar Magazine
“The elusive and very rare “Golden Ratio” reviewed by Tone Quest Report and Vintage Guitar both touting “best 1×12 combo we have ever reviewed”. Very few were made, around 20 from what I have read. Super high quality Dumble style boutique build!!!” Mountain Cat Guitars
“Up for consideration is an incredible combo amp. The amp that garnered the glowing review in the Tone Quest report, linked to below. Jason Arthur (JCA) studied with Ken Fischer and his amazing design makes this obvious. This amp has been played by folks with some incredible ears and chops, who had input in the final design as available here, including making the recommendation to have the Celestion Blue re-coned with hemp by A Broun Soun in San Rafael. CA. A Review of this particular amp is available here. Very few in existence – dual 6v6. flavors of Trainwreck Rocket and Tweed Deluxe, Fender Blackface Deluxe. Highly touch sensitive, truly amazing clean sustain and bloom. very touch sensitive. Chimey clean to mean all controlled via guitar volume.” Guitars Electric
“After spending some quality time with Jason’s “Golden ratio” amplifier here are some thoughts on my experience. Before delving into the details, I’ve been playing guitar for over 30 years mostly in cover bands or hidden away in some studio tracking all while tinkering endlessly chasing sounds..
After indeterminate amounts of amplifier purchases I ended up designing and building two of my own which have satisfied my needs to what seemingly has no end; However as guitarists do- we all suffer gear acquisition syndrome! So who isn’t up for trying something new?! Being a Dumble and Trainwreck enthusiast; Jason’s amplifiers’ instantly caught my attention.
Some of you might know but for those who don’t; Finding a truly responsive amplifier capable of cleaning up when dialed to scream is difficult. Not many amps actually pull this dynamic off. The Golden Ratio is legitimately dynamic and not just with guitar volume knob work, this amp breathes with every pick strike. Once you’ve gotten a feel for the amps behavior – you’ll hit new planes of expression musically.
The Golden Ratio’s power/volume from its tube rectified dual 6V6 output section is astonishing. Pairing the Celestion Blue with this amp dishes out superlative fidelity. The Alnico blue just works and hits that sweet midrange spot well seasoned with tight bass response and just enough top end bite to make the first couple of folks in the front row hop (as they should!). I was particularly fond of the Hi-Tilt and Plush setting with a 62 Stratocaster reissue which dished out Fender black panel vibes but with way better midrange content, no bass flub, none of that ugly power supply sag that squelched your pick response and dynamic response. Goosing the front end with any drive pedal was eargasmic. As a pedal platform the GR had enough capacity to cleanly handle looping + playing, delays, mod effects galore all while holding it together even with a battery of drive pedals fed into the front end.
From a build perspective dare I say no other guitar amplifier is intently overbuilt in this fashion.
We’re not talking about standard off the shelf parts or some kit built here- this is original recipe!
Starting with a machined extruded aluminum chassis, ¼” wall thickness, elegantly milled pockets for tube sockets, pots and jacks- this chassis is indestructible; very Boeing B-29 like thought applied in design. Jason’s amplifier is truly crafted in a “Build it once” and “Enjoy it forever” mindset. Inside the chassis you’ll find top shelf resistors, capacitors and pots, even the wire is better than what most fine cars use today. Expertly built cabinet work, even the rubber feet command authority.
Every part has been strategically selected and it shines thru sonically and visually.
If you have the opportunity grab one of these amplifiers, DO IT.”
It’s truly a breath of fresh air that will last a lifetime.”
Mike “Norton” Suchodolski
Jason C. Arthur/Designer
484-942-6004