Swart Amplifier Atomic Space Tone (AST) - Mojo Tone BV25

Michael Swart comments on the Atomic Space Tone:


The idea of the Atomic Space Tone hit me when I was working on a vintage Gibson Scout guitar amp. It had Reverb, Tremolo, and 15 watts of pure rocking vintage tone power but only three preamp tubes and two EL-84 output tubes. I thought to my self - I have never seen an amp that could do so much with so little and sound surprisingly good. But I knew it could be even better. I knew something could be built revolving around my favorite little tone generator, the 6V6. I sent a note of thanks to my cohort for the inspiration for one of the best amplifiers I have ever built and the only thing I have found to equal the soul and amazing tone of the ST-6V6se but with MORE power.

I call it the ATOMIC SPACE TONE. And damn if it's not a winner - this beast sounds amazing.

This amp brings more tube soul than I thought possible, even compared to some of my favorite vintage amps. We are talking ALL TUBE circuitry, even the Tremolo and Reverb, all leading into the excellent 12" Mojotone BV-25m speaker.

I am actually so excited by this amp both aurally and visually. It's the second in our Tweed Series which takes our excellent finger jointed pine cabinet and covers it with top quality tweed, adding a lacquer to give it durability and that vintage, timeless look. We then add a rich, dark lacuer tweed on the sides which gives this amp a totally distinctive appearance. When we play out with this beast, everyone that "knows" comes up to inquire about the AST, this on the sound AND looks. Just like the original ST-6V6se, there is nothing out there like it.



  • The AC is cleaned and rectified by the reliable JJ 5AR4, this a very robust tube providing excellent sonics due to the total lack of solid-state circuits in the rectification stage (SS rectification leads to a more hard/harsh tone and slams the tubes on power-up causing excess tube wear). A heavy duty, JJ 500V Surface mount capacitor is the mains filtering device.



  • Powered by Twin EH 6v6's putting out 18-22 cathode biased Watts; the twin 6V6s seem to really put out an amazing mixture of soul~tone. We love this combo! (You can also sub 6L6s for a bit more headroom due to the extra beefy Heyboer Power Transformer,



  • A 12AX7 does duty as the driver and bias regulated Tremolo. Ever heard tube tremolo? You will now. Simply put, if you're a tremolo fan, you won't go back.



  • Reverb is all tube. Tube Reverb is the only way to go and our implementation leaves the competition sounding two-dimensional.



  • The first preamp tube is another dedicated rocking 12AX7 to drive this beast to Mount St. Helens and back. Our whole driver/preamp circuit has been optimized from months of testing. The AST sings like no other.



  • Custom built, Heavy Duty, power and output transformers - HeyBoer USA - The New Leader



  • Carbon Comp Resistors for the BEST tone. Period.



  • Mallory, Sprague and JJ Caps - only the best, all considered for their appropriate roles



  • Finest silver tinned cloth & Teflon covered wire



  • Hand Wired, point to point



  • Standby Switch - amp warmed up|extends tube life



  • High and low inputs for high and low output pickups



  • Dedicated 2-button foot switch for reverb & tremolo



  • 12" Mojotone British Vintage Series BV-25m



  • And a hand-made, finger jointed pine cabinet covered in light with dark tweed tweed side panels. This cabinet is part of the magic of the Atomic Space Tone - We tested many different cabinet configurations and wood choices until we found the magic of the AST combo.



  • Dimensions: 18" T x 15 1/2 W x 9 1/2 D ~ 29lbs