1990s THD Plexi 4x10 UK-Style Boutique Tube Amp w/ Attenuator, Andy Marshall
$2,199.99
$2,199.99
Shipping calculated at checkout.
Up for sale, a 1990s THD Electronics Plexi 4x10” in exceptional condition and in perfect working order. Founded in 1986, THD (Total Harmonic Distortion) Electronics produces handcrafted, no-corners-cut boutique amplifiers with top-notch componentry and classic circuits. This Plexi combo, one of THD's first-ever designs, was directly patterned after Dave Friedman’s “Holy Grail” 50W Plexi, which had some different component values than the norm and sounded, according to THD’s Andy Marshall, “like the tone on the first Van Halen album all on its own - just spectacular.”
While visually presenting similar to a Fender Tweed 5F6-A Bassman, the circuit inside is akin to a Marshall Plexi, and the compact 4x10 form factor (loaded with Celestions) essentially makes this THD a more portable alternative to your favorite Marshall half stack. The result of significant prototyping to achieve the desired sonics, Andy Marshall worked directly with Friedman's Plexi, which, as Marshall posited, "had either been changed a little bit or they had used some components that were slightly different at the factory, but it was basically a ’69 small box JMP."
Further detailing the prototyping based on Friedman's Marshall and the resulting THD Plexi model, Andy Marshall notes, "It had [a] more musical character, and the harmonic overtones sounded like they just belonged with the note you were playing. You know, with some amps you can really hear minor and major thirds within the harmonic texture that’s created. This one was like that, it just did it a little bit better, and I think we succeeded in accomplishing what we set out to do very well."
This amp faithfully captures the early JMP/Plexi sound, with a highly dynamic character and silky smooth quality, delivering both muscular cleans and ripping crunch when cranked. Further customized by Andy Marshall later in its life, this particular Plexi has been augmented with an attenuator, mounted to the inside of the open-back enclosure.
This combo features a dual channel, dual input design, and controls comprise independent Volume knobs for each channel and Presence, Middle, Bass, and Treble EQ controls. Andy Marshall’s Hot Plate attenuator is arguably the most popular aftermarket attenuator on the market; this custom-built iteration works just as well as that celebrated design, enabling the user to get “cranked” tones at any volume level, with Compensation and Attenuation controls. The tube complement comprises two Electro Harmonix EL-34 power tubes, with two vintage RCA 12AX7s and two modern Mesa Boogie valves in the preamp.
The speakers include two THD Vintage 10” drivers and a pair of Celestion G10L-35s, one of which has THD's "Custom Longhorn" badging, which represented a proprietary treatment by THD to break in the speaker cone.
The solid pine lacquered tweed enclosure is extremely well-kept, with just a few requisite marks on the enclosure edges, and some staining on top from the feet of a different amp. A second set of amp feet (on the bottom of the cabinet) were also installed previously. The wheat grillcloth is quite clean, the original chickenhead knobs and leather handle are present, and the white silkscreen graphics show minimal wear on the chrome-plated chassis.
While visually presenting similar to a Fender Tweed 5F6-A Bassman, the circuit inside is akin to a Marshall Plexi, and the compact 4x10 form factor (loaded with Celestions) essentially makes this THD a more portable alternative to your favorite Marshall half stack. The result of significant prototyping to achieve the desired sonics, Andy Marshall worked directly with Friedman's Plexi, which, as Marshall posited, "had either been changed a little bit or they had used some components that were slightly different at the factory, but it was basically a ’69 small box JMP."
Further detailing the prototyping based on Friedman's Marshall and the resulting THD Plexi model, Andy Marshall notes, "It had [a] more musical character, and the harmonic overtones sounded like they just belonged with the note you were playing. You know, with some amps you can really hear minor and major thirds within the harmonic texture that’s created. This one was like that, it just did it a little bit better, and I think we succeeded in accomplishing what we set out to do very well."
This amp faithfully captures the early JMP/Plexi sound, with a highly dynamic character and silky smooth quality, delivering both muscular cleans and ripping crunch when cranked. Further customized by Andy Marshall later in its life, this particular Plexi has been augmented with an attenuator, mounted to the inside of the open-back enclosure.
This combo features a dual channel, dual input design, and controls comprise independent Volume knobs for each channel and Presence, Middle, Bass, and Treble EQ controls. Andy Marshall’s Hot Plate attenuator is arguably the most popular aftermarket attenuator on the market; this custom-built iteration works just as well as that celebrated design, enabling the user to get “cranked” tones at any volume level, with Compensation and Attenuation controls. The tube complement comprises two Electro Harmonix EL-34 power tubes, with two vintage RCA 12AX7s and two modern Mesa Boogie valves in the preamp.
The speakers include two THD Vintage 10” drivers and a pair of Celestion G10L-35s, one of which has THD's "Custom Longhorn" badging, which represented a proprietary treatment by THD to break in the speaker cone.
The solid pine lacquered tweed enclosure is extremely well-kept, with just a few requisite marks on the enclosure edges, and some staining on top from the feet of a different amp. A second set of amp feet (on the bottom of the cabinet) were also installed previously. The wheat grillcloth is quite clean, the original chickenhead knobs and leather handle are present, and the white silkscreen graphics show minimal wear on the chrome-plated chassis.
