I'm often asked about tube rectification in guitar amplifiers. For many players, it's a subject that could stand a little deeper scrutiny from an engineering and design perspective. First, keep in mind that a tube rectifier is not an audio amplifying device. If no audio signal passes through it, how does it affect an amplifier's sound? Let's have a look.
Your amplifier's preamp and power tubes require a DC voltage to operate. The amplifier's power transformer converts the incoming AC line voltage to the levels required. The power supply rectifier, whether of the vacuum tube or silicon diode variety, converts the AC voltage to DC. That DC voltage is filtered and then sent along to the various amplifying stages to do their specific tasks.
The hard-working power supply must be able to deliver the amplifier's maximum continuous rated power for an extended period of time. Most well-engineered amplifiers can operate continuously at full power for hundreds of hours without generating sufficient heat to injure the operator or cause a component to fail. Even so, things do heat up.
A rectifier tube in a typical tube-rectified power supply: R1 and R2 represent the internal copper resistance in the transformer's primary winding, and R3 and R4 represent the same in the transformer's secondary winding. RA represents the tube's internal resistance between the anodes and the cathode. In a silicon-rectified power supply, RA is much lower and therefore produces less heat loss.
When you play at low volumes, you're not placing a great demand on your amplifier's power supply. At gig volume, however, you start drawing significant power from it. When you run the unit for several hours straight, the copper wire in the power transformer gets hot. Copper wire, being an imperfect conductor, exhibits resistance to current flow, and this inherent resistance causes the wire to heat up as the power demand increases. The resistance of a given length of wire is fixed, which means something has to give when the temperature goes up, and that something is voltage. As your power transformer heats up, the voltage it produces decreases. In a typical amp this decrease isn't large, but it's noticeable.
When we introduce a tube rectifier into the equation, the effect of heat-induced voltage loss is exaggerated. The reason is that the rectifier also has some internal resistance that contributes to a total drop of as much as 50 volts under full load. That's a lot. Silicon diodes overtook vacuum-tube rectifiers long ago because they were much less expensive and assembly was less labor intensive. But there was another reason: They're more efficient, due to low internal resistance. That difference in internal resistance means silicon and vacuum tube rectifiers are generally not directly interchangeable. Using a plug-in silicon device in place of a tube rectifier can cause excess DC to appear at the filter capacitors.
When you play at low volumes, you're not placing a great demand on your amplifier's power supply. At gig volume, however, you start drawing significant power from it.
A tube rectifier may make the cut when the goal is to produce a vintage-correct reproduction amp. Even though we can engineer a similar amount of voltage sag into the power transformer, purists may see the absence of the original part as a cop-out to save money, when, in fact, it may simply result in a more reliable, maintenance-free design. However, inducing sag into the transformer design can cause the temperature in the power transformer to increase more rapidly over time, in which case a larger, heavier, and more expensive part may be required to manage this drawback. In some cases, getting a power transformer design to conform to modern regulatory limitations can be simplified by using a tube rectifier to provide an easier path to safety compliance. We often see reissue amps that differ in performance from the originals simply because they have to clear regulatory hurdles that were non-existent at the time the originals were created. A crafty engineer can often find workarounds to such obstacles, and clever application of transformer technology and tube rectification are valuable tools in the kit.
In my experience, the most practical use of a tube rectifier is in dual-voltage power supplies, where a high- and low-power mode is required. For the high-power mode, a large, stable power transformer is necessary to meet maximum performance parameters. The downside? A high-capacity power transformer tends to yield stiffer performance when not running at or near maximum potential, such as in a low-power mode. This is where the tube rectifier really shines: It can be used to exaggerate the voltage sag in a power supply that would otherwise exhibit an unforgiving feel.
Whether the design objective is aesthetic, practical, or genuinely novel, it's good to have choices. Besides the satisfaction of seeing more glowing tubes humming away in our amplifiers, it's nice to know that players appreciate the extra effort involved in creating new designs around these familiar bottles.
[Updated 10/14/21]
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Elliott Sharp is a dapper dude. Not a dandy, mind you, but an elegant gentleman.
I am writing this piece for a guitar magazine, so, necessarily, I must serve up info that is guitar-centric. And I can do that, at least a little bit. But Elliott is also a noted composer, runs his own little record label, plays woodwinds proficiently, is a guitar builder/tinkerer, author, gracious supporter of other musicians’ efforts, family man, and killer blues player—a blues scholar, in fact. So where do we, the public, conditioned to needing categories, pigeonholes, and easy assessment signals, put Elliott Sharp—an artist with a powerful work ethic and a long, illustrious career of making mind-bending sounds and conceptual works? How about putting him in the pantheon of the maverick and the multifaceted? Surely this pantheon exists somewhere! In mind, in heart. To those for whom such things resonate and inspire, I bring you Elliott Sharp.
One can obviously go to the information superhighway to find info on Elliott, and to hear his music, so I won’t go into too many details about where he was born (Cleveland) and when (March 1, 1951; as of this writing, Elliott is 74), or what he is best known for (being a crucial figure in the downtown New York City scene from 1979 to the present). He is Berlin Prize winner and a Guggenheim Fellow (among other honors). And I have never asked him what strings and picks he uses, so maybe I have already blown it here. But I realize now, having taken on this assignment, that inherent in writing about and trying to explain Elliott Sharp is an implicit TMI factor. There is so much going on here, so much diverse information that could be imparted, that I would not be the least bit surprised if some readers eventually glaze over a bit and start thinking of their own life’s efforts and goals as rather paltry. I get that! Although you shouldn’t.
E# @NaturalHabitat
Here, now, is my portrait of Elliott, accompanied by what I imagine is a day in the life of Elliott when he’s at home in New York City.
Elliott Sharp is a dapper dude. Not a dandy, mind you, but an elegant gentleman. He, like so many in New York and in the world of music/art/guitar, favors dark-hued clothing (yeah, a preponderance of black) and is most often seen wearing a classic slouch hat of obvious quality. He relocated from Buffalo via Western Massachusetts to lower Manhattan in 1979 to a zone that was, back then, quite treacherously decrepit, in an apartment that offered only an hour or so of heat in the winter, etc., etc. It was cheap, and things were always happening, and, in fact, it was the 1950s domicile of William Burroughs, Allen Ginsberg, and Jack Kerouac.The area became the nexus of an ever-expanding circle of iconoclastic, experimental artists of many stripes.
Sharp plays what passes for a fairly staid instrument in his collection: a bass and guitar doubleneck, in 1992.
Elliott is still in that building in the East Village, though it is now only his workplace and not his living space. I am trying to remember exactly when I met Elliott, but it was probably about 25 years ago, and he still had only the one small, original apartment and a shared music space in the Garment District. I, like countless others before and after me, stayed in that East Village apartment whenever I needed a place to crash and Elliott was elsewhere, and eventually he was able to secure the next door apartment and expand his space. This is where Elliott Sharp works every day that he is not touring, pretty much 9 to 6. The place is a bit funky and dusty, and it is filled with instruments, amps (some classics, like a mid-’60s Princeton Reverb and a tweed Champ), and other tools accumulated over many decades—in spite of the many times that certain ones had to be sold to keep bread on the table.
When he’s not composing, scoring films, recording other artists, or gigging with the bands he has been in or led for the last several decades (Mofungo, Carbon/Orchestra Carbon, SysOrk, Terraplane, The Bootstrappers, Aggragat), Elliott tinkers with guitars, pedals, mandolins. Elliott is, to me, the king of guitar transformation, and his tinkering is stunningly Frankensteinian as he guts, rebuilds, and alters all kinds of stringed instruments, both electric and acoustic. He recently told me that in the ’60s he built fuzz boxes out of tobacco tins to make money. How cool would it be to have one of those now?? If one does a search on Elliott Sharp, many photos will reveal what I'm talking about: the handcrafted doubleneck he was most often seen playing in the ’80s (there was maybe more than one), 8-string guitars, modified Strat-type guitars with completely different pickups.. He also has a fancy guitar or two, such as his Koll fanned-fret 8-string, upon which he has played many a solo recital. During Covid time,, things were a little slow in the cash-flow department and, as a family man with twins, a little extra income was needed. So Elliott started building really cool-looking guitars out of cheap
ones and parts from wherever and refinishing them in hip and attractive ways and called them Mutantu. He sold them to friends and friends of friends. Yours truly basically only changes strings on his guitars, appealing helplessly to experts to do any kind of work on his guitars and amps, afraid of costly errors. The maverick and multifaceted among us, like Elliott, possess no such fear.
Even a leader in experimental 6-string gets a little guitar face now and then—especially when he’s playing blues.
Photo by Scott Friedlander
So, back to that promised day in the life of Elliott Sharp (as imagined, with some degree of knowledge, by me): It’s early morning, and there is family to contend with. No bohemian lollygagging! So it’s feed the kids breakfast, do what parents must do. Then it’s off to the office (his studio), so Elliott dons a fine gray shirt (is that silk?), dark trousers, coat, and hat, and walks north from the family apartment on nearly the lowest point of eastern Manhattan to the East Village. The traffic and endless refurbishing of the Williamsburg Bridge roars familiarly overhead, the East River flows, and eventually a river of another kind, Houston Street, is crossed. Up the stairs to the fifth floor and the studio door is unlocked. Espresso is made. (There will be more of this.) The computer is turned on. And then ... who knows? Anything could be on the docket, but some sort of work will ensue for a good eight hours. Maybe a new graphic score for a German symphony is in the works (some of these have become visual artworks, too), or maybe it's time to try another mix of that Terraplane track, the one with Elliott’s friend, hero, and inspiration Hubert Sumlin—the one Elliott recorded not long before the famed Howlin’ Wolf guitarist joined his ancestors in the Great Beyond. Or maybe he’s recording a variation on his trio ERR Guitar (where he was originally joined by Marc Ribot and Mary Halvorson), called ERE Guitar Today, with Sally Gates and Tashi Dorji. Could happen—and it did. You can see Elliott’s studio in the ERE Guitar CD booklet.
Or maybe it’s guitar tinkering/building time. Where’s that delightfully chunky neck from China that would be awesome on that fake Tele body that was just refitted with no-name humbuckers (“sounded good once I removed the pickup covers,” Elliott observes) and a resophonic guitar tailpiece? By 5 or 6 it’s time to go home, maybe cook dinner tonight. And then ... my little imagined epic ends with a tasteful cinematic cliché: the dissolve.
The E# Way
Elliott Sharp has techniques that, in some cases, are all his own. No stranger to open tunings, prepared guitar, and other extended techniques, he often utilizes rhythmic, two-hand tapping to create spiraling, hypnotic patterns. His composing over these many years has employed and embraced genetics, Fibonacci numbers, algorithms, and fractal geometry. Though a mathematics and physics know-nothing myself, I see and hear a relationship between these elements as he has applied them to his uncompromisingly avant-garde compositions and these tapping patterns often heard in his solo work. Once he kicks in signal processing, stand back! What one hears sounds like four people (or other species and life forms), and the sensation is exhilarating. Sure, there could also be evidence of (here it comes) skronk (I can't believe I used that word), but Elliott certainly does not reside permanently in that world. Enjoying all kinds of sounds, from the lonesome moan of a resonator guitar to the aleatoric sputterings and squeals of a tormented electric guitar, is something he and I share, after all. Take, for example, two of his latest recordings on his zOaR imprint, Mandorleand Mandocello, which document his solo work on the two instruments, respectively. Both recordings investigate the instruments’ acoustic characteristics before, about half-way through, switching suddenly to electric, ultra-processed sounds. It’s a bracing experience that explains a few things about this man and the breadth of his aesthetic sweep. The sounds bring up images of recombinant DNA (information on which he has also imbued into his work), roiling lava, and the ever-expanding universe. Recommended!
Sharp applies his wicked two-handed-tapping technique to his 8-string, fanned-fret guitar built by Saul Koll.
Photo by Scott Friedlander
So, this might fit into the aforementioned TMI category, but Elliott Sharp puts out a staggering amount of recordings. Every time I see him (which is not often enough), he has a little pile of compact discs for me, often on zOaR. I saw somewhere recently that he has released 165 recordings, but I think there are probably more than that. It’s hard for even the data lords to keep up! But it’s not always Elliott Sharp pieces or improvisation/collaborations on these albums. Other artists whom Elliott knows and respects can be represented, such as Spanish electric guitarist/conceptualizer A. L. Guillén, late bassist/producer Peter Freeman, Italian voice and guitar duo XIPE, or Hardenger fiddle player Agnese Amico—all articulate and singular musicians whom Elliott assists by releasing their music. I am grateful for this. It’s obviously more “work” for Elliott, and he accomplishes it, along with everything else he takes on or imagines doing, with elegant aplomb. Though obviously a nose-to-the-grindstone worker, Elliott is generally low-key and relaxed, even after those espressos.
The last thing I want to write about is Elliott's interpretations of the music of Thelonious Monk. Are you surprised, even after everything else you have just read, that something like that exists? In 2003, Elliott released a solo acoustic guitar recording called Sharp? Monk? Sharp! Monk!, and stunned the world (well, those few who pay attention to such things). However, my first exposure to Elliott's Monk interpretations was the more recent Monkulations, expertly recorded live in Vienna in 2007. (You can hear it on Bandcamp). These recordings are, justifiably I suppose, controversial in certain corners, because they do not adhere to Monk's exact written particulars note-for-note. Yet the mood, gestures, rhythmic wonders, and even the harmonic depth of Thelonious Monk often emerges, and frequently in astonishing ways. I understand why some would take issue with this approach because it departs significantly from the jazz tradition, but I find it remarkably fresh, bold, and so delightfully E#. They reveal an aspect of Elliott’s thinking and playing that is surprising in some ways, but also so him. It is clear to me that Elliott has seriously examined and internalized Monk’s repertoire.
Spring(s) in the garden: Sharp can use just about any tool in his improvisations.
Photo by Norman Westberg
Elliott is an artist who plays more than one instrument, plays them all in unique, startling, and often innovative ways, composes rigorous conceptual works from chamber music to operas, makes electronic music with no guitar, plays mean blues guitar like a swamp rat, authors books (I highly recommend his mostly memoir IrRational Music, and a second book is emerging this fall), builds and modifies guitars and other devices, is stunningly prolific, and is an elegant gentleman. The planet is a better place with him and his work in it. The maverick and multifaceted often have a rough road to tread, as we all know. So check out Elliott Sharp's vast world if any of this seems interesting to you. Thanks, Elliott!
YouTube
Watch Elliott Sharp and Marc Ribot deliver a masterclass in free improvisation at Manhattan’s Cornelia Street Café in 2010—Sharp’s two-handed tapping and slide playing included.
Elliott Sharp’s Favorite Gear
This doubleneck guitar accompanied Sharp on many of his ’80s performances and is one of his earlier experimental instruments, as is this 8-string.
Road
Guitars
• Strandberg 8-string Boden
• 1996 Henderson-Greco 8-string
Amp
• Fender Deluxe Reverb or black-panel Twin Reverb (depending on size of venue)
• Trace-Elliot bass amp w 4x10 cabinet
(live rig uses both amps, run in stereo)
Effects
• Eventide H90 w/ Sonicake expression pedal
• Sonicake Fuzz
• Hotone Komp
• Hotone Blues
• TC Electronic Flashback 2
• VSN Twin Looper
Accessories
• Slides, EBows, springs, metal rods and strips, small wooden and ceramic square plates
Home
Guitars
• 1946 Martin OO-18 acoustic guitar
• 2006 Squier 51 (Sharp explains: “On New Year's Day 2007, I took the twins down to the East River in their stroller. They were 15 months old and knew a few words. As we rolled along, they started shouting “guitar, guitar,” and, sure enough, sticking out of a garbage can was a black Squier 51 that someone had attempted to ritually sacrifice. Brought it home and cleaned it, and it’s become a favorite couch guitar.”)
Obviously, any sound that emerges from the Triple-Course Bass Pantar is likelly to be interesting.
Studio
Guitars and stringed instruments
• Fender 1994 ’50s Telecaster built from a Fender-offered kit
• Mutantum lime green metalflake Strat w/Seymour Duncan Little ’59 pickups
• Mutantum solidbody “manouche” Strat w/classical neck
• Saul Koll custom 8-string
• Rick Turner Renaissance Baritone
• 1966 Epiphone Howard Roberts
• 1965 Harmony Bobkat
• 1984/’96 Heer-Henderson Doubleneck
• 1956 Gibson CF-100 acoustic guitar
• 1968 Hagstrom H8 8-string bass
• Mutantum Norma fretless electric
• Godin Multiac Steel Duet
• 2001 Dell’Arte Grande Bouche
• 1958 Fender Stringmaster 8-string console steel guitar
• 1936 Rickenbacker B6 lap steel
• 1950s Framus Nevada Mandolinetto
• Mutantum Electric Mandocello
• Arches H-Line
• Triple-Course Bass Pantar
Amps
• 1966 Fender black-panel Princeton Reverb
• 1980 Fender 75 (Per Sharp: “Cut down to a head and modded by Matt Wells into a Dumble-ish monster! For recording, it plugs into a 1x10 cab with a Jensen speaker or a Hartke Transporter 2x10 cab
• 1970 Fender Bronco
• 1960 Fender tweed Champ modded by Matt Wells
Effects and Electronics
• Vintage EHX 16-Second Delay w/foot controller
• Eventide H3000
• Eventide PitchFactor
• Lexicon PCM42
• ZVEX Fuzz Factory
• Summit DCL-200 Compressor Limiter
• SSL SiX desktop
• Prescription Electronics Experience
• Zoom Ultra Fuzz
• Korg MS-20 analog synthesizer
• Korg Volca Modular synthesizer
• Make Noise 0-Coast synthesizer
• Moog Moogerfooger Ring Modulator
• Moog Moogerfooger Low-Pass Filter
• Softscience Optical Compressor (for DI recording, custom made by Kevin Hilbiber)
Strings
• Ernie Ball Regular Slinky (.010–.046) or Power Slinky (.011–.048), for conventional guitar.
Jedd tells us how his dream came true and how he first started playing with Vince. We dig deep into how everybody’s favorite country guitarist raises the bar every time he picks up the guitar, how he gets his amazing clean tone, and we take time to appreciate all aspects of his solos—including how he builds them and how he plays such clean bends. As for why his concerts are so long? “He loves to play.”
In our current listening segment, we’re covering the Black Crowes and Jimmy Page’s Live at the Greek box set and a live recording from Burlington, Vermont’s Breathwork.
