Cesar Diaz built his reputation repairing amps for players such as Eric Clapton and Stevie Ray Vaughan. Now he's making a full line of amplifiers for us mere mortals.  At three grand, the CD-100 is no everyman’s amp. This is a simple single-channel affair with a sparse selection of features (built-in reverb, a half-power switch). The EQ section consists of high- and low-EQ controls; no mid knob is Included, although most of us would like to see one on an amp this expensive.

The Diaz’ circuit layout looks similar to that of a single-channel Twin Reverb. We noticed lots of new-old-stock parts—that is, never-before-used parts manufactured some years ago—in­cluding a power transformer for a Fender Bass-man 70. The amp is handwired, and it looks like a lot of time was spent building it. The tubes mount to the chassis, and the components are adequately shielded. The cabinet is covered with classy green Tolex, which looks stunning in con­junction with the red front panel.

We got excellent blues tones out of the CD­-100. It sounds like a hard-working Fender combo only about twice as loud. This amp's con­siderable gain Is perfect for generating fat, over-driven leads and crunchy tough rhythm tones. The reverb sounds big and spacious, though It was a little too wet for many of our testers’ tastes, even at minimal settings. This amp isn’t especially versatile, but if you long for righteous blues tones at excruciating volume, few amps can match the guts of the Diaz.  

Check out what the people think of the CD-100 at harmony-central.com

Guitar World

Right away, Cesar Diaz’s CD-30 “Club Classic” seduces you with its sophisticated good looks. Normally, Diaz gear is wrapped in Fifties-era lime green, but our test model came custom-covered in bright red “elephant hide” Tolex. That, in combination with the nicotine-aged, yellow Fender-ish grille cloth, gold ‘plexi” nameplate and white “chicken head” mobs on a bright blue silk-screened control panel, makes this an amp that is dressed to get noticed.

Diaz’s local NYC distributor described our CD-3O as “stock,” but that’s really a meaningless term in the world of custom-built, handmade amps. In truth, our CD-30 was a ‘snapshot” of an evolving work in progress, since amp gurus are constantly tweaking, rethinking and tinkering with their designs.  For example, this was the first CD-30 to car­ry a quartet of 6L6 power tubes. Cesar had been using 6V6’s (rated at about 30 wafts), but sources for these tubes had become unre­liable. Aside from tube-quality considera­tions, four 6L6’s also deliver more power (about 35 watts), a bigger sound and are more durable than the 6V6’s. If these beefier tubes are too much for you, the amp’s top panel has a Full/Half power switch. The Half setting produces a saggy sluggish feel that’s ideal for deep swamp blues, while the Full setting is snappy and remarkably nimble.

Other top panel features are hi and low inputs, controls for the master volume, reverb, bass (with a pull cut), treble (with a pull mid-boost), volume (with a pull brite), power and standby. There’s also a second sub-panel on the underside of the chassis, which can be accessed through the pine cabinet’s open back. This panel was pre-stenciled for a rotary voltage selector and an effects loop’s in and out, but our model swapped these fea­tures for polarity switch and a reverb on/off footswitch jack. Finally, this CD-30 was loaded with two luscious 10-inch, 35-watt G1OL-35 Celestions, but the baffle can also hold a 12-inch Vintage 30 Celestion if so desired. However, Cesar says that no one has everboughtaCD-30 with this 1x12 option— one strum tells the customer that these 35-watt lO-inchers are just too perfectly matched to the rest of the amp’s components.

A peek inside the chassis reveals how really well made the CD-30 is.  The perfect hand-­soldering is a study in fussiness. Electro­mechanical parts like the pots, switches and ceramic tube sockets are all top-shelf, and the caps and resistors (mounted on thick phenolic boards with brass eyelets,) have quality ratings appropriate to their function, since sometimes a low –grade part produces the best sound. Although this chassis is a work of art, it’s also the amps one and only design flaw: The chas­sis, which mounts vertically like a Marshall combo’s, lacks the metal rails and wooden stops that make the Marshall easy to disassemble. In this particular CD-30, the back panel held the chassis up. Safe removal requires that the amp be laid flat on its speaker baffle, or the chassis will crash down under its own weight...which it did.... into my lap...much to my distress and irritation.

To put it mildly, the CD-30 rips. With none of the pull switches activated, it’s Fender Heaven, and kicking in the mid-boost con­tour sends you “over the Pole” into UK/Bluesbreaker territory The pull boost switches give the player near-perfect control of a clipped signal’s warmth and sting.

This is the thickest-sounding Class AB amp I’ve ever heard—I kept looking over my shoulder to confirm that...yes...all that fat roar was coming from this diminutive beast. Cesar is justly famous for his ability to pull gorgeous distortion from tube chassis. This tone is no accident—it’s the result of Cesar spending years amp-teching for demanding performers such as Bob Dylan, Keith Richards and, especially, the late Stevie Ray Vaughan.  "That guy was crazy," Diaz recalls.  "Stevie was the only person I ever met who'd do a two-hour show, then stay up all night with me staring into an amp chassis trying to improve his tone.  He was determined that no one else sound like him, and a lot of my knowledge of frequencies came from those late night sessions.  Did you notice how my amps have a crunchy top...but a clean bottom?  That's something specific that we worked on."

But distortion is only half the story.  A Diaz set on clean is every bit as astounding as when it's set on gnarly.  The reverb seemed to kick in after a note was player, which kept the guitar up front, aggressive and never "lost in the tank."  We speculated that Cesar had hardwired the mix between the "wet" and "dry" signals at a "drier than Fender" ratio.  or maybe it was where he inserted the reverb into the signal chain.  Or maybe, like so much else about the CD-30...it was simply magic.

Check out what the people think of the CD-30 Club Classic at harmony-central.com

Cesar Diaz is well-known for his vintage amp restoration and as a technician to some of the biggest names in the business.  A few years ago, he ventured forth into manufacturing his own amps full time, instead of trying to fill his long-standing orders whenever he was off the road. His hand-wired amps were primarily known only to "insiders" and have been highly regarded by many artists including Bob Dylan, Stevie Ray Vaughan, G.E. Smith, Live, Collective Soul, and Jimmy Vivino, (whom you can hear playing through a Diaz CD-l00 and Vibramaster every night on Late Night With Conan O’Brien).

The P-XX was first designed as a preamp, and then the 20-watt power section was later added so it could be used for practice and playing smaller gigs. (By the way, "XX" Is the Roman numeral for 20, in case it wasn’t obvious.) It's available as a separate preamp only or as a combo with a Celestlon G10L-35 speaker. Both versions use the same chassis, and when it's assembled as a combo the tubes are mounted sideways instead of upright The P-XX Is completely handmade and has handwlred, point-to-point all-tube circuitry, like traditional tube amps. It can be set up for operation with either two 6V6 or two 6L6 power tubes, and different preamps tubes can also be used: However, the standard setup Includes two 12AX7s and two 12AT7 tubes. The amp’s tonal characteristics can be altered depending on which tubes are installed.  Charging power tubes does require adjusting the amp’s bias, although changing the preamp tubes does not require any Internal adjustments, so you can do it yourself. A tube location chart inside the cabinet tells what tubes can be used and where they go. In addition, a top vent is provided to allow the tubes to cool and prevents them from overheating and damaging the amp.

The P-XX has two inputs for High and Low gain and controls for Volume, Treble, Bass, Reverb, and Master Volume, and a slide Bright switch. Although there is no rotary Midrange control, the mids can be added with a footswitchable mid-boost pedal that’s included. In the tradition of many older amps, all the controls are numbered 1 to 12 and use pointer knobs.  The reverb is a spring reverb that’s similar to the original, longer, splashy Fender style.  The P-XX also Includes Jacks for preamp output and an additional speaker output, which are located on the Inside back panel.

For starters, don’t be fooled by its small size and low power. The P-XX combo is no wimp: It has a big sound that kicks serious butt, and even at low volume, It packs a huge sound with limitless sustain. The lows and mids are round and punchy, and the highs have a bell-like quality. The overall sound is much bigger and ballsier than you’d expect from a single 10” speaker.

The mid-boost makes the clean sound fuller, but you don’t really need It when you have the amp overdriven. The overdrive is pure natural tube tone that you can really feel. It has that magical quality and tube amp mystique that makes you feel connected to the amp, as it responds to every little nuance in the way you play. The harder you play, the harder the amp works and makes notes compress. The P-XX can even be used to drive a Marshall 4x12 cabinet. In fact, it sounds much bigger and better than the single speaker and powerful enough to use on a gig. Because of Its low power, the P-XX can be easily overdriven, so you don’t really need a stompbox for extra gain-it's already in there.

The P-XX isn’t just another retro amp, though it does have the appearance of an amp from the '60s. It’s handmade and built in the traditional way, designed to work hard and deliver maximum tube tone. The P-XX has the heart of older small Fender amps, but It can also crank out plenty of hefty overdrive and rawness. Pure and simple, the Diaz P-XX Is a very basic yet versatile combo and preamp that really gives you the freedom to create your own sound and let your own personality come through. And that’s what it's all about, right?

Check out what the people think of the P-XX at harmony-central.com

Guitar Player

If you want more than just vintage reverb, try the Diaz Vibra­master 1 ($650).  In addition to the classic 3-tube reverb circuit, you get tube tremolo and vibrato.  This hand-built beauty resembles a pint-sized Marshall head: It’s covered in cream Tolex and appointed with brown front and rear chassis panels and cream colored vintage-style knobs.  The front panel in­cludes depth and speed controls for the vibrato/tremolo, as well as dwell, mix, and tone knobs. The unit’s vibrato/tremolo selector switch, reverb and tremolo footswitch jacks, and accessory AC outlet are around back.  A unique reverb lock operates by turning a key on the back of the unit. Changing tubes is a snap, thanks to the pop-off front panel.

The Vibramaster is well made and features point-to-point wired circuitry. My only construction niggle: The chassis attaches to the cabinet with wood screws that go through the cabinet’s bottom into wood blocks at each end of the chassis. This design is probably roadworthy enough, but it seems out of place on a premium piece of gear. I’d prefer to see machine screws and threaded chassis holes. 

The Vibramaster is designed to be placed in-line between the guitar and amp. Though there’s no special provision for effects loop use, the instructions indicate that you can use the unit for any application—even keyboards and vocals. The Vibramaster’s reverb is brighter than either the Kendrick or The Works models; the Diaz added edge to even the dullest amp I played through.  On the downside, the Vibramaster was the noisiest of the three units. The controls are easy to use, and I had no problem dialing in a variety of sounds ranging from small-room reflections to cavernous shimmers. The vibrato is a true pitch shifting type with a bit of wah sound—different than the tremo­lo's volume modulation.  Because the reverb and tremolo circuits operate independently, you can choose reverb only, reverb with vibrato or tremolo, or vibrato or tremolo only.

Think of the Diaz Vibramaster as a high-quality, vintage-style multi-effects device; it can give any amp classic reverb, tremolo, and vibrato.

TREMOLO PEDALS. It’s just simple amplitude modu­lation — why do so many multi-effectors get it wrong? Mind you, I’m writing from the guitarist’s realm, where we live by the timelessly sexy pul­sations of the classic Fender and Vox amps. The wonderful thing about tube trem is the way it makes signals throb without sounding mechanical. The best non-tube simulations I’ve heard reside in Cesar Dials Texas Tremodlllo ($225), a lush-sounding pedal whose tone rivals the best vintage amps.

Cesar Diaz is another amp builder who noticed that guitarists were being unduly deprived of tremolo. Like the Deme­ter unit, the Diaz Texas Tremodillo ($225) is housed in a small, MXR-like metal box, but it comes in a variety of ultra-cool custom colors (outs had a metal-flake Godzilla-green finish). But even though the pedal is tiny, it’s packed with features.  There are two footswitches—one for by passing the effect and another for selecting full- or half-speed modes.  Controls include rate and dwell (effect depth) knobs. The unit’s LED blinks in time to the tremolo’s tempo, perfect for hypnotizing your bass play­er. AC addicts beware—there is no 9-volt adapter jack so you can only electrocute this ‘Dillo with batteries.

The Dials tremolo effect is warm, gritty and surpris­ingly tube-like for a solid-state pedal. With the dwell knob maxed out it has a vertigo-inducing irregular modulation pattern and produces a deep, rich pulsation. The rate con­trol provides a wider range of useful tremolo speeds than normally found on classic amps (about 130 to 530 bpm). The speed switch is an especially cool feature, letting you double the trem’s rate without losing the beat—perfect for trippy rave-up crescendos

Pity, isn’t it? Companies like Fender, Peavey, and Crate flood us with hip, sanely priced vintage-fla­vored combo amps, but the tremolo effect—sec­ond only to spring reverb in primitive cool—is so often deemed dispensable.  Until recently the tremophiliac’s only choices were to stick to a vintage amp or literal reissue (Fender’s ‘63 Vibroverb and ‘65 Twin Reverb reincarnations, for example), seek out the rare tremolo-enabled modern amp (Mesa’s Trem-O-Verb, Fender’s Vibro King), or use de­cidedly second-best tremolo stomp boxes or digital multi-effectors with amplitude modulation.

But there are new wobbles in the wind. Peavey helped in­stigate the shaking a couple of years bock with their rack-mountable tube trem/reverb, the Valverb. Demeter’s Tremu­lator brought tube-quality trem to the non-tube stomp box.  And now amp hotshot Cesar Diaz’ Texas Tremodillo ($225) offers another wonderful way to wiggle.

The Tremodillo’s army-surplus funkiness belies its state-of-the-shake sound, a buttery tone that equals or bests period tube tremolos. We tried repeatedly to scrutinize its oscilla­tions, but our analytical minds kept dissolving into a druggy, narcoleptic haze—proof positive of proper tremulation. And like the Demeter unit, the Trernodillo’s range Far exceeds ~60s tremolos: Our Fender Vibroverb reissue ranges from approx­imately 180 to 480 pulsations per minute; the Tremodillo goes from about 132 to 530. Demeter’s Tremulator, which con slow to about 65 or accelerate to an imperceptible blur, takes the widest-range prize. Of the three units, the Demeter boosted the most brilliance and clarity, but the Tremodillo was tops in hallucinogenic, high-cholesterol greasiness. Yum.

Diaz supplements the usual three controls—on/off, rate, and depth (Cesar calls it ‘dwell’)—with a speed’ footswitch that skips the rate knob between its slower and faster ranges, dou­bling or halving the modulation tempo. This simple but ingenious detail affords two synchronized presets’—very hip. With its se­ductive tone, wide range, and Fashionably low-rent styling (if not price), the Texas Tremodillo equals or surpasses the classic mod­els. And until the playing public once again deems tremolo an indispensable feature, it’s reassuring to know that such units can lend classic attitudes to modern amps.

Check out what the people think of the Texas Tremodillo at harmony-central.com

Cesar Diaz’s entries into the fray are the Tremodillo ($225) and the Square Face ($200).  Festooned with Texas Taco-Tone Art, these babies are the ultimate home-brewed, vintage-style doo-dads.  The Tremodillo has two speeds, which can be preset, via the Rate knob and variable depth, which is set via the Dwell knob.  The Square Face, Diaz’s take on classic fuzz, features Volume and Fuzz knobs and a footswitch.  A must for Norman Greenbaum fans.

Check out what the people think of the Texas Square Face at harmony-central.com

Check out what the people think of the new Texas Ranger at harmony-central.com