Guitar Amp Blog

I picked up my Dr Z Mazerati in the summer of 2003 after an exhaustive search for a real “tone-monster” amp that would quell my search for tone once and for all.  Dr Z amps are hand-built and hand-wired by a small team of talented craftsman resulting in amps that are slowly achieving a legendary status among touring musicians and tone snobs everywhere.  If you looking for serious tone and have a few bucks to spend, check out all of Dr Z’s amplifiers at www.drzamps.com or his top US dealer at www.fatsoundguitars.com in Cary, North Carolina.

I picked up my Mazerati at a small dealer in New Jersey.  All the talk about 3D sound and harmonic complexity may sound like marketing gibberish, but once you sit down with an amp of this caliber, you’ll realize there is some truth in there.  The Mazerati has a presence and voice that really stood out - especially when A/B’d against other mainstream amps.  To be fair, this is really more of a “Strat” type amp, but still has respective tones when used with humbuckers.

The Mazerati uses four EL84 power tubes to deliver about 32 watts.  The preamp section is powered by one 5751 and 12AX7 which helps notch down the gain and retains the sparkly chime at fairly high volume.  Also rare in a modern tube amp is a tube rectifier handled by a single 5AR4.  Peer inside the chassis and you’ll also see one of the largest transformers around - Dr Z doesn’t cut corners on components.

Simplicity is the hallmark of Dr Z amps.  Plug in and all you have to worry about is the volume and a single tone knob.  One tone knob may seem a bit stingy, but it covers a wide spectrum and has a tone for everybody in there.  Well, almost everybody.  This is not a high gain amp for metal or other saturated distortion applications, but is really geared more for country, blues and classic rock.  Notable players who use the Mazerati are Joe Walsh, Brad Paisley and Buddy Whittington of John Mayall Bluesbreakers.

Although I haven’t heard any clips, the Mazerati is also supposed to be a great amp for pedal steel guitar.

In late 2003, I picked up a pre-CBS, ‘65 Blackface Champ for about $390 on eBay. I was originally looking for a 70s silverface Champ, but when I saw the great condition of this pup, I changed my tune and put in a bid. Once the amp arrived, I was thrilled with condition and even more thrilled with incredible sound of such a pint-sized amp - only 6 watts when full cranked.

Although the amp came with all the original parts, I did slot it a new Celestion 8-inch speaker and all new tubes for the power, preamp and rectifier components. Vintage stuff is great, but making these few substitutions improved the sound tremendously.

The following weekend, I set out to do some recording with my new Fender Champ and compare it to some of the other Fender amps I own. I used an Shure SM57 to close-mic the amp and a Studio Projects C-3 about 3 feet away to capture the ambient sound. After a little adjusting to eliminate phase problems, I found a nice mix between the two mics.

I’ve always read that the Fender Champ records huge, and that’s absolutely true - you would never guess the size of this amp based on the samples I recorded. The clean sounds are great, but my favorite tracks are recorded with my PRS CE 22 played through the Champ cranked all the way up - bridge humbucker wide open. Nothing captures that 70s guitar sound quite like this combination.

In this second installment about the THD Univalve, I wanted to discuss some of the other features that make this amp unique. Probably the most surprising thing to most players is the wattage of this amp - it’s only 15 watts, but that can be deceiving. While this amp certainly won’t complete with a 100-watt Marshall head, 15 watts pumping out of a premium Class A tube amp can certainly get the neighbors to call the police - trust me.

To help tame this monster, the amp comes with it’s own built-in speaker attenuator as well as a half power switch to get a nice overdrive at lower volumes. Unless you use a booster on the front-end to push the preamp, all of the overdrive on this amp comes from the power tubes section, so the attenuator and half-power switch come in handy. Although the built-in attenuator does its job, I still thought I got a better sound using a Trainwreck attenuator built by Dr Z - the built-in unit can sound a little buzzy and snappy.

For recording, the amp also has a built-in 1/4″ line out jack on the back that can go straight into your mixer or channel strip. I usually shy away from these kind of direct setups, but recording the THD Univalve this way sounds good and doesn’t suffer from the “plastic” tone most of us associate with a direct connection. While I’ve used the direct recording option on this amp in the past, I still think it’s hard to beat a SM57 to capture the complexities and richness this amp can dish out.

Looking at the front panel of the THD Univalve, is a basic setup with a couple of twists. For starters, there are two instruments jacks labelled “Rock” and “Roll”, which is a clever way to say “Hi” and “Lo” gain. To play clean, the “Roll” channel provides plenty of headroom, but I always found myself running through the “Rock” channel and just backing off the volume for cleaner tone. Another option I preferred to increase the amp’s headroom was to run a 12AT7 or GE 5751 preamp tube in the driver socket - worked very well.

Beyond your typical Volume, Bass and Treble controls, there is another knob for “Attitude” that works much like a presence control and has considerable impact on the tone. I rarely ran the attitude knob below 12 o’clock because it drained to much life out of the amp at lower settings and robbed the amp of its sweet chimey ring in the top end. The last interesting feature is a small light bulb in the middle of the panel with an on/off switch that is wired up as a noise reduction circuit. This is an interesting idea, and it does work, but I seldom used it because I felt it chopped off too many highs in the process.

The last feature I wanted to cover was the setup of the power and preamp tube section. True to its name, the THD Univalve accepts a single power tube in addition to two preamp tubes, one labelled “Driver” and one labelled “Input”. When I first got the amp, I expected most of the tonal variation to come from different power tubes, but I later realized the preamps tubes were just as important. Using different combinations of preamp tubes in both the “Driver” and “Input” sockets yielded a wide variety of tone and greatly affected how much gain the amp would produce. Because of the infinite possibilities, I started keeping a log of the kind of tone produced by each preamp and power tube combinations - even down to the tube manufacturer - it all made a considerable difference.

If you get a hold of one of these amps in the future, don’t forget to eat and sleep the first few days, it’s really that much fun…

Back in 2001, I was just coming out of my modeling amp phase and was eager to get back to a nice, simple tube amp.  After the myriad of options available on Line 6 Flextone - not to mention a MIDI port for even deeper tweaking - I was ready for the less-is-more approach where my amplifier was concerned.

I had gone down to North Carolina to visit my mom and stopped by the local Borders to pickup a couple of magazine - one was the UK mag, “Guitarist”, which is expensive, but certainly one of the best guitar rags out there.  After reading a glowing review of the UniValve in the magazine and listening to sample track of ex-Rolling Stone guitarist Mick Taylor playing through one, I’d knew I needed to sit down with one once I got back to Philly.

A few weeks after I got back, I tracked down a little music store about 30 miles from home, so I hopped in the car one blistery cold Saturday afternoon to go have a look.  Without even turning it on, the amp was impressive with a metal grill cover, finished in a black powder coating.  Since the amp doesn’t offer a combo version, we hooked up a simple 1-12″ cab and I started running the amp through it’s paces - it hard work, but somebody has to do it right?

Right away I knew this amp was special - chimey clean tones coupled with blistering overdrive chocked full of complex harmonic overtones.  I knew in the first 5 minutes I was taking this amp home, but it was really hard to end the demo…I was having way to much fun.  Finally, we got it boxed up and the owner gave me a handful of old tubes to play with since the amp only came with a single Sovtek EL34 and a couple of cheapy 12AX7 preamp tubes.

In all honesty, when I first got the amp home and tried it out, I was very disappointed - it really sounded buzzy and thin.  Even after trying several of the other tubes in the amp (it’s self-biasing, so it can take a variety of tubes straightaway) nothing made it sound like the trial in the store.  I know, I know, it never does, but this was way off the mark.  After hitting a few discussion boards, it was clear the cheap speaker cab I had paired with the amp was probably the culprit.  Based on that input, I decided to pick up a THD 2×12 extension cab the next weekend to solve the problem.

I found a THD cab at Russo’s Music in Hamilton, NJ - one of the coolest music stores in the Northeast corridor.  Joe C helped me out and confirmed that the UniValve was indeed picky about the cab it was paired with - he was dead on.  Be sure to ask for Joe if you stop by Russo’s, the guy knows more about getting good tone than anyone I’ve met - and a cool guy as well.  Anyway, I got the cab home, hooked everything up and spent the next two hours immersed in tonal nirvana.  This was a perfect match - the Univalve paired with the Celestion Longhorn 12″ speakers in the cab sounded fantastic.  But it gets even better…

Along with the THD cabinet, Joe C also recommended I pick up an Electro-Harmonix EL34 power tube and a Chinese made KT88 to try out.  I loaded up the EL34 first and was instantly cranking out some amazing Marshall Plexi tones…everything from early ZZ Top to the classic Van Halen “brown sound”.  No doubt, this EL34 tube was the best sounding valve I had tried so far.

But the fun wasn’t over, I pull the KT88 out and gave it a go.  The KT88 is a “huge” vacuum tube compared to most others - it almost looks like a small Coke bottle.  Despite its looks, it also creates a fantastic sound in the UniValve, but is distinctly different from the EL34…kind of a snappy, tight overdrive that reminded me of Pete Townsend’s early tone with the Who.  Also, if you backed off the volume a bit with the KT88, its tone transformed into a beautiful, chimey clean tone that was perfect for emulating the sound of those early Beatle Vox amps.  I put a compressor pedal in front of the amp and it sounded even better.  The intro to “I Feel Fine” never sounded so good…

I’ll discuss some of the features of the Univalve in the next installment, but until then, here’s a stock pic of the Univalve:

By the spring of 1981, I was really getting into progressive rock with such bands as King Crimson, UK and Ultravox.  I had joined a new band in January with the best musicians I ever played with - a great drummer and keyboardist along with a decent singer.  I was listening to a lot of Robert Fripp and Al Dimeola at that time, and decided to go for a smaller amp with more gain - I chose the Music Man 112RD-65 amplifier - another fantastic Music Man Amp.

I bought this at McCord’s Music in Valley View mall, my favorite hangout, sometime in the early spring of ‘81.  About an hour after I picked it up, I played a gig with it at a small in club in Dallas’ Deep Ellum - it sounded great that night and I knew I had a gem.

This amp really ushered in my love for small amps.  Even though it had plenty of power, 65 watts, the single speaker really cut down the weight and made it a breeze to gig with.  Some people knock this amp for having a solid state preamp, but it gave it tightly compressed lead tone (ala early Boogie Mesa MK I) that I really liked.  The dual 6L6GC power tubes made it a seriously loud amp with lots of warmth when playing clean and some dirt when you cranked it up.

To improve the sound, I installed a Peavey Black Widow speaker with a much larger magnet that what came with the stock speaker.  Even though the Peavey was rated for higher wattage, I still managed to blow it out - oops!

I loved this amp and took it to college with me for a couple of years before I sold it to my girlfriend’s brother.  In hindsight, I should have kept the amp and got rid of the girlfriend, but such is life…

Here’s a pic of a truly great amp -

I still scratch my head to this day why I sold my Music Man HD-130 2×12, but I did, sometime in the summer of 1980. I remember trading it in for a fairly new Fender Twin that someone had stripped all the Tolex off of and painted white - call me crazy, but I thought it was cool. Tone wise at least, it’s hard to go wrong with a Twin… and it did sound good.

At the time, I was kind of evolving away from hard rock to more of a Police-ish and rockabilly style, which the Fender Twin fit perfectly. Shortly after getting the Twin, I got my first chorus pedal - a classic Boss CE-2 Chorus - and it sounded amazing coupled with that Fender sparkle. To be fair, my Music Man HD-130 probably would have sounded as good (if not better), but I wasn’t complaining…I was tone happy.

Our band did some demos at a studio in downtown Dallas in the late summer of 1980. I remember the engineer just shoved a SM57 in front of the Twin and we started the session. It sounded great. Although I used a Boss OD-1 for some overdrive and a little of the CE-2 Chorus pedal, most of those tracks were just my Ibanez AS200 plugged straight into the Twin with a little reverb on the amp - life was simple back then.

I gigged a lot with that Twin and pushed it pretty hard, but it never let me down once. As my choice in musical styles started to shift again in early ‘81, the Twin was on it’s way out, but it was a great ride while it lasted.

This isn’t the actual picture, but it looks pretty close to what I had…

Following the demise of my Marshall, I picked up a Music Man HD-130 2×12 at McCord’s Music in downtown Dallas sometime in early January 1979. Although this is a very Fender-ish type amp, it had a fantastic overdrive tone even at low volumes. A lot of great players defected to Music Man in the late 70s, Eric Clapton and Mark Knofler to name a few, but they never really caught on - I’ve always wondered why…

Along with great tone, this amp had a nice reverb tank, a very cool tremelo and a dual power switch to run at half-power when you needed a little less volume. This amp was built like a tank and was easily one of the loudest amps I’ve ever owned, played or heard - I mean scary loud! Most of the volume came from the incredibly efficient 2×12 custom speakers that were fitted with enormous magnets - and it made the amp weigh a ton.

My beloved guitar teacher in my early years, the master guitarist Mike Ellis, got one of these amps in the late seventies too…and he still has it…and still loves it. Of all the amps I’ve had, I can’t believe I let this one slip through my fingers.

I only had this amp about a year, here’s a pic:

In December 1978, I stumbled into McCord’s Music in downtown Dallas after finishing up my finals for the semester. I was playing in a good band at the time and felt I needed a “hotter” amp to gig with - yes, I needed a Marshall - or at least I thought I did.

At the back of the music store, I found a used 50-watt Marshall 2040 “Artiste” 2×12 amp that was in good condition and priced to move. After plugging in and convincing myself it sounded good (which it really didn’t), I put down a 5$ deposit and set out to finance this beast.

I had the amp on layaway for about a month and finally got it home in the first few days of January, 1979. Within the first 30 minutes of trialing my new amp, I knew I had made a big mistake - it sounded terrible. To my dismay, the tone was thin and brittle without a hint of dirt unless you had it full up - this was my first lesson in buyer’s remorse - it was truly awful.

Luckily, fate stepped-in and saved me from this “tone” disaster. A few days after taking the amp my band’s practice hall, our drummer called me with some bad news - the other guitarist had plugged into my amp after I left, turned it full up and exploded the transformer all over the practice room…it was complete toast. Not sure what to do, I took the amp back to the music store and they gave me a full credit toward another amp - I couldn’t believe it! I’ll talk more about the next amp I got in a later post, but in the mean time, here’s a pic of the short-lived “Artiste” - RIP, baby.

Since we’re on firsts, I thought it only fitting to talk about my first guitar amp. It was the fall of 1977 and I was still waiting to get my first electric. At the time, I was playing an acoustic Alvarez fitted with a in-the-soundhole Bill Lawerence pickup.

The pickup came before the amp - a friend of mine had restored an old guitar amp his dad picked up a garage sale - we played our acoustics through that for quite a while. So in the fall ‘77, I put a 50-watt Peavey Classic on layaway at the Melody Shop in Dallas - I think it was $250 at the time.

Once I got the money together and got the amp home, I was entering a whole new world - reverb, distortion and most importantly, volume! Although my plunky electrified acoustic sounded pretty lousy through this amp, I couldn’t have been happier with it - I’d turn off all lights and play in the dim illumination of the amp’s red jewel lamp (as the sweet smell of tubes wafted through the air…)

All in all, the old Peavey Classic was a great all-tube amp with a great clean sound and a fair amount of dirt when you pushed it. This model had 2×12s in it and seemed to weighed a ton - I was only 14 at the time, so it probably did…

My Peavey Classic served me well as I started playing in a bunch of rock bands at high school dances and private parties. I got my first electric about a year later, a black Gibson Les Paul Pro, and it really sounded great through that amp, especially with the P90s. Here’s a picture of that great amp :