When and how were you first exposed to electronics and guitar amplifiers specifically? (Please start at the beginning and bring us up to the present in terms of your hands-on experience, training, education, and any interesting stories along the way).
My father was an amateur radio operator in the late 30s-40s and a radioman in WWII. He showed me how to make radios and small amplifiers before I was even a teenager. I started taking guitar lessons when I was 13. My first guitar teacher had a Fender Showman amp, and the schematic was still in the back. I bought some old tube PA gear at a garage sale and set out to turn it into the Showman, via baggies of parts and the schematic. Back then, there were a lot of old radio guys around who had spare parts galore that would supply my amp habit cheaply. I set up my first “Showman” as a single clean channel, using overdrive pedals to get my sound (I was 14 by then) What I really wanted was a distorted sound. All of the guys I admired used Marshalls, which were out of my price range. Old Fender heads could be had in the $100-$150 vicinity, and were easy to modify, so that’s what I got. I bought a ’66 Showman, obtained schematics and sought out to build my first “Marshall”. When I was done, I found it sounded nothing like I expected. When I came across a real 50 Watt Marshall, I found even THAT didn’t sound like imagined it would, or “should” sound. So, I then collected as many different schematics of all the amps I could find. The patient techs at my local music store, Stan Cotey (Now the head of hardware at Digidesign) and Gene Tredway helped me out a lot. I studied the schematics to see the similarities and differences between them, then I built the circuits and noticed the differences in sound. I started making changes of my own to these classic designs to get the sounds I was hearing in my head and on records. By the time I was 15, I was doing custom mods for players in the area. I was working out of the back of Red’s Guitar Warehouse in Mt View, CA. Over the years, the vintage designs changed into totally new designs that don’t resemble their origins. I kept this up for many years. While in college, I was working as an amp repairman, speaker reconer and as a soundman at various locations in Chico, CA. One night I was working for David Lindley & El-Rayo-X. I brought my latest 100 Watt amp (a forerunner of the Tone Master) to the gig. David Lindley and Ray Woodbury listed to it. They A/B’d it with their Dumbles and Demeter amps. The amp spoke with a meaner, tougher sound and more authority than their amps, which had a smoother, more compressed sound. David smiled said “How much?”. I wanted so much to have a big star use my stuff that I quoted him low- $450. David hung his head and left the room. Ray made some excuse and left as well. Their manager came up and gave me the skinny on what had just happened- David and Ray had just spent 9 grand on 3 new amps, and this one sounded great at a fraction of the cost. I had lost the sale, he explained, because I was too cheap. However, one of his other clients would appreciate the amp very much, he told me, and that he wanted to buy the amp as a gift for this other artist. That artist’s name- Robben Ford. I also made a custom stereo guitar amp for Robben. It was my work for Robben Ford that got the interest of the folks at Fender. At this point, I need to make a few points about Robben Ford. The thing about Robben is, Mr. Dumble was a big fan and supporter of Robben Ford since the 70s. When Robben didn’t have an amp, Dumble made sure he had one. For that early support, Robben will always have a Dumble on stage as a way to say “thanks”. He could play through any amp and still sound like Robben. He would NEVER play anyone’s Dumble clone, as it’s more about the “Bro Factor” than a nuts-and-bolts amp thing. Robben is a 100% class act. Anyway, after that, I designed speaker drivers for car audio and PA and some custom sound systems in San Francisco. I left SF for LA, just before the LA riots. After that, I was offered a position with Fender in AZ. I worked at Fender for 4 years to the day. I designed a number of amps and speaker enclosures, custom shop and standard production. Some of the standard amps were re-designed for costing and manufacturing reasons, after I did the initial prototype. Others were my work totally, and remain that way to this day. Amps I worked on in total or in part include the Vibro King, Tone Master, Pro Jr, Dual Professional, Custom Vibrolux, Prosonic, Custom Vibrosonic, ’46 Professional limited edition, and Rumble Bass. I left in 1996. I could have kept re-hashing the same designs over and over, but I’d rather do something new, worthwhile and more challenging with my time. During and after Fender, I was doing amp repairs and restorations, mostly on old broken English stuff that was shipped over in containers. We’d pick up and deliver a load from Los Angeles once a month. My next visible amplifier venture was Smokey Amplifiers, which I started with my best friend and partner Annette in 1997. We started with making amplifiers INSIDE used packs of cigarettes. Later, we made the same amp in a Polycarbonate box that looks like an old cathedral radio but will fit in your pocket. Same amp, different look. We’ve sold almost 200,000 Smokey Amps to date, all hand made in USA. Smokey Amps were the answer to the folks that came up to me and said “I really like your amps- wish I could afford one”. As tube amps were always my first love, Zinky Electronics was born in 1999. We used my name because it was known for the custom and Custom Shop Fender amps I’ve done, and because “Smokey” was a good name for an amplifier made from a recycled cigarette box, but a terrible name for a tube amp. Our first amplifier was the MOFO, which was limited to 100 pieces. These were 50 Watt channel switching heads. Current owners/users include Billy F. Gibbons, Kirk Hammett (Metallica) , Dana Rasch (Beyond Chops), Doug Pettibone (Lucinda Williams), Shawn Harris (The Matches), Dan Wilson (Semisonic), Dan Hawkins (Christian Artist) AJ Dunning (The Verve Pipe), John Donovan (Copperseven), as well as producers Dusty Wakeman (Dwight Yoakam, Lucinda Williams), Jack Endino (Nirvana, Mudhoney, Hot Hot Heat), and Matt Hyde (Monster Magnet, Slayer, Porno for Pyros). Superfly was the result of many years work to make a 100% analog, 100% tube amplifier with full digital control. That came out in 2003, and is our flagship product. Our latest amplifier, Blue Velvet has been shipping since early 2004. With Blue Velvet, we’ve applied what we’ve learned about tube amplifiers into a light (43 lbs) and portable 1x12” combo with the sound you’d expect from a high end product with my name on it. That brings us up to the present.

As your experience grew with electronics and amp repairs, what were some of your favorite models, and why?
My favorite amp design as a kid was the 50s Supro design. Most of them were similar enough. That amp was simple, 2 knobs per channel, tremolo, and had a great smooth clean sound, and when you turned it up, it rocked. Jimmy Page put one to great use on the first Led Zep record. When I was 16 or 17, I bought my first AC-30 (A JMI non-top boost model). It worked perfectly well, and I hated everything about it. I gutted it and re-built it as a Supro with the AC-30 power amp. I was much happier, and kept it through college. Fender amps were easy to mod, but most of them were blackface amps, which with few exceptions used cheap transformers. So, if you wanted something worth a damn for high power/high gain use, you had to buy new iron AND re-wire the thing. I did like the Blonde Fenders very much- those were great. Some of the tweed ones were cool, but not all of them. I liked the vintage Gibson amps. They were harder to modify, but used better parts than the Fenders. Vintage Gibson amps are still relatively cheap. Selmer amps were cool English amps that were built well, like Fenders, but had better sounding circuitry for rock ‘n roll. Most of them were “50 Watt” amps that don’t put out more than 30 watts or so, but I still like ‘em. There were a number of off brand Tweed Deluxe knock offs from the 50s and 60s that are all cool in their own way.

When did you begin building amplifiers, and what did you want to accomplish as a builder? Have your goals changed or evolved at all since you started?
I began building custom tube amps from scratch in 1983, when I was about 16. Each amplifier was designed with a particular player and instrument in mind to obtain a particular sound. References for the sounds were always from records. The idea then and now was to re-create the sounds you KNOW, right there, in the room you are in. We don’t try to re-create the amplifier. There were thousands and thousands of vintage amps made. You CAN get the old amp, but often, it’s more about the player, the room and how it was recorded than the amp itself. So, I’d use aspects of the player’s technique to cull the desired sounds from the combination guitar, amp and player. What I later found out was that if an amp works for particular good player, there will be others it will work for as well. I also found that if the amplifier reproduces the natural ACOUSTIC sound of the electric guitar, you’re doing great. There are so many variables with pickups, strings, woods, etc. that if the amp is true to the acoustic sound, the player will either be happy, or he needs a new guitar. I almost always use STOCK vintage style pickups, with few exceptions, because the amp can provide the gain and output needed for players who require it. Zinky amp players run the gamut from Joe Perry and Billy Gibbons to Bryan Kehoe (of the Kehoe Nation, also played with Les Claypool, Jerry Cantrell & Ministry), Ron Heathman of Supersuckers and Doug Pettibone of Lucinda Williams to name just a varied few.
Describe the various models you’ve built and how they have resembled or offered departures from specific, well-known vintage models of the past. (Let’s include your ‘Fender’ period, too).
At Fender, I started with a hard rock amp that I had developed outside of Fender (the Tone-Master) and a model that was designed to work for small clubs, clean through rock tones, with tremolo and the surf/rockabilly reverb thrown in for good measure (Vibro-King). Both amps took the look of the Blonde period, both amps HAVE traditional Fender clean sounds, but neither of them used “vintage” circuitry.
Where vintage amps may sound good with the volume knob set between say, 4 and 5, it was very important that if the amp was cranked, it would rock and if it was turned down, it would sound clean and sweet. We sought out to make amps with no, or very few “bad” settings. I suppose I loosely used elements from blonde Fender amps, as well as a few cues from Marshall (Tone-Master), but they were new designs. While everyone remembers good things about their experiences with vintage amps from long ago, it was important that the sound of any new amp was RIGHT THERE, in the mind of the player, even if that sound would destroy the original, if you played ‘em side by side. Each amplifier I did for Fender was designed for a PARTICULAR style of pro player. We wanted the new products to be intuitive to the older players, yet versatile enough for the new players. The main idea was to get these new amps into the hands of top stars, which would spur sales. It worked. These amps returned Fender to the forefront when the previous Fender amps had horrid sound, with a visual warning of grey grille cloth and red knobs that said “Stay Away”.
With Zinky Electronics, we’re staying true to making products for pros. The difference here is that our name is not as famous as “Fender” for example, so we have to work extra hard to make the products BETTER sounding than my previous designs. Low volume performance is now important to us, where this was usually not of concern with the Custom Shop amps. Of course, this is in ADDITION to high volume performance. Our most radical departure was and is the Superfly, which is a 100% tube amplifier with 32 channels of full digital control. It was meant to be a professional amplifier for touring musicians who require lots of sounds night after night. As such, it is great. However, it’s too much amp for the folks who only want a clean sound and a dirty sound. We find some players who like the simplicity of only one tone control, and others who want full control of every nuance of the amp. We offer both. While the Superfly has 6 tonal “Modes”, which re-wire the amp for different sounds, none of them are any particular vintage design. Two of the modes DO sound similar to the sounds you’d hear on old records that were created with Leo Fender’s amps. Even so, the sounds and circuits of the amp all ZINKY.Can you summarize some of the unique things you like to do as a builder not covered in #4? (Any offbeat or non-traditional design approaches, types of components and values used, etc.).
As for nuts and bolts, we always use high temp. capacitors for EVERYTHING (even Smokey Amps). The reliability is SOOOO much better. We always derate the voltage values, using much higher values than needed. Once again, reliability. Reliability is the single most important thing in a tube amp. If the amp fails, it doesn’t just sound bad, it doesn’t sound AT ALL. We use film type resistors and not carbon composition resistors like some do. Carbon comp resistors look cool and were the choice years ago when film types were not available, but they are unstable over time, sensitive to heat and are noisy. Less noise = more tone, pure and simple. We currently use old style stick wound output transformers without exception. Bobbin wound transformers are much more common, but they do not have the efficiency that gives the dynamic sound we require. Our power transformers are designed for almost NO sag, once again, because dynamics are everything in music. Think about it- When you hit the strings hard, you want them to react in kind. Having the amp soften up when you lean into it is cute for an effect, or perhaps if you have a very light touch and light gauge strings, but it’s counter to a dynamic player’s needs. We use circuit boards, as you cannot have a truly high gain amp that is noiseless and stable (free from oscillations and electronic feedback) without them. In our boards, extra space is used for extra ground plane for shielding purposes (contributing to low hum and low noise). While there are cheap, poorly designed PC boards that give the method a bad name, we use military spec, double sided, plated through hole boards that would work even without solder. There are no Point-to-Point wired satellites in space for good reasons, and one of them is RELIABILITY. Our amplifiers are indeed serviceable, but I give ‘em a lifetime warranty and I’ll do any needed work at no charge, if the need ever comes up. Our warranty is on the AMP, not the buyer. Also, we figure that if the buyer has laid down a good deal of $$ for the amp, service and service parts (tubes) should be available from the source at reasonable prices.
Tubes are chosen for reliability, availability, and sound. I’d love to use NOS USA military tubes, but they haven’t been made for 20 years and you just can’t get ‘em on the road, so we won’t do it. We look at the whole signal chain and how it relates to the sound when we make a design. We like to make amplifiers that work with all types of guitars AND speakers. At Fender, the Prosonic combo was a good sounding amp, but it was absolutely speaker dependent. By this, I mean the combo sounded good, but change the speakers out and it was disappointing. I became aware of this when the speaker vendor used cones made from a different type of paper, then every amp sounded bad. There was only one speaker that ever sounded good with that amp. We had to wait for more than a month before we could ship Prosonic amps in quantity. Since then, I’ve made it a point that my amps will sound proper with any good sounding speakers.

What was the process involved in determining the kinds of speakers that would go in your amps? Did you try lots of different models and types? Do you offer a range, or do you stick with specific models for each amp you build?
When I was reconing speakers, I experimented with cones, voice coils, spiders, magnets and such in the same way I experimented with amplifier designs. I learned what differences these parts made, and I applied this knowledge to designing speakers. We started with a vintage design, then took it as far as we could to extend the performance and dynamic response. I found that like tubes, some of the vintage paper cones are long gone. Sure, people will make cones that LOOK like the old ones, but they won’t sound like them. The problem with the Prosonic speaker was traced to a cone that was less than 2 grams heavy. It was the wrong paper formulation, and the tone was 100% wrong. This happens from time to time with every large speaker company. But, the density, flexibility and hardness of the paper cone is very important to the tone. The Kurt Muller company still has the paper mill that was formerly owned by Celestion in the 40s, 50s and 60s, so you can still get those original Celestion paper cones from them. But I have not seen or heard any proper new 12” USA cones from the same period. The Voice Coil is another big component of the sound. Kraft paper was the vintage choice, and is still available today. Paper voice coils are lighter, which gives you a louder speaker with more dynamics, at the cost of lower power handling. We have used different voice coils depending on the application.
The magnet is next. Alnico will provide very strong flux density in the gap with lower weight than an equal strength ceramic magnet, and with less iron or steel in the gap, you’ll have less inductance and slightly more treble to the Alnico, all else equal. And they look cool. Other than that, there is no difference in sound. We don’t use ‘em because for no increase in sound, they are 3 times the price. We might in the future, if we have a product that requires the look of the Alnico bell in the back of a vintage-style combo. Neodymium is a rare earth magnet that offers very low weight with very high strength. These are highly sensitive to heat, and if you get ‘em hot once, they get lose magnet strength permanently. If I could get one that sounded right and would last, I could save 17 lbs on a two 12” combo, but I can’t do it yet, because I can’t get a Neo magnet and frame that will fit our preferred cone and voice coil. Speakers are a balance between output efficiency and frequency response, and for many others, cost. We design and buy the nicest sounding speakers we can find, which I’ve spec’d out all the parts for. They are made in USA by Eminence exclusively for us. They are a bit heavy at 12 Lbs, because it take a magnet that large to give us the dynamic response we like. Magnets are expensive, so you’ll rarely see one that large on a guitar speaker from most companies. We have two main speakers we use- We have the vintage style, with the paper VC and the high power style, with a Kapton (Du Pont high temp plastic) VC. They are otherwise identical, and sound very similar. Hard rock and metal players are better off with the Kapton, as it gives tighter bass response and higher power handling, where clean players would be best suited by the paper VC for sparkling high end and increased dynamic response. For eclectic players, we suggest a mixed cab with both types, giving the best of both words and different recording options. We try new speakers as they become available, but for our needs, nothing has bettered our own speakers so far.We often hear that the power section is the heart of an amplifier’s tone.

Regarding transformers, tell us about their design, what was involved in determining the right specs and characteristics for your amps, and who builds them?
Yes, indeed. The output section determines how the amp will sound, INDEPENDENT of pedals, etc. So, when a guy complains about a distortion box having a thin, buzzy tone, the problem is most likely the power section/output transformer of his amp. We use don’t use bobbin wound transformers. The type of laminations (grade of Iron) makes a difference in tone and frequency, as well as how the thing is wound, whether the primary and secondary are wound at the same time (Bifilar) or if interleaving the primary and secondary layers is done, and how many interleaves are used. Frequency response is very important to us, and we design for 30 Hz full power bass response. This produces a larger, heavier, more expensive transformer, but the bass is always tight and never flatulent. Once the low end saturates, the high end goes to hell as well. We have one company (who shall remain nameless, as it’s been a long search to find ‘em) who builds all of our output transformers, and we use different companies for the power transformer and reverb transformers in various amplifiers, chosen by which work best for that particular application. I can say that all of our transformers are currently made in the USA. In most cases, our transformers cost about twice as much, even in quantity, as what you’d find in most tube amps of similar rating.

How important is the choice of tubes you use? What brands do you ship in your amps and why were they selected, in particular? Do you burn-in all of your chassis before they are shipped?
All of our amps are burned in before shipment, and all of our power tubes are burned in before they go into amplifiers. In 50-120 watt amps, we use Sovtek tubes, short base 5881s mainly because I’ve been using them since 1987 and have had very few fail. Durability is the most important thing, followed by consistency and accessibility. Our transformers are designed to produce maximum power and tone with tubes we use today, not for the specs in the back of the RCA tube manual. Even though the new tubes may not work as well in that vintage amp, they’ll work better in ours. We use Sovtek and Electro-Harmonix preamp tubes for the same reason. Also, we run the tubes at the voltages that give the best tone, which, in the case of 5881s will DESTROY the NOS types. Our Blue Velvet runs EL-84s at very low voltages. We use Sovtek there again, but with that amp, you could use just about anything. I’ve tried others, but I didn’t hear or feel any real difference, so we’ll stick with the inexpensive, durable, and available Sovtek EL-84s.

How are your cabinets constructed? What types of wood do you use and why?
We use Baltic Birch completely and exclusively in our cabinet construction. Here’s an excerpt from an article on woods I am writing for our website:
Types of woods used in amplifier cabinets- Particle board, MDF, OSB, Pine, Hardwoods, Baltic Birch, other plywood.
Particle Board- Heavy, not very durable in wet or touring conditions. Made from very small chips and binder (glue). Cheap, easy to machine. Popular in low cost products. Avoid.
MDF- Medium Density Fiberboard. Essentially glue + pressed dust. Very dense, very heavy. Will swell if it gets wet. Better than particle board in all ways except weight, but it will still crack if it takes a big hit. Great for cabinets that never need to be moved. Did I mention heavy?
OSB- Oriented Strand Board. Mostly used for siding on construction projects. Looks a lot like pressed vomit. Made from real wood chips, better than particle board, but not by a whole lot. Often used in low cost PA gear, or by those who want low cost materials but don’t want to admit to using particle board.
Pine- This was the wood of choice in the 40s, 50s and 60s. Back then, sugar pine logs of diameters larger than 10 Feet were available, and therefore it was cheap to buy and stable (won’t crack or warp). The old growth wood has been depleted, so the pine of today is from much smaller trees, and so it is almost impossible to obtain large pieces (above 10” wide) of solid pine that is stable. Some manufacturers will join smaller pieces together to make one large piece. Pine will flex when used in a high power amplifier, imparting a tone of it’s own (good or bad, depending on how you look at it).
Hardwoods (Maple, Bubinga, Imbuya, Walnut, Purpleheart, Oak, etc)- have been used in deluxe decorative amplifiers. Some hardwoods (Maple in particular) although quite striking in appearance have problems with cracking and splitting, especially if subjected to dropping or rough treatment and are therefore not suggested for touring amplifiers. The more dense the wood is, the more rigid the cabinet will be, thus the more solid the sound will be (Less resonance=fewer cabinet losses= solid sound).
Baltic Birch is a particular type of plywood that comes from the Baltic regions (Russia). It is exceptionally smooth, void free, resonance free and strong. It is a premium wood that comes at a premium price. Baltic Birch is a low loss wood, so more of the power put into the speakers will turn into SOUND and less will be used to shake and rattle, or Resonate the cabinet. Once again, dynamics are the key here. Baltic Birch comes in 60” x 60” sheets, and for some cabinets, the cut yield is better with Baltic than standard domestic plywood.
Other types of plywood are available, from construction grade siding to high end plywood with solid furniture grade surface material that is even more expensive than Baltic(!). Most domestic plywood comes in sheets 48” x 96”, which is desirable if the cut yields are better with rectangular 4’ x 8’ sheets than 5’ x 5’ Baltic Birch square sheets.
Types of joinery used in amplifier cabinets - Finger Jointed cabinetry VS Dado jointed VS Dovetail Jointed
When using any type of solid wood, the joinery should be of the finger jointed (good) or Dovetail Jointed (better). Both types of joinery interleave both pieces of wood in the joint, but Dovetail joints (so named as the wood is cut with triangles (“dove tails”) cut from the pieces, so the pieces lock together and are held firm. This type of joinery is not recommended with any kind of plywood, as with heavy use/abuse, the plywood will tend to de-laminate at the joints and the joints will fail, flaking off over time. Finger joints use narrow “fingers” with cuts in between which works similarly to the Dovetail, without the locking feature. This is a strong and attractive method of joining solid wood, and it’s very quick to machine, if you have the tooling. This was the #1 way to do things in the 50s and 60s. The tooling required to cut finger joints in large sheets is quite expensive, or time consuming, so it is not often performed in small shops, but Dovetail joints can be done effectively in small shops
Standard Rabbet/Dado (groove/slot) joints are best for plywoods. This avoids the problems of feathering and delaminating while increasing the surface area for nailing/screwing/stapling.
For the Blue Velvet, we’ve started making some of our own cabinets, but we also use a top cabinet maker who produces cabinets for Bogner, Roccoforte, Rivera, Bad Cat, and many others.

How do you describe the sound of your amplifiers, and from a builder’s perspective, what enables them to sound like they do?
Our amplifiers sound like the guitars plugged into them, but with the option of making the sustain almost infinite and the bass HUGE. Tone control shadings are effective, but still natural sounding. They can go from fully overdriven to fully clean with only a twist of the guitar volume control , or sometimes just the player’s technique. This is accomplished by judicious choice of components, design and component placement/layout. I’ve tried to sort out all the truth from hype and translate it into an amplifier that will enable a player to make live music. I don’t credit any one design aspect or circuit with that, but can only say that it is the sum of everything we’ve put into them. One major thing about Zinky amps is that they are NEVER buzzy and fizzy sounding overdriven, at ANY volume, AND they are never dull sounding clean. That’s the hard part for many of these new guys. I heard a number of new highly touted amps from some high end builders at NAMM that were just painful to my ears. In fact, the only amps besides ours that I heard and liked were a re-issue 50 Watt from Marshall and the new Orange amps. Their UK designer, Adrian really gets it right. He’s to Orange what I was to the Fender Custom amps- totally new amps with the old look and even better sound than the old ones, along with reliability (unlike the old Oranges).