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
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
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
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
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
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
How are your cabinets constructed? What types of wood do you use
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
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).