Amp Wizard Howard Dumble - 1985 Guitar Player Interviewby Dan Forte
Jackson Brown is wandering the back stage caverns of San Francisco's Cow Palace looking a bit worried. "Where's Lindley?" he asks his road manager [...] "We're onstage in 15 minutes!"
A door at the end of the hallway is seeming blasted open by a torrent of beefy sustained lap steel licks. Inside, Lindley is squatting precariously, his Hawaiian guitar balanced on his knees. Crunching chords and crystal-clear single notes are pour out of a crude-looking amplifier about a foot in front of his face.
"I want this one, Howard," David says to a large man who is smiling like a proud father. "Not this model, not one like this, but this one, OK?"
"It's just a prototype." Howard Dumble points out.
"Fine," nods Lindley. "I'll take it."
David Lindley, of
course is notorious for using a vast array of exotic guitars from an instrument
collection that number well over 100. But on the road, he uses only one brand of
amplifier, a fact that makes Howard Dumble understandably proud. As Lindley told
Guitar Player in a July '77 interview, "I've got a lot of little amps,
but on the road, I always use Dumble amps because they never break down. We went
about getting the sound in those amps by taking an old Fender Deluxe to Howard
Dumble and saying, 'We want this, but bigger and louder.' And Howard got the
closest of anybody I've heard."
Howard Dumble, 40 [in September of
1985], grew up in Bakersfield, California, and began building transistor radios
from scratch at age 12. He took up guitar at 16 (he later did his fair share of
studio dates in Hollywood, which included working with songwriter Jim Webb), and
in 1965 built a series of amplifiers for Mosrite that were used by the Ventures.
An extensive tour backing Buffy Sainte-Marie financed Dumble's first "out of the
backyard and into a building" amp shop in 1968, in Santa Cruz, California. The
following year, Dumble came out with his Explosion model amplifier (his original
prototype still works), which later evolved in the Overdrive Special. His line
of amplifiers currently includes seven basic models: the Overdrive, the
Steel-String Singer, the Winterland and the Dumbleland for bass and guitar, the
rack-mount Phoenix, a no-frills 50-watt Dumbleman, and the Dumblelator--a tube
vs. sold-state impedance translator--as well as the Big Tex reverb unit. From
the beginning, he has remained a one-man operation, personally building every
one of his amplifiers by hand.
In spite of
their steep price tags--a standard 100-watt overdrive head sells for $1,925.00;
the Steel-String Singer and Dumbleland each go for $5000.00 before
options--Dumbles are always in demand, and Howard has his hands full keeping up
with orders. Besides Lindley and Browne, the impressive roster of Dumble users
includes Larry Carlton, Bonnie Raitt, Graham Nash, Stevie Ray Vaughan, Jay
Graydon, Ry Cooder, Tom Verlaine, Eric Johnson, Steve Lukather, Robben Ford,
Dean parks, Carlos Rios, The Beach Boys, Christopher Cross, Tiran Porter, Jimmy
Haslip, Jerry Miller, Thom Rhotella, Randy California, Terry Haggerty, Rick
Vito, Kenny Loggins, and many others.
In discussing what's so special
about his amplifiers, Dumble uses aesthetic more than technical terms. "That's
the bottom line," he stresses. "It's the emotional influence that's really
important; technology is secondary--it's just a vehicle. The idea is to have
lots of fun."
Improvisational specialist Henry Kaiser elaborates on what sets the
Dumble apart from the rest of the amp crowd: "Number one, you could drop the
thing out of a four-story building, replace any tubes that break, and it'll work
fine. It does appear to be the most durably built amp possible. Number two, it
seems to me that Howard, through a long intuitive working process, tunes the
amps and designs by ear so that they're very sophisticated machines for
producing a wide variety of tones and distortion colorations. Because of my
specific avant-garde bent, I'm really interested in tone and timbre, and I need
to have a really wide palette of tonal color available to me, and I've got about
four times as many colors available on the Dumble. Any other amp sounds awful to
me. I feel terrible if I play anything else--except for a Fender Champ."
In an august '77 Guitar Player feature, the late Lowell George of
Little Feat was more succinct. "It's like a Fender made right," he said of his
Dumble. "It's the best amp I've ever played through."
Your amps have a reputation for almost never breaking down. How do you build
in such durability?
Those are absolute guarded secrets. In fact, if
you take the amplifier apart, you can't detect how I do it. I definitely have
secrets that make the amp perform and last the way it does. With most companies,
it's just a misapplication of technology. you don't have to destroy the
product--you don't have to get a Variac and turn it up to 170 volts--to get good
results. An extreme amount of attention is paid to every connection. Plus, I
found which parts last and which ones don't.
What made you gravitate
towards electronics in the first place?
I loved music, for one
thing. Music's always been a passion. I used to listen to Les Paul and Mary Ford
as a kid. Also, I come from an engineering family; my father developed one of
the first automatic transmissions. It wasn't hard to absorb the technology; it
was just there to do. I also saw that I could make some bucks at it. I started
making small pocket radios from scratch for the kids in school for $5.00 a pop.
I was doing real well until one day everybody had one, and there were enough
radios in the class that you could hear the local rock station at a small din
through all the earpieces. So, the teacher finally busted me.
inspired you to first build an amp?
I was a junior in high school,
and this guy named Jack smith came over and wanted me to build a piece of
equipment for the junior baseball association. He said that he had access to a
"mountain of parts"--I said OK! We went down to this big warehouse, and there
were heaps of parts, so we gleaned as many as we could--all free. We built this
huge 200-watt power amplifier so they could announce to nine baseball diamonds.
As I understand it, it still works today. Then, Jack and I made some Dual
showman-type amps, although we couldn't get Fender transformers--they were very
tight about what they'd send you--so we used David Hafler transformers, which
made the amp sound quite extraordinary.
Prior to building your own
amps, had you taken apart others amps such as Fenders and Gibsons?
can draw some of the those schematics from memory [laughs]. Of course, I had to
absorb other approaches. In fact, my old Fender mods I did in the late '60s were
exactly the same as the schematics a lot of the later high-gain amplifiers used.
How did you come to make amps for the Ventures?
I was an
18-year-old kid in school in Bakersfield, and I went to see Semie Moseley, who
was the only person I had access to there. I walked in and just bold-faced said,
"I've got something that sounds like nothing else. You better hear it." And it
flipped him out; he said, "This is the best thing I've ever heard." He offered
to go in with me to build 10 amplifiers. He bought the parts and paid me $90.00
a week--for about four weeks, and then I had to work for free. But I still got
to build 10 amplifiers on a production basis when I was only a kid. They were
called Mosrite amps, but they were my design. Actually, I built 11, so I still
have the original one I built. The Ventures played through them and were really
interested, but it was a little too much rock for them. They wanted me to go
into business with them, but I decided against it, and went back to playing in
studios and in rock bands.
Did your early amps have certain qualities
lacking in commercially available amps of that period?
definitely made sure they had more frequency bandwidth. One thing I noticed
about the early guitar amps was that they were real limited, especially in the
lower end. But you have to be careful to make sure you still keep the proper
midrange and treble response. I found that out early on. You can't build a hi-fi
circuit and expect it to be a good guitar amp--it just doesn't work out. you
need a whole different response curve. But I did notice that if I put a little
more low-end into the preamp circuitry, it was much more tasteful and fun to
Once you got started, did a Dumble philosophy evolve?
I try to be flexible. I've always been aware that whatever I make has to
be crafted with the best intentions. Never have anything shoddy. Always makes
sure that it works and looks perfect. The actual techniques I use to get the
sound that I go after have evolved extensively. It's a growing process. That's
the toughest thing about staying with one thing. you're always thinking of new
ways to do it. Basically, I've kept the Overdrive the same but the other models
are open to flexibility.
What changes did the Explosion undergo
before it became the Overdrive Special?
The active circuitry changed
quite a bit, and the tone circuitry did also. But the concept of processing the
signal post preamp stayed the same. Most other high-gain amplifiers use a
pre-preamp gain boost, but I broke away from that quite early, in the late '60s.
I found that trying to build the signal up before the preamp had a tendency to
really overload the preamp, and you got nonharmonic tones and a very unmusical
end result. Plus, you ran into a lot of vacuum-tube problems with harmonic's.
So, what I wanted to do was get all that wonderful oomph and beautiful
sustain and harmonic richness without the electronic troubles.
you making what was to become the overdrive before you made the Steel-String
The Steel-String Singer came later, but I actually started
making a series of amplifiers called the Dumbleland in about '66, and I still
make them. That was the forerunner of the Steel-String Singer. I didn't change a
whole lot about that; it was a design way ahead of its time. It was too much
power and too silky clean for people. It's perfect for Stevie Ray, though. He
has a hard time playing an Overdrive.
Why is the Overdrive so
It's a different kind of signal handling. In the
Overdrive, I approach gain levels that are extremely intense; within the linear
region, I have a signal gain capability of one million. So if you stuck 10
microvolts in, you'd get 10 volts back. And I do it with stability, and it's
still very musical. The best way to approach an Overdrive is real slow. Walk up
to it, look at the knobs, have it turned down real low, and then get a
feeling for it. Learn what to do with your fingers to make it respond well. If
you walk right up to it, it has a tendency to absolutely frighten some people.
The secret control on the Overdrive's panel section is the ratio control, which
controls how much overdrive is fed back into the circuit. If you turn that up,
it's Rock City.
How different is the Overdrive Special you customized
for David Lindley from a standard model?
I might have changed the
value of a capacitor to some extent, so that it has a different treble response,
but the circuitry is basically the same.
Lindley says that for
certain sounds he's looking for, you sometimes borrow his guitar and Dumble for
the weekend to match the amp to the guitar?
That's true. The
amplifier responds so differently to each guitar that to get some effects, I
need to use the player's guitars, instead of my own. That's one the great things
about the amplifier; it doesn't modify any guitar into any one sound or
homogenize it. It expands whatever you start with. The amplifier is a real
important part of the sound regeneration system, but it needs to be very
responsive to whatever the guitar is delivering. The philosophy I try to keep in
the amplifier is that whatever you can hear in your head, this will help you get
Stevie Ray Vaughan calls his Steel-String singer the "King Tone
There are some different things about Stevie's. His is set
up more like a bass amp, modified to accommodate the guitar range. It's not the
usual lead guitar "Singer" approach. One thing he liked was that he could turn
the volume control all the way up and it didn't distort--it just got louder. He
does make it distort sometimes because he has about 50 megatons of pressure when
he attacks the strings [laughs]. He gets an incredible amount of signal out of
his guitar, and most amplifiers can't take it. He did his first album with a
bass amp I'd made for Jackson Browne.
Some players describe Dumbles
as different, more powerful, more durable more efficient versions of a Fender
That's a good way to describe it--in a limited fashion. There
are some great qualities to a small Deluxe. You get a great harmonic structure
at a small acoustic volume. It's real pleasing, especially when you're playing
by yourself. But that sound is not convertible into a group ambience--it's gone.
So, in the respect that I try to get something comfortable and very musical,
only in a bigger fashion, that's a good analogy. But the circuitry is not even
close. I use vacuum tubes, and transformers and knobs, but the similarity stops
there. To get the result I want, I have to use unique circuitry. It's my tone
circuits and coupling circuits and the way I process phase-inversion.
Can you "Dumble-ize" a Fender amp to the point that it shares the
Dumble philosophy and sound, or would it be a compromise?
compromise. The actual physical construction of the Fender limits what can be
done. In fact, after the last Steel-String Singer mod I did to David Lindley's
amps, he no longer uses the Fender Bassman I Dumbleized for him. He wanted this
luscious transparency and response--like floating in white clouds--and I came up
with special circuitry. I can use a Fender chassis, but you have to rip
everything off of it, fill in all the holes, and re-drill it. They're just a
little bit too squashed. A distance of half a centimeter makes a big difference
in the way something sounds. It's a science involved with what's called circuit
Instead of a single bright/deep switch, most of your amps
have separate bright and deep switches. Can you use both at the same time?
Oh, you bet. It gets luscious low notes that you could float on and
beautiful, crystalline highs that are silky as glass.
How many watts
are the various models?
The overdrives are 100 watts, but they're
switchable down to 50, and I do make a special 150-watt Overdrive, which is a
lot of fun. The range in power goes from a 25-watt recording amp called the
Hotel Hog up to the 450-watt Winterland, named after the concert hall in San
there be an ultimate amp for you, or are the Overdrive and Steel-String Singer
too distinctive to be combined?
Well, the Phoenix series is where
I've done that--so you can combine things--because it's a rack-mounted affair.
You can by all the separate preamps, with or without overdrive, and a choice of
50-, 100-, or 150-watt power amplifiers, and hook them together. The overdrive
section is expanded--instead of two overdrive controls, you have four.
After experimenting with various speakers, what do you favor?
I've gone with everything, there are a lot of things I still like. The
most versatile is the EV. But all manufacturers, include Altec and JBL, make
wonderful speakers that do specific jobs other speakers can't do. I divide
speakers into two classifications: the efficient and the low-efficient. Both are
very useable. Low efficiency speakers are things like Celestion and Jenson and
PAS. Usually because of the physical construction, they don't get the same
acoustic level per watt as the Altecs, JBLs, and EVs do. There's an advantage to
that, because you can make the amplifier work harder to get the same acoustic
level, and a whole different kind of harmonic structure results. I love the
sound of JBLs, especially for chords, but I had a lot of trouble with 4" voice
coil not traveling in a linear fashion. The actual coil would short out against
the magnet structure. The Altecs didn't do that, so I was using them up until
'79, when EV started coming out the the EVM series.
How does your
philosophy on speaker enclosures contrast with other companies?
think mine's different. I just don't believe in a baffle board with a couple of
sides. Everything is designed to respond tonally. Even my open-back enclosures
use air to the optimum. It's an ongoing process; I'm still finding out things
that are useful. There's a definite technique to developing enclosures. Instead
of increasing the output all from the front by feeding more watts in, I designed
a special series of open-back enclosures so that there's actually an air pole
inversion process--I make the air respond in an in-phase relationship, both in
front and in the rear of the enclosure. So, from the same amount of speakers,
it's almost a doubling of sound.
Does that change the tonal
Yes. The low end is absolutely luscious. You feel like
you're floating on a football field filled with marshmallows. And it gives a
singe to the midrange that puts solos right out there. It works great for chords
and solos, but especially well for slide. It's the kind of enclosure that
Lindley and Lowell George used.
Is there a single emotional aim
you're shooting for, or many?
It's a whole panorama. I don't believe
in being confined. There are hundreds, perhaps thousands or millions, of valid
guitar tones. When the air becomes electric, that's the right sound, no matter
what the one is. It's that sound exciting the senses.
Guitar Player Magazine - September 1985