Note:
The 2004 version of the London Power STUDIO has been updated
to fit into a 2U chassis, and is available in 10W only. New
photo coming soon!
The STUDIO
is the "most" original and unique musical instrument
amplifier on the market!
This is
not just bold advertising hyperbole: it is what the owners
of the LONDON POWER STUDIO amp tell us! The
range of tone is immense. The touch response superb. Dynamics
are euphoric.
The STUDIO
amp is a "ten watts and less" all-tube instrument amplifier
with many classic voices. It has the quick attack of a large
fixed-bias amp or the round warmth of a cathode-biased amp
at the flick of a switch. You can have shimmering highs, exquisite
mids and tight bass. You can plug in your guitar and overdrive
the preamp, the power stage, the front-end of the power amp,
or any combination, or use the effects loop as a crunch boost,
producing mild compression right up to "full shred". Go ahead.
Develop your own "tweed metal" sound. You can get the sound
of any vintage amp you desire, or nearly any modern amp that
appeals. How can so many sounds come from "just" a power amp?
And one without the usual tone controls?
It's simple!
Seamless
output level control
The LONDON
POWER STUDIO amp is like having an amp with a built in
variac. The STUDIO's unique linear AC regulator is
controlled by the POWER
SCALE control, which dials the voltage of the output
stage down to levels impossible for other circuits. And it
does it without nuisance noises normally associated with DC
regulators. There is no voodoo, just simple science: we maintain
the shape of the output tube transfer-curve so the tone it
produces is consistent regardless of the power output. This
is easier to do than it sounds, and the character of each
tube plugged in is unaltered. The output tubes can interact
with the speaker in their inimitable way that tone-killing
attenuators can never mimic.
But isn't
it now much easier to over-drive the output stage?
It definitely
is. This is why there are two options for maintaining the
interplay between the rest of the amp and the output stage.
The first is manual, by way of the LIMIT
control. This literally lets you limit the amount of distortion
produced by the output stage when POWER
SCALE is dialled down. The second way is automatic,
using the tracking switch, T. In this mode, additional circuitry
is Power Scaled to maintain the "relative drive level" to
the output stage. You can still manipulate the LIMIT
control to fine tune this effect. But now you have access
to "single-control Power Scaling" when you want it.
"Soft"
rectifier effect
Tube rectifiers
are quite in fashion these days. Having more of them is also
quite a fad. Their "magic" is their internal resistance, which
provides enhanced droop to the supply voltage under load.
This is also called "sag", which is not a very inspiring term,
despite its cool effect on tone, which is inspiring.
It is mostly a "feel" thing. As the amp is driven harder,
it pulls more current from the power supply, and the supply
voltage drops down. It recovers when the signal strength decreases,
and has an over-all compression effect. This makes it easier
to sustain a note or to have the amp "sing". Our Power Scale
circuit has a "soft" rectifier effect just like a tube, so
there is some sustain built in. Every power supply has unavoidable
sag, as real-world components always have some internal resistance.
You might think that a scalable power supply would isolate
this effect and sound stiffer as it is dialled down. Happily,
you would be incorrect.
Our soft
rectifier exhibits singing tone enhancement at all power levels.
It also filters out line noise and rectification noise that
would add harshness to the sound. Plus, we have added our
SUSTAIN
circuit to give infinitely variable supply compression. You
can use SUSTAIN
independently from the POWER
SCALE, for mild compression, to extreme novelty
tones. When both are used together, you can hold a note forever
and easily roll it into harmonic feedback at will. This is
what Electric LadyLand sounds like!
And,
of course, pure tone ...
Extensive
choke filtering and high-value Solen polypropylene capacitors
maintain tonal purity. DC heaters and DC-standoff heater operation
makes hum disappear.
The audio
circuitry is built with as much care and attention to detail
as the amazing power supply. The circuit is based on a classic
design incorporating four 12AX7s plus one 12AT7 and two standard-pin-out
octal power tubes, but has a few modern twists enabling the
musician to find his own voice. The PRE
control sets the gain through the three preamp stages, along
with the HI-1
and HI-2
switches. CONTOUR
is an active-EQ control and PRE-OUT
sets the signal level to the SEND
jack. The INPUT
control is a volume control between the preamp and power amp,
receiving its signal from the RETURN
jack. The SERIES
switch breaks the link between the SEND
and RETURN
jacks when external effects are being used. The LIMIT
control, discussed above, acts like a post-phase-inverter
master volume allowing over-drive of the power amp front-end.
With these three controls, an amazing range of distortions
is possible.
Of course,
POWER
SCALE functions like the "ultimate master volume",
letting you get ripping tones or fuzzed-out haze from the
output stage. Each is cool. Combining a bit of each is far
out!
Unlimited
sonic versatility
Every
control to the right of the INPUT
control affects the feedback factor of the amp, without altering
the feedback loop directly - except for the VIBE
control. VIBE
lets you dial out the feedback loop completely and explore
a whole new range of textures. SPARKLE
is a high-frequency contour, while SHAPE
is a low-frequency contour in "historic but not traditional"
locations within the power amp block. BODY
will fluff your hair. Well, not exactly.
Our new
double-ended BODY
control gives you access to single-ended sound at either end
and push-pull sounds in the middle. This is particularly useful
when dissimilar tubes are fitted - you can dial up the "single-ended"
tone of either tube at a whim. The BRN
and BLU
designations are not for "brown sound" and "blue sound", but
refer to the output transformer primary colour-coding. When
you install or replace tubes, it will be obvious which is
the "brown" tube and which is "blue".
Ideal
tube habitat
Speaking
of tubes, the STUDIO comes with three sets of output tubes:
6V6s, 6L6s and EL34s. It also comes with a bias tool and meter,
with the bias procedure in the owner's manual. You can start
right away biasing tubes hot, biasing tubes cold, trying different
tube types, and mixing things up. Yes, put in a 6V6 and a
6L6. Plug in a KT88 and an EL34. Any tube combination you
can think of will offer up new soundscapes to explore: 6V6,
6L6, 6CA7, 6550, EL34, KT66, KT77, KT88, and their variants.
Tube life
is always an issue in any amp that is capable of being a "screamer,"
and might be relegated to that role for its entire life. But
the STUDIO amp represents "Heaven on Earth" for any grade
of tube. This is a safe environment, especially when the POWER
SCALE is dialled down where tube life will be extended.
It is the perfect place for your expensive NOS tubes to safely
dispense their nostalgic glory.
More
great features
Plus...
You are not confined to the realm of fixed-bias tone, as in
99% of MI amps. You can select cathode bias with the K
switch. You can also select higher/lower bias settings in
any bias mode using the heat switch, labeled H.
Fixed bias is typically "fast" and "bright" but can be "muddy"
at high bias settings. True cathode bias sounds round and
power is limited to about 2-3W to assure ANY tube will be
fine. Most cathode-biased amps incorporate a bypass capacitor
so that the sound difference when compared to fixed bias is
not that great. We say "no" to bypass caps in the output stage.
Truth in biasing is upheld!
And what
are those T-U-P
switches? Each output tube has its own triode-ultralinear-pentode
switch. Pentode operation is what 99% of all musical instrument
tube amps use. It is dynamic and spongy when the VIBE
control is dialled all the way out. Ultralinear is cleaner
with no loss of power. Triode operation is rounder with less
output. No other guitar amp offers all three operating modes
of the output stage, let alone individual control for each
tube!
The STUDIO
amp is stable into ANY load impedance because of its massive
custom Hammond output transformer. There are direct-impedance
taps to match 2,4,8,16 ohm loads when maximum power and bandwidth
are needed. Otherwise, simply follow the rear-panel instruction
and connect your cabinet to any jack that sounds good!
A transformer-isolated
line output allows connection to other gear while driving
cabinets at the same time. Ground loops are eliminated, and
the line-out signal is an unaltered replica of the speaker
drive signal.
The
low-watt advantage
The STUDIO
amp can play louder and quieter than any other "low-watt"
recording amp, but maintains touch response at every level.
You can dial the output power down so low that you can talk
over your guitar. Playing or recording this quietly is great
when you suddenly get inspired at 3 AM in an apartment, but
most recording will be done at slightly louder levels to minimize
microphone noise. Or, you can crank it right up and blast
through your usual cabinet. With an efficient speaker, such
as the LONDON POWER STANDARD TONE* cabinet or our SESSION
112*, the "dialled down" amp can easily keep up with drums
while creating heavy crunch tones. *Described in the London
Power DIY Speaker Book.
Although
the STUDIO amp was designed for use in quiet studios
and personal recording spaces "at home", many musicians use
their STUDIO amp on stage. It can be the distortion
track and be the answer to every sound man's prayer. Line
outputs and all of their tone alterations may all but disappear
now that the STUDIO lets you wail at a whisper!
Many people
think that low-power amps are only good for getting great
overdrive tones. The STUDIO gets these, but also has
a sweet clean sound. Warm tweed clean. Clear modern clean.
And any other clean you can imagine!
And
reverb, too!
Just when
you thought it couldn't get any better - how about built-in
reverb? The STUDIO uses London Power's proprietary
push-pull reverb driver and a full-length Accutronics delay
line to create lush reverb. This is clean ambiance like you
might get from a digital reverb unit, but a little warmer,
and not muddy like the usual single-ended driven tube reverbs
of other amps.
For even
greater versatility, combine the STUDIO with any 2-channel
preamp! The STUDIO's low noise floor and wide bandwidth
shows up the noise of other gear you might use with it. Sorry!
We didn't design that other stuff.
Ironclad
durability
The LONDON
POWER STUDIO is built to last. Metal film resistors are
used in low-level areas, with flame-proof power resistors
where it counts. The spacious interior of the 2U rack cabinet
allows easy maintenance - although this should never be required
- and excellent thermal management, as the tubes are external.
The plastic plate supply caps are Solen polypropylenes - they
will outlast any other capacitor type, eliminating the need
for a "cap job" - EVER! The custom shielded Hammond chokes
and output transformer produces clean, full-bandwidth audio
fit for the most critical ears. Dual primaries on the custom
shielded Hammond power transformer assure worldwide AC mains
compatibility. All of the circuitry is hand-wired on sturdy
Teflon circuit cards (eyelet boards). Sealed military-style
pots from PEC never need cleaning, and the high-quality 1/4"
jacks are all chassis mounted. Everything except tubes and
reverb tank is covered by London Power's Twenty Year Warranty,
but your grandchildren's grandchildren will still be creating
new sounds with the STUDIO!
Amazing.
Original. Toneful. Unique. Exactly what you expect and more
from LONDON POWER: helping musicians find their own
Ultimate Tone!
