Lab systems CAGE 30A User manual

CAGE 30A
Class A
Amplifier
Owners Manual

Cage 30A
A Few words from the Chief Product Engineer
ow sweet can a guitar amp sound?
H
Just try the Cage 30A to find out.
After thirty years of working with valve guitar amps; first as a hobby, then
as an engineer, I have seen and heard many guitar amps, some I liked, others
weren’t fit for the human ear. As the design engineer for Labsystems I have used
what I have learnt to get Labsystems products respected for both sound and
quality. Now I have designed a product for me, a product that makes me grin
from ear to ear every time I plug in my old strat.
People ask me “What does it sound like?” I can only give one answer “The
Cage 30A”, unique in every way, it has the sounds of many; but it has it’s own
unique quality. Two channels, foot switchable, the first channel being the clean
channel !!! Well that’s what I call it. It’s not your stark hard sounding clean,
more your sweet valve break up when pushed hard type clean channel. Sweet and
clean when played lightly, explosive and coloured when played hard. The touch, the
feel off the pick, a joy to play.
Channel 2. What I wanted was a controlled gain front end, that would
give sustain with touch that would ring back out to a sweet end tone with coloured
harmonics, but also retaining the natural sound of the instrument. I achieved this
goal by staggering the gain structure through out 5 triode stages.

Cage 30A
Pre Amp Stages
ffect Loop
he Output Stage
From the guitar input we go straight into a single “Class A” gain stage to
drive both clean and overdrive channels. The clean channel then goes through
another stage of gain, followed by the passive Eq section, then to the channel
switch. The overdrive channel goes through a further four stages, the last stage
being a cathode follower to drive the passive Eq controls then to it’s master volume
and finally the channel switcher.
I went with the side chain design in order to retain the straight through
sound of the amp and mixing the effects in. There is a balance pot on the back of
the amp to blend straight through and effects together. The first valve stage in the
loop is of a cathode follower type to get a good low impedance drive to the send
output jack. The effect returns jack feeds straight into the balance pot and then
into a class A gain stage to drive the phase splitter.
I started off with the idea of an output stage with the power that would
break up at a playable level with a smooth but defined break up. There was only
one choice, double ended class A 30-Watt using EL84 output tubes self-biased
with some negative feedback. A presence control was used to achieve a sweet top
end. To complete the overall picture I used a 5U4-rectifier valve to give supply
sag to compliment, sustain and add harmonic content to the fundamental note.
After 11 prototype output transformer designs and about 6 months of testing and
redesigning, I achieved the results I was looking for.
E
T

Cage 30A
T
T
he Magic Eye
he Building
Well you can call me crazy, and I probably am;, but when I was a kid,
building electronic valve gismos as a hobby, there was one thing I loved to add to
any project and that was the old tuning display valve used in old valve radios.
Believe it or not they are still available. I added one to this project to display
output saturation level. Just another touch to add to the uniqueness of this amp.
This amp is built to the highest standard with the idea in mind that it would be
reliable and always be repairable. It is built on 8 high quality military style double
sided tag strips. I used the highest quality components, each type tested for it's sonic
quality as well as it's reliability. Sprague orange drops and silver mica capacitors
used in both pre amps and the effect loop, xicons low inductance capacitors throughout
the output stage to give better transient attack. 1 and 2 Watt carbon resistors even
though that power is not needed, making the amp more reliable. I guarantee that I
myself build and test every single Cage 30A to make sure it meets the highest
standard possible. Hand building is a very slow and tedious way of building but the
end result is well worth it. Every Cage 30A has it's own serial number etched on the
Trafolite front panel.
Every exceptional product needs input from many others. I had plenty from
every guitar player who came to my R & D Lab, but over the past two years of taking
the Cage 30A from my mind and turning it into a product, there is one guitar player
I cannot thank enough, Phil George. He spent what seemed to be an endless amount
of his time dragging 5 guitars to my Lab. I would say, “Just keep playing that
Phil” while I continually tuned the amp I'd ask his opinion and in most cases we were
hearing the same things. Thanks Mate.
Take care of it and it will last a lifetime
Also thanks to my partner in Labsystems;
Derek, for not giving me a hard time for taking so long in developing this one
product. I would normally have done about 8 products in the same time.
However, the Cage 30A is a unique looking guitar amp with it's own unique
sound. .

12AX7
12AX7
12AX7
12AX7
12AX7
12AX7
12AX7
12AX7
12AX7
12AX7
EL84
EL84
EL84
EL84
DOUBLE ENDED CLASS A
OUTPUT STAGE
SIDECHAIN EFFECTS
PHASE SPLITTER
FEEDBACK
MAGIC EYE
DISPLAY
VALVE
CHANNEL 2
CHANNEL 1
BASS (PULL SW)
MID
TREBLE
BASS (PULL SW)
MID
TREBLE
VOLUME
CHANNEL SWITCH
PRESENCE
VOLUME
BRIGHT SWITCH
GAIN 1
BRIGHT SWITCH
GAIN 2
SMOOTH SWITCH
INPUT
SPEAKER
BLEND
EFFECTS LOOP
RETURN
SEND
TRANSFORMER
TAPPED OUTPUT
8 OR 16 OHM
SPK IMP SWITCH
CAGE 30A
AMPLIFIER SIGNAL FLOW
SWITCHING
CHANNEL

Setting Style....................................................
BASS
INPUT
BASS
MIDDLE MIDDLE
TREBLE TREBLE
VOLUME GAIN 1 GAIN 2 VOLUME PRESENCE
POWER MAINS
STANDBY
PULL
BASS BOOST
PULL
BASS BOOST
PULL
CHANNEL TWO
PULL
BRIGHT
PULL
BRIGHT
PULL
SMOOTH
CHANNEL ONE CHANNEL TWO
CAGE 30A
Class A
Amplifier S N 001/
Setting Style....................................................
BASS
INPUT
BASS
MIDDLE MIDDLE
TREBLE TREBLE
VOLUME GAIN 1 GAIN 2 VOLUME PRESENCE
POWER MAINS
STANDBY
PULL
BASS BOOST
PULL
BASS BOOST
PULL
CHANNEL TWO
PULL
BRIGHT
PULL
BRIGHT
PULL
SMOOTH
CHANNEL ONE CHANNEL TWO
CAGE 30A
Class A
Amplifier S N 001
/
Setting Style....................................................
BASS
INPUT
BASS
MIDDLE MIDDLE
TREBLE TREBLE
VOLUME GAIN 1 GAIN 2 VOLUME PRESENCE
POWER MAINS
STANDBY
PULL
BASS BOOST
PULL
BASS BOOST
PULL
CHANNEL TWO
PULL
BRIGHT
PULL
BRIGHT
PULL
SMOOTH
CHANNEL ONE CHANNEL TWO
CAGE 30A
Class A
Amplifier S N 001/

Cage 30A
CAertificate of uthenticity
This is to certify this Labsystems Cage 30A Serial
Number has been personally hand built and tested.
Only the finest of components have been hand selected and
for sonic purity, and only after extensive
listening tests.
Given the respect it deserves, the Cage should serve you
well for many years.
Should your Cage require service; as all fine equipment
does from time to time, please return it to it’s original builder,
the person whom painstakingly hand soldered every little
component. All thoroughbred machinery requires delicate and
special attention from it’s original builders to maintain it’s
pedigree and thoroughbred heritage, the Cage is no exception.
Signed by the designer, engineer, and hand builder
Timothy R. Evans
Labsystems
individually graded