Matchless Amplifier C-30 Instruction manual

For All C-30 models
Thank you for choosing a MATCHLESS brand instrument amplifier. Your amplifier has
been carefully hand-crafted using only quality materials. The chassis of your amplifier is
completely hand wired employing construction techniques of military electronics
manufacturers. We utilize point to point wiring instead of a printed circuit or bread board.
The wiring is silver coated stranded copper in a Teflon jacket for extra resistance to heat and
decay. We use mica filled phenolic tube sockets that are shock mounted to a rugged welded
steel chassis. Our hand wired paper bobbin transformers are designed for 100% duty cycle.
Vacuum tubes are selected for tone, low noise and performance. This kind of craftsmanship
and attention to detail enables us to offer to the purchaser our six year guarantee.
MATCHLESS amplifiers are ruggedly built, and aside from the periodic tube or indicator
lamp replacement, should require very little maintenance. We have designed every
MATCHLESS product to be a trouble-free, roadworthy, studio quality amplifier.
Your MATCHLESS is a straight forward amplifier devoid of bells and whistles. It is
an all tube design including the power supply rectifier. Cathode bias operation is utilized for
the output stage. The top-boost channel uses two 12AX7’s tubes in the first preamplifier,
while the 6 position vari-tone channel uses an EF/86-6267 pentode tube. This configuration
offers a unique tonal difference between the two channels.
All C-30 amplifiers incorporate a MASTER volume control feature and a HI-LO
power setting switch enabling the artist to take full advantage of the harmonic rich nature of
an all vacuum tube design. MATCHLESS amplifiers are available in a variety of
configurations. An effects loop is available as an option for most amplifiers. MATCHLESS
amplifiers may be ordered as single, dual or quad combos as well as separate head and
cabinet configurations.
Speaker cabinets are available for use with rack mount amplifiers or as auxiliary
cabinets for all combo amplifiers and amplifier heads. Cabinets can also be ordered with
custom impedance ratings; this is especially useful when multiple speaker systems are used.
Your MATCHLESS is an all tube design. If your experience is limited with regard
to vacuum tube instruments amplifiers, you should become familiar with the characteristics
that differentiate vacuum tube designs from their solid-state counterparts… Aside from the
tone or sonic performance.
1. Vacuum tube amplifiers require a “warm up” period of up to one minute before
they become operational, and they usually sound better as they “cook”. This is due to the
fact that electrons only flow when the cathode of a tube if fully heated. This is also the reason
vacuum tube amplifiers run so much hotter than solid-state design.
2. Many vacuum tube amplifiers incorporate a STAND-BY switch, which aside from
muting the amplifier, performs a more valuable function of removing current from the circuit
while allowing the heaters to remain energized. The STAND-BY mode is used during short
breaks and is usually preferred to turning the amplifier off. This allows the amplifier to cool
and greatly enhances the useful life of the output tubes.
NOTE: MATCHLESS amplifiers are biased hot and should not be allowed to idle with no
input signal or long periods of time.
3. Tube type amplifiers are inherently sensitive to speaker impedance matching.
This is due to the relationship of the internal resistance’s of the output transformer, the
output tubes, and the load they are required to drive. A load imbalance can cause loss of
power, self-oscillation, or excessive current to flow in the output stage. In severe cases this
condition can cause the output transformer to run hot and may damage and destroy the
output tubes. This kind of damage is not covered by the warranty. The impedance switch,
located at the rear of the chassis, is used to match the amplifier to the speaker load. This
rotary switch has three positions and can match the amplifier to four, eight, or sixteen ohm
loads. This switch should be set before the amplifier is turned on. MATCHLESS single and
four-ten cabinets are normally eight ohms. Dual speaker models are normally four ohms.
When it is desired to use additional speakers with an amplifier, or multiple speakers with an amp
head, it is necessary to calculate the proper impedance setting. This is easily accomplished using a simple
ohm’s law formula:
Load 1 x Load 2
Load 1 + Load 2
8 Ohms x 8 Ohms
________________ = 4 ohms
8 Ohms + 8 Ohms
The correct setting for two 8 ohm cabinets connected in parallel should be the four ohm
setting at the amplifier. It is also possible to connect speaker systems of unequal impedance
values using the same formula, simply set the impedance switch to the value closest to the
result. Remember that volume output may be also be unequal, as the lower impedance
speaker is likely to be slightly louder because it demands most of the power from the
amplifier. Also, be sure that the power handling capacity is adequate.
The use of “power-soak” devices is not recommended on your amplifier. These
devices can severely shorten the life of the output tubes which should be replaced as a matched
quartet. Replacing vacuum tubes can be quite expensive. If however one of these devices is
an integral part of your sound, choose one that is well designed and built by a reputable
company. When the amplifier starts to sound dull, it’s time to replace the output tubes.
Always replace tubes with premium quality tubes only! Cheap tubes will not sound good and will
not last. MATCHLESS sell replacement tubes for all models. Please contact your dealer or
call the factory.
This switch supplies power from the A.C. mains and is used to turn the
amplifier off and on as well as the switched A.C. outlet at the rear of the amplifier. The
amplifier on status is indicated by the illumination of the “MATCHLESS” logo on
the front of the amplifier.
This switch serves as a mute for the amplifier, and is used when changing or
unplugging a guitar cords or taking breaks, especially if volume control setting are to be set
and left. Additionally, the stand-by mode allows the amplifier to cool down, extending the
life of the output tubes. Substantial amounts of current flow through the output tubes
whenever the amplifier is operational, even with no signal from an instrument! A stand-by
status indicator is located on the front panel. The stand-by indicator lamp can be wired to
illuminate for either state. Stand-by or operate. All MATCHLESS amplifiers come from the
factory wired to indicate the operate mode.
PRECAUTION! Cathode biased class A amplifiers do not like to “idle” for prolonged periods. These
amplifiers draw more current idling than they do while being played. Use the stand-by mode or turn the
amplifier off if you are not going to play for a while. Save your tubes!
All Amplifiers manufactured after November 1993 incorporate a “Speaker Phase” reversal
switch at the rear of the speaker system. Reversing the motion of the speakers can influence
clean and distorted sound, especially if a direct signal is taken from the guitar and “mixed”
with a miced amp. If two amplifiers are used in stereo, reversing the speaker polarity of one
amplifier creates a whole new tone dimension.
Your MATCHLESS amplifier employs a line safety fuse for protection against
damage. The line fuse offers protection against irregularities in an A.C. source, tube failure,
component failure, severe overload to the output amplifier, and other conditions that prove
unsafe or damaging to the amplifier. If an amplifier blows a line fuse, an investigation into its
cause is required. Correct any problems that may be found before putting the amplifier back
in service.
Never replace a line fuse with one of a higher amperage rating! Not only is it unsafe, but it
leaves your amplifier unprotected in the event of a tube or component failure and voids your warranty.
Use this chart to determine the correct fuse type for your amplifier:
C-30 Chassis (USA)
C-30 Chassis (Japan)
C-30 Chassis (Europe)
3AG size
3AG siz e
3AG size
3 Amp rating
3 Amp rating (Slo-Blo)
2 Amp rating
For amplifiers designed to operate at non-standard voltages, the required fuse size and rating
will appear on the manufacturer’s tag affixed to the inside of the amplifier cabinet, or at the
fuse holder on the chassis. When in doubt, consult your dealer or contact the factory.
If you are traveling with your amplifier, and are uncertain about the voltage requirements
and fuse type, please contact the factory. In some countries the line voltage may vary slightly
from the voltage at which an amplifier may be set. This may require modification of the fuse
About the
Your MATCHLESS amplifier employs two very different tube types and circuit designs for the
preamplifier channels giving each channel its own distinctive response and personality. This enhances
the versatility of our “simplicity” of design philosophy.
Your MATCHLESS amplifier has two input channels or preamp paths. Each preamp
has two inputs, one just above the other. The purpose of having two inputs is that the upper
input (input 1) provides more gain than the lower one (input 2). Instrument pickups vary in
signal strength and the user may find one input offers a better match than the other, and this
may vary among instruments. As a rule, older instruments usually have lower output strength
and may sound punchier through the input with more gain (input 1), while instruments with
newer style pickups that may be much hotter, may perform satisfactory with less gain (input 2),
and improve the headroom of the amplifier. Feel free to experiment and decide for yourself
which input sounds best with your instruments.
This channel has three controls, VOLUME, BASS, and TREBLE. This is the
“triode” channel. This channel offers a two stage active tone circuit employing a second pair
of triode amplifiers. This circuitry is popularly referred to as a “tone-boost” or “treble-boost”
circuit. The Bass and Treble controls are highly interactive and capable of a wide variety of
textures. Channel 1 may be preferred for that early British sound that we have become so
endeared to. If you play a RICKENBACKER or GRETSCH guitar through this channel,
you will recognize this familiar sound instantly.
This channel utilizes a “pentode” vacuum tube as the first preamplifier stage and is
followed with a six position rotary switch to control the tone envelope. This preamplifier
tube is capable of more gain than channel one and is capable of being overdriven harder.
The tone control for this channel is passive. This may become the channel of choice for a
“heavier” sound, especially when overdriven and used in conjunction with the MASTER
volume control option. The multi-position rotary tone switch varies the dimension or width
of the tone envelope. The minimum position (counter clockwise) will procedure a thinner
sound that will become thicker and thicker with each clockwise click of the switch. This
switch has a total of six tonal textures.
About the
MATCHLESS amplifiers are cathode biased and operate mostly in a Class “A” mode. This
means that current flows continuously through the output tubes whether a signal is present
or not. Most amplifier designs employ the more popular “AB” or “AB1” biasing technique,
which although capable of producing more power for a given tube configuration and
transformer size, produces crossover distortion and more odd order harmonics. This is why
MATCHLESS amplifiers are described as having a smooth tone that won’t fatigue ears even
at a high volume.
The MATCHLESS design also does away with controlled or corrective negative
feedback, allowing the amplifier to run “open loop” or wide band. This is why your amplifiers
sound full and rich at low or high volume levels.
These are what we call “features of design” and very much a part of the distinctive
There are four controls that enable the user to adjust the parameters of the power
amplifier section. The controls are the IMPEDANCE switch, the HI-LO power switch, the
CUT control and the MASTER VOLUME control. The impedance switch is used to correctly
match the speaker load to the amplifier, as mentioned earlier. This control (located at the rear
of the amplifier) should be set and left in the proper position before the amplifier is turned on.
This switch is located at the rear of the amplifier and determines the overall output
power of the amplifier. In the “HI” position all four output tubes are functioning and the
amplifier is producing maximum power. C-30 amplifiers are conservatively rated at thirty
watts. In the “LO” position, two of the output tubes are turned off and power is reduced
approximately 50%. Cathode bias levels are adjusted for each power setting. This function is
very useful in recording studios or small clubs where less power may be preferable. The low
power setting also produces its own distinctive tone and should be explored fully.
The MASTER volume control function is activated by push-pull switches
attached to it. When the switch is pulled out, the master volume control circuit is
active. In the bypass mode (pushed in), the master volume control is completely out
of the signal path. The MASTER volume control adjusts the overall gain of the
output amplifier regardless of the Hi-Lo power setting and functions with channel
one and channel two. Normally this control would be set at its maximum (fully
clockwise) position or bypassed (switch pushed in). This allows the power amplifier to
run at full gain. This would be the normal configuration for a cleaner sound.
For a dirtier sound, the MASTER volume control enables the preamplifiers to be
overdriven without having the amplifier at full volume. Pull out the MASTER volume control
to activate the circuit, then turn the control fully counter-clockwise. No sound will come
from the amplifier at this point. Now turn the volume control of the channel you are using
fully clockwise or nearly so. Turn the Master volume control clockwise until sound is
produced from the speakers. Experiment with the settings of both the channel volume
control and the MASTER volume control until the desired results are achieved. Remember,
if the channel volume control (on either channel) is “cranked” up, and the MASTER
volume is turned down, an over-driven sound is produced. Experiment with both controls
simultaneously to understand more fully how their interaction affects overdrive
By using the Channel volume, Master volume and the Hi-Lo power setting switch, a wide
range of tonal spectra may be explored. Once again, let experimentation be the mother of invention!
The CUT control varies the bandwidth, or high frequency response of the power
amplifier. This is characterized by fewer heights or less top end. The CUT control is used to
soften or take the edge off a harsh instrument or tone setting. The effect is subtle before the
halfway point on the control and increases the amount of cut from midpoint to full. The CUT
control is most effective when the Master volume is bypassed or set for maximum gain.
Aside from routine vacuum tube and indicator lamp replacement, your
MATCHLESS should require very little in the way of maintenance. Periodically
examine the four output tubes visible from the rear of the chassis. Any tendency of
one or more of these tubes glow reddish in the plate area is an indication of an
imbalance in the amplifier. This should be checked out by a technician or by
substituting a fresh set of matched output tubes. If over a period of time or hard
playing the amplifier sounds weak or dull, this may be an indication that the output or
preamp tubes are “tired” and probably need renewal. If one or more of the preamp
tubes become abnormally microphonic or the amplifier whistles with the controls at
maximum (with nothing plugged into the inputs) a replacement may be required.
When replacing output tubes, make sure they are a matched quartet. Adjusting the
Bias is not necessary.
Never attempt to replace vacuum tubes while the amplifier is on or the amplifier is hot. To
replace tubes remove the back panel of the amplifier. Preamplifier tubes usually have a
twist-lock shield that must be removed before the tube can be removed from the chassis.
Output tubes and rectifier tubes employ either a spring and a cap arrangement (called a tube
hat) or a base clamp. The base clamp is loosened by un-tightening the screw on the side of
the clamp. The spring and cap version is gently lifted off the tube and moved out of the way.
When replacing output tubes, always check the amplifier out before replacing the back
panel. Make sure that the amplifier functions normally and that none of the tubes appear to
be overheating. This is usually indicated by an abnormally bright tube or a reddish glow
from the plate area. If all looks well, replace the shields, caps, or re-tighten the clamps.
Replace the rear panel and test the amplifier again.
Matchless employs incandescent bayonet style lamps to illuminate the logo, stand-by
indicator, and the front panel or dashboard. All the lamps are of the same type for simplicity.
A lamp type #47 is recommended for all lamps, although a type # 44 may be substituted if a
brighter look is desired.
There are five lamps used to illuminate the front panel of the amplifier. When one of these
lamps requires replacement, the entire chassis must be removed from the cabinet. To do
this, first remove the power cord from the amplifier. Then remove the back panel by
loosening the hold-down screws. Remove the two wires that provide power to the logo.
These are pull-off connectors. If the amplifier is a combo, disconnect the speaker plug
located next to the fuse holder. Carefully remove the four screws on the top of the cabinet
while supporting the weight of the chassis with one hand. Slide the chassis out to replace the
bulbs. To re-install the chassis, simply reverse the process.
There are four lamps used to illuminate the logo. If the logo appears unevenly lit one of
these lamps is probably out. The lamps are located in a reflector assembly known as a light
box. The light box is positioned just above the speaker(s) and is removed by removing the
securing screws and disconnecting the two wires that supply power from the chassis. The
wires are connected with quick disconnect spades. Use a long screwdriver for easy access to
the screws. If the amplifier is configured as a head, the chassis must be removed first.
To replace the stand-by lamp, unscrew the colored reflector lens and replace the lamp.
Make sure that the power is off before replacing this lamp, otherwise arcing may damage the
Never place drinks on top of the amplifier for obvious reasons. Liquids can cause the
glass envelopes of the hot vacuum tubes to crack possibly shorting out the amplifier. Liquids
can also cause damage to switches and potentiometers and generally reduce the reliability of
your amplifier as well as require an expensive repair. If an accidental spill does occur,
remove the amplifier from the cabinet, remove the tubes, and thoroughly clean and dry the
chassis before attempting to use the amplifier.
Be mindful not to restrict airflow to the back of the amplifier.
Never replace the protective fuse with one of a higher amperage rating. If an
amplifier starts blowing fuses, it may be warning of an impending problem with the
amp and should be looked over by a professional.
Your MATCHLESS amplifier is equipped with a multiple primary winding enabling
the user to set the amplifier for various voltages and line frequencies available in foreign
countries. This is an internal connection change and should be done by a qualified
technician. MATCHLESS amplifiers can operate on voltages ranging from 110-120 volts
A.C. at 60 Hertz and 220-224 volts A.C. at 50 Hertz. It also can be switched to 100 volts A.C.
at 50 Hertz. As well as 220-240 volts A.C. at 50 Hertz. If you have any questions about this
conversion, please contact the factory.
MATCHLESS offers an effects loop option for most amplifier models. An effects
loop enables the user to insert any desired effects device between the channel preamplifier
and the power amplifier. MATCHLESS amplifiers provide two independent loops, one for
channel one and one for channel two. The effects loop jacks are located on the rear panel of
the amplifier. The upper jack is for the “Tone-Boost” channel, while the lower jack is for
the “Pentode” channel. Each jack is configured in a Ring, Tip, Sleeve manner similar to a
recording studio console insert point. Each jack is of the normalizing type and contains the
send and return information on a single ¼“ stereo phone jack. The Tip is used for the send
signal and the Ring is used for the return signal. The Sleeve is ground. The SEND signal is
derived just after the channel volume control and the RETURN signal is inserted at the
phase inverter, just before the Master volume control.
A Stereo “Y-cord” is required for loop operation. When the loop is not being used, the signal
is “normalized” through the jack.
The effects loop option is intended for use with guitar type foot pedals and semi-pro
level rack type effects. It is not designed to drive effects units requiring high level signals
(+4), as encountered in a professional recording studio.
Your MATCHLESS amplifier comes supplied with an operation instruction
manual, an IEC power cable, a spare fuse, indicator lamp and panel knob.
An effects loop and balanced line outputs are available on most amplifier
models for an additional cost.
Getting Started With
Matchless Amplifiers
Tips On Tone
MATCHLESS manufactures a variety of models, each with its own personality and
character. The choice of speaker cabinet type has as much to do with tone as does an
amplifier itself. Speaker cabinets with two twelve inch speakers tend to emphasize midrange
frequencies and tone texture may be characterized as nasal. The DC-30 and ESD cabinets
utilize two different twelve inch speakers. One is rated at 30 watts while the other is rated at
25 watts. This combination is very much part of the tone of our twin-twelve design. The 25
watt speaker breaks up a little earlier than the 30 watt speaker. This adds greater flexibility
of tone especially when microphones are used with the amp. The speakers can be
differentiated by the size of the magnet structure. When mic’ing a DC-30 or ESD speaker
cabinet you will discover how flexible this combination is. Our ESD-85 cabinet utilizes two
75 watt speakers. The twin-twelve design offers a tone reminiscent of the fabulous sixties.
Four-ten-inch speaker enclosures have smooth, deep, bass, and silky heights with less
midrange. Country players are very fond of this combination. The overall smoothness of this
design is wonderful for power chord lovers, too! Our four-ten cabinet can be used with C-30
or Clubman ’35 amplifiers. Single speaker models produce a clean, rich tone and perform
well in almost any situation. These are a smart choice for recording and small club dates.
Jazz-design. Matchless also offers a Two-Ten, Four Ten, Four-Twelve, dissimilar TwoTwelve, Two-Ten cabinet, each with its own distinctive character. All Matchless speaker
cabinets utilize toward each other, are a real pleasure to listen to. The distinctive “Class A”
design with “no negative feedback”, employed in all Matchless amplifiers, allows every
instrument to be heard in a fresh new way. This design philosophy offers an openness and
richness of tone that clearly distinguishes MATCHLESS instrument amplifiers from all
Matchless has put together a collection of typical control settings that may be used as
a starting point with several popular guitar types and Matchless amplifiers. Several selected
guitar models and musical styles are chosen for illustration and experimentation. These
offerings are not to be considered the absolute ultimate setting for your guitar or musical
style, only a helpful starting place. Locate a guitar type closest to your own, and tonal
characteristics from the chart and set the controls as illustrated. Vary the control settings as
indicated by arrows and shading. In addition to suggested control settings, experiment with
Hi and Lo power settings as covered in the Operation Instructions Manual.
Typical settings are shown for each sample guitar type for channels one and two.
Remember that the “Tone Boost” tone controls on Matchless amplifiers are highly
interactive, so explore!
When using the Master Volume control for a dirtier tone keep in mind that a master
volume control cannot duplicate faithfully the sound of a heavily overdriven amplifier. A
truly overdriven amplifier has the output amplifier, transformers, and speakers contributing
much to the overall distorted tone. This is not the case with a master volume control which
is primarily used to overdrive the preamplifier. At best it should be considered a tone unique
unto itself. We feel that it is important to mention this fact as there are many who believe a
master volume control will produce the same effect as turning the amp up to ten. It can’t.
The following diagrams are offered to assist the user with some basic tone set-ups. We hope
you find these suggestions a useful starting point with your Matchless!