Oldfield Amplifiers Marquis Thirty User manual

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Marquis Thirty
Owners Guide
Oldfield Marquis Thirty
Marquis 30
Pentode
Triode
Top Cut
12
Volume 1 Volume 2

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Congratulations
Welcome to the Oldeld family and thank you for putting your trust in Oldeld Ampliers.
We value that trust as much as you will enjoy your new Oldeld amplier.
Your new Oldeld amplier is built to provide you with the best tonal experience and dura-
bility available in a guitar amplier. As with all Oldelds It is hand built with you, the player,
as the central focus of our eorts. By using the highest grade components, point-to- point
vacuum tube circuitry and ne craftsmanship, your amplier will inspire many hours of musi-
cal satisfaction and lasting enjoyment.
Thanks,
The Oldeld Team

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Table Of Contents
Important Safety Instructions..................................................................................... 4 thru 5
Overview...................................................................................................................... 6
Front Panel Controls And Features............................................................................. 7 thru 8
Rear Panel Controls And Features.............................................................................. 9
Tube Layout................................................................................................................. 10
Warranty...................................................................................................................... 11

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Important Safety Instructions
Δ For your safety read, retain, and follow all instructions. Heed all warnings.
Δ Only connect the power supply cord to an earth-grounded AC receptacle. This amplier is
designed to operate on standard North American 115V AC and should only be plugged in to
a receptacle meeting those specications.
Δ WARNING: To prevent damage, re or shock hazard, do not expose this unit to rain or
moisture.
Δ Unplug the power supply cord before cleaning the unit exterior (use a damp cloth only).
Wait until the unit is completely dry before reconnecting it to power.
Δ Maintain at least 6 inches (15.25 cm) of unobstructed air space behind the unit to allow
for proper ventilation and cooling of the unit.
Δ This product should be located away from heat sources such as radiators, heat registers,
or other products that produce heat.
Δ This product may be equipped with a polarized plug (one blade wider than the other) or a
three-prong grounded plug. This is a safety feature. If you are unable to insert the plug into
the outlet, contact an electrician to replace your obsolete outlet. Do not defeat the safety
purpose of this plug.
Δ Protect the power supply cord from being pinched or abraded.
Δ This product should only be used with a cart or stand that is recommended by the manu-
facturer.
Δ The power supply cord of this product should be unplugged from the outlet when left
unused for a long period of time, or during electrical storms.
Δ This product should be serviced by qualied service personnel when: the power supply
cord or the plug has been damaged; or objects have fallen, or liquid has been spilled onto
the product; or the product has been exposed to rain; or the product does not appear to
operate normally or exhibits a marked change in performance; or the product has been
dropped, or the enclosure damaged.
Δ Do not drip or splash liquids, nor place liquid lled containers on the unit.

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Δ CAUTION: No user serviceable parts inside, refer servicing to qualied personnel only.
Do not expose the circuit of the amplier under any circumstances.
Δ CAUTION: By nature vacuum tubes get very hot during operation. Do not touch vacuum
tubes until they have suciently cooled.
Δ Oldeld ampliers are capable of producing very high sound pressure levels which may
cause temporary or permanent hearing damage. Use care when setting and adjusting vol-
ume levels during use.
Δ Failure to comply with any of these safety precautions could result in damage to the
amplier and in worst cases bodily harm. Noncompliance with any safety precaution may
void any stated warranties.

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Overview
The Oldeld Marquis Thirty is a Class A 30 watt all tube, point to point hand wired guitar
amplier. The amplier has two distinctly dierent channels with channel 1 using the warm
and creamy EF86 preamp tube. It will provide you with rich warm tones when played clean
and an all-out cranked tone at higher volumes. The amp is extremely responsive to your
attack and guitar volume. Your amp is built to last a lifetime and will give you countless
hours of enjoyment whether on stage, in the studio, or in the home.
Feature summary:
• Two channels with high and low inputs for each channel
• 30 watts output power into 8Ω with Pentode / Triode operating modes
• All tube, hand-wired point to point circuitry
• 4 x EL84 power tubes
• 12AX7,12AT7 and EF86 preamp tubes
• 5R4 rectier tube
• Finger–jointed cabinet

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Front Panel: Controls And Features
1 • Inputs For Channel 1: These are the high and low impedance inputs for channel 1. Chan-
nel 1 uses an EF86 as the preamp tube and bypasses the tone controls.
2 • Inputs For Channel 2: These are the high and low impedance inputs for channel 2. Chan-
nel 2 uses a 12AX7 as the preamp tube and uses the tone controls.
3 • Volume 1: This control determines the overall loudness of the amplier when the instru-
ment is plugged into channel 1. As the volume control is rotated towards maximum the
amp will become not only louder but rich harmonic overtones will mix with the tone as
well.
4 • Volume 2: This control determines the overall loudness of the amplier when the in-
strument is plugged into channel 2. As the volume control is rotated towards maximum
the amp will become not only louder but rich harmonic overtones will mix with the tone as
well.
Note: Channel 1 and Channel 2 are out of phase with each other and can not be jumper’d as
a player might do with some other 4 input ampliers.
5 • Treble: This control determines the amount of treble frequencies present in the ampli-
er tone. At the maximum setting the amplier is at it’s brightest. This control also adds
a bit of bite to the amplier as it is turned towards maximum. This control does not aect
the tone of channel 1.
6 • Middle: This control determines the amount of mid frequencies present in the amplier
tone. The mid control eects are less dramatic than the treble and bass controls and tend
to soften the overall amp tone as the control is turned towards the maximum setting. It
should also be noted that as the middle control is turned towards the maximum setting the
player will notice that the treble and bass controls have less eect on the overall tone. This
control does not aect the tone of channel 1.
Oldfield Marquis Thirty
Pentode
Triode
Top Cut
12
Volume 1 Volume 2

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7 • Bass: This control determines the amount of bass frequencies present in the amplier
tone. Too much bass will make the tone less focused and could sound “muddy”. This con-
trol does not aect the tone of channel 1.
8 • Top Cut: This control is a high frequency roll o control for the amplier’s overall tone.
This control aects the tone of both channels.
Note: When setting up the tone for both channels it is recommended that the player start
with channel 1 and use the Top Cut control to dial in the tone for that channel. The player
then has the 3 tone controls available for adjusting the tone of channel 2 while leaving the
Top Cut control unchanged.
9 • Pentode / Triode Mode: Allows user to select between full and half power output. Do
not change power settings unless the amplier is in Standby Mode.
10 • Pilot Light: Illuminated when the amplier is on.
11 • Standby: Switch to On to play through the amplier. Do not take the amplier out of
Standby for at least 30 seconds after turning the Mains On to give the tubes time to warm
up to operating temperature.
12 • Mains: Switch to On to power on the amplier.

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1 • Fuse: Slo Blo fuse. Replace only with recommended value stamped on the back of your
amplier. Failure to comply with the recommended value could seriously damage the unit.
2 • Power Inlet: Inlet for the 3 prong power cord. Your amplier is designed to use 120VAC.
Using any other voltages will seriously damage the amplier.
3 • Main Speaker Jack: Connect the main amplier speaker to this jack.
4 • External Speaker Jack: An external speaker can be connected to this jack.
Note - A speaker must be connected to one of the speaker jacks at all times. Failure to do
so will result in serious damage to the unit. The combined speaker load of the main and
external speakers should not exceed 4 ohms.
5 • Impedance Selector: Set the impedance selector to match the impedance of the at-
tached speakers.
6 • EF86 Pentode / Triode Switch: Allows the player to select between full and half power
output for the EF86 on Channel 1. Do not change power settings unless the amplier is in
Standby Mode.
Rear Panel: Controls And Features
EF86
Pentode Triode

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Tube Layout
This is the view from the rear of amplier.
Tube Notes:
Please refer to the warnings section before handling tubes.
Biasing: This amplier is cathode biased. Replacing power tubes will not require a rebias-
ing of the amplier. Replace power tubes only with a matched quad to achieve optimal
tone from the amplier and avoid power tube issues.
EF86
Pentode Triode
EL84 EL84 EL84 EL84
12AT7
12AX7 12AX7
EF86
5R4