Oldfield Amplifiers Dual 40 User Manual Download Page 9

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Tube Layout

RECTIFIER TUBE: 5R4.

Replace only with high quality 5R4 (or compatible) tube.

POWER TUBES: EL34 (x2).

Replace only with a high quality matched duet of EL34 tubes.

The Dual 40 is a fixed

biased amplifier and therefore will need to be re-biased when changing output tubes.

PHASE INVERTER TUBE:

Replace with any high quality 12AX7 tube.

PER-AMP GAIN TUBE Channel Two:

Replace with any high quality 12AX7 tube.

CATHODE FOLLOWER TUBE Channel One:

Replace with any high quality 12AX7 tube.

PER-AMP GAIN TUBE Channel One:

Replace with any high quality 12AX7 tube.

Summary of Contents for Dual 40

Page 1: ...1 Oldfield Amplifiers User Guide Dual 40 6740...

Page 2: ...mplifier is built to provide you with the best tonal experience and durability available in a guitar amplifier As with all Oldfield s it is hand built with you the player as the central focus of our e...

Page 3: ...3 Table Of Contents Important Safety Instructions 4 5 Overview 6 Front Panel Controls And Features 7 Rear Panel Controls And Features 8 Tube Layout 9 Warranty 10 Operational Notes 11...

Page 4: ...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 thi...

Page 5: ...f producing very high sound pressure levels which may cause temporary or permanent hearing damage Use care when setting and adjusting volume levels during use Failure to comply with any of these safet...

Page 6: ...yment whether on stage in the studio or in the home The Dual 40 has two very distinctly voiced channels Channel One leans towards the British style tones and Channel Two is purely American Each channe...

Page 7: ...Controls the volume of Channel Two Rotating the control clockwise will make the Channel Two volume louder and increase overall gain and harmonics 9 Channel Two Treble Rotating the control clockwise wi...

Page 8: ...When operating in triode mode the amp will produce roughly half of the full power It needs to be noted that while in Triode Mode the amplifier tone is different than when operated in full Pentode Mod...

Page 9: ...40 is a fixed biased amplifier and therefore will need to be re biased when changing output tubes PHASE INVERTER TUBE Replace with any high quality 12AX7 tube PER AMP GAIN TUBE Channel Two Replace wit...

Page 10: ...lifier panel switch must be in the mode 2 position in order for the footswitch to work 3 Boost 1 Selector Stomp the Boost 1 footswitch to activate the boost function for channel one When the channel o...

Page 11: ...arge Power Transformer Output Transformer And Choke These items are guaranteed for one year after date of purchase against manufacturer s defects If a failure occurs due a defect in manufacturing Oldf...

Page 12: ...Mode Switch 2 Mid 1 Switch Off Channel One Mode 1 Gain 2 O Clock Channel One Mode 2 Gain 2 O Clock Master 11 O Clock Tone Controls Treble 1 O Clock Middle 12 O Clock Bass 11 O Clock 80 s Hair Band To...