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MF MD HG01 Acoustic Guitar Month 07-11-18

THD YJSHORTD Yellow Jacket Short Standard Duet

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Product 210392
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An adapter that permits the use of an EL84 power tube in place of a 6L6, EL34, or 6550 in grid-bias amps. There are no adjustments to make and no mod...Click To Read More About This Product

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Converts your amp to Class A EL84 operation.

An adapter that permits the use of an EL84 power tube in place of a 6L6, EL34, or 6550 in grid-bias amps. There are no adjustments to make and no modifications are necessary. You simply plug the Yellow Jacket into the amp's output tube sockets, plug the provided EL84s into the Yellow Jacket, turn on the amp, and play.

Yellow Jacket converters not only rearrange the pin locations of the tubes, but they also provide the necessary current limiting on the screens and cathode as well as blocking the amplifier's grid-bias voltage, configuring the EL84 in a Class-A, self-adjusting cathode-bias circuit.

When the Yellow Jacket Converters are installed in larger amplifiers intended for 6L6s or EL34 output tubes, the high plate and screen voltages are reduced and current is limited to protect the EL84 and drop output power. When a pair of Yellow Jackets are used in a Marshall 50W or similar amplifier, the overall power drops to about 20W and takes on more of the character of an old Vox AC30. The distortion is smoother and more even and the output is both substantially reduced and more compressed due to the Class-A nature of the Yellow Jacket. In a 100W amp like a Twin Reverb or Marshall 100, either two or four Yellow Jackets can be used. If only two are used and the other two sockets are left empty, the output is dropped to about 20 watts. With four in place, the amp puts out about 40W and takes on a whole new warmth and richness.

Will they hurt your amp? No! Yellow Jacket converters are safe for all amplifiers and transformers. Because all Yellow Jacket Converters limit voltage and current internally, they put no extra strain on amplifiers' power and output transformers or internal components. Using the Yellow Jacket in higher-powered amplifiers actually reduces the strain on the transformers and internal components because it reduces the overall wattage of the system. Furthermore, the heater (or filament) current of the EL84 is lower than that of the 6L6, EL34, or 7591, so the Yellow Jacket will reduce the strain on the filament windings of the power transformer as well.

  • Use an EL84 in place of a 6L6, EL34, or 6550 in grid-bias amps
  • Tubes included
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The Best Way to have a New Amp

By Omar Sostre

from Puerto Rico

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I put two of them in my JSX Head looking for that British sound at the Crunch Channel it doesn't have.Having two 6l6s at the corners and two EL-84 in middle,now my amp has it all.Amazing modern sound at the Ultra Channel and the best Marshall/Voxx sound at the Crunch.The Yellow Jackets gave my amp that extra mid/high sound it didn't have.The overall sound is very bright but not harsh,articulate,the bass is very solid and very powerfull at low volumes.Still very loud.I didn't notice any power loss with this configuration.I'm more than happy with my Converters.Buy them if you want a totally new sound to your amp.

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