More Information

How will they change my amp?

It's like getting a whole new amplifier! In Champ and Deluxe type amplifiers, the Yellow Jackets® converter output is smooth, strong and more even than with the stock 6V6s. When the Yellow Jackets® converters are installed in larger amplifiers intended for 6L6s or EL34 output tubes, the high plate and screen voltages are reduced as well as current limited to protect the EL84 and to drop output power. When a pair of Yellow Jackets® converters are used in a Marshall® 50 watt or similar amplifier, the overall power drops to about 20 watts 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 Jackets® converters. In a 100 watt amp like a Twin Reverb or Marshall® 100, either two or four Yellow Jackets® converters can be used. If only two are used and the other two inside or outside sockets are left empty (see Using Yellow Jackets® in 4 tube amps), the output is dropped to about 20 watts. With four in place, the amp puts out about 40 watts and takes on a whole new warmth and richness. A further option in a 4-tube amplifier is to leave two of the original tubes in place and replace the other two with Yellow Jackets® converters. This gives a combination of class-A and Class-AB operation and sounds quite sweet and complex. In the cases of the YJ7591 converters, the overall output power remains the same, but the sound becomes fuller and the rare 7591 are replaced with common and inexpensive EL84 tubes. In old Ampeg Reverb Rockets and the like, you experience a warmth and sweetness that you could never get with the now rare 7591 tubes.

Will they hurt my amp?

No! Yellow Jackets® converters are safe for all amplifiers and transformers. As all Yellow Jackets® converters internally limit voltage and current they put no extra strain on amplifiers' power and output transformers or internal components. Using the Yellow Jackets® converters in higher powered amplifiers actually reduces the strain on the transformers and internal components, as 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 Jackets® converters will reduce the strain on the filament windings of the power transformer as well.

How do I get one?

First, determine the type of power tubes your amp uses (contact us or the amp's manufacturer if you're not sure). Next, call your local music store. If they are out of stock, contact us and we will be able to point you to a Yellow Jackets® resaler in your area. We will be happy to answer any questions you might have on any of our products. Click here for more detailed information on Yellow Jackets® including schematics, diagrams, pin-outs and more!

What's the difference between Pentode Version and Triode Version?

In guitar amplifiers most power tubes are pentodes. Pentodes have five electrodes, while triodes have three electrodes. The Yellow Jackets® pentode versions provide more bite and attitude, while the triode versions provide greater power reduction and more linearity.

If you are looking for power reduction and response with more bite and attitude, choose the pentode version. If you're looking for maximum power reduction and want to tame the response of your amp, then go for the triode version.