The YJS is a specialized, current-limiting/voltage-conditioning adapter for use in most 20 to 100 watt amps that use 6L6, EL34, 6550 or 6V6 output tubes. The YJS is for amps with fixed bias power tubes. (Fixed bias tubes have their cathode connected directly to ground and a negative DC voltage applied to their control grid). All Yellow Jackets® converters come with JJ Brand EL84/6BQ5 vacuum tubes.
- All Yellow Jackets® converters come with JJ Brand EL84/6BQ5 vacuum tubes.
- Converts most audio amplifiers with 6L6s, EL34s, 6550s, or 6V6s and similar-based tubes to EL84s without modification or rebiasing.
- Converts: Class AB to Class A operation
- Drops Output Power: 70% to 90%.
- Safe for all common amplifiers and transformers.
Yellow Jackets® converters are a type of specialized adapter which permit the use of EL84/6BQ5 power tubes in place of 6V6, 6L6, EL34, and 7591 type vacuum tubes. Yellow Jackets® converters allow you to harness the musicality of EL84 vacuum tubes in amps that don't use them already - it's like getting a whole new amplifier!
There is no rebiasing involved, which makes modifying your amp's tone very easy. Yellow Jackets® converters give you simple Class-A operation from any amp. They not only rearrange the pin locations of the tubes, but also provide the necessary plate voltage drop and current limiting on the screens as well as blocking the amplifier's grid bias voltage while configuring the EL84 in a Class-A, self-adjusting cathode-bias circuit. In other words, there are no adjustments to make and no modifications necessary, you simply plug the Yellow Jackets® into the amp's output tube sockets, (in cathode-bias amplifiers) screw the ground wires under one of the output tube socket mounting screws, plug the provided EL84s into the Yellow Jackets® converters, turn on the amp and play.
All Yellow Jackets® have a one year warranty against manufactured defects.
For more information, see Yellow Jackets TC
YJS-Triode Instruction Sheet 
480.755.4712