Naming

All MRJ Custom Electronics amplifiers use these 4-digit naming conventions. This allows for quick and easy identification of the major parts and internal configuration of each amplifier, just by hearing its name.

For example, the MRJ "8580" amplifier has 8 gainstages in the lead channel, 5 preamp tubes total, 8 is the designation I've given to its particular circuit, and the ~100 Watt push-pull power amp section is identified by 0.

Power amp section (4th Digit):

0 = ~100 Watt, push-pull, 4 power tubes (6L6, EL34, etc.)
5 = ~50 Watt, push-pull, 2 power tubes (6L6, EL34, etc.)
9 = ~100 Watt, push-pull, 2 power tubes (KT88)
6 = ~30-40 Watt, push-pull, 4 power tubes (6V6)
4 = ~20 Watt, vintage push-pull, 2 power tubes (6V6)
3 = ~30 Watt, push-pull, 4 power tubes (EL84)
2 = ~15-18 Watt, push-pull, 2 power tubes (EL84)
1 = ~2-8 Watt, single-ended, 1 power tube