METROPOLIS TUBE LAYOUT

Most amp problems, ie: microphonic squeals, crackling, low power, mushy bass response etc... can be traced to bad or weak tubes. Remember, tubes are like car tires, they get worn out through use and need to be replaced. Sometimes they can go bad very quickly, even when new. Just as a light bulb works great one day and it blows the next time you hit the power switch, it's unfortunate but a fact of tube life. How loud you play and how long you play for affects how often you need to re-tube your amp. If you play alot, changing the power tubes once a year is normal , pre-amp tubes can often last twice as long, even longer.

When changing power tubes try to use a matched set of EI Yugoslavian brand power tubes, you will not have to re-bias your amp since it has a CLASS A circuit design. Other brands of tubes will work fine, we just recommend EI Yugoslavian tubes so you can maintain the original tone of your METROPOLIS. CHINESE 12ax7 pre-amp tubes work great to maintain the original tone of your amp. SEAN'S TIP: Keep an extra set of tubes around, tubes always seem to go bad when you have that really big gig at the FORUM!

V1: 1st Gain Stage, 12ax7

V2: 2nd Gain Stage, 12ax7

V3: Phase Inverter, 12ax7

V4, V5, V6, V7: EL84 Power Tubes

V8: Rectifier 5AR4 or GZ34

V9: Reverb Driver, EL84

V10: Reverb Driver, 12ax7

V11: Input Buffer Reverb Mix Tube, 12ax7