Factory matched full tube set for your Dirty Sink 20w amplifier. Preamp tubes include: (2) JJ ECC83S short-plate version for higher gain preamp and tone-stack circuits, (1) JJ ECC83S for the FX loop and (1) Sovtek 12AX7LPS long-plate tubes for the phase-inverter circuit. Power tubes include (2) Apex matched JJ 6V6 power tubes. The key to the best performance for the Dirty Sink amplifier is that your preamp and tone-stack tubes must be higher gain with low noise and low microphonics. All tubes are selected, installed and tested on the bench by our amp designer prior to shipping your order. Each set is made to order and ships within 3 – 5 business days.