The Summit Audio 2BA - 221 is a top - notch microphone/line preamplifier. It features continuously variable microphone impedance, allowing you to fine - tune the sound. With separate and individually controlled solid - state input controls, it can mix a microphone input with a Hi - Z or line input into a variable vacuum tube output. This combination of variable impedance and solid - state/tube stages offers excellent sonic control. It's built with high - quality full - voltage tube and solid - state signal paths and the best components. The 2BA - 221 has a dedicated power source for its 48V phantom power, so it won't draw current from the main circuits. The variable tube output control is a great feature. It lets you access a wide range of tones, from clean solid - state sounds to rich harmonics. The single 12AX7A Tube provides a warm, rich tone and is easy to find and replace. Summit Audio is known for its well - built gear. Their design philosophy focuses on the whole package, with many refinements over the years, making the units durable for touring. Key features include a single - channel preamp with variable input impedance from 100Ω to 10kΩ, Hi - Z instrument and line inputs, simultaneous microphone and Hi - Z inputs with separate gain controls, three variable gain stages, separate solid - state and tube outputs, a variable high - pass filter, a 20dB pad, a polarity reverse switch, an insert jack for external processors, and the ability to stack with other 2BA - 221s for a modular mixing device. Technical specs show it has single - channel operation, multiple input and output options, 48V phantom power, a max gain of 75dB, a maximum output level of 25dBu, a frequency response of 10 Hz - 50 kHz (-1dB), an average equivalent input noise of - 135dB from 10 Hz - 20 kHz, a 12AX7A vacuum tube, dimensions of 9 ½” x 8” x 1 ¾”, a weight of 7 pounds (3.15 kg), and multiple simultaneous outputs with variable tube output gain.
Using the Summit Audio 2BA - 221 is straightforward. First, connect your microphone to the XLR input or your instrument to the ¼” inputs. You can adjust the input impedance according to your needs, ranging from 100Ω to 10kΩ. Use the separate gain controls for the microphone and Hi - Z inputs to get the right sound level. The variable tube output control is a great way to experiment with different tones. Turn it up for richer harmonics or keep it low for a cleaner solid - state sound. When it comes to the 48V phantom power, just make sure it's properly connected to its dedicated power source. As for maintenance, keep the unit clean and free from dust. If the 12AX7A tube needs replacement, it's easy to find and install. When stacking multiple 2BA - 221s, follow the instructions for the stacking inputs and outputs to form a modular mixing device. Also, make sure to use the unit in a stable environment and avoid exposing it to extreme temperatures or humidity.
