PA507Ge is a microphone preamp with a saturation stage based on a germanium transistor. The device has a Pad button, so it can be used as a saturator chain in the line-level signal path.
Germanium transistors are electronic components that were commonly used in the 1950s and 1960s. They have a vintage sound that is warm, rich, and full of character. This is because germanium transistors have a different frequency response and transfer characteristic than their modern silicon counterparts. They also have a lower noise floor, which means that they can capture subtle nuances in your recordings that might be lost with other types of transistors. Additionally, they have a smooth overdrive curve that provides a unique fuzzing sound when they are overdriven.
Of course, there are some downsides to using germanium transistors. They can be more expensive than silicon transistors, and they can be harder to find. They are also more sensitive to temperature changes, which means that they may drift after preheating.
Overall, though, the unique sound of germanium transistors is well worth the extra effort and expense.
The device has two knobs - Gain and Bias. The first one changes the gain of the first amplification stage, and the second one changes the germanium output transistor bias current. Combining them allows you to find the sweet biasing point, reach the desired saturation level, and even achieve a fuzzing effect.
The output transformer adds subtle harmonics to the signal, making the sound even more alive.
- Max gain: +50dB
- Frequency range: 30Hz-20kHz (+/-1.5dB)
- Input type: Balanced
- Output type: Balanced (transformer)
- Amplifying element: hybrid (Si and Ge transistors, opAmps)
- Phantome power: Yes, using racks +48V source
- Pad: Yes (0/-22dB)
- HPF: Yes (20/75Hz)
- Phase reverse: Yes