A mass spectrometer and methods for obtaining the mass spectrum of a single macromolecular or biomolecular ion in a mass spectrometer. The methods include creating single macromolecular or biomolecular primary ions in an ion trap by ionization of a macromolecule or biomolecule; ejecting half of the primary ions for detection with a first charge detector; ejecting half of the primary ions to impact upon a conversion dynode, thereby creating secondary ions for detection with charge amplification detector such as a channeltron or an electromultiplier or an MCP.