Preamplifier
- Aaron
- Accuphase
- Akai
- Audia Flight
- Audio-Connection
- Audiolabor
- Audionet
- Audiovalve
- Audio Team
- AVM
- Ayon
- Ayre
- BASF
- Blaupunkt
- Bose
- Brinkmann
- Burmester
- Camtech
- Canton
- Classé
- Copland
- Crown
- Cyrus
- Vorverstärker
- Denon
- Densen
- E.A.R
- Epicure
- Fisher
- Grundig
- Harman/kardon
- Hitachi
- JVC
- Kenwood
- Krell
- Kücke
- Linn
- Luxman
- Mal Valve
- Marantz
- McIntosh
- Musical Fidelity
- NAD
- Naim
- Nikko
- Onkyo
- Optonica
- Paragon
- Parasound
- Pass
- Pentagon
- Phase Linear
- Philips
- Phonosophie
- Pioneer
- Pro-Ject
- QED
- RMS Audio
- Revox
- Rotel
- Sanyo
- Siemens
- Soulution
- Sony
- Symphonic line
- T&A
- Technics
- Tensai
- Toshiba
- Uher
- Yamaha