Power Stages
- Accuphase
- Akai
- Arcam
- Audio-Connection
- Audionet
- AVM
- B&W
- BASF
- Burmester
- Cambridge
- Camtech
- Denon
- Densen
- E.A.R.
- Einstein
- First Watt
- harman/kardon
- Hitachi
- Jadis
- JVC
- Kenwood
- Krell
- Linn
- Luxman
- Marantz
- McIntosh
- NAD
- Naim
- Nakamichi
- Nikko
- Nytech
- Onkyo
- Optonica
- Parasound
- Pass
- Philips
- Phonosophie
- Pioneer
- Restek
- Revox
- Rotel
- SAC
- Sony
- T&A
- Technics
- Tensai
- Thorens
- Toshiba
- Uher
- Vincent
- Yamaha