| Z Audio | Retailer |
| Zalytron Speakers | US Speaker Source |
| Zanden | Tube Amplifiers |
| Zen clones | DIY Tube Audio Site |
| Zenn Audio | Tube Amplifiers |
| Zenn Audio Comp. | Tube Amplifiers from Singapore |
| Zetex | Semiconductors |
| Zeuslab | Schematics |
| Zingali Loudspeaker s.r.l. | Horn Speakers |
| ZR-Speaker Lab | Speakers, Tube Preamplifiers |