Brands/models:

China

• Andoer
• Aune Audio
• Aiyima Audio
• Bluedio
• Brainwavz Audio
• Cayin
• Dark Voice
• Douk Audio
• Edifier
• FiiO
• Fosi Audio
• Gustard
• Hidizs
• HiFiMan
• iBasso
• KZ
• Little Dot
• Loxjie
• Matrix Audio
• Nobsound
• OPPO
• Sabaj
• Shanling
• SMSL
• Superlux
• Tin Audio
• Topping
• xDuoo
• YaqinAudio

Russia (post-Soviet)

• REEZOLDINI
• Soyuz (by the name it sounds Soviet, but it was founded in 2013)

USSR

• Apro
• Arktur
• Daina
• Elektronika
• Estonia
• Festivals
• Junost
• Kliver
• Latvia
• Ljux
• MAC 1 Type 10 speakers
• Majak
• Melodia
• Odysseus
• Orbita
• Radiotehnika (35AC-1, S-90)
• Rekod
• Romantika
• Rossia
• Rostov
• Simfonija
• Tembr
• VEF
• Vega
• Vesna
• Zvezda

Some of them look similar. Maybe most of them made by the same people or by the same factory?

People

• Alexander Jan-Belyaevsky
• Kerno Roland Paulovich
• Lacis Dzintars Arturovich

[https://goldenageofaudio.blogspot.com/2011/11/ussr-audio-classics.html](Some photos of Soviet audio equipament)

Could not find any info about audio companies in Cuba, DPRK/"North Korea", Vietnam, Belarus and others. It seems they don't produce this kind of technology?