Barrel Power Supplies

Power Adapter Barrel Connector Compatibility

Power Adapter Barrel Connector Compatibility Table

System	Voltage	Current	Barrel Size	Polarity	Official PSU Model
Group 1 – 9V DC, 5.5mm × 2.1mm, Centre Negative
ZX Spectrum +2 / +2A / +3	9V DC	2.1A	5.5 × 2.1mm		Sinclair PSU (various OEM)
Sega Saturn	9V DC	1.5A	5.5 × 2.1mm		MK-2103
Super Nintendo (PAL)	9V DC	1.3A	5.5 × 2.1mm		SNSP-002E(FRG)
NES (PAL)	9V DC	1.3A	5.5 × 2.1mm		NES-002E
Atari Jaguar / Jaguar CD	9V DC	1.2A	5.5 × 2.1mm		PA-1400 / MK-4120
Sega Mega Drive / Genesis (Model 1)	9V DC	1.2A	5.5 × 2.1mm		MK-1602-05
Sega Master System	9V DC	1.2A	5.5 × 2.1mm		MK-3025
Group 2 – 9V DC, 3.5mm × 1.35mm, Centre Negative
ZX Spectrum (16/48K)	9V DC	1.4A	3.5 × 1.35mm		Sinclair PSU
Atari 7800	9V DC	1.0A	3.5 × 1.35mm		C018187
Atari 2600 (VCS)	9V DC	0.5A	3.5 × 1.35mm		C017945
Group 3 – 9V DC, 4.75mm × 1.7mm, Centre Negative
Sega Game Gear	9V DC	1.2A	4.75 × 1.7mm		MK-2103 (shared PSU with Saturn in some regions)
Group 4 – 6V DC, 4.75mm × 1.7mm, Centre Negative
Game Boy (DMG-01)	6V DC	0.7A	4.75 × 1.7mm		DMG-03 / MGB-005
Group 5 – 9–10V DC, 4.75mm × 1.7mm, Centre Positive
Atari Lynx (Model 1)	9V DC	1.0A	4.75 × 1.7mm		PA-1400
Atari Lynx (Model 2)	9V DC	1.0A	4.75 × 1.7mm		PA-1400
Sega Mega Drive / Genesis (Model 2)	10V DC	0.85A	4.75 × 1.7mm		MK-1633
Group 6 – 7.5V DC, 4.0mm × 1.7mm, Centre Negative
Sony PlayStation (PS1)	7.5V DC	2.0A	4.0 × 1.7mm		SCPH-113

Notes & Warnings

• Sega Mega Drive / Genesis Model 1 vs Model 2 – Model 1 is centre-negative, Model 2 is centre-positive. Swapping these power supplies will damage the console.
• Sega Saturn – uses the same barrel as Model 1 Mega Drive but requires more current (1.5A). A weaker PSU may boot the system but cause crashes.
• Sega Master System – compatible with Mega Drive Model 1 PSU (same voltage, current, and polarity).
• Sega Game Gear – draws a high current; cheap adapters often cause humming in the audio and unstable video.
• Super Nintendo (PAL) – uses 9V DC centre-negative. NTSC models often shipped with AC adapters instead of DC, making them incompatible with the PAL PSU group.
• Nintendo Entertainment System (PAL) – same as PAL SNES, but NTSC NES (US/Japan) typically shipped with a 9V AC PSU. Do not interchange with PAL systems.
• ZX Spectrum (16K/48K) – requires a regulated 9V DC centre-negative supply. Original Sinclair PSUs were unregulated and can output up to 14V off-load, risking damage to modern peripherals.
• ZX Spectrum +2 / +2A / +3 – higher current draw (2.1A). A weaker Spectrum 48K PSU is not sufficient.
• Atari 2600 (VCS) – early units use a simple 9V DC centre-negative PSU at low current. Many modern replacements are compatible, but original adapters are prone to failure with age.
• Atari 7800 – same barrel size and polarity as Atari 2600 but requires more current (1.0A). A 2600 PSU may power it but risk instability.
• Atari Lynx (Model 1 and Model 2) – both require 9V DC centre-positive. Using a centre-negative adapter (e.g. Spectrum, Master System, Mega Drive Model 1) will damage the system.
• Game Boy (DMG-01) – uses a 6V DC PSU, centre-negative. Do not use 9V adapters intended for other Nintendo or Sega consoles.
• Sony PlayStation (PS1) – requires 7.5V DC at 2.0A. Using 9V adapters directly can overheat or damage the console. The barrel plug (4.0 × 1.7mm) is smaller than most Sega/Nintendo connectors and not interchangeable.
• General note on amperage – it is safe to use a PSU rated at a higher current (A) than required, but never lower. Voltage and polarity must always match.