The Short Answer
- Choose the Topping DX3 Pro+ — if your headphones are easy to drive (under 150Ω, above 95dB sensitivity) and you want a compact, smooth-sounding all-in-one under $150
- Choose the FiiO K5 Pro ESS — if you own power-hungry planars or high-impedance dynamics, or want maximum output headroom for future headphone upgrades
Both are excellent. The difference comes down to output power and character.
Side by Side
| Topping DX3 Pro+ | FiiO K5 Pro ESS | |
|---|---|---|
| Price | ~$149 | ~$149 |
| DAC Chip | LDAC/ESS9038Q2M | ESS9038Q2M |
| Output Power (32Ω) | 640mW | 1,500mW |
| Output Power (300Ω) | 200mW | 240mW |
| Headphone Output | 6.35mm | 6.35mm |
| Balanced Output | No | No |
| Inputs | USB, Optical, Coaxial, Bluetooth | USB, Optical, Coaxial, FiiO Dock |
| Line Out | RCA | RCA |
| Gain Switch | Front panel | Underside |
| Footprint | Compact | Medium |
| Bluetooth | Yes (LDAC) | No |
Output Power: Where They Differ Most
The FiiO K5 Pro ESS puts out 1,500mW at 32Ω vs the DX3 Pro+’s 640mW. On paper, that is a 2.3× difference. In practice, the gap matters when driving:
- HiFiMAN Sundara (94dB, 37Ω) — both drive it cleanly, but the K5 Pro ESS has meaningfully more headroom for dynamic peaks
- Sennheiser HD 600/650 (97dB, 300Ω) — both work, but the K5 Pro ESS delivers more current at high impedance, which some listeners feel improves control and dynamics
- Beyerdynamic DT 990 Pro (96dB, 250Ω) — the DX3 Pro+ is sufficient at moderate volumes; the K5 Pro ESS drives it to higher levels without strain
For the most common sub-150Ω headphones — ATH-M50x (38Ω), DT 770 Pro 80Ω, Beyerdynamic DT 770 80Ω, Sony MDR-7506 (24Ω) — the DX3 Pro+’s 640mW is more than adequate. You will not hear a difference in day-to-day listening.
Where the K5 Pro ESS’s power advantage becomes audible is with demanding planar magnetic headphones and high-impedance dynamics played at high volumes or with high dynamic range recordings.
Sound Character
Both use ESS DAC chips (the K5 Pro ESS uses the same ESS9038Q2M). Measured performance is similar. The perceived difference between them in listening is subtle and largely a function of amplifier implementation.
Topping DX3 Pro+: Slightly smoother presentation. Less tendency to sound harsh on treble-forward headphones. The Bluetooth input (with LDAC) is a practical advantage for wireless use cases.
FiiO K5 Pro ESS: Slightly more energetic in the upper midrange. The higher output power gives a sense of greater dynamics and control with demanding headphones. Some listeners describe it as more “alive,” though measured distortion is similar.
Neither is a dramatic character difference. Synergy with your specific headphones matters more than the DAC/amp comparison itself.
Bluetooth: The DX3 Pro+ Exclusive
The Topping DX3 Pro+ supports Bluetooth 5.0 with LDAC, allowing wireless connection from a phone or tablet at up to 990kbps. This is a practical feature if you use your phone as a source — you avoid a USB cable while maintaining high-resolution audio.
The FiiO K5 Pro ESS has no Bluetooth. If you primarily use a USB connection from a PC or Mac, this is irrelevant. If you frequently switch between PC and phone sources, the DX3 Pro+’s Bluetooth input is a genuine advantage.
FiiO Dock: K5 Pro ESS Exclusive
The K5 Pro ESS has a proprietary dock for FiiO’s M-series portable DAPs. Dock a FiiO M11 or M15, and the K5 Pro ESS becomes a desktop amplification stage for the portable player — you get the DAP’s streaming and playback capabilities with the K5 Pro ESS’s desktop power. For FiiO DAP owners, this is a useful home integration feature. For everyone else, it is irrelevant but costs nothing.
Gain Switch Location
Minor but worth noting: the DX3 Pro+ has a front-panel gain switch, making it easy to switch between low gain (for sensitive IEMs) and high gain (for demanding headphones). The K5 Pro ESS has its gain switch on the underside — you pick it up and flip it to change. If you regularly switch between different headphone types, the DX3 Pro+’s front-panel gain is more convenient.
Which Should You Buy?
Buy the Topping DX3 Pro+ if:
- Your headphones are the ATH-M50x, DT 770 Pro (80Ω), Sony MDR-7506, Sennheiser HD 560S, or any other sub-150Ω headphone
- You want Bluetooth LDAC for wireless phone connectivity
- Desk space is limited — the DX3 Pro+ is smaller
- You prefer a front-panel gain switch
Buy the FiiO K5 Pro ESS if:
- Your headphones are the HiFiMAN Sundara, HE400SE, Beyerdynamic DT 990 Pro (250Ω), or Sennheiser HD 600/650 (300Ω)
- You plan to upgrade to more demanding headphones in the future
- You own FiiO DAPs and want a desktop dock
- Output power headroom matters more than Bluetooth