Overview

3e Audio is a Shenzhen-based audio manufacturer focused on making “great-sounding and high performance audio products that everyone can afford to enjoy.” The company primarily serves ODM/OEM clients and DIY enthusiasts, centering on Class D amplifiers built around TI’s TPA3251/3255 chips. Their latest finished amplifiers (A5 stereo, A7 mono/stereo) implement Post-Filter Feedback (PFFB) to push distortion lower and make frequency response highly load-invariant. The lineup emphasizes measurable performance and pragmatic feature sets over cosmetic luxury.

Scientific Validity

Independent measurements show 3e’s latest designs achieving transparent-level performance with margin. Archimago measured the A5 stereo at about –104 dB THD+N at 5 W into 4 Ω (XLR) and the A7 Mono at better than –100 dB THD+N at 5 W into 4 Ω (XLR), with continuous “hi-fi” power around 120 W (A5) / just over 200 W (A7 Mono) at ≤0.1% THD+N. Output impedance averaged just over 10 mΩ across 20 Hz–20 kHz, corresponding to damping factor >300 (4 Ω), and the frequency response remained essentially flat into 2/4/8 Ω and a reactive speaker load—evidence of well-executed PFFB and load-invariant behavior. Single-ended (RCA) performance remains excellent albeit a few dB behind XLR, as expected. These results place the products decisively within transparent territory for distortion, noise, output impedance, and FR linearity. [1][2]

Technology Level

Rather than inventing a new silicon platform, 3e concentrates engineering effort on implementation quality: optimized PFFB networks, careful gain structure, and low switching-noise control. The A5 uses dual TPA3251 in PBTL for lower noise/distortion at moderate power, while the A7 variants use TPA3255 for higher power. The finished units expose socketed, user-replaceable op-amps (e.g., OPA1656, OPA1612, LM4562, etc.) in DIP-8, and provide balanced XLR/TRS and RCA inputs with a bypassable analog volume and selectable RCA gain. This is modern, desirable engineering that competitors can emulate but still reflects meaningful know-how. [1][3]

Cost-Performance

Representative products and current market prices (as listed when retail opened):

• A5 (stereo, with 38 V / 5 A PSU): 240 USD.
• A7 Mono (with 48 V / 5 A PSU): 180 USD.
  Both are finished products with balanced inputs and PFFB. [2]

We looked for the cheapest product(s) with equal-or-better user-facing functions and measured performance. Sub-$300 competitors often cited—e.g., Fosi V3 Mono and Topping PA5 II/II+—do not surpass the A5/A7’s best-case THD+N at 5 W into 4 Ω under comparable conditions (V3 Mono is ≈100 dB SINAD via XLR, Topping PA5 II family tests are typically ≤~100 dB). Therefore, as of this review date we did not find a cheaper equivalent-or-better finished alternative; CP = 1.0 by definition. [2][4][5]

Equivalence note (why others are excluded): Even where power and I/O are comparable, the cited lower-cost models do not meet or exceed the A5/A7’s < –100 dB THD+N @ 5 W / 4 Ω benchmark alongside comparable features, so they are not valid comparators under the strict “equal-or-better” rule. [2][4][5]

Reliability & Support

The designs are simple, cool-running Class D with external GaN PSUs, few wear parts, and robust protection behavior noted under stress testing. The warranty is 1 year per the official manual; support is provided directly via email/Skype; and documentation is reasonably complete for a first-party offering. Long-term field data are still limited given the recent launch, and the warranty term is average rather than generous—hence a cautious but positive score. [1][3][6]

Rationality of Design Philosophy

3e’s philosophy is measurement-first: invest in the parts and topology (PFFB, proper gain staging, balanced inputs, quality op-amps) that lower distortion, flatten load-dependent FR, and improve usability (auto-sensing, volume bypass). Costs largely map to audible outcomes rather than cosmetics or mythology, which is rational for users seeking transparent amplification. [1][3]

Advice

If you want state-of-the-art transparency from compact boxes at accessible prices, 3e’s A5/A7 line is an excellent fit. For listeners with modest transparency needs and strict budgets, mainstream options (e.g., Fosi/Aiyima/Topping budget amps) can sound audibly transparent in many setups, but on the lab bench they don’t quite match the A5/A7 on sub-–100 dB distortion with load-invariant FR. Choose A5 if your speakers are average sensitivity and you value lowest distortion; pick A7 Mono when you genuinely need more headroom or a monoblock layout. Use balanced input and volume-bypass for the best numbers, and size the PSU to your load.

References

[1] Archimago’s Musings — Part I: 3e Audio – A5 Stereo and A7 Mono… Features and initial measurements, accessed 2025-08-26. Key data: output impedance ≈10 mΩ, damping factor >300 (4 Ω), load-invariant FR; device architecture, I/O, gain. https://archimago.blogspot.com/2024/11/part-i-3e-audio-a5-stereo-and-a7-mono.html

[2] Archimago’s Musings — Part II: 3e Audio – A5 Stereo and A7 Mono… power, distortion, and the subjective, accessed 2025-08-26. Key data: A5 ~–104 dB THD+N @ 5 W / 4 Ω (XLR); A7 Mono < –100 dB @ 5 W / 4 Ω (XLR); ~120 W / ~200 W at ≤0.1% THD+N; AliExpress launch prices A5 240 USD / A7 Mono 180 USD. https://archimago.blogspot.com/2024/12/part-ii-3e-audio-a5-stereo-and-a7-mono.html

[3] 3e Audio — A5/A7/A7 Mono User Manual (PDF), accessed 2025-08-26. Key data: user-replaceable DIP-8 op-amps (e.g., OPA1656); inputs/outputs; RCA gain; 1-year warranty. https://www.3e-audio.com/wp-content/uploads/2024/11/A5_A7_A7-Mono-User-Manual_202411.pdf

[4] Audio Science Review — Fosi Audio V3 Mono Amplifier Review (thread), accessed 2025-08-26. Key context: measured ~100 dB SINAD via XLR, output power behavior. https://www.audiosciencereview.com/forum/index.php?threads/fosi-audio-v3-mono-amplifier-review.53474/

[5] Topping PA5 II / II+ — Product pages & community measurements (context for market presence and typical performance level), accessed 2025-08-26. https://www.audiosciencereview.com/forum/index.php?threads/topping-pa5-ii-stereo-amplifier-review.47362/ , https://www.amazon.com/LEAUDIO-Topping-Amplifier-Balanced-LEAUDIO-PA5II/dp/B0CQYD5BRS

[6] 3e Audio — Contact Us (support channels), accessed 2025-08-26. https://www.3e-audio.com/contact-us/

(2025.8.25)