Ampapa D1 Integrated Amplifier

Small footprint, serious engineering — and those VU meters

I picked up the Ampapa D1 on Amazon from Douk Audio/Ampapa because it promised more than the usual cute-screen mini amp. The screen is excellent — bright, legible, with fluid VU meters — but it’s not just a gimmick. Inside, the D1 brings the 2025 feature set that should be standard on Class D: post‑filter feedback (PFFB) for better linearity and load‑invariant response, and a proper high‑pass filter (HPF) to protect your mains when handing off bass duties to a subwoofer. The parts selection and overall execution are genuinely thoughtful for the price.

Ampapa is a newer sub‑brand from Douk Audio (the same folks behind a sprawling catalog of DIY‑friendly amps, DACs, and accessories). In recent years Douk has been steadily refining its higher‑tier designs, and Ampapa looks like the channel for those more polished, living‑room‑ready products.

I’ll cover build, features (PFFB/HPF, tone, I/O, Bluetooth), day‑to‑day performance, measurements (from the manual and third‑party testing), and how it compares to similarly sized amps like the Aiyima A80. I’ll also show a tidy starter stack pairing the D1 with SMSL’s SU‑1 DAC.

Unboxing and Build Quality

The presentation is clean and secure. In the box you’ll find the amplifier, a power adapter (varies by kit), a remote, and documentation. The chassis is a dense, compact brick with chamfered edges, clean screen glass, and a solid volume encoder. The star of the show is the wide display with genuinely useful VU meters that track input level in real time.

Details I appreciate:

• Metal chassis with tight panel gaps, no flex.
• Clicky, confident encoder; responsive UI.
• Properly labeled rear panel with RCAs, balanced‑style TRS inputs, speaker posts, and pre‑out.

Size, Screen, and a note on the Aiyima A80

If you’ve seen or used the excellent Aiyima A80, the D1 will feel familiar in footprint and “desktop hi‑fi” intent. Both serve the same use case: a compact integrated that doesn’t feel like a toy. The D1’s VU meters are nicer (cleaner UI, better motion), and if you already own a separate DAC, the D1’s adjustable HPF for sub integration arguably makes it the better pick for system building. I’ll include side‑by‑side photos with the A80 so you can see the layouts and screens.

Features and Performance

The engineering that matters in 2025

• Post‑Filter Feedback (PFFB): By taking feedback after the output filter, the D1 keeps its response flatter into real speakers (variable impedance) and can improve damping, distortion, and treble linearity. Translation: more consistent tonality and control across different speakers.
• High‑Pass Filter (HPF) for mains when using a sub: Adjustable between 30–200 Hz with a 12 dB/octave slope. This protects small bookshelves from excursion and cleans up headroom when you cross over to a powered subwoofer. There’s also a full‑range mode when you’re not running a sub.
• Tone controls: ±10 dB bass/treble for quick system‑wide tweaks; easily bypassed.

Inputs, outputs, and connectivity

• Analog inputs: RCA and TRS (balanced‑style) line‑level.
• Bluetooth 5.2: Qualcomm QCC304X with SBC/AAC/aptX/aptX‑HD — handy for casual listening with good enough fidelity.
• Outputs: Banana speaker posts and a fixed/line‑level pre‑out (rated 3.5 V). The pre‑out makes the D1 a simple hub for sub integration or for feeding powered speakers.

Pairing idea: SMSL’s SU‑1 is a super‑affordable, clean DAC that matches well here — a fine “starter stack” with the D1.

Day‑to‑day impressions

With neutral tone controls (defeated), the D1 comes across clean, tight, and load‑invariant — exactly what I hope to hear from a modern PFFB Class D. Treble stays composed on trickier 4–6 Ω loads, bass is controlled, and the noise floor is inaudible at the seat. The HPF is the killer feature: crossing mains at ~80–100 Hz transformed small bookshelves into confident nearfields with a sub, and the D1 didn’t break a sweat at reasonable room levels.

Bluetooth is convenient for guests, and aptX‑HD kept things artifact‑free for casual use. For critical listening I preferred the RCA/TRS paths from a DAC.

Sound Impressions

• Tonality: Neutral‑leaning and honest; no “glassy” top end when paired with realistic loads.
• Dynamics: Punchy with good macro contrast; HPF enabled + sub adds significant headroom and composure.
• Stage and separation: As expected for a competent solid‑state integrated — it gets out of the way.

Tip: If your speakers are small, start with HPF at 80–100 Hz and nudge to taste; if they’re floorstanders, leave the mains full‑range and use the pre‑out to blend a sub gently below 50–60 Hz.

Comparisons

Aiyima A80

The A80 remains a great compact integrated with a solid display. The D1’s VU meters are nicer, and the inclusion of an adjustable HPF for the mains makes it much easier to build a 2.1 (or 2.1.2) system without risking woofer over‑excursion. If you already own a separate DAC, the D1 is my pick; if you need more digital I/O baked in, consider what the A80 variant you’re eyeing includes and price accordingly.

A simple starter stack

The D1 + SMSL SU‑1 is a clean, affordable combo that punches above its size. Use the SU‑1’s fixed output into the D1, set HPF to match your speakers/sub, and enjoy.

Specifications and Measurements

Specifications

• Brand/Model: Ampapa D1
• Audio inputs: RCA / TRS / Bluetooth 5.2
• Audio outputs: Banana speaker posts / Pre‑Out
• Max output power: 300 W ×2 (4 Ω) peak
• THD+N: 0.002%
• SNR: ≥ 114 dB
• Frequency response: 20 Hz–20 kHz (±0.4 dB)
• High‑pass filter frequency range: 30 Hz–200 Hz
• High‑pass filter slope: 12 dB/octave
• Bluetooth chip: Qualcomm QCC304X
• Bluetooth codecs: SBC / AAC / aptX / aptX‑HD
• Input sensitivity: RCA 2 V, TRS 4 V
• Pre‑out rated level: 3.5 V
• Matched speaker impedance: 4–8 Ω
• Treble/Bass adjustment range: ±10 dB
• Input voltage: DC 24–48 V / ≥4 A (5.5×2.5 mm)
• Dimensions (W×D×H): 155×124×42 mm (6.10×4.88×1.65 in)
• Net weight: 742 g (1.64 lb)
• Package dimensions: 268×192×95 mm (10.55×7.56×3.74 in)
• Package weight: 1.73 kg (3.81 lb)

Example power outputs (from product table)

• 4 Ω: 120 W + 120 W
• 6 Ω (48 V/5 A supply): 110 W + 110 W
• 8 Ω: 102 W + 102 W

Note: Maximum headline “300 W ×2 (4 Ω)” figures are typical instantaneous/peak ratings; continuous power depends on supply and load. The example table above reflects more realistic continuous outputs with the listed supplies.

Measurements

• Manufacturer’s Audio Precision plots (SINAD/THD+N, FR, crosstalk) in the manual show very low distortion and flat response with PFFB engaged. See the manual page for full charts: link in the alert above.
• Additional third‑party technical review with measurements: YouTube: Deep‑dive measurements of D1

I’ll include selected graphs from the manual here for convenience once I’ve captured them:

Method notes: I verified noise at the listening position and checked tone control behavior (±10 dB limits, clean bypass). HPF corner frequencies measured close to nominal settings, with the expected 12 dB/octave slope.

Rating Explanation

Pragmatic rating: 5/5

Why:

• PFFB implementation yields clean, speaker‑agnostic results; adjustable HPF is the right way to integrate a sub.
• Excellent ergonomics and UI for the size; VU meters are genuinely useful.
• Strong parts selection and I/O for the price; Bluetooth that’s good enough when needed.
• Frequent vouchers make the value even better.

Who it’s for:

• Small to mid‑size rooms where a compact integrated makes sense.
• Builders of 2.1 systems who want to protect mains and maximize headroom.
• Listeners who prefer neutral, low‑noise, low‑distortion amplification.

Caveats:

• No onboard DAC — pair with something like the SMSL SU‑1 if you need digital inputs.
• Peak power marketing can be confusing; check your supply and speaker sensitivity for real‑world SPL.

Conclusion

The Ampapa D1 nails the mix of form and function: it looks great on a desk or shelf, but more importantly it behaves like a modern amplifier should. PFFB keeps the sound consistent across loads, the HPF makes 2.1 integration seamless, and the UI/screen feel premium in daily use. At around $199 — often less with vouchers — it’s an easy recommendation and a terrific foundation to grow a compact system.

I’ll update this page with comparison photos (D1 vs A80 front/back and with the SU‑1 stack) and add measurement captures from the manual so everything’s in one place.