
@v-mire.net
Why everyone praises the Ampapa D1 amplifier with TPA3255 2x 300W

@Williston Audio Labs
This Little Amp Has a SHOCKING Feature

@Souzoukan Technical Report
Revealing the performance of the Chinese-made Ampapa D1 with a glass window

@HiFi Huff
FUN! Comparing SIX Integrated Amps from $199 to $25,000. Also, are Separates BETTER?

@Old Guy Hifi
Not in price but in Performance! The Ampapa (Douk) D1 Hifi Amp.

@Christian Schwarzbeck - China-HiFi
Ampapa D1 – Der kompakte High-Tech-Verstärker mit 3 Eingängen, VU-Metern, PFFB & Hochpassfilter!
- A Natural Partner for A5: H5 is designed to visually and sonically complement the A5 amplifier, sharing a compact black HiFi look while adding tube warmth, MM phono input, tone control, and refined subwoofer integration for a richer, more complete stereo system.
- Flexible Phono and RCA Input: Use MM Phono for MM turntables and RCA Line In for DACs, CD players, streamers, computers, and more. The 20Hz HPF helps tame unwanted vinyl rumble, keeping record playback cleaner, steadier, and more controlled.
- Dual Outputs with Subwoofer Control: Dual RCA outputs let H5 feed two amplifiers or powered speakers at the same time, making it easier to expand your HiFi setup. SUB Out with 180/250Hz LPF helps reduce boomy overlap with main speakers for fuller, cleaner, better-integrated bass.
- Optimized GE-4BZ6 Tube Character: Tuned around GE-4BZ6 tubes with 180V tube drive, H5 brings smooth warmth, rich midrange body, and natural analog depth to vocals, jazz, and vinyl playback, giving you a refined tube sound from the start without chasing tube upgrades.
- Shape Sound With Refined Control: Bass and treble controls make quick sound adjustment easy, while shielded tube power and 4th-gen relay help reduce interference and switching noise. A pluggable NE5532 op-amp leaves room for experienced users to explore different sound flavors.
- Brand: Douk Audio
- Model: H5
- Audio Input: MM Phono / RCA
- Audio Output: 2× RCA Outputs / SUB Out
- Frequency Response:
Phono Input: conforms to RIAA characteristics
RCA Input: 20Hz–20kHz (±0.3dB) - THD+N: Phono Input: 0.15%; RCA Input: 0.5%
- SNR: Phono Input: ≥78dB; RCA Input: ≥104dB
- Input Sensitivity: Phono Input: 5mV; RCA Input: 1V
- Max. Output Level: Phono Input: 500mV; RCA Input: 2V
- SUB Max.Output Level:
180Hz cutoff frequency: 3.2V
250Hz cutoff frequency: 5.5V - High-Pass Filter Cutoff Frequency: 20Hz
- Bass / Treble Range: ±6dB
- Input Voltage: DC 12V ≥1.5A, 5.5 × 2.1mm
- Package Size (W × D × H): 265 × 240 × 65mm / 10.43 × 9.45 × 2.56in
- Package Weight: 0.8kg / 1.76lb
- 1 × H5
- 2 × 4BZ6 Tubes
- 1 × DC 12V Power Supply
- 1 × User Manual
FAQs
Q: Does the 20Hz high-pass filter work with all inputs?
A: No. The 20Hz HPF works only in Phono input mode. It is designed to help reduce ultra-low-frequency rumble from turntable playback, such as record warp or turntable vibration.
Q: What devices can be connected to SUB Out?
A: SUB Out uses a single RCA connector for powered subwoofers and sends low-frequency signals only. The LPF applies only to SUB Out. Bass and treble controls do not affect SUB Out, while the volume knob controls both RCA outputs and SUB Out together.
Q: Does H5 support op-amp replacement?
A: Yes. H5 includes one socketed NE5532 dual op-amp. You may replace it with compatible dual op-amps such as OPA2604, OPA2134, LM49720, or MUSES02.
Q: Does H5 support tube replacement?
A: Yes. H5 uses 4BZ6 tubes and supports replacement with the same 4BZ6 tube type only. Do not use other tube models unless compatibility is confirmed with us. Always power off H5 before replacing the tubes.
Q: Can RCA 1 and RCA 2 be switched independently?
A: No. RCA 1 and RCA 2 output the same signal simultaneously and cannot be switched independently.
Q: Which input should I use for a turntable with a built-in phono preamp?
A: Please connect it to the RCA input. The Phono input is designed for turntables without a built-in phono preamp. Connecting a built-in phono preamp turntable to the Phono input may cause noise, distortion, or abnormal sound.
Q: What power adapter should I use?
A: Please use the included DC 12V/2A power adapter. If using another adapter, make sure it is a high-quality DC 12V adapter rated at 1.5A or above.
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Douk Audio H5
Designed Around the Whole System
H5 was developed to do more than pass signal through a tube stage. With 20Hz HPF and 2-stage LPF, it helps clean up vinyl rumble and make subwoofer integration easier. Paired with A5, H5 fits naturally into a refined HiFi system.
- Input: MM Phono / RCA Line In
- Output: 2×RCA Out / SUB Out
- Filters: 20Hz HPF / 2-Stage LPF
- Tone Control: Bass / Treble ±6dB


























