COVID-19 Update:

Due to the pandemic situation of COVID-19, the Hong Kong Post Office has stopped the conventional global shipping which causes a higher shipping cost. Therefore we made an adjustment on shipping price of our attenuator. In such, here we promise that once the Hong Kong Post Office service resumes, the attenuator price will be adjusted again. We sincerely apologize for any inconvenience caused to you.

A High Quality Passive Pre-amplifier

The PPA-01 passive pre-amplifier is for music lovers who can appreciate the best a passive pre-amplifier can offer.

The design of PPA-01 is based on our proven VR-connected transformers to provide smooth mechanical 59 steps volume control switch from 20dB-80dB. Additional features include 59 steps gain control switch, 59 steps auto-transformer (C Core), 90 degree auto-transformer installation, flexible GND usage combination, and more.

PPA-01 is also an entirely passive design with literally zero extra power sources plugged into the audio signal path, meaning that no power is required and neither distortion nor interference are added by active components or power lines to this device. All these are 100% designed and handcrafted in Hong Kong.

How will you be surprised by the PPA-01

Whether you are already a fan of passive pre-amplifiers or somebody who has never tried a passive pre-amplfier before, this PPA-01 will surely enable you to have a delightful music experience.

A switch providing a selection of gain control with distinct 1x, 3x, 5x and 10x gain options, you can expect accurate positioning to get excellent, sweet and thick sound quality from this PPA-01.

Adopting a 59 steps auto-transformer (C Core) with the latest “cool-melted method” technology, no metal clamp is needed to stabilize the auto-transformers – you can imagine how successfully it maintains the high performance of sound from material mismatch as compared to a traditional transformer design.

You can also imagine its performance is superior to that of the conventional passive pre-amplifiers utilizing even the best VR-connected transformers.

Please realize that our PPA-01 uses only a 59 steps mechanical volume control with a 59 steps auto-transformer (C Core) design which effectively prevents the sound quality from worsening, the output control of a digital switch-connect external remote device can feature the most gorgeous sound experience.

PPA-01 Key Features

Selectable Gain Control Switch

With the application of the Magnetic Hysteresis theory, the winding coil around our 59 steps auto-transformer (C Core) induces a magnetic force that delivers a high built quality of sound, with 1x, 3x, 5x and 10x gain options

Gain Options Sound Descriptions
1X Accurate Positioning, High Quality
3X Sweet Treble, High Quality
5X Sweet Treble, Thick Bass
10X Extraordinary Thick
(suitable for digital-sounded/piercing devices)
59 Steps Mechanical Volume Control Switch

59 steps auto-transformer (C Core) is the core of PPA-01 technology. Differs from the traditional VR-connected transformer based control, C core transformer based volume control switch offers a special, gorgeous yet satisfying sound that defines irresistible high performance.

59 Steps Auto-transformer (C Core)

Using a confidential core material, our 59 steps auto-transformer (C Core) uses no metal clamp for stabilizing, but adopts a new “cool-melted method” technology. The result is a satisfying performance without the drop of sound quality caused by the material mismatch due to the use metal clamps in the conventional transformer design.

We use two auto-transformers in the PPA-01 passive pre-amplifier. What is more special about the 59 steps auto-transformer (C Core), would be the angle made of 90 degree of two auto-transformers during installation, which effectively minimizes path distortions caused by R and L channels interactions.

To make our 59 steps auto-transformer(C Core) more special, we install the two auto-transformers in our PPA-01 passive pre-amplifier at a 90 degree angle to effectively minimizes path distortions caused by R and L channels interactions.

GND Specials

We offer the flexible use of House GND and Audio GND. There is no restriction on connecting both the GND ports to the ground box, or shorting both House GND and Audio GND by connecting a jumper wire when you need to. Our PPA-01 is designed to satisfy the requirements of all music lovers.


Core Type: C Core
Core Material: Confidential
Voltage Steps
Voltage Steps: 59 steps
Output Range
Measuring Condition:
Connect output amplifiers with input impedance not lower than 10kΩ to avoid malfunctions, as the output impedance of this PPA – 01 is 10kΩ.
Output Range +20dB – 80dB
Gain Range
Gain 1X 3X 5X 10X
Coil Ratio 1:1.00 1:3.10 1:4.97 1:10.39
Frequency Response
Measuring Condition:
Turn to the highest volume level with a 10kΩ resistor loading.
Frequency Response 20 – 20kHz (+/- 3dB) at 1X gain
Audio Connections
Inputs 3 RCA
Outputs 1 RCA
GND 1 HG, 1 AG
Overall Dimensions
Width 350mm
Depth 280mm
Height 80mm
Gross 6.8kg
Net 4.0kg
Series Type Stepped Attenuators/ 15A Resistance Taper (For 1X Gain)


Part No. Product Name Download
PPA-01 PPA-01 Passive Pre-amplifier

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