SANSUI AU-20000
Prologue: This legendary Sansui AU-20000 (Japan Domestic Market model at 100V) has gone through Master-grade 'Takumi' Restoration performed in Japan. Sound signature preserved to original 1970s/80s factory specifications by veteran Sansui technicians.
Nothing is rushed. Nothing is excessive.
This entire restoration work takes two to three months, allowing the amplifier to settle naturally, as it should. What remains is not merely an amplifier, but a piece of Japanese monozukuri—quiet, enduring, and made to be lived with. It will reward its owner with many unhurried hours of listening, where music is allowed to breathe.
Background:
The AU-20000 is Sansui’s flagship masterpiece from the Professional Series during their golden era of manufacturing and the most powerful.
It is a high-performance integrated stereo amplifier known for its exceptional build quality and power output. It delivers a continuous 170 watts per channel into 8 ohms, with less than 0.05% total harmonic distortion, ensuring clean, distortion-free audio even at high output levels.
This amplifier is constructed with premium components throughout, including durable switches, potentiometers, high-quality filter capacitors, and output devices.
It also features a high-performance MM (Moving Magnet) phono preamp, a headphone amplifier, tape circuits, tone controls, and muting functions for versatility. One standout feature is its gorgeous moving coil power meters, adding both functionality and a visual touch of elegance.
Overall, the Sansui AU-20000 is a statement piece that embodies the peak of 1970s Japanese HiFi engineering. With its outstanding build quality, powerful performance, and added features, it's one of the ‘holy grail’ of Sansui’s amplifier in vintage HiFi circles.
The Sansui AU-20000 is a pre-main amplifier is a high-power unit built to deliver robust performance along with specialized features for dedicated audiophiles. It utilizes an all-stage direct connection pure supplementary OCL (Output Capacitor-Less) system with triple push-pull output stages, allowing for powerful output while keeping distortion low.
The amplifier includes a CR+NF equalizer with dual amplifier configurations for precise sound reproduction, as well as triple tone control for adjusting bass, midrange, and treble. For those who prefer an unaltered sound, the tone defeat option provides a flat response.
A standout feature is its large power supply unit equipped with a high-performance toroidal transformer and a stabilized circuit, ensuring consistent power and stability even during dynamic peaks. Additionally, it offers switchable input sensitivity and impedance settings, allowing compatibility with a variety of sources and equipment setups.
For protection, the AU-20000 incorporates triple protection circuits, which safeguard against over-temperature, DC asymmetry, and conditions outside the safe operating area (ASO), ensuring long-term reliability and safety.
The amplifier utilizes high-speed class AB amplifiers with bipolar output devices, a common design architecture from the era, delivering both efficiency and powerful performance. Though the phono preamp lacks MC (Moving Coil) capability, this can be easily remedied by adding a high-quality step-up transformer to the setup.
Type
- Stereo pre-main amplifier
Power and Performance
- Effective Power: 170W + 170W (both channels, 20 Hz to 20 kHz, 4.8Ω)
- Total Harmonic Distortion: 0.05% or less (at rated output)
- Cross Modulation Distortion: 0.05% or less (70 Hz : 7 kHz = 4:1 SMPTE)
Frequency and Sound Characteristics
- Frequency Response: 10 Hz to 50 kHz (+0 -1dB, 1W)
- Output Bandwidth: 5 Hz to 30 kHz (IHF, 8Ω)
- Damping Factor: 80 (8Ω)
Noise and Channel Separation
- Hum and Noise:
- Phono: 70 dB or more
- AUX: 80 dB or more
- Channel Separation:
- Phono: 55 dB or more
- AUX: 60 dB or more
- Power Amp: 65 dB or more
Phono Specifications
- Phono Input Sensitivity: 1.5, 3.6 mV (30, 50, 100kΩ)
- Phono Maximum Allowable Input: 800 mV (at 6 mV sensitivity)
- RIAA Deviation: ± 0.2 dB (30 Hz to 15 kHz)
General
- Dimensions: Width 460mm x Height 178mm x Depth 400mm
- Weight: 23.6kg
“The Sansui AU-20000 Integrated Amplifier, is one hell of a beast. Ever since I've been interested in listening, experiencing, comparing and specifically collecting, vintage/classic hifi, the AU2OK has been on my wishlist.”
“Wow - What an amplifier...Heaps, I mean heaps of effortless power. It looks like it means business, and so it proves, performance matches the look. The volume control feels silken like in the hand, you know it just wants to be turned clockwise. And keep turning.”
“Had the TT hooked up to the 20K and sounds very sweet”
stereonet.com
“I could not be happier with how revealing this integrated is. The detail and emotion revealed in the music is astonishing particularly on expertly recorded CD's. Steely Dan's AJA on this amp was a brand new listening experience when I first played it.”
audiokarma.org
“I just got my AU 20000 completely restored. The Au 20000 is really a magnificent vintage integrated amp. It is so transparent and revealing. Good in good out. If you play a good LP that has been produced well it will blow you away, Also if you put a LP on that is worn or poorly produced it will sound bad, no hiding bad vinyl. The Au 20000 has great bass also. So Smoooooooth”
hifiengine.com
There are also a number of videos on YouTube discussing the Sansui AU-20000, covering its features, sound quality, and performance in various settings. Many reviewers highlight the AU-20000's solid build, high power output, and its vintage design, emphasizing Sansui’s engineering excellence in this model.
For instance, videos from channels like Skylabs Audio provide detailed overviews of Sansui’s AU line, often listing the AU-20000 among the top favorites for its power and tonal clarity. Other videos also explore the AU-20000 alongside competing amplifiers like the Pioneer SX-1250, comparing their sound profiles and aesthetics
For a more comprehensive look at its performance, you can check out these videos:
- Our Top 5 Favorite Sansui AU Integrated Amplifiers
- Sansui AU-20000 Review and Comparison
These videos offer a good look into the AU-20000's capabilities and why it remains a beloved choice among vintage HiFi enthusiasts.
For this Sansui AU-20000, we are really proud of this restoration project. It presents the essence of what VintageJapanHiFi is about : we source for the finest amplifier that was ever built by Sansui, we send it to our Takumi (ex-Sansui craft masters) to restore it to its original glory, no expanses spared.
Here's the story:
When we purchased it from its original one-owner, it was already in working condition without any operational issues, however, the only minor issue was that the ground screw for phono section was missing in the back panel.
Since it is the ‘best’ integrated amplifier Sansui has ever produced, we decided to give it a completed service and went ahead for a full restoration service, costing us almost USD$1000 when completed.
It has been meticulously cleaned and restored, both inside and out, by our ex-Sansui engineers here in Japan. While there are minor vintage wear marks on the side and back panels, while the front faceplate remains in excellent condition.
Since its return, it has been put through more than 4 weeks of testing by us at Vintage Japan HiFi. The results? It sounds as powerful and clear, truly exceptional for a piece of its era.
Condition Overview:
- Cosmetic Condition: 9/10 – Very excellent overall, with little minor signs of age.
- Performance: 10/10 – Operating at peak specifications with amazing sound clarity and depth.
A detailed breakdown of the service completed on the amplifier will be provided for the new owner, along with clear, high-quality pictures. This ensures transparency about the work done, including any replaced components and any other improvements made to restore the unit to its original specifications. It's an important step for both peace of mind and maintaining the amplifier's value over time.
Note:
Our overhaul service focuses on preserving the original sonic character of the amplifier. We only replace non-functioning electronic parts, ensuring each piece remains true to its factory specifications. Unlike the common practice in many US HiFi workshops, where all capacitors, transistors, and other components are replaced, our ex-Sansui engineers and technicians advise against this, as it changes the amplifier’s authentic sound profile. We honour this approach to maintenance and restoration. However, if you’re looking for more extensive "recapping," feel free to reach out by email for a personalized service quote.
All control knobs and switches have been professionally cleaned and lubricated. However, scratchy noise cannot always be completely eliminated and may reappear over time. This is an unavoidable characteristic of vintage Hi-Fi equipment due to age and component wear. It should not be considered a defect, but rather a natural sign of the unit’s history and originality.
Please refer to our disclaimer notes for further details.
If this occurs, gently rotate the relevant control knobs (volume or balance) back and forth several times before use. In many cases, this will significantly reduce or temporarily eliminate the noise.
Please visit our YouTube channel, vintagejapanhifi_real, to enjoy audio demos of our special HiFi equipment, including vintage classics like the Micro Seiki DD-5, Sansui AU-20000, Hitachi IA-1000, and Yamaha CA-1000III. These recordings capture each piece’s unique sound profile and performance, helping you experience their quality before making a purchase.
You can also follow us on Instagram at vintagejapanhifi_real for the latest updates, images, and insights into our curated selection of vintage Japanese audio gear.
For any vintage audio hifi equipment:
Please be aware that, given this vintage hifi equipment's age, certain switches and original parts are no longer in production. While we’ve thoroughly cleaned and lubricated any “gari gari” scratchy controls (as they’re called in Japan), it’s simply not possible to eliminate this characteristic entirely since volume knobs and switches cannot be disassembled.
We recommend regular servicing every 2 to 3 years, depending on the equipment, to keep this vintage hifi in peak condition. This advice applies to all vintage equipment—be cautious of sellers who claim "brand-new condition" or “better than original.”
Minor scratchy sounds in control knobs are typical for vintage gear and should not be seen as a defect but rather a natural sign of its history since it does not affect the actual performance or introduce noise into the audio signal source unless being operated.
If this occurs, gently rotate the relevant control knobs (volume, or balance) back and forth several times before use. In many cases, this will significantly reduce or temporarily eliminate the noise.
For optimal sound quality, we advise pairing this amplifier with high sensitivity speakers (88-92 db). If you need guidance on amplifier matching, feel free to reach out for assistance. If you need guidance on amplifier matching, feel free to reach out for assistance.
"Where audio heritage meets absolute trust”
Welcome to the ultimate destination for golden-era Japanese audio engineering. Buying premium Japan Domestic Market (JDM) hi-fi equipment online should be an exciting, seamless experience. Below, we answer our community's most frequent questions regarding voltage, restoration, shipping, and logistics to give you absolute peace of mind.
1. Restoration & Maintenance
- The Takumi Overhaul Process: Every restored component undergoes an exhaustive, archival-grade restoration by our elite Japanese Takumi technicians. This includes deep internal chassis detailing, advanced chemical treatment of all potentiometers and switches to permanently eliminate artifact noise, targeted replacement of aged or leaking capacitors, precision re-soldering of compromised micro-joints, and fresh installation of period-correct belts or bulbs. Circuitry is then meticulously re-biased to original factory specifications.
- The Endurance Bench Test: To guarantee absolute reliability before international transit, every restored unit undergoes a rigorous 24-hour stress test (operating 8 hours straight per day over 3 consecutive days) to monitor thermal stability, power delivery, and sonic purity.
- Authentic Japanese Components: We preserve the original sonic signature of your gear by utilizing premium, high-grade Japanese components—such as Nichicon, Elna, and Rubycon capacitors, and made-in-Japan transistors. To maintain absolute design integrity, certain discontinued vintage parts may be meticulously sourced from donor units of the exact same model.
2. Premium Shipping & Packaging
- Transparent Shipping Rates: Vintage components are exceptionally heavy (often weighing 20kg to over 40kg). Shipping fees are calculated accurately at checkout based on actual weight or volumetric size. Rates are tied directly to the live, official reference rates of our premium carriers (EMS, DHL, FedEx) and reflect current global carrier tariffs.
- Our Packing Standard: Every unit is engineered to survive cross-ocean journeys. We use heavy-duty, double-walled boxes and custom high-density foam molding. For turntables, heavy platters, counterweights, and headshells are completely removed and packed securely underneath the chassis to protect delicate spindles and tonearm bearings.
- Pre-Shipping Video Validation: As a mandatory final step in our workflow, every piece of equipment undergoes a meticulous, final in-house audio testing and functional bench test right before packing. We film this process and upload the high-fidelity video directly to a private Google Drive folder for your personal review before the unit departs. If any anomaly is detected, it is routed back to our workshop for final servicing at our own cost.
3. Voltage Requirements (JDM vs. International)
- The 100V Requirement: True JDM (Japan Domestic Market) audio equipment is engineered strictly for Japan’s native 100V power grid. If you live in the US (120V), Europe/UK (230V), or Australia (240V), plugging the unit directly into your wall will damage the delicate vintage circuitry.
- The Solution: Operating a 100V unit on a high-quality, isolated step-down transformer is incredibly simple, safe, and does not degrade sound quality. Our team can recommend or supply the exact wattage transformer required for your specific model to ensure perfect, lifelong operation.
4. Duties, Taxes, & Currency
- Customs and Import Taxes: International shipments are subject to the import laws, customs duties, and VAT of your destination country. These fees are the sole responsibility of the buyer and are collected by the courier upon delivery (DAP / Delivered At Place). We handle all export customs paperwork flawlessly on the Japanese side to ensure swift clearance. We do not offer DDP (Delivered Duty Paid).
- Multi-Currency Secure Checkout: Our storefront allows you to securely browse and checkout in multiple major global currencies using fully encrypted methods, including international credit cards, Apple Pay, Google Pay, and Alipay.
- Exclusive 3% Wise Discount: For maximum efficiency, we recommend utilizing Wise (Bank Transfers) for your investment. Clients opting for Wise receive an exclusive 3% privilege discount, which stacks directly on top of our ongoing 8% to 10% cross-border tariff mitigation discounts. Contact our team prior to checkout to have this applied to your invoice.
5. Workmanship Warranty & Returns
- 15-Day Workmanship Warranty: We back our elite restoration craftsmanship with a dedicated 15-day warranty. If you encounter any unexpected operational issues upon unboxing, simply notify us within 7 days of delivery. Should a component require technical attention, we will immediately collaborate with you on an efficient solution, which may involve remote diagnostics or coordinating and subsidizing support with a qualified, third-party vintage audio technician local to your area.
- 15-Day Return Window: To qualify for a return, the item must be in its exact received condition, packed securely in its original specialized materials, and pre-approved with an official Return Authorization (RA) number. Approved returns are subject to a restocking fee to cover the complex logistics of international re-importation.
For a complete, transparent breakdown of our terms, step-by-step claims instructions, and restocking details, please review our official FAQ page and different policies on Terms of Service, Return and Shipping.