Unison Research S6 Black Edition Tube Integrated Amplifier
Need advice? Want a price match?
Talk to Mike
Third-generation owner
Call or text: 410-239-2020Yes, that's literally his cell
Family-Owned Authorized Dealer
Family-Owned Authorized Dealer
We're an authorized dealer for every brand listed on this site, so your warranty is valid and fully supported. We're a real brick-and-mortar shop in Chestertown, MD with shelves of actual inventory, not a drop-shipper. Family-owned and run for three generations, since 1978.
Delivery and Shipping
Delivery and Shipping
Free shipping for most items over $100! Local delivery up to 500 miles more with minimum qualifying purchase.
See our shipping policies for details. We will contact you after your order.
Unison Research S6 Black Edition Tube Integrated Amplifier
The Unison Research S6 Black Edition celebrates one of Unison Research’s most iconic amplifiers with enhanced technical design and a refined, modern look. With a power output increased to 40W and a sleek, piano-black wood panel and gunmetal finish, the S6 Black Edition is crafted to satisfy the most discerning audiophiles. Each detail, from the circuitry to the innovative input selection, has been reimagined to deliver pure Class A amplification that’s as beautiful to hear as it is to behold.
Unison Research New Special Editions
In celebration of Unison Research’s legacy, the S6 Black Edition is part of a special series, joining Black Editions of the Simply Italy and Triode 25 amplifiers. Each model in this exclusive collection features advanced technical upgrades and a refined, piano-black wood finish. With its enhanced circuitry, increased power output, and meticulous craftsmanship, the S6 Black Edition is crafted for audiophiles who seek both sound and sophistication. Be sure to explore the other Black Edition models for a complete Unison Research experience that combines style with substance.
S6 Black Edition Key Features
- Dual Mono Amplification: Enhanced for optimal soundstage and separation.
- Cathode Capacitor-Less Technology: Eliminates phase shift and low-frequency coloration, achieving a rich, natural sound.
- Advanced Input Selection Circuit: Micro relays and Return GND technology minimize noise and maximize channel separation.
- Integrated DAC3 Module: 4 analog and 3 digital inputs (USB up to PCM 384kHz and DSD256, Toslink, and SPDIF) for versatile connectivity.
Revolutionized Sound Quality
The S6 Black Edition introduces Cathode Capacitor-Less technology, removing traditional electrolytic capacitors from the power valves’ cathodes. This breakthrough in design maintains the integrity of the low frequencies, providing a clean, detailed response down to the lowest harmonics. By operating entirely in Class A with an ultralinear 20% tap, the S6 produces a sound that is richly dynamic and immersive, reproducing subtle micro-details with enhanced clarity.
Optimized Power Management
Featuring a 7-section winding transformer, the S6 Black Edition is built to drive demanding modern loudspeakers, delivering a consistent 40W output for precise, effortless audio reproduction. The dedicated negative grid voltage power supply enhances control and stability, while carefully positioned polypropylene capacitors in the power supply ensure smooth transients and expansive dynamics.
Exclusive Gold Lion Valves
Equipped with premium Gold Lion tubes, including two ECC83 triodes for preamplification and six KT77 tubes in parallel for output, the S6 Black Edition is fine-tuned for peak technical and acoustic performance. These valves are matched to deliver a lifelike sound experience, with an open, vibrant presentation free from distortion or feedback.
The Listening Room Experience
Your listening space is unique, and so are your needs. That's why we take the time to understand your preferences, your room acoustics, and your sonic dreams. We'll guide you through our range of hi-fi options, ensuring you find the perfect match for your space and budget. We believe in personal connections, exceptional service, and expert advice because when it comes to sound, there's no one-size-fits-all solution. Contact us to learn more.
Specifications
| Specification | Detail |
|---|---|
| Output power | 40W on 6Ω |
| Signal valves | 2 x ECC83 Gold Lion |
| Output power valves | 3 x KT77 Gold Lion in parallel for each channel |
| Input Selector | Relay Input Selector with Return GND Technology |
| Circuit Technology | Cathode Capacitor Less (CCL) technology, no autobias |
| Noise Level | Noiseless as a solid-state amplifier |
| Polarisation | pure Class A in ultralinear configuration with tap at 20% (power valves) |
| Bias | Adjustable for each power valve |
| Inputs | 4 line RCA, 1 USB, 1 SPDIF, 1 Toslink |
| Outputs | 1 subwoofer RCA (stereo) |
| Bandwidth (-1dB) | 15Hz – 30kHz |
| Dimensions (x y z) | 35 x 49 x 22 cm |
| Weight | 25Kg |
How is the S6 Black Edition different from the standard S6?
How is the S6 Black Edition different from the standard S6?
Unison Research rebuilt the output stage. The Black Edition uses six KT77 Gold Lion tubes, three in parallel per channel, where the standard S6 used six EL34s, and it is rated at 40 watts into 6 ohms, 15% more than the standard model. The standard S6 mixes automatic and manual bias; the Black Edition drops the auto-bias entirely and biases the output tubes from a dedicated negative grid supply, which lets Unison remove the electrolytic capacitors from the output tube cathodes. It also adds a DAC with USB, coaxial and Toslink inputs, and extends the -1dB bandwidth down to 15Hz.
How do I set the bias on the S6 Black Edition?
How do I set the bias on the S6 Black Edition?
With the front meter and the bias pots, one output tube at a time. Unison recommends checking after each power-on. Press the V2 button for the left or right channel, then turn the matching V2 pot until the needle sits exactly between the green and red zones. Repeat for V3 and V4, then run the whole cycle once more, because the three parallel output tubes interact slightly. A needle in the green lowers power and raises distortion; a needle in the red shortens tube life sharply. An Allen key is included.
What speakers suit the S6 Black Edition?
What speakers suit the S6 Black Edition?
Unison designed the output transformer, with seven winding sections, for maximum power transfer into 6 ohms, and rates the amplifier at 40 watts per channel into that load. There is one speaker output per channel rather than a choice of taps. Unison publishes no minimum speaker sensitivity, so match it on your speaker's impedance and efficiency. Get in touch with Mike with the model you plan to use.
Can the S6 Black Edition play digital sources and feed a subwoofer?
Can the S6 Black Edition play digital sources and feed a subwoofer?
Yes to both. Alongside four RCA line inputs it has USB, coaxial S/PDIF and Toslink inputs feeding a Sabre ES9018K2M DAC. USB handles PCM up to 384kHz and native DSD up to DSD256 (DoP up to DSD128); the coaxial and optical inputs take up to 192kHz. Unison posts the USB drivers and the DAC manual on the S6 Black Edition page of its website. There is also an unfiltered subwoofer output for connecting a powered sub.
Is the S6 Black Edition set up for US 120V power?
Is the S6 Black Edition set up for US 120V power?
Yes. Unison Research sets the mains voltage at the factory for the country each amplifier ships to, and the user cannot change it, so a unit for the US is built for US mains. On 100 to 130V units the mains fuse is a 6.3A slow-blow. Allow about 30 seconds after switch-on before turning the volume up; Unison says it sounds its best after about 15 minutes.
