Helios MkII
from $22,900 Made to order
Request a build slot Deposit, lead time and warrantyAll units in the photos are real. Some photos are AI-enhanced to improve image quality.
Headphones and loudspeakers
Headroom for hard-to-drive headphones
Its headroom is aimed at hard-to-drive planar headphones as well as sensitive loudspeakers.
Sound
Detailed and holographic
The presentation is detailed and holographic, with a punchy, easy bass.
Made to order
Silver capacitors, custom-wound iron
Two chassis: the amplifier and an external supply with a kenotron rectifier, galvanic isolation, custom-wound transformers and chokes. Mundorf silver capacitors are part of the standard build.
Helios MkII
Numbered unit — Opus No. on the nameplate
- Model
- Class A single-ended integrated amplifier on G-811 triodes, 15 W
- In brief
- Single-ended pure Class A, 15 W per channel, on two chassis.
- Queue deposit
- 50% · from $11,500
- Lead time
- Seven pieces of gear a year, each built by hand to order. Current lead time: six months or more.
- Push-pull (PP)
- The stock build is single-ended. A push-pull version is built to order for +50% of the price. Push-pull from $34,400 Request a push-pull build
- Origin
- Made in Kazakhstan by Dmitriy Gubchenko
- Warranty
- 1 year (extra warranty available: +1 or +2 years)
Part of the Dominion collection
- Music it suits
- Vocal · jazz · rock · demanding planar headphones
-
- Inspired by the Altec Lansing 1570B
From the atelier
Helios MkII is a single-ended Class A integrated on G-811 triodes, 15 W per channel. It was designed with the Altec Lansing 1570B monoblocks as the reference point, and its headroom is aimed at hard-to-drive headphones such as the HiFiMan HE-6 or Audeze LCD-3 as well as sensitive loudspeakers. The presentation is detailed and holographic, with a punchy, easy bass. Note that the G-811 and the original RCA 811 are different tubes from modern budget derivatives such as the SV811-10.
We state the power the amplifier delivers in pure Class A at the stated distortion; the figure comes from the unit’s own measurement report.
All tube amplifiers are built as two-chassis designs by definition, with a galvanic-isolation transformer and a ground-lift switch.
Two chassis: the amplifier and an external power supply with a kenotron rectifier, galvanic isolation, custom-wound transformers and chokes. Mundorf silver capacitors are part of the standard build.
- Output: 2 × G-811 (811 / 811A or EU/US equivalents optional)
- Driver: 6P3S; input: 6Zh4
- Rectifier: 2 × 6D22S or 1 × 5C3S
| Component | Manufacturer | Country of origin |
|---|---|---|
| Output tubes G-811 | NOS, selected | US / EU / UK (NOS) / Other Vintage |
| Driver tubes 6P3S | NOS, selected | US / EU / UK (NOS) / Other Vintage |
| Input tubes 6Zh4 | NOS, selected | US / EU / UK (NOS) / Other Vintage |
| Rectifier tubes 6D22S | NOS, selected | US / EU / UK (NOS) / Other Vintage |
| Signal capacitors | Mundorf (Silver) | Germany |
| Transformers and chokes | Demograf Audio (custom-wound) | or analog by Hashimoto / Tango / Tamura |
| Volume control | ALPS | Japan |
Photo {n} of {total}
Simplified diagram of the stock configuration. The exact circuit for your options is confirmed with the atelier.
When delivering to countries that have imposed sanctions, we do not install sanctioned components; we fit vintage and modern equivalents instead.
Specification
Download the brochure PDF · EN · 0.8 MB
Measured on the stock configuration; options may change the figures.
- Use
- Universal: loudspeakers and headphones
- Output power
- 15 W per channel at 8 Ω (Push-Pull version with double power available on request)
- Amplifier class
- Pure Class A
- Channels
- 2 (Stereo)
- Inputs
- Analogue RCA (Optional: Balanced XLR)
- Headphone outputs
- 1 × 6.3 mm TRS, 1 × XLR 4-pin (Optional: 2.5 mm, 3.5 mm, 4.4 mm Pentaconn, dual XLR 3-pin, or Electrostatic/EST connector)
- Speaker outputs
- Standard binding posts (Demograf Audio terminals optional)
- Load impedance
- 8 Ω (Optional: 4 Ω / 16 Ω customisation)
- Output tubes
- 2 × G-811 or other types optionally
- Driver tubes
- 6P3S
- Input tubes
- 2 × 6Zh4 or other types optionally e.g. EL8 / ML6 etc.
- Rectifier tube
- 2 × 6D22S for a warmer/darker tone or 1 × 5C3S for a brighter signature (option)
- Volume control
- ALPS potentiometer (Demograf Audio stepped attenuator optional)
- Internal wiring
- Proprietary “RareCoreFusion” Alloy wire (other options available)
- Special features
- Ground Lift switch (selectable ground loop isolation)
- Mains
- 100 / 120 / 230 V — set at order time, plug to match (NEMA, Schuko, BS 1363 / type G)
- Weight (with power supply)
- From 45 kg / 99 lb
- Dimensions
- From 450 × 450 × 250 mm
Custom options
Stock items are included in the price. Every option is agreed with the atelier before the build starts.
Circuit
- MkII Single-Ended (classic detailed sound) Stock
- MkII Push-Pull (double the output power, a fuller midrange and bass) +50% from $34,400
Input tubes
- 6Zh4 tubes Stock
- EL8 Valvo — for more detailed sound
- AL4 — for heavier bass and midrange
- EF14 — for a more natural midrange, e.g. opera and symphonic music
- ML6 — for more neutral sound
Rectifier tube
- 6D22S — for darker sound Stock
- 5C3S — for brighter sound
- Other Type (on request)
Output tubes
- G-811 Stock
- 811 tubes
- 811A tubes
- Other Similar Tube (EU / US)
Power-supply tubes
- Tubes Stock
- Premium Vintage Tubes
Component upgrades
- Premium Capacitors Suite (Duelund)
- Tango, Tamura or Hashimoto transformers and chokes, fitted on request
- Silver AMRG Resistors & Premium Cardas Wiring Kit
- High-End Connectors Suite (e.g. Furutech Top-Tier plugs)
- Solid-core Copper Speaker Connectors
- Premium Solid-core Copper Connectors with Galvanic Gold/Silver Plating
- Integrated Tone Control Block Module / Filter
- Transformer taps for 4 or 16 Ω (additional winding)
- Bi-wiring integration supplement
- Tri-wiring integration supplement
- One additional Analogue RCA Input
- One additional Analogue XLR Balanced Input
- Demograf Audio High-End Swiss-Stepped Pre-Amp (similar to Stevens & Billington TX-103)
- Variable GAIN Control Module
- 4.4 mm Pentaconn Output Termination
- Dedicated STAX Electrostatic Output Interface
- Fully Balanced XLR Amplifier Architecture
- Additional Reserve Matched Pair of low-noise Tubes
Mains inlet, outlets & contacts
- AC Input: Standard Spec — IEC C14 Chassis Input Stock
- AC Input: Heavy-Duty Spec — IEC C20 High-Current Inlet
- AC Output: European Standard — Schuko (Type F)
- AC Output: US / Japan Standard — NEMA 5-15R (Type B)
- AC Output: British Standard — BS 1363 (Type G)
- AC Output: Universal Interface — Direct IEC C13 Outlets
- Contacts: Pure Copper Unplated (Organic & Balanced Tone) Stock
- Contacts: Gold Plated e.g. Furutech FI-09(G) (Warmth & Rich Midrange Texture)
- Contacts: Rhodium Plated e.g. Furutech FI-09(R) (Fast Transients & Fine Detail)
Finish & chassis
- Standard configuration Stock
- Priority build (+50% of the price)
- Precision-Milled Metal Chassis (CNC milling)
- Contoured Bent-Metal Enclosure
- Exotic Hardwood Chassis
- Glass-Integrated Aesthetic
- Premium Wood Inlays & Accents
- Solid-Billet Metal Enclosure
- Advanced Galvanic Finishing
- Custom Dimensions & Form Factor
- Parameter Status Display
- Multifunction Remote Control Suite
- Protective tube cage (child & pet safety)
Regional version
- 230 V — Schuko plug (Europe) Stock
- 120 V — NEMA plug (North America)
- 100 V — NEMA plug (Japan)
- 230 V — BS 1363 / type G plug (UK · Middle East)
Pairs well with
Which tubes does the Helios MkII use?
Stock tubes are G-811 output triodes, a 6P3S driver, 6Zh4 input tubes and two 6D22S rectifiers. 811 and 811A tubes can be fitted instead; a reserve matched pair is available.
How is the Helios MkII serviced?
Each unit ships with its own measurement report. The circuit is kept simple and serviceable, and Demograf Audio gear is serviced for as long as parts exist.
How is it delivered?
Shipping and insurance are paid by the buyer and shown as a separate line in your quotation. Every unit is packed for long-distance transport in heavy-duty flight cases and a wooden crate.
Which mains voltage and plug?
Each piece of gear is built for 100 V, 120 V or 230 V mains with the matching plug (NEMA, Schuko or BS 1363 / type G). The voltage is fixed at order time, so tell us where the unit will be used.
How long does the Helios MkII take to build?
Build time is six months or more from the queue deposit, depending on the configuration and the queue; delivery takes from one month after completion. The atelier builds seven instruments a year. A priority build is available for an extra 50% of the price: your unit is moved ahead in the build queue.
* Photos are taken from real systems and show the specific configuration of a particular customer; your unit can look the way you want — all our equipment is fully customisable.
