Article · Published 2026-10-29
Demograf Endymion and Audio Note Ongaku compared: single-ended 211 and 845 amplifiers
The 211 and the 845 are transmitting triodes used in several single-ended amplifiers, among them the Audio Note Ongaku, a 211 integrated amplifier from Audio Note (UK). This guide puts the Demograf Endymion, which is built for the 845, the 211 or the 805, next to the Ongaku and its copper-wired sibling, the Jinro. It sets out circuit, tubes, power, outputs, size and how each is sold, using the makers' own published data, and then suggests how to decide. It does not rate the sound of any of them: we have not measured or listened to the Ongaku or the Jinro, and numbers on a data sheet do not settle how an amplifier sounds in your room.
Endymion, Ongaku and Jinro in short
- Tubes. All three are single-ended class A amplifiers on a directly heated transmitting triode. The Ongaku and the Jinro use the 211; Endymion is built for the 845 as standard, with the 211 or the 805 to order.
- Power. Audio Note gives about 20 W per channel into 4 or 8 Ω for both models. Endymion is rated at 20 W per channel with the 845, 15 W with the 211 and 25 W with the 805, all at 8 Ω, and a push-pull build doubles that.
- Headphones. Endymion has a 6.3 mm and a 4-pin XLR headphone output as standard, and other connectors, including an electrostatic one, on request. Neither Audio Note page lists a headphone output.
- Price. Audio Note does not show prices on its product pages; they are quoted on request. Endymion is made to order from about $37,200.
Specifications side by side
| Demograf Endymion | Audio Note Ongaku | Audio Note Jinro | |
|---|---|---|---|
| Circuit | Single-ended, pure class A, integrated; push-pull to order | Single-ended, pure class A, integrated, zero negative feedback | Same circuit and topology as the Ongaku, with copper instead of silver wiring |
| Output tubes | 2 × 845 (211 or 805 to order) | 2 × 211 / GE VT-4C | 2 × 211 |
| Other tubes | 2 × AL4 (EF55 to order); rectifier 4 × 6D22S (2 × 5C3S to order) in a separate power supply | 1 × CV4068, 1 × 6463; rectifier 2 × 5R4WGB | 1 × ECC82 / 5814A, 1 × 7044; rectifier 2 × 5R4WGB |
| Rated output | 845: 20 W, 211: 15 W, 805: 25 W per channel at 8 Ω; double in push-pull | About 20 W per channel into 4 or 8 Ω | About 20 W per channel into 4 or 8 Ω |
| Loudspeaker impedance | 8 Ω; 4 Ω or 16 Ω winding on request | 4 or 8 Ω | 4 or 8 Ω |
| Inputs | Analogue RCA (balanced XLR on request) | Line level, 100 kΩ, 450 mV for full output | Line level, 100 kΩ, 450 mV for full output |
| Headphone outputs | 6.3 mm and 4-pin XLR; 2.5, 3.5, 4.4 mm, dual 3-pin XLR or electrostatic on request | Not listed on the maker's page | Not listed on the maker's page |
| Volume control | ALPS potentiometer (stepped attenuator optional); ground-lift switch | Not stated on the maker's page | Not stated on the maker's page |
| Mains | 100, 120 or 230 V, set at order time | 100–120 V or 220–240 V, 50/60 Hz; 200 W | 100–120 V or 220–240 V, 50/60 Hz; 200 W |
| Weight and size | From 45 kg; from 450 × 450 × 250 mm, with a separate power supply chassis | 48 kg; 305 × 305 × 640 mm (h × w × d) | 38 kg; 305 × 305 × 640 mm (h × w × d) |
| Warranty | One year (extra +1 or +2 years) | Not stated on the product page | Not stated on the product page |
| Price | From about $37,200, made to order | Not shown on the maker's page; on request | Not shown on the maker's page; on request |
| Made in | Kazakhstan, by Dmitriy Gubchenko | United Kingdom | United Kingdom |
Audio Note data from the maker's pages, audionote.co.uk/ongaku and audionote.co.uk/jinro, read on 29 October 2026; Endymion data from our model page and the price list of 27 October 2026 (the model page shows the current price). We have not measured or listened to the Ongaku or the Jinro. Audio Note, Ongaku and Jinro are trademarks of their owner, with which we are not affiliated.
211 or 845?
Both tubes were designed as transmitting triodes, both run at plate voltages of around a thousand volts in a single-ended amplifier, and both give roughly 15 to 25 W in single-ended class A, which is several times what a 300B gives. The difference is in how they are driven: the 211 has a higher amplification factor and needs a smaller drive signal, the 845 a lower one and a larger swing from the driver stage. That is why the driver tubes differ so much between these designs. Audio Note builds the Ongaku around the 211; Endymion takes the 845 as standard and the 211 or the 805 to order, so the output tube is a choice you make at order time rather than a fixed property of the model. Our guides to the 300B and the 845 and to transmitting tubes in single-ended amplifiers cover the tubes in more detail.
Twenty watts and your loudspeakers
At about 20 W, all three amplifiers drive a wider range of loudspeakers than a 300B or a 2A3 design, but they are still single-ended triode amplifiers: the first watts are delivered gently and the headroom ends sooner than with a large push-pull or solid-state amplifier. A loudspeaker around 90 dB at 1 W and 1 m in a medium room is a sensible lower limit; efficient designs such as our Cassandra at 95 dB leave plenty in reserve. Our guide to loudspeakers for single-ended amplifiers has the sensitivity-by-power table, and single-ended or push-pull explains what the push-pull Endymion trades for its doubled power.
Headphones
This is the clearest difference in the published specifications. Endymion is described as a universal amplifier for loudspeakers and headphones: the 6.3 mm and 4-pin XLR outputs are standard, and 2.5 mm, 3.5 mm, 4.4 mm, dual 3-pin XLR or an electrostatic output can be fitted to order, so the same chassis can drive planar, dynamic or electrostatic headphones. The Audio Note pages describe loudspeaker amplifiers and do not list a headphone output. If you listen on headphones as well as loudspeakers, that alone may decide the question; the headphone amplifiers page compares all our models with a headphone output.
Silver, copper and the separate power supply
Audio Note publishes its building materials in detail: the Ongaku is wired in silver throughout, including the transformer windings, with tantalum resistors and Black Gate or Audio Note silver-foil capacitors; the Jinro uses the same circuit with copper in place of silver, and the two differ in weight (48 and 38 kg). Endymion puts its rectifiers, four 6D22S kenotrons with choke filtering and galvanic isolation, in a separate chassis, uses custom-wound transformers and is wired with our own RareCoreFusion alloy wire, with other wire on request. Materials lists are useful for understanding where the money goes; they are not, on their own, a measure of sound.
Price, and how each is sold
Audio Note (UK) does not show prices on its product pages, so ask Audio Note or its representative in your country for a quotation for the Ongaku or the Jinro. Endymion is built to order, one at a time, in Kazakhstan: the lead time is 6 months or longer and a 50 % deposit reserves your place in the queue, with the balance due after the measurement report of your unit, before shipping. The output tube (845, 211 or 805), single-ended or push-pull, the headphone connectors and the mains voltage are fixed in the quotation. Shipping and insurance are paid by the buyer and shown as a separate line in your quotation. What goes into the price of a made-to-order tube amplifier is set out in what a tube amplifier costs and what you are paying for.
How to decide
- Start with the loudspeakers. Note their sensitivity and impedance and the room size; at about 20 W, check that a single-ended amplifier is enough, or consider a push-pull Endymion.
- Decide about headphones. If you need a headphone output, name the connector and make sure it is offered.
- Choose the tube. If you already prefer the 211, the 845 or the 805, check which models take it.
- Ask for prices and terms. Get a written quotation from Audio Note's representative and from us, with delivery and warranty spelled out.
- Check the mains. Confirm the voltage and plug for your country with either maker.
- Plan the space. All three weigh 38 kg or more, and Endymion has a second chassis for the power supply; measure the shelf before you order.
Questions
Is a 211 amplifier the same as an 845 amplifier?
No. The tubes share a base and run at similar voltages, but they need different drive and different operating points, so an amplifier is designed around one of them. Endymion can be built for the 845, the 211 or the 805; the choice is made before the build starts.
Can a 20 W single-ended amplifier drive ordinary loudspeakers?
Often, yes, in a normal room with loudspeakers of about 90 dB or more. With low-sensitivity loudspeakers or a large room, a push-pull design gives more headroom.
Can Endymion drive electrostatic headphones?
Yes, with an electrostatic output fitted to order. The electrostatic headphone amplifiers page explains what such an output involves and which models take it.
Write to us by e-mail or WhatsApp with your loudspeakers, your headphones and your room, and we will tell you plainly which Endymion configuration fits.