A 300B amplifier delivering single-digit or low double-digit power is hardly unusual. Doing it for $1,499 while also providing a transformer-coupled headphone output, 4- and 8-ohm speaker taps, custom transformers and Cardas internal wiring is a much more interesting proposition.
That is what makes the Layer Audio Design GEN-300B worth a closer look after CanJam SoCal 2026. It is a single-ended Class A integrated amplifier designed to serve both headphone listeners and owners of suitably efficient loudspeakers, without wandering into the five-figure territory that has become increasingly common for ambitious 300B designs.
Who Is Layer Audio Design?
Layer Audio Design is a small direct-sales audio company with a very compact product catalog. Its current lineup includes the GEN-300B, a GEN-2A3 integrated amplifier, the Henry Audio DA256 DAC and several accessories, while the company describes its design philosophy as a combination of measurement, materials research, vibration control and extended listening.
There is not a long corporate history or decades-deep back catalog to lean on here, which matters when comparing Layer with established tube-amplifier manufacturers. The GEN-300B therefore has to make its case almost entirely on engineering, features and price, and that is where things become more interesting.
What Is the GEN-300B?
The GEN-300B uses a fully discrete, all-tube signal path built around two 6N8P driver tubes, two 300B output tubes and one 5AR4 rectifier. Layer operates the output stage single-ended in pure Class A and rates the amplifier at 10 watts per channel into 8 ohms, with separate 4- and 8-ohm speaker connections.
Ten watts clearly places some limits on speaker choice. The GEN-300B is intended for high-efficiency loudspeakers rather than insensitive floorstanders with difficult impedance curves, but that is hardly unusual for a single-ended 300B design. The more distinctive part of the package is what Layer has done for headphone users.
Rather than installing a separate solid-state headphone stage, the front headphone output is tube-driven and transformer-coupled from the main amplifier circuit. In other words, headphone listeners are not buying a 300B speaker amplifier with an unrelated headphone circuit tacked onto the front panel.
Inside the GEN-300B
Layer specifies custom-wound Japanese transformers, Amtrans film capacitors and Cardas internal wiring through the signal and power paths. The company notes that the Amtrans capacitors come from the same component series used in Audio-Technica’s NARUKAMI amplifier, although sharing a capacitor family obviously does not make the two amplifiers equivalent designs.
Connectivity remains deliberately simple. The amplifier provides an RCA line-level input and a direct power-amplifier input for use with an external preamplifier, while Bluetooth is available as an option with Layer stating that the wireless module is electrically isolated from the analog circuitry. There is no built-in DAC or network streaming platform, so this remains an analog integrated amplifier first.
Layer Audio Design GEN-300B Specifications
| Specification | GEN-300B |
|---|---|
| Amplifier topology | Single-ended pure Class A |
| Output power | 10W/channel into 8 ohms |
| Output tubes | 2 x 300B |
| Driver tubes | 2 x 6N8P |
| Rectifier | 1 x 5AR4 |
| Inputs | RCA line level, direct power amp |
| Optional input | Bluetooth |
| Speaker outputs | 4 ohms / 8 ohms |
| Headphone output | Tube driven, transformer coupled |
| Internal wiring | Cardas |
| Dimensions | 13.19 x 8.27 x 10.43 inches |
| Weight | 36 lbs / 16 kg |
There are still some meaningful gaps in the published specifications. Layer does not currently list frequency response, THD, signal-to-noise ratio, headphone output power, headphone output impedance or input sensitivity, all of which would be useful when matching the GEN-300B to a broader range of headphones.
There is also a small inconsistency in Layer’s own documentation. The September production page lists the amplifier at 40 pounds, while the December preorder page lists 36 pounds with the same chassis dimensions, so I would wait for Layer to clarify the final weight before treating either figure as definitive.
What About Difficult Headphones?
Layer says the standard front-panel headphone output was designed around safe operation and broad compatibility rather than maximum output into the most demanding planar-magnetic headphones. The company subsequently developed the COPULA, a speaker-tap-to-4-pin-XLR adapter that connects directly to the GEN-300B’s binding posts and provides access to considerably more of the amplifier’s available output.
That solution is aimed at unusually inefficient headphones rather than conventional models or IEMs. Layer specifically warns against treating the speaker taps as a universal headphone output, which is sensible advice when the source on the other end is capable of delivering several watts.
Why Is It Unique?
None of the individual ingredients are revolutionary. Single-ended 300B amplifiers have existed for decades, transformer-coupled headphone outputs are well established, and 8 to 10 watts per channel is familiar territory for this topology.
What is unusual is getting all of those elements in one chassis for $1,499. Once custom output transformers, tube rectification, speaker taps and a serious headphone implementation enter the equation, 300B amplifiers usually become expensive rather quickly.
Layer’s relatively low pricing makes the established alternatives particularly revealing. For example, Woo Audio’s WA5 (2nd gen) is priced considerably higher at $6,499, while Feliks Audio Eos reaches nearly $14,000.
Price & Availability
Layer Audio Design’s website lists pricing from $1,499 to $1,939. Bluetooth, finishes, headphone-output configuration and optional Cuprum isolation feet can alter the final price depending on the chosen configuration. However, a BATCHDEC26 coupon code currently takes $150 off the regular price.
Ultimately, pricing is likely to be the GEN-300B’s biggest advantage and its biggest question mark. Custom transformers, tube rectification, Cardas wiring and a transformer-coupled headphone output are not the ingredients one normally associates with a 300B amplifier at its price point. So long-term reliability, consistency between production batches and support will matter every bit as much as the parts list.
The Bottom Line
The Layer Audio Design GEN-300B is not interesting because it changes what a 300B amplifier can do. It is interesting because Layer is offering a legitimate single-ended Class A design with 10 watts per channel, speaker outputs and a proper tube-driven headphone connection at a price well below most established alternatives.
There are still technical questions that need answers, particularly around headphone output, distortion and the conflicting published weight figures. Layer also lacks the long track record of Woo Audio, Cayin or Feliks Audio, which is something buyers should consider before treating an aggressive introductory price as the only criterion.
But as one of the more unexpected products to emerge from CanJam SoCal 2026, the GEN-300B has a very clear reason to exist. At $1,499, it makes the economics of serious 300B amplification considerably harder to ignore.
For more information: layeraudiodesign.com
Related Reading:
- Best In Show At CanJam NYC 2026: The Headphones, DACs, Amps, And IEMs Everyone Was Fighting To Hear
- The Best DACs, Headphone Amps And DAPs From CanJam London 2026
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