FiiO EA13 Full-Size Vacuum Tube Audio Power Amplifier – A First with Six Valves and 2 x 28 Watts in Class A

The newly unveiled FiiO EA13 Full-Size Vacuum Tube Audio Power Amplifier represents a notable first for the brand. For the first time, Guangzhou FiiO Electronics Technology Co. Ltd. has developed a stereo integrated amplifier in which both the voltage amplification and power stages rely entirely on valves. Two Sylvania NOS PCF80 valves are joined by four JJ Electronic EL34 output valves in a push-pull circuit operating in pentode mode and Class A. FiiO specifies an output of 2 x 28 watts into 8 ohms. With four analogue inputs, separate speaker connections for 4 and 8 ohm loads and a 6.3 mm headphone connection, the EA13 has been designed as the centre of a traditional stereo system rather than a purely technical statement.

Key Facts FiiO EA13 Full-Size Vacuum Tube Audio Power Amplifier

• Product: Analogue stereo valve integrated amplifier
• Positioning: FiiO’s first stereo valve integrated amplifier
• Circuit: Push-pull operation in pentode mode, Class A
• Valve complement: Two Sylvania NOS PCF80 and four JJ Electronic EL34
• Output: 2 x 28 watts into 8 ohms
• Inputs: Four analogue stereo inputs via RCA
• Outputs: Separate 4 and 8 ohm speaker terminals, 6.3 mm headphone connection
• Features: 40-step analogue volume control, mechanical stereo VU meters, 12 V Trigger
• Standby: Automatic after 30 minutes without an input signal

A New Product Category for FiiO

FiiO has built its reputation primarily around portable audio players, headphone amplifiers, D/A converters, streaming products and compact desktop components. The EA13 now takes the company into the traditional market for full-size stereo valve integrated amplifiers for the first time.

Crucially, this is not a hybrid design in which valves are used merely to add a particular character to one part of the signal path. Both voltage amplification and the output stage are valve-based. Input selection and volume control are integrated into the amplifier, removing the need for a separate preamplifier.

Six Valves Across the Amplifier Stages

Two Sylvania NOS PCF80 valves are used for voltage amplification. These originate from older stock and were originally manufactured by the US company Sylvania.

The output stage is equipped with four EL34 valves from the Czech manufacturer JJ Electronic. FiiO attributes an open and transparent presentation to the PCF80, while describing the EL34 as warm and full-bodied. These remain manufacturer claims that only a listening test can properly assess. What is technically clear is that all six valves play an active part in amplification.

Push-pull Class A Output Stage

The power amplifier uses a push-pull circuit operating in pentode mode and entirely in Class A. FiiO refers to classic valve amplifier designs from the 1950s as a technical influence, although the EA13 is not presented as a replica of any particular historic model.

Rated output is 2 x 28 watts into 8 ohms. That makes the FiiO EA13 principally suitable for efficient standmount speakers and appropriately chosen floorstanding designs. Power output alone, however, is not enough to determine a suitable pairing. Both sensitivity and impedance behaviour are particularly important when matching loudspeakers to a valve amplifier.

Purpose-built EI-core Output Transformers

The output transformers developed specifically for the FiiO EA13 perform a central role in the circuit. Their EI cores are made from laminated silicon steel, while the transformers themselves are potted using epoxy resin and fine sand before being housed in sealed enclosures.

This construction is intended to suppress mechanical vibration, improve electromagnetic shielding and protect the components against moisture. Separate speaker terminals are provided for loudspeakers with nominal impedances of 4 and 8 ohms, allowing the amplifier to be matched accordingly.

Separate Power Supplies for Audio and Control Circuits

Power for the digital control functions is kept separate from the supply serving the analogue audio circuitry. FiiO’s intention is to prevent elements such as the lighting and VU meter control system from introducing interference into the signal path.

The amplifier also uses axial metal-film coupling capacitors and large filter electrolytic capacitors from Nippon Chemi-Con. According to FiiO, these components were selected to support low losses, low distortion and a stable power supply.

40-step Analogue Volume Control

Volume is adjusted through a stepped analogue control offering 40 fixed positions. Each step uses matched precision resistors.

FiiO says this arrangement should provide consistent changes in level while keeping deviations between the left and right channels as small as possible. It is also intended to avoid the wear and low-level channel imbalance sometimes associated with conventional carbon-track potentiometers.

Four Analogue Inputs and 12 V Trigger

Four analogue stereo inputs on RCA sockets are fitted to the rear panel. These can accommodate sources such as a D/A converter, a streaming transport with an analogue output, a CD player or an external phono preamplifier. Input selection is handled from the front panel.

A 12 V Trigger input allows the EA13 to be switched on and off together with compatible components. If no input signal is detected for 30 minutes, the amplifier automatically enters standby. This reduces power consumption while also limiting unnecessary operating time for the valves.

Headphone Listening Comes with a Caveat

A single-ended 6.3 mm headphone connection is located on the front panel. Using it is not entirely straightforward, however: FiiO instructs owners to disconnect the speaker cables before listening through headphones.

For extended operation without loudspeakers attached, the manufacturer additionally recommends fitting suitable load resistors to the speaker terminals. This precaution is intended to prevent the valve amplifier from operating for long periods without an adequate load. The technical reasoning is understandable, but the procedure is considerably less convenient than an automatically switched internal load.

Mechanical VU Meters and Protected Valves

The FiiO EA13 features a comparatively substantial, CNC-machined and sandblasted aluminium front panel. Its one-piece chassis is intended to provide both mechanical stability and electromagnetic shielding.

The valves are recessed into the enclosure and protected by a large removable metal cover. Ventilation openings along the sides help dissipate heat, while vibration-damping feet are designed to reduce mechanical influences.

Two mechanical VU meters with LED backlighting display the level of each channel. Illuminated controls echo the warm colour of the meters without overwhelming the otherwise restrained design of the amplifier.

The Most Important Advantages at a Glance

• FiiO’s first stereo valve integrated amplifier: The EA13 introduces an entirely new product category to the company’s range.
• All-valve amplification: Two PCF80 and four EL34 valves handle voltage and power amplification.
• Class A operation: The push-pull output stage delivers 2 x 28 watts into 8 ohms.
• Flexible loudspeaker matching: Separate terminals are provided for loudspeakers rated at 4 and 8 ohms.
• Four analogue inputs: Several traditional HiFi sources can be connected without requiring a separate preamplifier.
• Precise volume adjustment: The analogue control offers 40 fixed positions using matched resistors.
• System integration: A 12 V Trigger input enables linked power control with compatible components.
• Reduced valve running time: Automatic standby is activated after 30 minutes without an input signal.
• Protected valve layout: The valves are recessed into the chassis and covered by a removable metal guard.

Price & Availability

Guangzhou FiiO Electronics Technology Co. Ltd. has yet to announce either the European price or a firm availability date for the FiiO EA13 Full-Size Vacuum Tube Audio Power Amplifier.

Getting to the point

The FiiO EA13 does not cautiously test the waters with a compact valve hybrid. It takes FiiO directly into the market for full-size stereo valve integrated amplifiers with six active valves, a push-pull Class A output stage and purpose-built output transformers. Four analogue inputs, a 12 V Trigger and automatic standby make the otherwise traditional amplifier concept easier to accommodate within a modern HiFi system. The headphone connection is the clear exception: disconnecting the loudspeakers and potentially fitting external load resistors is cumbersome in everyday use. Even with that limitation, the EA13 is a remarkably committed debut in this product category for Guangzhou FiiO Electronics Technology Co. Ltd.

Technical Specifications