Italian audio manufacturer Riviera Audio Laboratories has revised an existing preamplifier and power amplifier. The Special Edition version, the APL01SE preamplifier and the AFM100SE mono power amplifier, are Riviera Audio’s current flagship pair.
Reference tube preamplifier
According to its designers, the APL01SE represents the ultimate expression of Riviera’s preamplifier expertise. Every aspect of the design has been carefully optimized to prioritize musical performance over mere technical specifications.
The audio circuit is entirely tube-based and utilizes a Class A Zero Feedback configuration for exceptional musical results and remarkable technical performance. The SRPP design is optimized to deliver the specific type of distortion with a so-called auditory harmonic distribution that guarantees absolute transparency for the human ear, a hallmark of Riviera’s designs.
The power supply is linear and based on a transformer with a capacity of approximately 200 VA. Designed with music in mind, it utilizes unusual and elegant solutions such as a dual inductive Pigreco filter and a parallel stabilization circuit for controlling the anode supply. The APL01SE uses a total of six separate stabilized power supplies.
The balanced (true) inputs feature high-quality mu-metal core transformers with external mu-metal shielding. The volume control is equipped with a high-quality, motorized TKD potentiometer with an internal ladder configuration that is truly unmatched on the market. The result is comparable to that of the best step attenuators, while offering the fine-grained precision characteristic of a true potentiometer. Furthermore, the potentiometer is elastically mounted to the chassis to prevent vibration transfer.
The balance control is implemented with two separate potentiometers for left and right, mounted on the output to avoid the quality degradation typically encountered with the standard solution of two potentiometers cascaded on the input.
The output signal is routed through specially developed, exceptionally high-quality transformers for both balanced and unbalanced outputs. This ensures that both outputs deliver the same reference quality. Riviera believes that the mechanical behavior of a device, especially a preamplifier, significantly impacts the sonic output. Therefore, significant attention has been paid to the mechanical design. The APL01SE weighs over 25 kilograms, with many components milled from solid aluminum. Everything in this device is designed to contribute to a reference-quality output.
Riviera Audio APL01SE: Technical specifications
- All-tube audio circuit
- Class A, Zero Feedback
- Solid-state power supply with double pigreco filter, stabilized with unconventional circuitry.
- Five unbalanced line inputs (RCA)
- Two balanced line inputs (XLR) (transformer)
- 1 x Adjustable Aux Input
- Input/output for recording device
- Transformer outputs
- Two balanced + two unbalanced line outputs (suitable for multi-amping)
- Gain factor: 10.5 dB
- Input impedance: 47 kOhm
- Installed tubes: 2 x 6350/6463
- Remote control
- Dimensions: 44 x 49 x 19.5 centimeters
- Weight: 27 kilograms
The Riviera Audio AFM100 Special Edition power amplifier is a Class A reference mono power amplifier that combines all the core values of Riviera amplifiers. The AFM100SE also uses no feedback, features a hybrid design (tubes for voltage amplification, solid-state drives for power), and pure Class A operation. The AFM100 SE delivers 100 watts into 8 ohms in Class A (200 watts into 4 ohms) and is capable of driving loudspeakers with the utmost fidelity.
The voltage amplification is provided by a pure triode operating in Class A in the most linear manner possible, while the power amplifier section uses a total of twenty semiconductors, each capable of delivering 150 watts of power.
The power amplifier section’s power supply, which utilizes an oversized transformer rated at over 500 VA, is equipped with a sophisticated inductive Pigreco filter. The total smoothing capacitance is over 130,000 µF. The deliberate absence of current-limiting systems guarantees the amplifier’s stability, even under complex loads. Thanks to its refinement and control capabilities, it is suitable for use in both single-amplifier and multi-amplifier systems.
Specifications
- Power 100 Watts (at 8 Ohms)
- Class A, Zero Feedback
- Hybrid circuits
- 1 x unbalanced line input (RCA)
- 1 x balanced input XLR (transformer)
- Gain factor: 22 dB
- Input sensitivity: 220 mVrms for 1 Watt/8 Ohm (2.83 Vrms); 2.2 Vrms for 100 Watt/8 Ohm (28.3 Vrms)
- Input impedance: 47 kOhm
- Fitted tube: 1 x ECC82/12AU7
- Dimensions: 26 x 58.5 x 27.5 centimeters
- Weight: 35 kilograms
