Audio Hungary QUALITON A35i Integrated Amplifier

Audio Hungary Qualiton A35i Integrated Tube Amplifier

35 Watts per Channel. 7581A Vacuum Tubes. Automatic Bias System. Custom Toroidal Transformers. Hungarian High-End Engineering.

The Audio Hungary Qualiton A35i Integrated Amplifier combines traditional vacuum tube amplification with modern engineering, precision control and exceptional attention to transformer design.

Delivering 2 × 35 watts into suitable 4-ohm or 8-ohm loudspeakers, the Qualiton A35i is designed for listeners seeking the distinctive experience of a premium valve amplifier without sacrificing everyday convenience.

Its carefully developed circuit features four 7581A output tubes, two 12AX7 and two 6922 small-signal tubes, a proprietary Automatic Bias System and custom-manufactured toroidal transformers.

Three RCA stereo inputs, one balanced XLR stereo input, relay-controlled source selection and motorised ALPS volume control provide practical connectivity for a contemporary high-end audio system.

With an elegant minimalist chassis, remote operation and a relatively compact footprint, the A35i brings together classic valve technology and modern integrated amplifier functionality.

35 Watts per Channel of Premium Tube Amplification

The Qualiton A35i delivers a manufacturer-rated 35 watts per channel, using four 7581A output tubes across its two stereo channels.

In comparison with the earlier Qualiton A20i platform, the updated amplifier benefits from higher-output valves, revised transformer engineering and more sophisticated electronic control.

The 35-watt output rating makes the A35i suitable for a broad selection of appropriately matched loudspeakers.

As with any amplifier, final compatibility depends on speaker sensitivity, impedance behaviour, listening distance, room acoustics and preferred playback levels.

Four 7581A Power Tubes

The output stage of the Qualiton A35i tube integrated amplifier is designed around four 7581A beam tetrode vacuum tubes.

These high-performance valves are employed in matched sets, helping the manufacturer maintain consistent operating conditions across the output stage.

The standard factory tube complement consists of:

• 4 × 7581A power output tubes
• 2 × 12AX7 small-signal tubes
• 2 × 6922 small-signal tubes

All eight vacuum tubes are included as part of the manufacturer’s published package contents.

Tube Rolling with Automatic Bias

One of the A35i’s most attractive engineering features is its proprietary Automatic Bias System.

According to Qualiton, the amplifier is designed to accommodate compatible 7581A, 6L6, 5881, KT66 and KT77 output tube types without requiring modifications or manual bias adjustment.

The system continuously monitors output tube behaviour and adjusts the operating bias conditions.

It also works to equalise the quiescent currents of the power valves, an important consideration when using high-permeability transformer cores.

Important: Use only tube types and matched configurations expressly approved by the manufacturer. Tube substitution must follow the operating instructions and electrical safety requirements.

Automatic Bias System and Tube Management

The following genuine technical image from the Chameleon Audio media library illustrates the Automatic Bias System.

The manufacturer-designed control circuitry helps maintain balanced operation of the output tube stage throughout normal use.

Integrated Soft-Start Protection

The Automatic Bias System incorporates a soft-start function intended to prevent excessive output tube current during initial power-up.

This controlled start-up also helps reduce unwanted switching noises associated with amplifier activation.

By managing the initial operating conditions of the valves, Qualiton combines convenient operation with careful protection of its precision output stage.

Custom-Built Toroidal Output Transformers

Qualiton places particular emphasis on transformer construction, a critical aspect of vacuum tube amplifier engineering.

The A35i employs proprietary output transformers designed and manufactured in the company’s own transformer workshop.

These transformers use large-cross-section, high-permeability toroidal magnetic cores.

The manufacturing process incorporates specialised winding arrangements with multiple sections and controlled layer placement to support the intended electrical bandwidth.

The finished assemblies are housed in metal shielding enclosures and potted using epoxy compound to reduce mechanical vibration.

Qualiton Transformer Engineering

This authentic technical photograph from Chameleon Audio illustrates the custom output transformer construction.

Transformer design plays an essential role in the electrical performance of a valve amplifier, affecting impedance matching, frequency response and power handling.

Custom Toroidal Power Transformer

The A35i’s power transformer is also designed and manufactured in-house.

It uses a high-permeability toroidal core and a carefully developed winding arrangement intended to maintain efficient operation under demanding conditions.

Qualiton specifies double electromagnetic shielding for its power transformers, together with epoxy potting to reduce vibration and mechanical noise.

These engineering measures complement the output transformer construction and the amplifier’s dedicated power supply design.

Three RCA Inputs and One Balanced XLR Input

The Qualiton A35i offers four stereo line-level analogue inputs:

• 3 × stereo unbalanced RCA inputs
• 1 × stereo balanced XLR input

This configuration makes it possible to connect compatible digital-to-analogue converters, network streamers, CD players and external phono stages.

The amplifier is an analogue integrated amplifier. Its published specifications do not include an internal DAC or phono stage.

Precision Relay-Controlled Input Selection

Source selection is handled through a network of precision miniature Japanese relays.

Qualiton specifies relay contacts using gold-overlaid silver contact materials selected for reliable switching and low contact resistance.

Front-panel indicator LEDs show which input is currently selected, combining convenient operation with the amplifier’s understated appearance.

Motorised ALPS Volume Control

The A35i uses a high-quality motorised ALPS volume potentiometer.

ALPS is a recognised manufacturer of precision electronic control components.

The motorised arrangement allows listening volume to be adjusted directly from the amplifier or through the supplied remote control.

The control is integrated into the amplifier’s analogue signal path as part of its line-level volume management system.

Four-Function Remote Control

The supplied remote control provides four essential operations:

• Volume increase
• Volume decrease
• Mute
• Input selection

The remote features a minimalist matte-black design that complements the A35i’s restrained industrial styling.

Premium Components and Selected Tubes

Audio Hungary employs carefully chosen components in the A35i, including:

• Tested and matched output tube sets
• Low-noise selected small-signal tubes
• Gold-plated ceramic tube sockets
• Gold-plated audio terminals
• Film capacitors in the audio circuitry
• Selected ceramic composition resistors
• Long-life, high-temperature-rated power supply capacitors

Component selection is one part of Qualiton’s broader design approach, which combines mechanical construction, transformer development and electronically managed valve operation.

Extended Frequency Response

Qualiton specifies two frequency response conditions for the A35 platform:

5Hz to 85kHz (-3dB) at 1 watt and 22Hz to 80kHz (-3dB) at the rated 35-watt output.

These figures illustrate the amplifier’s electrical bandwidth at different operating levels.

The manufacturer also specifies less than 0.5% THD across the power range from milliwatts to rated output within the 20Hz–20kHz measurement bandwidth.

Noise Performance and Gain

The official specification lists a signal-to-noise ratio greater than 98dB below rated output, measured from 20Hz to 22kHz without weighting.

With A-weighting, the manufacturer specifies more than 110dB below rated output.

Amplifier gain is specified as +30dB at an 8-ohm load, with 0.5V input sensitivity for rated output through either analogue input type.

4-Ohm and 8-Ohm Loudspeaker Compatibility

The A35i is designed for loudspeaker load impedances of 4Ω to 8Ω, according to the manufacturer’s electrical specifications.

The suitability of a particular loudspeaker is also influenced by its sensitivity, impedance curve and the listening environment.

Chameleon Audio can assist with system matching and recommend speakers appropriate for the amplifier’s available output power.

Compact and Elegant High-End Design

Despite its comprehensive valve circuitry and substantial transformer assemblies, the Qualiton A35i maintains compact dimensions of approximately 29 × 37 × 19cm (width × depth × height).

Its net weight is approximately 15kg.

The visual design emphasises clear lines, understated controls and a distinctive arrangement of exposed vacuum tubes.

Because valve amplifiers generate heat during operation, adequate ventilation above and around the chassis is essential.

Audio Hungary Qualiton A35i Key Features

• High-end stereo vacuum tube integrated amplifier
• 2 × 35W rated stereo output
• 4 × 7581A matched output power tubes
• 2 × 12AX7 and 2 × 6922 small-signal tubes
• Proprietary Automatic Bias System
• Integrated soft-start operation
• Manufacturer-approved alternative output tube compatibility
• Custom toroidal output transformers manufactured in-house
• Custom power transformer with double electromagnetic shielding
• Three stereo RCA inputs
• One stereo balanced XLR input
• Precision relay-based source selection
• Motorised ALPS volume control
• Remote control with volume, mute and input selection
• Gold-plated ceramic tube sockets and audio terminals
• 4Ω–8Ω loudspeaker load compatibility
• 15kg compact integrated amplifier design

Qualiton A35i Technical Specifications

Specifications follow the manufacturer’s published Qualiton A35 information. The A35i designation is retained from the Chameleon Audio product listing. Technical information may be revised by the manufacturer.

What Is Included in the Box?

• Qualiton A35 integrated amplifier
• 4 × 7581A output tubes
• 2 × 12AX7 tubes
• 2 × 6922 tubes
• Remote control
• Standard mains power cable
• TX10 Torx wrench
• Pair of gloves
• User manual

Qualiton A35i Frequently Asked Questions

How powerful is the Qualiton A35i?

The amplifier delivers 35 watts per channel into compatible 4Ω to 8Ω loudspeakers.

Which output tubes does the A35i use?

Four 7581A output tubes are supplied in the standard factory configuration.

Does the Qualiton A35i require manual bias adjustment?

No. Its proprietary Automatic Bias System monitors and adjusts the operating conditions of the output tubes.

Can I use different output tubes?

Qualiton lists 7581A, 6L6, 5881, KT66 and KT77 compatibility through its Automatic Bias System. Follow the manufacturer’s guidance for approved matched tube sets.

Does the A35i have a balanced input?

Yes. One stereo balanced XLR input is provided, alongside three stereo RCA inputs.

Does it include a DAC or phono stage?

Neither an internal DAC nor an MM/MC phono stage is specified. Compatible external components can be connected through the analogue inputs.

Can I control the volume remotely?

Yes. The supplied remote offers volume up, volume down, mute and input selection.

Does it have soft-start protection?

Yes. A soft-start function is integrated into the Automatic Bias System.

What transformers are used?

Qualiton uses custom toroidal power and output transformers manufactured in its own transformer workshop.

What loudspeakers are suitable?

The A35i is designed for 4Ω to 8Ω loudspeaker loads. Speaker sensitivity, impedance and listening requirements should be considered when selecting a match.

What is the frequency response?

At 1 watt, the manufacturer specifies 5Hz–85kHz (-3dB). At the full 35-watt rated output, it specifies 22Hz–80kHz (-3dB).

How much does the amplifier weigh?

The net weight is approximately 15kg.

Is the A35i suitable for international customers?

Contact Chameleon Audio to confirm available stock, the appropriate mains-voltage configuration and international shipping arrangements.

Explore More Qualiton Components

For increased output power, explore the Qualiton range at Chameleon Audio, including higher-powered integrated and power amplifiers.

A dedicated external Qualiton phono preamplifier may also be considered for turntable systems.

Official Manufacturer Information

Qualiton A35 – Official Manufacturer Specifications

Download the Qualiton A35 User Manual (PDF)

Why Choose the Qualiton A35i?

The Audio Hungary Qualiton A35i Integrated Tube Amplifier combines a carefully engineered vacuum tube output stage with modern everyday functionality.

Its 35-watt stereo power output, advanced Automatic Bias System, custom toroidal transformers, balanced analogue connectivity and remote-controlled operation make it a compelling integrated solution for carefully matched high-end stereo systems.

Traditional Tube Engineering. Modern Control. Precision-Built Qualiton Performance.

Qualiton A35i at Chameleon Audio

Contact Chameleon Audio for the current price, stock availability, loudspeaker matching and international delivery options.