AVA Ultravalve Vacuum Tube Amplifier
Best tube amplifier for audiophiles seeking classic warmth and modern precision.
Experience exceptional audio with the AVA Ultravalve Vacuum Tube Amplifier. Built on a heavily modified Dynaco Stereo 70 circuit, this amplifier delivers outstanding resolution, tonality, and bass control. It utilizes common, readily available tubes for easy maintenance and offers impressive dynamics, even with demanding speakers. Featuring a tidy build with a polished stainless steel chassis and a ground float switch, the Ultravalve provides high-end performance for discerning listeners. Its ultra-quick response time ensures a lively and engaging soundstage, making it a rewarding addition to any audio system.
$1999.00
Owner Satisfaction
4.7
/ 5
Category Rank
421
/ 1719
#421 in Power Amplifiers
Price vs Category Average
-76%
Below average
Output Power
35
/ watts per channel
Who it's for
- Audiophiles seeking rich, classic midrange sonic textures
- Budget-conscious listeners wanting high-end performance and upgradeability
- Tinkerers who enjoy customizing their sound profile
Who should skip it
- Owners wary of recurring maintenance and tube replacement expenses
- Listeners using low-sensitivity speakers requiring high power
- Users with limited space or poor ventilation setups
Performance breakdown
Sonic Resolution
Delivers exceptional clarity and detail that rivals modern high-end designs.
Tube Maintenance
Uses widely available tubes, making long-term upkeep simple and affordable.
Dynamic Response
Ultra-quick transient response provides a lively and engaging musical presentation.
Build Quality
Polished stainless steel chassis offers a premium, professional aesthetic.
Speaker Compatibility
Versatile impedance support handles demanding speakers with surprising authority.
Bass Control
Tight, articulate low-end performance that defies typical vintage tube limitations.
Key Specs
Output Power
35 watts per channel
Output Tubes
6CA7 (EL34 or KT77 compatible)
Rectifier Tube
5AR4
Small-Signal Tubes
6GH8A
Chassis Material
Highly polished stainless steel
Channels
2
Amplifier Class
Tube
Impedance
4, 8, and 16 Ohms
Features
- Based on modified Dynaco ST 70 circuit
- Uses common, readily available tubes
- Ground float switch included
- Supports 4, 8, and 16-ohm speakers
- Ultra quick response time
- Highly polished stainless steel chassis
- Tidy build with mixed wiring methods
What customers say
The AVA Ultravalve Amplifier is celebrated for delivering exceptional sonic performance that rivals much more expensive units. Its core appeal is a detailed, dynamic sound signature featuring a lush midrange and smooth highs, creating an expansive soundstage. Users consistently praise the amplifier's musicality and surprising power reserves, making it versatile for various speakers. While the utilitarian design is noted as plain, this is accepted as AVA prioritizes superior internal components and sound quality. Backed by reliable customer support, the Ultravalve is viewed as offering unparalleled value. It is highly recommended for serious listeners seeking true high-end sound without the premium cost.
Know before you buy
While 35 watts per channel is modest, the Ultravalve is designed with impressive dynamics and bass control that allow it to drive a wide range of speakers effectively. It is compatible with 4, 8, and 16-ohm loads, making it versatile enough for most high-fidelity setups.
Yes. The Ultravalve uses common, readily available tubes—specifically 6CA7 (or EL34/KT77) output tubes, 6GH8A small-signal tubes, and a 5AR4 rectifier. You will not have any trouble sourcing replacements or experimenting with different brands in the future.
The ground float switch is a practical feature designed to help eliminate ground loop hum, which can sometimes occur when connecting the amplifier to other components in your system. If you hear a persistent buzz, toggling this switch often resolves the issue by isolating the chassis ground.
While the Ultravalve is built on the foundation of the classic Dynaco ST 70 circuit, it features heavy modifications by Audio by Van Alstine. These updates modernize the internal components and circuitry to provide significantly better resolution, faster response times, and tighter bass control than the original design.
The Ultravalve is built with a tidy, high-quality internal layout that is designed for longevity and ease of service. Aside from periodic tube replacement as they wear out, it does not require specialized maintenance, though it is always good practice to keep the polished stainless steel chassis clean and free of dust.
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$1999