Monster Power HTS3500MKII Line Conditioner

Description

The Monster Power HTS 3500 MKII Home Theater Reference PowerCenter was designed during the era when increasingly elaborate home-theater systems were placing greater demands on AC distribution, surge protection, and system connectivity. More than a conventional power strip, the HTS 3500 MKII combines Monster Clean Power filtering, surge suppression, sequential power switching, line-voltage monitoring, and protection for telephone and coaxial connections in a substantial rack-mountable chassis. It became a popular accessory for enthusiasts who wanted a single control center for an entire audio/video system.

At the heart of the HTS 3500 MKII is Monster’s Clean Power Stage 3 filtering, designed to reduce high-frequency electrical noise and isolate connected components from interference generated elsewhere on the AC line. Monster divided its filtering into circuits intended for digital, audio, and video equipment, reflecting the company’s belief that different types of electronics could benefit from separate noise-filtering paths. The unit also incorporates surge suppression rated at approximately 2,775 joules, along with Monster’s Dual Mode Protection system, which provides visual and audible indication when protection has been compromised.

The MKII is particularly well equipped from a connectivity standpoint. It provides 10 AC outlets, with switched and unswitched groups allowing the user to keep certain source components continuously powered while controlling amplifiers, displays, or other equipment from the front-panel switch. A timed outlet arrangement provides additional flexibility for system sequencing. Monster also incorporated 12-volt DC and AC remote-control inputs, allowing the PowerCenter to respond to another component’s trigger or accessory outlet.

A prominent illuminated analog voltmeter on the front panel displays incoming AC voltage, giving the owner a quick visual indication of fluctuations in the household supply. The HTS 3500 MKII also protects telephone lines and cable, satellite, and antenna connections from surge events. This combination made it particularly useful as the central power hub for a complicated home-theater rack, where a receiver, separate amplifiers, disc players, display, cable box, and other equipment might otherwise require several power strips and individual protection devices.

The unit’s sequential power-control system is another useful feature. By controlling the order in which connected equipment receives power, the HTS 3500 MKII can help prevent the large simultaneous inrush that occurs when an entire rack is switched on at once. An 8-foot high-current power cord was supplied, and rack-mounting hardware was available, making the PowerCenter suitable for both dedicated theaters and conventional equipment racks.

Contemporary user experiences were generally positive, although opinions about audible improvements from power conditioning varied. One owner reported that the MKII produced a “substantial improvement in sound quality,” describing greater resolution, dynamics, soundstage, and range while reducing perceived noise and fatigue. Another owner reported improvements in bass, black levels, and shadow detail after installing the unit, while also appreciating the additional outlets and surge protection.

A period Audioholics review, quoted in enthusiast discussions, concluded that the HTS 3500 offered excellent flexibility and described it as an exceptionally strong value among multifunctional power centers at its price.

The Monster Power HTS 3500 MKII therefore remains an interesting piece of home-theater history. Its combination of extensive connectivity, substantial surge protection, voltage monitoring, remote switching, and AC filtering made it much more sophisticated than an ordinary surge protector. For vintage and classic home-theater systems, it remains especially attractive as a centralized power-management component.

Review Quotes

• “Substantial improvement in sound quality,” with improvements in resolution, dynamics, soundstage, and range. — Audio Asylum owner review
• “It may just be wishful thinking,” but one owner reported improvements in both audio and video performance. — Moe’s Home Theater
• A period review called it “one excellent product” in terms of build quality, performance, features, and ergonomics. — quoted via HardForum

Product Specifications

• Type: Home-theater reference power conditioner / surge protector
• Model: HTS 3500 MKII
• AC outlets: 10 total
• AC filtering: Monster Clean Power Stage 3
• Surge protection: Approximately 2,775 joules
• Protection: Monster Dual Mode Protection
• Voltage monitoring: Front-panel illuminated analog voltmeter
• AC input: 120V AC
• Maximum load: 15 amps / approximately 1,800 watts
• Power cord: 8-foot high-current Monster PowerLine cord
• Remote control: 12V DC and AC trigger capability
• Power sequencing: Yes
• Coax protection: Cable TV, satellite/DBS/DSS and antenna connections
• Telephone protection: Yes
• Switched outlets: Yes
• Unswitched outlets: Yes
• Digital filtering: Dedicated digital noise filtering
• Audio/video filtering: Separate filtering circuits
• Rack mounting: Supported
• Chassis: Full-size metal rack/equipment component design