Audio · Head-to-head
Furman Classic Series PL-8C vs Tripp Lite by Eaton Isobar 6 Ultra (ISOBAR6ULTRA)
Which should you buy? Our verdict on both, pulled from our full The Best Power Conditioners and Surge Protectors: 4 Compared (and One to Skip) comparison.
The PL-8C publishes a clamping voltage, a maximum surge current, an attenuation curve in decibels and an over-voltage threshold, which makes it the easiest unit here to actually evaluate. The Isobar 6 Ultra does the protection job at least as thoroughly for a small fraction of the outlay, and it is the one we would put behind most televisions.
Furman Classic Series PL-8C
Buy itA 1U rack conditioner that publishes a clamping voltage, a surge current rating and an attenuation curve in decibels, which is more than most of this category will tell you.
- Specifications state a spike clamping voltage of 188 V AC peak at 3,000 amps and a maximum surge current of 6,500 amps, so you can compare it against something.
- Noise attenuation is published as 10 dB at 10 kHz, 40 dB at 100 kHz and 50 dB at 500 kHz, with the line impedance range stated, rather than described as a trademarked technology.
- Extreme Voltage Shutdown latches the outlets off above roughly 140 V AC and needs a manual reset, which is the right behaviour for the wiring faults that actually destroy equipment.
- Furman calls the SMP circuit non-sacrificial, but the manual says the Protection OK light can go dark after a severe event and that the clamping rating is then compromised, with the unit needing service.
- Spike protection modes are listed as line to neutral only, so there is no line to ground or neutral to ground suppression.
- The safety agency listing is TUV; Furman does not publish a UL 1449 let-through rating or a joule figure for this model.
Tripp Lite by Eaton Isobar 6 Ultra (ISOBAR6ULTRA)
Buy itBudget tier, network-grade surge numbers, and the only unit here whose datasheet spells out suppression on all three conductor pairs and names its UL 1449 edition.
- Rated 3,330 joules with a 330 V UL 1449 let-through rating, listed to UL 1449 5th Edition and rated at 97,000 amps of surge current split across normal and common mode.
- Suppresses full normal mode line to neutral plus common mode neutral to ground and line to ground, which most budget strips quietly leave out.
- Six outlets in three isolated filter banks built from toroidal chokes, ferrite rod-core inductors and VHF capacitors, with EMI/RFI attenuation published as 40 to 80 dB, plus a lifetime limited warranty.
- Twelve-amp breaker and a 1,440 W ceiling, so a large power amplifier plus the rest of a system can trip it.
- Six outlets only, on a strip rather than spread across a rack panel.
- No over-voltage relay: a sustained high-voltage fault is handled by thermal fusing rather than by shutting the outlets down and telling you why.
Side by side
| Furman Classic Series PL-8C | Tripp Lite by Eaton Isobar 6 Ultra (ISOBAR6ULTRA) | |
|---|---|---|
| Our verdict | Buy | Buy |
| Best for | Someone with a rack who wants a conditioner that documents its own behaviour, plus retractable lights and a front convenience outlet as genuinely useful extras. | Almost everyone: a television, a receiver, a console and a streamer that need real surge protection with no conditioning story attached. |
| Price tier | $$ · mid-range | $ · budget |
The bottom line
Our overall pick is the Furman Classic Series PL-8C - A 1U rack conditioner that publishes a clamping voltage, a surge current rating and an attenuation curve in decibels, which is more than most of this category will tell you. Choose the Tripp Lite by Eaton Isobar 6 Ultra (ISOBAR6ULTRA) instead if almost everyone: a television, a receiver, a console and a streamer that need real surge protection with no conditioning story attached.
Want the full picture, including the other options we compared and the popular one we'd skip? Read the complete The Best Power Conditioners and Surge Protectors: 4 Compared (and One to Skip).