@erik_squires
"Zero Surge® was incorporated in March 1989 by J. Rudy Harford." He is the founder, and was the former owner and president. And yes, he’s the license owner.
https://zerosurge.com/about-us/Look at the SMP circuit on the page you linked. Are you blind or clueless as to what a MOV looks like? There are clearly MOVs.
https://www.furmanpower.com/sites/furmanpower.com/files/_/Power-Report/smp-circuit.jpgStill don’t believe me? "Furman’s Series Multi-Stage Protection Plus (SMP+) addresses some of the shortcomings of traditional MOV-based protectors by employing a variety of circuits to clamp, absorb, and dissipate transient voltages without having the device sacrifice itself. The company claims that MOVs used in a properly designed circuit will not fail.
Furman’s SMP+ circuitry takes pages from both shunt-and series- mode playbooks and adds its own twist. Along with a high-voltage MOV and a high-amperage thermo-fuse varistor, SMP+ uses a tuned circuit that includes series inductors, a bridge rectifier (which con- verts AC to DC power), and high-voltage capacitors."
https://zerosurge.com/wp-content/uploads/2016/10/Sound_and_Vision_July2007_Zero_Surge.pdf"SMP allows Furman products to offer this protection without damaging any of their own internal components—that is, they are virtually non-sacrificial"
https://www.mixonline.com/technology/furman-sound-implement-smp-technology-381312"• Zero Surge’s patented filter technology protects sensitive electronics from even worst case surges, repeatedly, without degradation or failure. MOV-free."
https://zerosurge.com/wp-content/uploads/2017/09/zero-surge-brochure.pdf" • No sacrificial or wear components (no MOV’s)"
https://www.brickwall.com/pages/the-worlds-best-surge-protectorsThe series mode surge technology patent states, "Provides an inductor system as the first means of protection."
"A branch circuit SPD (Surge Protection Device) using an MOV in front of, in back of or sideways of, a small ferrite core series inductor, labeled as ’series something’, is in my opinion, a marketing persuasion by our competitors intended to ride on our back and confuse you, and the only way to promote a product ’looking like ours’ without violating our patents. Are you a Switch or a Filter?
An MOV is a semiconductor switch. Switches will wear out and can suddenly fail when stressed. The monitoring of these switching devices over time as ’functional’ is tedious and a guessing game at best. A filter properly designed for its application will not wear out and will only fail if misapplied. Think about your passive LC subwoofer crossovers...when will it wear out?...perhaps when you wire it up to 440V just for fun?...or when you listen to too much music?" Michael McCook, SurgeX International
Furman purposely added MOVs to create a hybrid surge protection device that does not violate the patent. Due to the patent, Furman can not call the design series mode technology, and renamed it SMP+ in 2005.
SurgeX does not have the same basic technology as other series mode designs. They have added ASM (Advanced Series Mode) technology. This adds an extra winding to the air-core inductor to further improve the surge protection and lower the let-through voltage.
https://www.ametekesp.com/-/media/ametekesp/downloads/white-papers/surgex-ametek_white-paper_advance....
You do seem right about McIntosh, as the MPC1500 appears to use series mode surge technology as a repackaged Torus. "Torus Power Technology under license from Plitron Manufacturing Inc."
https://www.mcintoshlabs.com/-/media/Files/mcintoshlabs/DocumentMaster/us/mpc1500om05L.ashxWhat led you to believe that PS Audio licenses series mode technology? They use a circuit breaker, fuse, and MOVs for surge protection in the Power Plant regenerators. Paul McGowan does not like large inductors, and advertises how the Power Plant regenerators have low inductance.
Inductance is not good for transparent sound quality. It reduces current and rolls off the highs. Inductors are called chokes for a reason. I won’t deny that many people like them, as evidenced by people that find series mode technology transparent, and all of the Furman & Audioquest fans.
