Power amps into surge protector/Conditioner or DIRECT to wall? Final verdict?

I just did a little bit of research sadono and I believe you have you facts wrong.

• SurgeX sued Furman for trade-mark infringement and false advertising. They did not sue them for patent infringement. They cannot legally use a term/logo like SMP (Series Mode Protection) which appears to be a trademarked term and false advertising likely because it implies a relationship to SurgeX, but I am guessing on that last part.
  

• The SurgeX site has a reference to their two original patents. They are from the 80's. 
  
• https://patentimages.storage.googleapis.com/12/92/3b/86aee532396c8d/US4870534.pdf   
  
• https://patentimages.storage.googleapis.com/d5/03/32/db000be262ff24/US4870528.pdf
  

Any protection from those would be long over. I looked on USPTO (patent database) and there are new ones, but they seem to add features or include a transformer in the circuit.

A whole house surge protector is nothing but a bunch of large MOVs put across the AC lines (and to ground which is also important). This is not a bad thing, this is a good thing. It will have no impact on the sound at all.  Schneider/Square-D, Eaton and any number of well known and reputable companies make these. They are relatively inexpensive, but there are larger and smaller ones. If you are in a lightning prone area, go for the big one. It is not going to survive a lightning strike right next to your house, but can survive one in the neighbourhood.

The good thing about putting one at the panel, is then you have the inductance of the AC wires from your panel to your equipment to soften the spike. I would like to think that any competent piece of audio equipment, especially really expensive equipment has some level of built in surge protection as well. The combination of the whole house and the in-equipment is likely to get you through most anything.

Simple power bars with simple surge protection will put more MOVs across the line. Being at your equipment, that is going to help even more. Some basic power bars add some inductance, which will help more, but that will add impedance to high current draw.  Some devices will go even further with larger inductance and circuits after the inductor and provide (in combination with your whole-house protector), protection for just about anything, but it does increase impedance between the AC line and your equipment. You can decide if there is any sonic impact of that or not.

sadono,  Can you please describe what "real" series mode surge protection is?

The picture of the Furman unit here: https://www.furmanpower.com/series-multi-stage-protection-smp on the left (from the large inductor and over) seems to match what is described/drawn in the SurgeX patents I linked to from the 80’s. On the right appears to be some traditional MOVs, and probably some voltage detection to turn on/off the relay on the right side. The additional use of the MOVs is a good thing and probably makes the circuit on the left perform better.

sadono91 posts11-05-2019 11:18pm
This is not true! The part of SMP that is series mode surge technology is always on. However, this section is more limited in its capabilities with let-through voltages, compared to real series mode surge technology. The MOVs and EVS (Extreme Voltage Shutdown), other parts that makeup SMP (Series MULTI-STAGE Protection), have a delay before kicking in.

... and that apology would be nice now.

1) I will admit they use it ONCE. It is not in the US trademark registry, so I’m unsure that it is still officially registered.

- Don’t need to register a trademark technically, but whether you admit it or not, you would be wrong:
http://tmsearch.uspto.gov/bin/showfield?f=doc&state=4808:lh0t5p.3.5

2) One of the patents still covers the original concept. Patents can expire. The series mode surge technology patent states, "Provides an inductor system as the first means of protection." Furman’s SMP uses a MOV as the first means of protection.

Nope, that is not how patents work. The original patents, which is the basis for what SurgeX called series mode, were filed in the 80s. You cannot protect anything that was in those original patents.
Putting a MOV in front of the inductor does not negate the use of the same technology after the MOV. It is an improvement, not a limitation.

3A) Through the use of capacitors and resistors, a series mode product releases current back to the neutral wire. This actually provides a sort of passive power factor correction. Depending on the power conditions and the load, greater power could be provided. Plus, no one said you have to plug an amplifier into it.

Incorrect. The capacitor bleeds power via a large value resistor. This will provide no effective change on the power factor, good or bad. It will not increase the power available in any effective way.
I didn’t say it had to be plugged into an amplifier, but I was noting that the technology has application issues.

3B) "Power line surges within a building may be as large as 6,000 Volts, 3,000 Amperes, with a duration of 50 microseconds, according to the industry standard ANSI C62.41."

"•IEEE (The Institute of Electrical and Electronic Engineers) states that 6000V is the largest transient that the interior of a building would experience.

No, that is not what ANSI C62.41.1 says. It is mainly a discussion around the data, much of it poor, and potential probabilities. The 1.2/50us voltage, 8/20us current combination wave was from a previous spec, but was found to be reasonable.


The 6KV was arrived at by a combination of some data showing 4kv strikes at a maximum rate of 0.1/year in some indoor installation, and a typical arc-over AC wiring of 6KV, hence providing a natural spark-gap protection.

By interior of the building, they mean some distance from the service panel, and the 6KV/3KA is really industrial, with residential defined in C62.41 much lower ... the reality is, hits much greater than 2KV/1KA are quite rare residential, but if you get a local lighting hit, you can get hit with more than 6KV/3KA.

•IEEE defines its harshest interior surge environment as one that could experience 100 surges of 6000V, 3000A in a years time (category B3).
•A new federal guideline recommends that a surge protector utilized in a harsh environment should be capable of withstanding 1000 surges of 6000V, 3000A or ten years worth of IEEE’s category B3.

No, the IEEE documents most definitely do not say that. They actually discuss high incidences of B3 ringwaves, 6KV/500A, 100KHz, which are induced by motor starting, large breakers turned on, etc. in heavy industrial and large commercial settings, never in a residential application like home audio / video.

•UL (Underwriters Laboratories) now provides a new adjunct testing service (in addition to the 1449 safety classification) that will test surge protectors to the 1000 surge, 6000V, 3000A federal protocol."

Looking at the most recent 1449 ... nothing in there about that. That said, you can always get UL or anyone else to do a test like this.

Real series mode surge protectors are the only devices rated with the A-1-1 certification.

"A-1-1 Certification
The U.S. Government’s highest classification for surge suppression."

"•Grade A is the best endurance – 1,000 surges of 6,000 Volts / 3,000 Amps with no degradation.
•Class 1 specifies the best voltage suppression of 330 Volts peak for 6,000 Volts / 3,000 Amps surges.

If you are just going to cut and paste from SurgeX literature, what is the point?

The Grade A-1-1 was from a US Government procurement document that was withdrawn over 15 years ago! The only one who puts that into their literature is SurgeX.


For the record, a 50KA MOV, which in terms of audiophile equipment is not very expensive, will withstand 1000+ 6KV/3KA hits.

•Mode 1 is Line to Neutral (L-N) suppression. This avoids ground wire contamination and is recommended for interconnected equipment."

Ya, no. Recommended by SurgeX maybe because they cannot protect Line/Neutral to ground, and considering most would be plugged into the same power bar/surge protector this makes not sense. Line/Neutral to Ground surges can be very damaging. A big common mode surge on Line/Neutral causes a rise of the potential of all the electronics in the chassis, then you get a spark from the electronics to the grounded metal ... and poof ...

Adding a sacrificial MOV is superfluous to real series mode surge technology. Furman only added them to make up for the tiny inductor used in their SMP circuit, which makes it a design flaw.

Their inductor is actually fairly substantial, and the winding are heavy. Unless you can compare the two inductors for value and saturation current, your comment is at best a guess.

4) Why would I apologize? Furman still lost, and your argument is a red herring. Furman’s SMP is not real Series Mode® surge technology. From your earlier referenced material:

No, they didn’t "lose". They settled, and remember both were suing each other. No details of whatever agreement they arrived at were ever discussed. Furman likely changed the name to avoid wasting money on lawyers fees with little benefit. The total value of SurgeX was $2.5 mill when sold in 2006.

He also recognized that the act of shunting the surge to ground pollutes the ground with energy that often enters the sound or video system. This was causing equipment disruption, malfunctions, error-codes, reboots, and downtime that degraded performance and increased dealer costs.

The MOV does not even engage till well over the line voltage, it would not shunt anything, and you could shunt to ground with a GDT (which all of Europe does) and solve this issue if you were truly concerned.. The simple reality is this technology cannot be used on L/N to ground coupling modes because it would violate leakage current requirements (and be very expensive).

sadano,

1) This is from the Ametek website, "To resolve the problem, he took on the challenge to reinvent the surge suppressor by developing a Series Mode® protection circuit " ... do you notice that ® after Series Mode, that is the trademark. That means, if you are Furman, you can’t use Series Mode to brand a product related to surge suppression if you don’t want to get sued. To violate the trade-mark, you just have to use that wording in your marketing materials or branding materials.


2) There are current patents that protect new variations of a series surge protection circuit. The original patents, from the 80s, have long expired. You cannot create new patents to protect old material. Half the circuitry in the Furman is essentially what is in the 80s patent. Anyone can use that technology at this point which was the SurgeX Series Mode protection (you can’t use the trademark nomenclature though).

Again, from the Ametek site, "In 2005, SurgeX upped the ante by introducing Advanced Series Mode® (ASM) surge elimination technology. ASM improved on the original technology by incorporating a reactor with two opposing air core inductors to slow surge current down to a trickle. " This is not the technology that Furman is using.


3) SurgeX’s series mode protection is non sacrificial, but it is not perfect. It relies on an inductor as a filter element to block the high speed surge waveform before dumping what is left into a capacitor. As you know, in audiophile circles, adding inductance in front of a power-amp is often frowned upon. It of course also has a limit to how big a surge it can take before the inductor saturates, the diodes blow, or the capacitor is degraded. Adding MOVs in front of this type of surge protector, especially big ones, can significantly increase how big a surge the combined device can handle. Using both, as Furman does, is a feature, not a design fault especially at a given cost point, and the Furman units are competitively priced.

4) I will accept that apology now ...

SurgeX Suit Triggers Furman Response

By AVNetwork Staff (Systems Contractor News) January 28, 2005 Business

• Furman Sound has responded to a complaint filed by New Frontier Electronics d/b/a SurgeX, rejecting its claims in U.S. Federal Court and filing a counter claim against New Frontier. New Frontier’s complaint is in part for promoting MOV-based power conditioning products as Series Mode products.
• SurgeX, citing the false advertising and promotion prong of Section 43(a) of the Lanham Act, is claiming that the Furman Series II line of products use MOVs (Metal Oxide Varistors) as the main surge suppression technology and that the promotion and marketing of these products as Series Mode is false, deceptive and/or misleading.
• Furman purports that the words in question, "series mode," refer to a common electrical configuration and are not owned by any individual or organization. Furman’s Series II line of products does employ this technology, said the company, however the technology in Series II units goes above and beyond typical series mode protection with a total package called SMP Plus.
• All SurgeX power conditioning products incorporate advanced technology, referred to as Series Mode, to mitigate surge and transient energy without the use of any diversionary or sacrificial components such as MOVs.
• Furman Sound...www.furmansound.com
• SurgeX...www.surgex.com