Monster Power Review Error
Editor Gary Comments: The following letter from Monster Cable are published in response to Part 3 of Doug Blackburn’s series on Power Conditioning which appeared in Issue 34 of Widescreen Review. The letters are self-explanatory and shed new light on the subject of power conditioning. Dear Gary: Thank you for doing an overview on the field of Power Conditioning. More education is needed to let consumers know just how important power conditioning is to audio and video performance. I began working with power conditioning circuits in the early 70s, longer than I have been working with cable. It’s taken this long for the general public to become aware of the audible and visual benefits of power conditioning. Let me congratulate Widescreen Review for increasing consumer awareness even further. I hope more reviews and articles on power will take place in the future. As most Widescreen Review readers know, Monster has developed its expertise in the cable business. I have known for many years that the improvements that power conditioning can make will often be equal or greater than that achieved with cables. In fact, I believe that it is the single most cost-effective improvement that one can make to their system. However, I am not satisfied with Doug Blackburn’s review of our products and the milestones they represent in this field. Before Monster Power, the idea of power conditioning belonged to an elite few—serious audiophiles and some videophiles. Cost of entry was $1,000 or more, and the products were very limited in their surge protection capabilities and user-friendly features. On the other end of the scale, were "surge protectors" sold to high-end consumers. Although lower in cost, $100 to $150, they did not offer any serious filtering capabilities and focused their selling propositions on warranty protection and insurance coverage. They were still just glorified surge protectors. When we designed Monster Power products, we designed them to offer the best of both worlds, and for each of the products to be a "category killer" in their respective price points. Even in the HTS 800 that the reviewer tested, he only told part of the story. First it’s a state of the art surge protector in that price point of around $100 (depending on satellite and RF options). It has more than doubled the surge protection of other units, while offering a "dual mode" shut off capability of both an alarm and precision fuse (not a circuit board trace, as in some units). It also has a very heavy duty Monster Power Cable that has the convenience of being two feet longer than normal (8 feet instead of 6 feet). Although the reviewer mentioned the cool feature of color-coded and labeled outlets (so it’s easy to UNPLUG something), he didn’t mention that there was spacing for three transformers that do not block the other outlets. The reviewer incorrectly states that the contacts are not designed for high-powered amplifiers. The contacts are in fact good enough. It’s the filtering circuit that is not designed for high-powered amplifiers. We don’t claim that it is, and actually disclaim it, although it is well suited to the higher-end receivers on the market today. Oh yes, the RF circuits in this unit are much lower loss yet provide better surge protection than other power conditioners. On the issue of RF shielding and coupling, I checked the coupling from section to section on the RF section of both an HTS-2000 and an HTS-3000. This is the most difficult filtering challenge since the connections are designed to transmit RF energy. Up to 100 MHz, there was over 80dB of isolation. At 1 GHz we still measured over 30dB of isolation on adjacent RF circuits. Isolation to the power circuits was even higher at over 40dB at 1 GHz and over 90dB at 100 MHz. The noise floor of the instrument we used (a Hewlett Packard HP8752B) is only around 40dB at 1 GHz. This is state-of-the-art filter isolation. What also was not so obvious was the "Clean Power" filtering that is included in this unit, which is exceptionally noteworthy at this price point. So instead of criticizing us for not having the filtering circuits of higher priced units, I think that we might deserve some recognition of having the best filtering of any power product in this price range. As a manufacturer, we try to build products to a given price point, and offer the consumer as much value for their money as possible. I think that the HTS-800 offers more value than any other product before it in its price range and should be recognized for it. As for the comments on the HTS-2000, I also have some of the same issues. The HTS-2000 has more surge protection than any other product before it, over 1665 joules. It is the only metal-cased product in this price range that offers both superior surge protection and power filtering. Richard Marsh designed special circuits for the HTS-2000 to give it a high degree of filtering; what we call "Stage 2" power conditioning. There is also filtering isolation between the high level, low level and digital outlets themselves, so the interference generated from one component can’t interfere with an adjacent component plugged into another filter. The use of separately tuned filters for different products has not been available at ANY price range, much less than in one that costs $200. The reviewer is mistaken in the design of the high current section of this unit, where he claims that there are cores in the circuit that limit high power handling in the amplifier sections. Richard Marsh, designer of Clean Power, is well known for his expertise in audio design as well as power, and has properly designed a power circuit for high-powered amplifiers. There are NO filter losses for the designated high current 120v/60Hz ac power outlets, as there are no cores as the reviewer describes in the high current path. The power cord (#14AWG) passes directly through an RF ferrite for RF common-mode signal rejection. Therefore, there is no series loss at 60Hz and these outlets will handle far more current than the 60-watt amp limit that the reviewer says! The High Current outlets on all products from the HTS 1000 and above will easily handle the full ac rating of the unit (>1800 Watts) with less loss than the large gauge power cord alone. It should be noted that there are no products at or anywhere near the price range that have filtering and surge protection for high powered amplifiers. Also for the quality of the filter cores the writer refers to, there is no way that anyone can tell by looking at a core just what materials it is made of, and thus, what its performance will be. The materials we use are a composite of different metals blended in a particular ratio to give the desired performance at 60Hz and at RF frequencies. In addition, the cores are used only for other, low level circuits and are labeled for use with DVD-Video players, video etc. which do not need to be High Current. In addition, the rating on a core is far higher for those that are wired as common-mode rejection filters. Unless the writer unwired the board and looked at the under-side of the PCB [printed circuit board], or had a schematic, he cannot tell how it is wired, and thus what power level it can handle. He does not know that they are wired common-mode or differential-mode. However, he calls them all common-mode wound. In fact, we use both common-mode and differential-mode windings on the cores of our products. The reviewer also fails to mention that we have upgraded the power cable in the HTS-2000 over the HTS-800 and that it is fully shielded from RF; another feature not found in units at this price level. The reviewer also does not mention that this is least the expensive all-metal chassis power product on the market, which is safer in high surge areas where overheating might occur. In addition, we offer a remote turn-on version for an additional $30 which allows one to trigger the turn-on of their components through their TV or Control Center/ Receiver. As for the HTS-3500, there is no mention of the other benefits that we have included in that unit as well. In addition to absolutely huge surge protection (over 2590 joules), it has better filtering than any other power product before it (both measured and audible). The reviewer also did not comment on the sequential turn-on capability of this unit that is a great convenience to home theatre owners with lots of equipment to turn on and off. And last, but not least, it is the only power conditioner that incorporates an expanded scale voltmeter in the front panel that allows one to monitor the voltage sag in the home to make sure that all of the components have enough voltage to perform at their peak levels. I could go on and on, and you can probably tell if you’ve read this far, that I am passionate and proud of the products that we have brought to market. We have loaded them with well-thought-out features that were not mentioned, which make them "complete" power products that offer performance and convenience. Filter performance is Richard’s expertise, having designed the highly regarded MIT Z box. He has placed his latest technology in the Monster Power products and we believe they represent the state-of-the-art, especially at their respective price levels. All in all, there is a load of features that we have built into the Monster Power products that were NOT mentioned in this survey. If all of the features had been compared, the review would have shown many Monster firsts. Telling only part of the story does not give an accurate representation of the products and their benefits to the consumer. I hope I have brought some of them to light in my reply.
Noel Lee, The Head Monster, Burlingame, California,
Contributing Editor Doug Blackburn Comments:
I believe my evaluations of the Monster PLC products in Issues 33 and 34 were right on the money given the caliber of the competition and the standards that were applied equally to all of the products reviewed regardless of price. Most of the other products reviewed were painstakingly assembled by hand. Monster nailed their market with these products and my comments about the HTS-2000 and HTS-3000/3500 as they appeared in the original review indicated such. Both products were found to offer 50 percent of the sonic and/or video performance improvements of other products selling for roughly three times as much as the Monster products. Under the circumstances, I’m not sure how much better Monster could have done in this particular PLC review/survey. They were the underdog in price and performed very well considering the competition. Perfectionist standards were applied to all of the PLC products under review. These standards go above and beyond the gross capabilities of the devices under scrutiny. The objective was to painstakingly evaluate very small, but still meaningful, performance differences between and among all the products evaluated. I had a fair amount of experience with PLC equipment prior to this review summary, including reviews of other PLC products. I’ve completed a number of DIY projects focusing on the effectiveness of different filter devices. Consider also that this review consisted of 18 products from 8 manufacturers and took 13 months to complete. There is no audio or video reviewer anywhere who has spent this much time with this many PLC products. The focus of this review was strictly sound quality and video quality. Nobody got extra points for volt meters or delay turn-on circuits or indicator lamps or user friendliness. Product descriptions and features were in Part 2 in Issue 33. The subjective review of the products in Issue 34 focused only on the sound and video performance of the PLC products. Nothing else weighted the evaluations. Mr. Lee’s letter refers to a factual error in the review in Issue 34 where I indicate concern over the current handling capabilities of the high current circuit in various Monster PLCs. In fact, the only Monster PLC about which I indicated that I had this particular common-mode filter concern was the HTS-3000/3500. My concern originated from block diagrams of filter networks Monster silk screened onto the top cover of both the HTS-3000 and HTS-3500. The 4 block diagrams all appear to be common mode filters with parallel capacitors. When you look inside the HTS-3000/3500, you see 4 common mode filters on the PCB; and one of them is larger than the others, but still nowhere close to the size I would expect to see in a high current amplifier circuit. Well, it turns out that the block diagrams Monster puts on the tops of their HTS-3000/3500 are "generic" and do not represent the actual filtering present in the high current section of the HTS-3000/3500. After the Head Monster pointed this out, I did disassemble the main circuit board of the HTS-3000/3500, turned it over and traced the high current circuit. They are, of course, correct. There is no common mode filter in the HTS-3000/3500 high current circuit. With no small-ish common mode filter in the high current circuit, I can raise the maximum amplifier power I would recommend connecting to the HTS-3000/3500 to a single high current 120-watt amp or a 100-watt 5-channel receiver. This is not to say that the HTS-3000/3500 would burst into flames with a high current 200 watt stereo amp or 150 watt 5-channel amp connected to it. The HTS-3000/3500 will meet Monster’s claims for it—it is completely safe when used with high powered amplifiers. But if you have perfectionist sensibilities and are interested in the very best sound quality the HTS-3000 and HTS-3500 can deliver, heed my amplifier guidelines. Mr. Lee considers the HTS-800 a state-of-the-art product in the circa $100 price range. I can see his point when I look at it from his perspective. But the review did not take lower price into account. Sound and video performance as compared to the best available performance at any price was the only evaluation criteria. But the active filtering devices in the modestly priced HTS-800 were overwhelmed by bigger and better parts in the more expensive products including the more expensive Monster products. Perfectionist enthusiasts were recommended to go for something better, including one of the more expensive Monster PLCs. That doesn’t mean the HTS-800 is not useful to the general consuming public where perfectionist standards simply do not exist. The general public thinks perfectionist audio and video hobbyists are either incomprehensible or silly, depending on who you talk to. "It’s the [HTS-800 high current] filtering circuit that is not designed for high-powered amplifiers. We don’t claim that it is, and actually disclaim it…" (Noel Lee) There is no information on the HTS-800 package that indicates any recommendations for appropriate types of amplifiers to connect to it. "These outlets will handle far more current than the 60-watt amp limit that the reviewer says!" The 60-watt amp reference referred to a high current stereo amplifier and was contained in the review text referring to the HTS-800. In fact, a 500 watt amplifier would probably "perform" when connected to the HTS-800. The question is… would one find that performance satisfying from a perfectionist point of view? The recommendations in the review are "perfectionist" in nature and do not represent the gross current handling capabilities of the products. Higher powered amplifiers than this were recommended for the HTS-2000 and HTS-3000/3500 based on the more robust construction of the 2000-3500. I hardly believe that decades of experience with electrical/electronic design leaves Monster at a loss as to how to measure alterations of the current pulses drawn by powerful amplifiers as the output of the amplifier(s) increase. The amplifier must be reproducing music into real loudspeakers. The use of generated sine wave inputs and dummy loads will not reveal the problems. After a decade of listening to PLCs, I don’t have much trouble hearing current limiting/ clipping/pulse alteration when it happens. As to the size of the core not being a very good indicator of resistance to saturation… that all depends on where in the frequency spectrum you are looking for saturation and the profile of the current… steady state or pulsed current (as amplifiers use AC) produce different results. In the case of power amplifiers and 50-60Hz AC power, the cores must resist saturation at audio frequencies at all costs… the current pulses from amplifiers are strictly audio frequency domain events. Resistance to saturation at audio frequencies is pretty well judged by the size of the core, the gauge of the wire wound around it, and the number of turns of wire around the core… provided the core is not a completely unsuitable material for the job. The common mode filters used in the Monster PLCs are appropriate for the circuits they are employed in. I’m not sure anyone has done, or is doing, current domain measurements in the depth or detail required to reveal what happens to the frequency content of the current pulses as audio amplifier power demands increase. The effects are audible and repeatable and not difficult for a careful observer to hear. Whatever happens is something beyond what is revealed by "gross" measurements that account for virtually all measurements done on PLCs, even with spectrum analyzers. My role in this review was not to reveal what designers and manufacturers have been missing for decades, but to describe the video and audio performance of these products in my reference system—regardless of how thoroughly the products have been measured. I agree that the protection offered by the video surge suppression is a valuable feature. I don’t agree with introducing RF sources to the inside of a PLC, which is presumably attempting to filter those same frequencies from the power line. These video sources should really be isolated from one another, as well as from the AC circuitry inside the PLC. It was not within the scope of the articles in Issues 33 and 34 to comment on the relative performance of each wire, connector, electronic component, and assembly detail in all of the products that were evaluated. However, I knew that readers would want some idea as to why my amplifier power recommendations for the Monster products were what they were. WSR readers can judge for themselves whether they would subject their PLC products to the same level of scrutiny that I did, or whether I went way overboard for their personal situation or needs. Here again, I believe the dissatisfaction with my findings comes from what perspective you have when you examine the product. My perspective was "perfectionist." The general public couldn’t care less about perfectionist standards. I’m sure Monster Cable has made some very repeatable measurements about the gross capabilities of the Monster PLC products. But gross measurements do not tell the whole story. There are underlying issues that are not measured or explained by conventional gross measurements. In this instance, gross measurements do not mean the use of crude instrumentation. It means "bulk" measurements… pushing the product to the limit to see what conventional measurements tell you the product is doing and whether it is safe. These conventional measurements do not reveal the whole story—even when the measurement equipment used is very costly and high quality. These instruments and measurements are invaluable in product design, development, and assembly. But they do not answer all the questions at the perfectionist performance level. The reviewer did not mention Monster power cords being shielded because he did not mention any of the PLC products’ power cords being shielded or not. There are an almost infinite number of details that could have been reported on the 18 products from 8 different manufacturers. You have to draw the line somewhere. Mr. Lee says: "The High Current outlets on all products from the HTS-1000 and above will easily handle the full ac rating of the unit (>1800 Watts) with less loss than the large gauge power cord alone." I have absolutely no doubt that this is a true statement. This, again, is a statement of a gross measurement which does not prove that there is no alteration of the sound quality of a connected high current amplifier at limits far below the gross capabilities of the device. "He does not know that they are wired common-mode or differential-mode. However, he calls them all common-mode wound. In fact, we use both common-mode and differential-mode windings on the cores in some of our products." Okay, fine. The 4 block diagrams on top of the HTS-3000/3500 all look like common mode filters, and there are four "donut" filters on the PCB that all look like common mode filters. If they aren’t, it’s not that consequential. The proof of the performance was in the listening and viewing. The HTS-2000 has two filters, which look like the same common mode filters; and the HTS-800 has two ferrite bar cored inductors which are, presumably, differential mode filters. The next time I review products with block diagrams on the top cover, I’ll remember not to trust them. Monster’s equipment protection policy was mentioned in Part 2 in WSR Issue 33 and in the feature comparison charts in Issue 33 and 34. Monster achieves their protection with readily available devices—they just use more of them than you might usually find in a typical PLC. "The reviewer incorrectly states that the contacts are not designed for high-powered amplifiers." Regular home AC outlets are not paragons of electrical performance for high current amplifiers. It was outside of the scope of the review, but I recommend 15 amp or 20 amp commercial grade electrical outlets for amplifiers and even for other components if possible. Hospital grade outlets are an unnecessary expense. Commercial grade outlets are priced about midway between ordinary home outlets and hospital grade outlets. I also recommend using screw-down terminals on AC outlets, not the slip-n-grip holes on the backs of many AC outlets. Household AC outlets only have 2 outlets on their stampings, too. The Monster HTS-800 has 6 in series plus jumpers to 2 more in parallel with those. I’ll stick with my assessment of the capabilities of the HTS-800. Fine for non-perfectionist users, but budding perfectionists should go for something with a bit more meat on the bones like Monster’s HTS-2000 or 3000/3500. In conclusion, I’ll cop to the common mode/high current circuit error reference to the HTS-3000/3500 if/when Monster cops to and changes the misleading block diagram on the top cover. I stand by all of the other performance assessments made in the review. WSR readers are free to form their own opinion about where the truth lies. It’s quite possible we are both right—when the whole thing is viewed only from Monster’s position—or only from my position. Monster aimed their PLCs at their target market and specific price points and hit those marks incredibly well. Does that approach hold up to perfectionist standards? Perhaps expecting that, too, is expecting too much. Here’s the bottom line which could, arguably, have been more forcefully communicated in the subjective review in Issue 34. For what the Monster PLCs cost and the design constraints present at each price point, they are impressive products. If this had been a field of sub-$500 power conditioning devices, Monster products would no doubt have been among the top performing products. Perhaps it was the scope and focus of the review which resulted in less positive commentary on the Monster products than Monster was expecting. When the competitive products sell for $600 to $2,000+ and your products are $100 to $400 it’s quite an achievement to "tie the other five manufacturers’ PLCs for texture of the highs… and lag only slightly in the midrange" as well as to achieve 50 percent of the sonic performance of products costing three times as much. Editor Gary Reber Comments: As Doug Blackburn has stated the scope of the subjective review process was to evaluate "sound and picture performance" regardless of price. The recommendations in the review were "perfectionist" in nature. Yet I found the Monster PLCs to be the value choice in performance and out front on several features that no other company’s products offer. As Noel Lee states, I too regard Monster’s PLCs as the "category killer," offering much more value than ever expected for the price. As Doug states, that translates to at least 50 percent of the sonic performance of products costing three times as much. Audio Review Editor Richard Hardesty uses two HPS-3000s in his Mark Levinson and Proceed reference home theatre review system, and at the magazine’s offices use the HPS-3500s for our high-end home theatre laboratory. We have found them to work well with our 200-watt per channel amplifiers and provide excellent filtering and surge protection. It can be said with confidence that if all of the features had been compared, the review would have shown many Monster firsts, but that was not the assignment I gave to Doug. We did, however, cover many of the features of the PLCs in Issue 33, but strictly narrowed our attention to subjective performance evaluations of the PLCs in Issue 34. In conclusion, our readers need to consider the Monster PLCs as offering much of the "perfectionist" performance of other manufacturers’ PLC at substantially less cost. But when the ultimate performance is the result desired, expect to pay a premium price. Monster actually has a new "high-end" PLC scheduled for release by the time you read this. Monster promises the new HTS-5000 will be the ultimate performance "category killer" at substantially less than $1,000. Stay tuned.
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