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News prosperityPhoto through growth of the month P 2,3

Market Watch Our Partners

Who’s inside Powersoft


P 5,6

The Story P7




What you will find… If we wrote only about “technical matters” we would probably succeed in publishing 3 issues before none or very few of you would bother to take another look.


(our news letter) will talk about different matters, interesting That’s why facts, news and the people that navigate in and around our world. The idea is to install a means of communication between Powersoft and all its friends and we hope between them and Powersoft. In fact we will give space to all of those who wish to know more or who want to tell us about interesting arguments or simple trivia. The aim of the newsletter is to allow all its readers and hopefully contributors the opportunity to get to know each other better over and above just basic facts such as name, email address and extension number. We hope that every now and again we will be able make you smile, raise a doubt or stimulate your curiosity. WWW.K-SERIES.IT - WWW.POWERSOFT-AUDIO.COM

What They say about us P8 Tech Zoom P9

Where P 10


Powersoft Amplifiers at International Convention Centre Durban

Located in the port city of Durban South Africa, the ICC Durban was originally built just over 10 years ago, and has since hosted various international conventions, including the International Aids Conference in 2000. Moveable walls allow for a number of different venue configurations, including the option for the halls to be opened up to form one large venue with seating for 5000 delegates. In celebrating its 10th anniversary, the ICC Durban launched the new extension to their facility – the Arena. As a multi-purpose platform for international events, the Arena is able to offer the perfect staging for any occasion. The Arena also consists of three halls – each hall being able to be sub-divided into separate rooms. The venue is a multifunctional arena, which is designed in such a way that it is flexible enough to host events such as theatre and live performances, indoor tennis, wrestling, gymnastics, equestrian events and even motocross. With such a wide variety of activities to host, the audio design required the same flexibility. The tender for the design, supply and installation of the Audio/Visual system was awarded to TDC Africa (Pty) Ltd – a South African company with offices in both Johannesburg and Durban, with an impeccable track-record for large-scale audio and visual installations within Southern Africa. TDC Africa partnered up with Prosound (Pty) Ltd – one of the largest professional audio and lighting companies within Sub-Sahara Africa, established over 35 years ago. Prosound has also been involved in the design, supply and installation of some of the largest professional audio installations within Southern Africa, including the landmark Sun City entertainment complex. TDC Africa has been using Prosound (Pty) Ltd extensively as it’s ‘technology partner’, as a supplier and a service provider. Prosound’s Prosound involvement with this project was based on two objectives. The design and supply of audio/visual systems to the extensions, and also the design, supply of equipment and engineering capabilities provided by its hire department for the official opening of the arena. Peavey’s MediaMatrix audio processing system was used as the main control and processing system for all the audio feeds, with distribution of all audio over Ethernet, via a number of fibre links in the venue. The PA system within the exhibition halls is a distributed overhead design consisting of Electro-Voice loudspeakers, with each loudspeaker being driven by its own power amplifier channel. The amplifiers used were the new Powersoft Digam Q-series, with remote control option installed into the amplifiers. A total of 4 equipment racks were installed at various points in the roof service area of the Arena, each rack filled with a number of Powersoft Q-series amplifiers as well as Powersoft Power Control Hubs.

Powersoft amps installed: - 24 x Q3002 - 43 x Q3204 - 7 x TU-4 insulation unit - 15 x Powersoft Control Hub - Powersoft Remote control

& Monitoring Software

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NEWS Powersoft supplies United

Audio Starlight, in

Sweden, with a total of

48 pcs K10DSP Amps Before the Stockholm Jazz Festival, earlier this year, United Audio Starlight AB invested in 24 new Powersoft K10DSP amplifiers, says Anders Lindstedt at Svensk Musik TTS AB. AB “After several test runs and evaluations, the choice was obvious and Svensk Musik TTS AB provided United Audio Starlight’s Starlight V-Dosc with Powersoft.” According to Björn Lehnberg, at United Audio Starlight, Starlight there were several reasons for choosing Powersoft. ”The K10’s ability to continuously deliver power at low impedance, combined with the functions of the built-in DSP, has given us a tool that we have never before had access to. We can push each loudspeaker to the limit, without breaking anything” “Powersoft manages to deliver a high amount of power over long periods of time, even in loads at low impedance. This is not exceptional for Powersoft, but they are however the only manufacturer who can offer a DSP that works as a crossover/ compressor/limiter/delay at the same time as it supervises the load, and controls the power sent out to the speakers”. ”Furthermore, adjusting the output impedance, in order to compensate for the length of the loudspeaker cables, has an effect on the sound in a very positive way. The DSP makes it possible to retain a preserved damping factor no matter where the loudspeakers are situated”. ”Since the internal feed back from the amp outputs run through the DSP, you can compensate for a calculated resistance in the loudspeakers. In that way you will retain the damping factor even when using very long cables. The cable and its resistance will in a way become a part of the K10’s own amplifier circuit”. The positive experience with Powersoft during the Jazz Festival and summer tours led to a new order from United Audio Starlight for another 24 pcs of K10DSP! These amps were delivered late October.

PHOTO OF THE MONTH This photo was taken in the R & D hardware department bathroom that gives a warning to all concerned, that, translated into English, means “We kindly ask all users to raise the seat and flush the toilet, thank you” Take note that this notice is attached to the wall using Powersoft Advanced Technologies packing tape! Now if the person that put up the sign, did it by chance then we don’t really care but if he chose it on purpose then he is a genius and we want to know who it is W W W . K- SE RI ES .I T - W W W .P O W E RS OF T- A U D I O.C O M

“We kindly ask all users to raise the seat and flush the toilet t oilet! oilet ! thank you” stuck up with “Advanced Technologies” tape.

market watch…our Partners This section will let you know, one by one, all our Partners. For this first edition, it is our pleasure to introduce you our partner from... A as Argentina.

Equaphon’s headquarter is in Buenos Aires, Argentina. At 2976 Gutenberg Street, the company has its administration, engineering, production, technical service and whole sale; it also counts with a shop at downtown city exclusively for sales. Since the end of 2003 the company is representing Powersoft, from the beginning the company betted in the diffusion of our “revolutionary technology”. With several presentations all over the country, constantly informing people about the greatest advantages of Powersoft, they never gave up and, since a while, very positive results have been achieved. Equaphon made all the Spanish translation of the owners’ manuals for the complete series of amplifiers, as well as most of the Spanish publications of Powersoft. They supplied and supported the major rental companies of Argentina, collecting an outstanding reference list with the biggest live events of that country. In the short term we w ill work in getting a better share in the market, offering the best deal for the end users in professional audio power amplifiers and now, with the L-Series we have the possibility to attack other segments of the market, such as DJ’s and small discos”, said Ing. Carlos Maiocchi, president of Equaphon sistemas de Sonido Srl. Other than Powersoft, Equaphon exclusively distributes B&C speakers since more than 10 years, its own brand STS speakers and APB-Dynasonics consoles. (in the right photo, President Ing. Carlos Maiocchi and Vice President Rubén Branca)

For more info about Equaphon, log on

?Did you know

that the Idle feature of the

K Series Series can let you save up to 50% of energy? Especially for fixed install, with long periods of “silence”, a single amplifier would consume 170W t o produce no audio. When the Idle function is enabled, the consumption is reduced down to 80W, savings 90W per amplifier. If you consider, for example, an average idle period of 10 hours per day with 15 amplifiers installed, the total amount of energy savings would be 90 (watts saved per amp) * 10 (hours per day) * 15 (total amplifiers) = 13.500 W/h equal to 13,5 kW/h per day. You can keep going and calculate the energy saved per year, which is, more or less, 5.000 kW/h. Considering an average cost of 0,15 € per kW/h you save up to 750€ per year. Moreover, not dissipating energy into heat, the amount of air conditioning required is also drastically reduced, which leads t o an even bigger saving.

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50% Moreover You can activate the IDLE function of the K serie s from the internal Menu/Settings/AmplifierSettings/Idle Mode or via the Power Control Manager software. You can also set the amount of time the amp should wa it before entering the IDLE mode since no input signal is present. As soon as the input signa l is back, the amp will automatically and pr omptly “wake-up”, in a matter of few nanoseconds.

WHO’S INSIDE POWERSOFT Interview with Claudio Lastrucci Ciao Claudio, You really couldn’t wait for this could you? So………Lets go!

What is your role within Powersoft? In theory, I am the founding Managing Director, but in practice a bit of everything but in particular I follow the product development and new technology. technolog y. We won’t ask how clever you are, for that we only need to switch on a K10 and listen, Tell us how it all got started..... About 25 years ago, in my homemade laboratory, where I had transistors, chemical products, motors, musical instruments and other strange things, Lets say an approach to development on a large scale. A major passion for recorded live music, which also led me to play the piano, drums and the saxophone for about fifteen years. I studied electrical engineering and then went on to university university and gained my degree in a fairly short period of time. The setting up of the company, with my brother Luca and Antonio Peruch, friend and university chum, both of whom are also electrical engineers. I would say that curiosity has always been my drive and the joy of creating. -

As you know, the idea behind this interview is not to know about you as in Powersoft but you as in Claudio. It appears that you have an attraction for all that makes noise and they say that you have a past as an explosive expert. Is it true? Tell us more…… Maybe all youngsters have at some point been curious about the chemical properties of some materials…… the possibility to contain energy in such an efficient way and then to be able to release it in short spaces of time is the base b ase behind explosive compounds which has some similarities in acoustics and in general in high energy physics; I was very curious about this from a young age and whilst enjoying myself, delve into this argument, fortunately with no physical damage….. I am however….. Just to be clear, curious about physics and not the application of this kind of technology within the military field. -

In the Powersoft “cellar” one day I saw many strange objects, like an alternator (they say for the Formula One Ferrari) a gadget gadg et that looks like E.T. with a strange ball… do you know anything about it? In the past fifteen years that we have been in business and even before, there have been numerous developments of products that have been a huge success or rather have sold well and an d others that have remained dreams that still keep me enthralled; there have been products developed from acoustical, chemical, physical, electronical and mechanical. You mentioned a power converter developed for a well known Italian company that applied itit within the racing competitions at top level, obviously I can not say anymore even though many years have passed. It was a great idea that combined electrical mechanics with high powered motors. A strange ball? An ambitious project, unfinished, developed for personal mobility…maybe one day we will see it out on the streets, but the road is very long. -

?Did you know that

DSP of the K series amps

….offers you, in addition to the usual ones, ALL PASS filters? Those filters passe all frequencies equally, but change the phase relationship between various frequencies, by varying its propagation delay with frequency.

Your drums, do you still have them or have you sold them to buy gun powder? As I said before, music was a great school for me; drums were my second love afte r the piano. I had fun for 10 years and every now and again I have a little go, it’s a shame but there is not time for everything, that’s what life is about. Now, if you could just come down for that monocycle and sit here with me for a few moments, I’d like like to ask about your heirs and your growing family. The monocycle is great fun, not easy, that enables me to get some good exercise. I’d like to use it more often. I have a wonderful family; my wife Silvia who has been my companion for 10 years and I have two fantastic children aged 1 and 3.5 years -

Generally, the filter is described by the frequency at which the phase shift crosses 90°. ALL PASS filters are generally used to compensate for other undesired phase shifts that arise in the system due to, for example, the usage of other filters, such as Butterworth, Bessel, Linkwitz-Riley filters or other EQs. For this reason, the ALL PASS filters are very useful, not changing the magnitude but only the

Tell us now about the must fun thing you have ever done. I would sat that the most fun/thrilling was bungee jumping from 111 metres over the Zambesi river in Zambia, wow!

phase of the signal, allow the sound designers to “adjust” the overall phase response of the DSP, restoring a linear behaviour, which means, in the

Now tell something that you have yet to to try. I would like to try a flight in space or at least a short orbit stay, but I think that could be difficult. However I must say that I hope to be able to continue working in an exciting environment surrounded by exceptional people like I am today Thanks Thanks and keep up the good work Thanks to you!

end, a simple delay. Now you probably understand why Powersoft wanted to offer in its DSP option up to 16 different EQs per channels: a bunch of them should be “ALL PASS”!

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Tom Bensen

- Tell us what you do and what your responsibilities are in Powersoft.. Since we formed Powersoft Audio USA, Inc. in June of 2005, I assumed the position of Vice President of Sales and Marketing. Specifically, I overlook the US operation in all aspects of business development, daily sales and sales support activities – i.e., the management of our sales force (independent rep network); key customer/key account management, as well as overseeing all marketing activ ities, such as trade shows, press and PR. Sales/product training is also a very important component of our efforts in the US. It’s an area I pay particular attention to, making sure that customers and sales reps are fully trained in the operation of all our products and related software. With the advent of the K-DSP series, it is even more critical to make sure both customer and sales person understand the incredible innovations that only Powersoft products offer to the industry. “Getting the message out there” is probably the role I enjoy the most. To me, there is no greater satisfaction than that of introducing an industry veteran who thinks he has “seen everything” to Powersoft through a K-series demo. To see their faces when a K-10 or now, a K20DSP “goes to work” is always exceptionally gratifying. It’s amazing at how many “converts” we have once they have seen and heard Powersoft. I am especially proud of the fact that in a very brief time, Powersoft, and most notably the flagship K-Series products, have become one of the major contenders in the eyes of professionals in the USA. - So, what is the attraction to Pro Audio? You can’t work in Pro Audio if you don’t live it and love it. To me it is more than a job or career; it is very much a lifestyle that mixes friends, customers and family into an inseparable combination. For example, each year when I go to work in New Orleans at the Jazz and Heritage Festival, it is a wonderful reunion of people who are more than just customers or co-workers. It’s like being with an extended family. It’s really the same feeling we all get when we go to trade shows and other industry functions as well. I think we all feel it. If you don’t, well maybe you should get a “real” job...Hah! - How and when did you start dealing d ealing with "this world"? I actually started out over thirty years ago, in a related industry – as a broadcaster. I was both an engineer and an announcer, working in several NY area radio stations while in college and immediately after graduating. After moving into the audio industry in 1977, I worked for a number of interesting companies over the years, including Beyer Dynamic, Ramsa (Panasonic) and AKG. I founded a major NY Metro area rep firm in 1986 which I kept for ten years. After selling my firm, I worked for Crest Audio in Paramus, NJ; and then Group One, the US distributor of XTA. Shortly after leaving Group One, I began my association with Powersoft. - What do you do for fun? I enjoy music, theatre and especially love going to concerts and festivals. Oh, and there is the boat. I am an avid sailor and have been for many years. Recently, I purchased a classic sailing yacht, a 13.5 metre Cheoy Lee. We belong to a sailing club and have made close friendships with people from all walks of life who share the same passion. - Tell us something about your family... We have two daughters one nearing 22 years, who is attending Parsons School of Design in NYC, and our other daughter is in middle school, soon to turn 12. My w ife is the co-host of a nationally syndicated radio broadcast show “Good Day USA, with Doug Stephan”, which is broadcast every morning from 6:00AM to 10:00AM, Eastern Standard Time. We live on Long Island but also maintain a residence in NYC. - Tell us something we don't know about you. I am the Vice Chairman of the Long Island Music Hall of Fame (, which is a Not-for-Profit organization dedicated to music education and cultural preservation. I helped found the organization four years ago and am quite active in its many programs and activ ities. It is a very rewarding, and we work hard to make a difference through our outreach and educational programs. - You have the chance to tell something to the Powersoft community Please go on... I can truly say that in all my years in the Pro Audio industry, Powersoft is the most unique, advanced, and exciting amplifier technology that I have ever seen. The company approach to engineering, style and performance is like no other, and in my opinion, has no equal. What makes it even better is that as a family owned business, that sense of “famiglia” is carried throughout the entire operation. I feel very much a part of the Powersoft family and am proud to represent Powersoft in the USA. W W W . K- SE RI ES .I T - W W W .P O W E RS OF T- A U D I O.C O M

THE STORY: What a life as ….. A product manager

I have never in my life been able to do one thing at a time. When I was a boy I did two sports (probably not very compatible, seeing that state of my knee) then I studied engineering whilst working in my own rental company (ever tried it? don’t bother) in our rock band I was the singer and the saxophone player! I know what you are all thinking, but I promise you that my girlfriend (now my wife) has always been the same one, poor thing! I now find myself as a product manager (already chaotic) not for one but for two companies that operate in the professional audio sector, a world of dangerous people (all of you reading this article!) often crazy, but basically “good guys” united by a immeasurable passion for live music and theatre. Now I think about it, are there product managers in companies that make ice cream making machines? Machines for making pasta? If they sack me after writing this news letter maybe I could think about it….. Those of you that have had “the pleasure” of meeting me, will know that I love my job, I put my heart into it and all in all, despite the 158 flights (1 flight = 1 take off & 1 landing) taken in 2006 and the other 130 taken to date in 2007, I still enjoy myself. I’m not sure how long I can survive on airline food and nostalgia for my sofa and remote control, but the most important thing is that the number of take offs is the same as the number of landings!

Every time I have to leave on a business trip, which is about 8-10 times a month, my mother asks “where to this time?” and after having registered the answer follows the classic question “now what is it you do exactly?” which just goes to show that despite 10 years of trying to explain she still hasn’t understood what is or who is a “product manager” The reason, maybe, is because probably neither have I, seeing as, depending on the season, budgets or simply the position of the planets, I could be asked to answer questions about sales (“who me?” – Keeping my finger over ”product manger” on my business card – “for complaints please knock on the door labelled Sales….”) or I am reminded that we are late with the publication of the newsletter or the updated version of the user manual! In fact it is not by chance that when I present myself to new clients I always tell the same story: “you must understand that there are two types of engineer; the good ones that slave away in the R & D department and the pretend ones, that get sent all over the world telling fairy tales. If I’m here ……” Obviously I count on the sense o f humour of the person I have in front of me and often it helps to break the ice, even though there is a little truth in that story: I don’t want to talk badly of all product managers in the world, on a personal level I would be an average technical engineer, but probably I cover the right role i.e. that technical/human interface between supplier and customer. If you are too technical you can’t get to grips with the “social” problems that clients pose to you, or you are so precise that you are not able to stop yourself from telling your client to their face that the product (that you are trying to sell) has problems… If you are a sales man you filter details and use numbers so that the client generally doesn’t even try to understand or even ask about technical aspects. By the way, I apologise in advance to all my “technical” and “sales” colleagues before I receive threatening phone calls and emails. I had to write something for this newsletter!

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Over the past few years, travelling around the world, I have seen a bit of everything and before long (maybe when I retire) I will write a book. For now you will have to be happy with a few anecdotes! One of the most interesting experiences that I face on a frequent basis, is that, of me presenting technical seminars in English (?!?), in the countries where it is absolutely necessary a translation to the native language. The main problem is that in these countries or you are really good at languages (therefore you do translations) or you understand electronics and the two things don’t necessarily go together. This is what happened recently….. After the initial stages - I speak, the translator translates, the audience tries to understand – we pass on to the operational phase – I speak, the translator tries to translate, the audience understands by putting everything together: the slides, my English, my hand movements, the pseudo translation, the stuttering of the person at my side – and the more alert members of the audience find themselves very proudly explaining the technical concepts in their language to the translator who then finally pretends to understand, looks at me with a mixture of satisfaction and embarrassment and makes me realise that we can carry on. After a couple of hours of this show, entitled CLASS D, myself and the 20 or so members of the audience, take a hard earned coffee break, which is the main concern of the general manager who has long since stopped trying to understand what we are talking about and is continually asking me how many more breaks there would be during the day so that he can organise accordingly. When they realise that I do actually drink the coffee, they try to convince me to have something a little stronger! I then had to explain that, because of my allergies I don’t drink alcohol. From that moment on they look at me with the same expression of concern that I would give to a boy without an arm, no without a leg, which is worse. From there on in begins the second act entitled PFC, with the help of the technical repair man, who using his hands mimics the variation of the mains tension, whilst I am impersonating the PFC, using my hands to mimic the pulling of the electric current from him in order to maintain the rail bus adequately charged. Unfortunately there weren’t twins available to impersonate +Vcc & –Vcc A standing ovation, with everyone having understood, even the translator.

The Author, Luca Giaroli, Powersoft product manager and MAC fanatic, earns his living, travelling around the world, telling what he can, but hopes one day to become rich with the sales of his book. We would like to invite you, the readers, to send in your stories, your experiences, your phrases, photos and anything that you would like to share regarding “our world” to with a promise/threat that the most interesting items will be published in the forthcoming editions.

What they say about us

Powersoft K10 High-Power Amplifier This high-revving powerhouse is an industry top performer. By David Rittenhouse, USA, 11.15.2007. David Rittenhouse is a regular contributor to Pro Audio Review.

You may be saying, “Wow, another high-powered amp on the market. Ooh — let me run out and buy it now because it’s the best new thing and this reviewer said it was awesome.” (Please note the sarcasm.) But I will spare you of any hype as I tell you about the new Powersoft K10, an amp that many of you may not be familiar with. However, I am speaking honestly when I say that you need to consider and hear the K10 before buying something else. This isn’t the flash-in-the-pan/fly-by-night amp story you may expect. The K10 is the real deal.


Just like Ferrari and Lamborghini,

this little powerhouse comes from Italy. And much like those high-dollar and exotic sports cars, the $8,395 unit packs a large punch in a small, sleek frame. The K10 sits in a 1U rack space and delivers 6,000 watts at 2 ohms per channel at a weight of only 26.4 lbs. Its bandwidth is rated at 5 Hz – 30 kHz at an 8-ohm load with a damping factor of >5000. Slew rate at 8 ohms is rated at 50 V/uS. A-weighed signalto-noise ratio is >110 dB from 20 Hz to 20 kHz with distortion rated typically at <0.05 percent. The K10 also is equipped with a universal/worldwide operating power supply with Power Factor Correction (PFC) for extremely low main AC input consumption and a wide operation range. You can also set the maximum power output for each channel and the maximum current draw on the mains. The K10 has optional DSP, putting it in the “majors” of live amplifier options. All speaker processing can be handled at the amp. Its DSP features one of the coolest impedance adjustments to the damping factor (±2 ohms). This only applies to the low-end frequency range (400 Hz and below) to correct for the amount of cable you are using from the amp to your subs, for example … very impressive. The K10 can also be networked (via an Ethernet option) with other Powersoft amps to be monitored and adjusted in real time with a laptop. The processing keeps a running log of temperature and faults that can also be accessed from the amp network. All of the processor changes can be mapped out and stored on a smart card (Powersoftproprietary), which is interchangeable from amp to amp. If, perchance, you choose not to use the optional network, each amp can be connected to a laptop running the given Powersoft Remote control software via a RS485 interface on each amp. Finally, all functions can be controlled from the amps front panel menu screen without a laptop.

In Use: I was delivered a big, fully-loaded (with DSP and Network capabilities) K10 for a demo, which equates “beat it up and see what it will do.” Out of the box, I had to put on a power connector (20 amp) Edison since it came with bare wire ends; I understand this, since Powersoft won’t know who will use this amp and with which power source. Outside of that, everything was ready to go. The amp currently networks via USB to CAT5, so I was sent those adapters and the remote software for my PC. The amp looks slick, but since it is only a single rack space the screen is pretty small … I guess you have to give up some things for the size. The day after I received the amp, I had somewhat of an emergency: I had multiple shows out and was lacking an amp for a simple DJ rig. While it might have been slight overkill, I sent the K10 out to unveil its power for the gig. The amp performed flawlessly, handling the subs with great ease; everyone at the Georgetown University gala were happy. With this said, I had to take the amp back in the shop and play around with the DSP and Remote control from my laptop. The DSP has everything and more you would need, plus menus navigation is laid out logically. The remote control software is a breeze (once you have network IDs assigned correctly) and truly makes this a system tech’s dream. The fact that you can monitor load and temperature in real time, as well as current draw and usage, makes the K10 its own manager in its own league. Once I worked up a standard DSP program for my EAW SB850s, I had the chance to test out the impedance adjustment for the cable gauge and length to my subs. So, about 100 feet of 12-gauge wire to my subs was adding about 1.7 ohms to my overall load. With that adjustment made at the amp, I could now accurately monitor the load on the amp and make it work more efficiently. This — along with the peak, power limiting and input sensitivity control — allows the user to set and control proper gain structure and output configurations to have the most efficient power ever. Powersoft claims this amp (and all of their K Series amps) to be >95-percent efficient. That is a pretty impressive statement that I may not have believed until I heard and saw this amp run quiet and cool on a 20-amp breaker and still provided gut-pounding power. My dual 18-inch subs have never sounded so good; they moved air with power from a 1U amp that sounds better than the “old-tradition” two-space, heavy, obviously-inefficient amp. I only wish I had a full complement of Powersoft amps to test out and to power up a full rig … a goal for another time.

Summary: If you are in the market for a powerful, sleek, chest-pounding amp that is fully loaded with all the latest features and runs more efficiently than anything else, the K10 is your amp. The fact that it sits in a single rack space and provides more power than the amps each of us have and use (and does with greater ease and f ull DSP) means it is truly the top breed, exotic race car of which we all dream.

Powersoft has built a great series of protection circuitry into the K10, including full DC protection against infrasonic signals, VHF (Very High Frequency) protection, Thermal Protection (indicating a warning before the protection process shuts the amp down), AC protection and clip limiters that can be disabled (although that is not recommended). The input gain and sensitivity is userselectable in the standard European dB steps of 26, 29, 32 and 35 dB. As with any live amp nowadays, the K10 comes with XLR inputs and Neutrik 4-pole Speakon connector on the outputs. K4,K6,K8,K10,K20 – The Amplification Platform – W W W . K- SE RI ES .I T - W W W .P O W E RS OF T- A U D I O.C O M

Technical ZOOM Why’s and what’s of adjustable output impedance power amplifiers by Tiziano Morganti

An ideal audio power

amplifier is a device that will generate an output voltage that is an exact replica of the input voltage, multiplied eventually by a constant value (the gain), and regardless of the output current delivered to the load. This is a voltage controlled ideal voltage generator, with zero output i mpedance. The output current doesn't cause any voltage drop.

This is the desired behaviour of most audio amplifiers, and K-Series is better than others, with its sub-milliohm output impedance, thousands damping factor and

150 A peak capability.

What happens if we add a resistor in series with the output of the amplifier? The damping factor falls down from thousand to units, bass reflex enclosures start to sound boomy, and transients are less tight and definite. Nothing desirable at all... But do this happen? Yes, in at least two cases: long cable runs, and loudspeaker voice coil heat-up.

So, why did we add an adjustable “emulated” resistor in series with the


output of our K-Series? Because we can make its value to compensate parasitic cable and/or hot voice coil effect, in order to maintain the correct damping factor.

Applications of this unusual feature: feature:

How we implemented this resistor? The KDSP board acquires the output


voltage and current signals, sampled at 96 kHz just like the main input audio signal. A fraction of the output current signal is added to the signal output by the KDSP. For example, suppose that for a given amplifier output current I, we add a contribution of 2 times the current to output voltage. With no load, and a 0 V input, we will obtain a 0 V output. If now we sink a 1 A current from the output, we will see that the output voltage will raise up to 2V, thanks to the “I” contribution. We built a generator which output voltage increase with output current, a typical negative resistance behaviour. Positive resistance, voltage drops with current, negative resistance, voltage increase with current... Changing the factor from 2 to another value, changes the emulated resistor value (2 factor => -2 ohm, -6 factor => +6 ohm).

Most of the i mplementation effort was taken to guarantee the stability of the system despite of ADC/DAC and DSP latencies, and to manage situations where user settings caused and unstable behaviour of the whole negative output resistance amplifier + load

Did you ever seen a -4 ohm output impedance amplifier with a 2 ohm load? system without causing any destructive oscillation...

cable loss compensation voice coil increase in resistance due to heating compensation, even dynamically adjusted with the estimated voice coil temperature damping factor “creative” adjustment, to create a more dry and damped or boomy bass response active loudspeakers with reduced loading volume: a negative resistance has the effect of reducing the Qes of the driver, allowing for smaller enclosures for the same driver More? Perhaps...The

programmable output impedance for power amplifiers is an outstanding and unique feature, internationally patented by Powersoft.

W W W . K- SE RI ES .I T - W W W .P O W E RS OF T- A U D I O.C O M

Where we have been: InterBee 20.11-22.11.2007 @ Makuhari Messe Onkio Tokki Ltd attended the InterBEE exhibition last month. InterBEE is a reference event within the International Broadcast Equipment industry and it is regarded as one of the major broadcasting tradeshow in Japan. More than 700 Companies were exhibiting and more than 36.0000 visitors attended the show. OnkioTokki displayed the full Powersoft range with a particular focus on our flagship. The K-Series, that has encountered a big interest for its unique and top end features.

ACF 14.11-17.11.2007 @ Brusselles Exhibition Center Ampco Belgium attended the 12th Edition of the ACF(Audio-visual Creative Fair) show in Bruxelles. This bi-annual tradeshow for pro-audio, lighting and video is a key meeting point for the AV industry for Belgium and Luxemburg. More than 100 exhibitors took part to the show that registered an attendance of approximately 14.000 visitors. This has been the first official event where Ampco Belgium had the chance to introduce to the industry the Partnership with Powersoft for Belgium and Luxemburg. Therefore for this first appointment the message was to disclose to the market the full range of Powersoft product portfolio, but as a matter of fact, the K-series attracted the biggest interest from the attendance for its leading pro audio performance .

Where we will be: ENTECH is THE entertainment technology show for the entertainment industry including the latest professional audio, lighting, broadcast, audio visual and staging products, supplies and services.A MUST SEE event for all professional entertainment technology users, the biggest industry event of it's kind in Australia.

Our Partner in Australia Production Audio Services will attended the exhibition showing our full product portfolio.

We would like to invite you, the readers, to send in your stories, your experiences, your phrases, photos and anything that you would like to share regarding â&#x20AC;&#x153;our worldâ&#x20AC;? to with a promise/threat that the most interesting items will be published in the forthcoming editions.

With our best wishes for a MERRY CHRISTMASSSS! and a wonderful NEW YEAR!!

W W W . K- SE RI ES .I T - W W W .P O W E RS OF T- A U D I O.C O M

INSIGHT - The Powersoft Newsletter - n°1  
INSIGHT - The Powersoft Newsletter - n°1  

INSIGHT n°1 - December 07 - the first issue of Powersoft newsletter