• Interview with Carlo Lastrucci (Powersoft)

    Carlo Lastrucci, president of Italian power amplifier manufacturer Powersoft, was interviewed by Doctor ProAudio.


    ¤ [Doctor ProAudio] - Let's start from the beginning. How and why was Powersoft formed back in 1995?
    ¤ [Carlo Lastrucci] - Some friends, fresh of engineering studies, decided to put together the passion for music and their entrepreneurial spirit and start the Company. The name reflects the two main souls of the Company, Power and Software.

    ¤ [DoPA] - Powersoft is synonymous with Class-D amps. These days we are all used to compact and light power amps, but it surely must have been difficult in the beginning. What were there early days like and how hard was it to gain market share?
    ¤ [CL] - The early days have been quite difficult because the digital era has not really started and some of our ideas were really too ahead for the time. But perseverance has been the secret to achieve the success we are experiencing now. In some period it has been very hard and frustrating, but we never gave up.

    ¤ [DoPA] - A few years ago there were not many options as far as efficient power amplifiers but now Class-D amplification is common place. Will that make it more difficult for Powersoft to differentiate from the rest in the future? What sets Powersoft apart from other manufacturers doing Class-D amplifiers?
    ¤ [CL] - It is true, nowadays Class-D amplifiers are available from many sources and the competition is growing, however we believe that we can keep the distance with a number of additional added values. The first being the know-how and experience in managing this technology. It is not really an easy task to make a good sounding Class-D amplifier especially when we are talking of certain level of power. In addition we believe that the secret of a pro audio amplifier is mainly related with the performance of the Power Supply where again Powersoft is representing the top you can find in the market since the beginning of its history. Last but not least, the manufacturing quality is another aspect that can make a huge difference in terms of both reliability and performance. Manufacturing quality means both process and components, we believe that also from this side Powersoft can make the difference.

    ¤ [DoPA] - I find it interesting that most established name-brands in in the power amp market still do not have 1U amplifiers … other than Chinese ones (a lot of which seem Powersoft-inspired).
    ¤ [CL] - Powersoft has at least 7-8 recognised copies manufactured in China. Originally we have been offered many times to manufacture in China, and the copy was brought to us as a sort of demonstration of their capabilities. However we believe the main reason for this is that the design of Powersoft amps is really appealing, if you look inside it is like a piece of art and this has become attractive for many Chinese Companies to enter into the market with something different.

    ¤ [DoPA] - What is Powersoft's approach to designing an amplifier?
    ¤ [CL] - When we design a new product we always try to think ahead and make something differently from others. We do not want that the market could say about one of our amp, "…so another one…" and we try to always add what can be useful for the End-User and how flexibly we can make it work. An example of this is the fact that our amplifiers can work without any reduction in performance at 2 Ohm. We tried to explain that this was in the interest of the users because they can work with fewer amplifiers. Only in the next period people started understanding that this is a true benefit for them.

    ¤ [DoPA] - Many users may not be aware that Powersoft product also goes into many self-powered speakers of many brands. How much of Powersoft's business is OEM?
    ¤ [CL] - The OEM business represents nowadays a solid 40% of our audio total turnover. Again this is another example of the fact that our perseverance has been stronger than the resistance of the market. At the beginning when we launched the idea we had very cold reaction from the market, but now also that part of the business is rapidly growing.

    ¤ [DoPA] - A lot of users out there still do not trust Class-D for use with high frequencies. Are there any serious psychoacoustics testing on this that could throw some objective light on an otherwise very subjective discussion?
    ¤ [CL] - I cannot speak in general about Class-D, but in all the occasions when we made blind A-B comparisons, this bad feeling about Powersoft in high-frequencies has disappeared. This can tell something to users, my suggestion is try without prejudice and then take your own decision, but not believe to rumors or what you have read somewhere. In the end it is their own business and they have the right to make something that makes sense for them to be successful in what they do, so don't take these important decisions on the basis of what somebody else told.

    ¤ [DoPA] - Class-D amps need a passive low-pass filter at the output. That makes the top of the frequency range deviate from a very flat response in conventional amps, and that response changes depending on the load impedance. That would an argument against Class-D in high frequency, would it not?
    ¤ [CL] - Again I cannot talk about Class-D in general. It is true that in general the output filter is the most critical part of a Class-D amplifier especially in terms of performance at high frequencies; however this is again a general concern that does not apply to Powersoft amps. Comparing the frequency response of a Powersoft amplifier with any linear amplifier in the market will disclose a big surprise in term of flatness in the entire frequency band and against load changes. Again not all Class-D amplifiers are the same.

    Logotipo Powersoft
    ¤ [DoPA] - Some people's objections with regards to SMPS Class-D amps is with regards to reliability with less than ideal AC supplies as well as performance with AC low voltages (digital gear has traditionally benefited from UPS type units)
    ¤ [CL] - Again, I cannot speak in general, but you have to consider that in the power Supply of our main series, K, Q and D we integrate an additional technology that is called Power Factor Correction (PFC) that is really beneficial especially in those situation where the mains specifications are not stable and clean. This means that the electronic inside the amplifier is working at stable conditions despite of the bad generator and this guarantee a higher reliability and also no bad impact on the performance due to the fluctuations of the mains.

    ¤ [DoPA] - So far Powersoft has not seemed to show much of an interest in protocols for audio transport such as EtherSound or Dante, with only some Cobranet support. Why? Will that change in the future?
    ¤ [CL] - First of all we have to clarify that it is not a matter of interest but more a matter of concern that the audio industry has not managed to agree A standard for the benefit of our Users. We do not believe that it is in the benefit of the users to have so called "standard" protocols for which you have to pay a license. In addition to this the fact that we are involved also in the OEM or power modules business obliged us in thinking looking at both sides of the business. Starting from this perspective, while it could be sustainable to pay a license for a rack amp, it will be very difficult to support a license fee for a power module doubling the cost of it. This was the reason why we have developed a protocol ourselves, called AESOP (Audio Ethernet Simple Open Protocol), investing resources directly and then we have given the entire result of this work to AES in order to release a license free protocol. This protocol is able to transport on a single CAT-5 cable monitoring information plus digital audio streams (2 stereo channels) using AES-3 digital protocol. Unfortunately this is still not widely known, but it is a good solution open to everybody. However we have to admit that now it seems the industry is converging to what we have been looking for since years a really LICENSE-FREE protocol, AVB.

    ¤ [DoPA] - Do you have any plans for AVB?
    ¤ [CL] - We are already working on AVB and for sure our future plans will include the development of this protocol and we sincerely hope that the particular economic interest of few Companies will not block the completion of this development.