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Why no pre-out for a subwoofer?
I didn’t want to have a piece of wire from the preamplifier section hanging around. My topology didn’t allow me to bring the preamplifier’s output to the rear of the amplifier where all the i/o sockets are. I remember once adding a voltage indicator to a preamplifier. The sound was degraded enough to be audible. I didn’t want the same for the Birth 100 although I understand that customers want features. However sometimes they don’t understand that certain features may degrade performance. I of course do consider the possibility to add more features to future products. And, I do believe that simple things can be better.
Why four toroidal transformers rather than two or one with multiple secondaries?
A dual-mono design requires one transformer per channel. Since the preamplifier is single-ended, it needs a +105V power supply while the push/pull output stages needs ±40V so a single transformer can’t do the job. On the other hand electro-magnetic interference is much higher in multiple secondary transformers than between two transformers one next to each other. In addition during dynamic passages one transformer feeds the power stage (which needs a lot of current) while the other transformer free of the load feeds the preamplifier stage with enough current to operate without any degradation in performance. Basically the same principle that is traditionally applied in dual-mono designs has been taken a step further and is now applied to two separate and critical parts of the amplifier.
What does your reference system consist of in which you tested the Birth 100 during R&D?
I don’t like using just one reference system for the development of an audio product. Fine-tuning a product using just one system might lead to a product that won't perform well in another. I do have a reference system where I do most of the development but I often visit friends and evaluate how my product sounds in their systems. This might not sound very professional but works. Most of the development was done with PMC OB1 speakers and a custom-made pair of speakers I trust, Lavardin IT and Norma amplifiers for comparison and a Bonnec EVO CD player.
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What particular performance parameters did you look for?
I must admit that when it comes to audio I am not a big fan of measurements. I prefer to implement an initial idea, listen to how it sounds, then take it step by step until I get the desired result. This is because there doesn’t seem to be much correlation between measurements and audio-quality parameters. Hence my criteria are strictly musical. I am a musician, not pro but heavily involved on tenor sax in quartets which play modal/modern jazz. At 13 I started on guitar but switched to saxophone at 25 and attended the conservatory where I also learnt to play a bit of Jazz piano and compose on it. Hence I wanted my amplifier to sound as close as possible to the real thing. Of course everyone wants that but what I do is a comparison between the sound I have in mind from my own live performances and the sound that comes from the amplifier. Then I try to alter my circuits to produce a closer match. I pay particular attention to the timbre of instruments, natural dynamics, imaging, musicality and timing. When the music is right it touches my soul. That's when I know everything is as it should be. The difficult part is trying to identify the source of something that sounds wrong to then correct it. I don’t mind that my amplifier has a damping factor of only 17. I’ve heard amplifiers with a damping factor of 100 or 500 that sounded horrible. Sadly a damping factor of 500 is good for marketing. What to say of a damping factor of 17?
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What companies/products do you admire in this sector and who do consider some of your best competitors?
Any company that sells similar products at a similar price is considered a serious competitor. I admire companies which have a long history and managed to thrive over the years by retaining their original quality and building a strong brand name. I also admire companies and products which embed innovative technologies for practical reasons and not just for marketing purposes.
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What other products should readers expect from you in the near/er future?
As mentioned earlier, a CD player is on its way. It’s a top loader with the famous Philips CD PRO mechanism featuring asynchronous 24/192 USB support and balanced and unbalanced outputs. A phono stage might be next (I'm already testing some ideas) but I think that a pre/power set could be more attractive. I know that for some customers 70wpc are insufficient so my plan is to build an amplifier with around 200 watts or so. I haven’t decided yet if this will become an integrated amplifier, pre/power set or a pair of monos. A DAC is also something I would like to produce—it's partly implemented in the CD player already—but the timing must be right. To be honest, I first have to wait and see how the market responds to our first product and take it from there. |
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Black Pearls is currently a small company with limited funds. I can’t dream of growing big by the end of the month although I’d love to. I will take it step by step just as I do with my circuit designs and see how it goes. I want to produce quality and competitive products that customers would be proud to own.
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