Jeg mener å ha rca-kabler av god kvalitet, sjøl om de ikke koster skjorta. Lydmessig er de iallefall helt topp i mitt oppsett. Jeg benytter Black Magic Revelation både ic'er og høyttalerkabler, og nest rimeligste Nord Ost strømkabler på forsterker og cd-spiller. Det er ikke antydning til brum eller støy, iallefall ikke hørbart. For noen år tilbake, opplevde jeg at DM-10'en brummet litt, men det skrev seg fra en trafofeil i nabolaget. Da trafoen ble bytta, forsvant brumminga.
Hva angår byggekvalitet og at forsterkere som er bygd for balansert drift, nødvendigvis må ha bedre og meir kostnadskrevende oppbygging ( = dyrere forsterker ), så har jeg lest meg til at også filosofien til Thomas Sillesen i Densen Audio Technology med "Zero Feedback Technology" basert på arbeidene til Matti Ottala, krever særskilt høg kvalitet på innmaten i forsterkerne. Det følgende er sakset fra nettsidene til Densen:
"The most important technical aspect of our productrange is the zero-feedback technology. In the seventies Finnish Professor Matti Ottala discovered the importance of low-feedback. Until then all amplifiers were designed using high feedback. Matti Ottala's breakthrough started a lot of low feedback designs. The benefits of the low-feedback designs compared to the standard high feedback designs were much faster amplifiers, better soundstage, detaillevel, transparency and so on. This leed to recognition of transistorised high-end amplifiers, and the beginning of the demise of tube amplifiers among high-end amplifiers.
The reason that feedback is used (though in smaller quantities than in the past) is that it is used to compare the input with the output, and adjusting the input so the output is exactely the same as the input. This way -at least in theory- the amplifier itself have no influence on the signal as these influences will be adjusted away.
With the introduction of the new DM series all Densen models are zero-feedback designs. This means there is no feedback loop in the amplifier. The problems connected with feedback technology are the following (whether it is low or high feedback): The signal always takes some time to pass through the amplifier stages, therefore the comparison of input andoutput is not the comparison of exactely the same signal. This means that the theory that feed-back should improve sound by avoiding influence on the signal from the amplifier stages is simply theory and not true.
The fact is that feedback -no matter what degree- alters the signal and the result is: -dynamics will be compressed, -micro details compensated away, -details smeared, -soundstage altered, -speed slowed down, -transparency smeared and so on.
Naturally you will not have these problems with a zero-feedback design.
However the basic design must be extremely much better than feedback designs, otherwise the amplifier will not be stable. We are one of the few companies in the world (the only one ?) capable of doing this and the result of this is simply stunning, the combination of a MUCH better basic design and the zero-feedback technology results in: Extreme dynamics, detaillevel, amount of microdetails, perfect soundstage, transfer speed, transparency, and wide open sound. Combining this technology with the extreme care we take in the listening tests, during the development of our products, we can proudly say our amplifiers combine perfectly, high technology with extreme musicallity. In the future ALL products from Densen will be zero-feedback designs."
Er det noen grunn til å anta at forsterkere som er bygd for balansert drift, skal ha bedre byggekvalitet, eller låte bedre, enn f. eks. Densen's forsterkere, eller andre forsterkere som baserer seg på zero feedback-prinsippet?
Og igjen: Hva skulle fordelen være med balansert drift?
mvh. VilhelmW