As we are in the mood for some technical background, let is continue our “inside story” …
Besides vinyl playback, PC audio has emerged as the source for audiophile stereo systems. Not long ago, CD playback had the dominant position, but that is diminishing more and more. For this reason, a DAC with a state of the art USB input is mandatory these days.
Our offering, the VIVACE has one of the most sophisticated USB inputs on the market, regardless of price. It features an asynchronous data transfer, an isolation barrier and a low noise clock management. Ok, asynchronous data transfer, meaning the transport (PC) is slaved to the DAC has become quite common in the past two to three years. So, that’s not unique anymore. But the VIVACE USB input has more to offer: a complete galvanic separation of the PC-ground from the DAC-ground leading to a huge reduction of transmitted HF noise originating from the PC circuitry.
Most digital equipment manufacturers leave out the galvanic isolation, the vast majority for cost reasons, and the rest claiming that galvanic isolation introduces a new jitter source. We at LINNENBERG are not willing to trade off one thing (noise reduction) against another (mild jitter generation). With our specially developed double slave USB circuit we can have it both: no additional jitter + 100% noise reduction.
In order to explain our decision to introduce the UNISONO power supply, we have to go into greater detail here as well. Numerous compact sized high end audio components use a wall adapter these days. There are very good reasons for that:
- eliminating the noisy and mechanically vibrating transformer inside the gear
- mains voltage range from 100 – 260 VAC, making export easy
- low power consumption, green technology
When using a highest quality wall adapter, like the one we supply with our gear, the result is very satisfying. Nevertheless, we won’t keep quiet about the fact, that there are drawbacks using this technology:
- a wall adapter, even the very best has some residual HF noise
- the industry standard barrel connector, common to all low voltage DC adapter enables exclusively a single voltage due to the two contact (poles) limitation.
- limited current capability, moderate impedance
Some third party vendors as well as some original manufacturers figured out soon, that replacing the wall adapter with a conventional power supply increases the sound quality of the actual audio device, because two of the above listed drawbacks are eliminated.
When you go “plug and play”; and that’s what everybody offers, a serious problem remains: Your complete audio electronics is operated by a single voltage. 5V, 12V or 15V are ordinary voltages. You just have one of these and that’s it, while your gear needs a bunch of different voltages; some positive, some negative (referred to ground 0V). Now, one needs to know, that every audio component on the market using an outboard wall adapter or an open frame switch mode supply inside the gear MUST use additional DC-DC-converter in order to generate all those different voltages an audio circuit NEEDS. That’s fact, regardless of price. A well known Swiss company, once famous for their tiny tape recorders – as well as other manufacturers which we won’t name either – goes so far to generate tube voltages (anode voltage, heater voltage) out of a single DC voltage power input. Remember: a DC-DC-converter is a switch mode power supply, and you need lots of them!!! What ever you do, some residual HF noise will leak in to your audio signal.
To cut a long story short; UNISONO in conjunction with the DPP models dismissed all switch supplies inside the gear, eliminating a possible source of grain.