Audio-gd ACSS og Krell CAST forstærkerprincip

[LarsHP]

ACSS = Audio-gd Current Signal System
CAST = Current Audio Signal Transmission

Audio-gd / Kingwa skriver bl.a.:
ACSS (Audio-gd Current Signal System) is Audio-gd's system for transmitting audio signals in the current domain. This concept, first seen in 1966, we have used for many years, and since 2006, have evolved the technology to include all audio signals in our systems from the digital source to the power amplifier. Since 2005, ACSS comp5nts have become Audio-gd's most popular products.

Audio-gd's ACSS er lig Krell's CAST. Krell's hjemmeside siger om dette forstærkersystem:
CAST (Current Audio Signal Transmission) is a proprietary technology by Krell Industries, LLC that effectively combines the signal gain stages of components connected in CAST into one gain block. CAST technology virtually eliminates the noise and distortions created from the use of multiple voltage gain stages. A Krell system connected in CAST transfers the signal in the current domain, throughout the signal path to the amplifier output stage where only one current to voltage conversion (I-to-V) takes place. CAST enabled products include a transmitter and receiver circuitry that transfers current from an extremely high output impedance (source) to a low-impedance input (load), minimizing the cable's effect on signal transmission. CAST technology expands the usable audio signal bandwidth well over 2 MHz; ensuring harmonic reflections are virtually immeasurable in the audible frequency range. CAST allows signal transmission over extended lengths of interconnect cable, allowing flexible placement for your components, without signal degradation.
(...)
By maintaining the musical signal in the current domain from beginning to end, an entire CAST system behaves as if it is one component. With CAST, circuit board properties and signal transmission aberrations between components are eliminated. Cable impedances and their effects on the transmitted signal are non-existent.
Læs hele smøren her: http://www.krellonline.com/cast.html

Begge dele er et balanceret signal. ACSS fra Audio-gd bygger altså på samme forstærkerprincip som Krell's CAST - dvs. det er strømstyrke-styret, og det er derfor Ampere og ikke Volt, der tages udgangspunkt i, når output f.eks. defineres. I stedet for 2V eller 5V i output, så er det x mA, der opgives.

Kingwa (Mr. Audio-gd) skriver selv:
With strong research and development capability in audio technology, Audio-GD offers a complete series of Hi-Fi equipments - DAC, preamplifier and power amplifier - with our signature “Audio-GD Current Signal System“ (ACSS) technology. Our ACCS technology transmits all audio signals via “Current” domain which offers the least colored, most detailed and neutral sound. In addition, we also master advanced audio technologies like power regeneration technology and full balanced audio technology. Our technology is on a par with the international famous audio equipment manufacturers.

Og et andet sted skriver han:
The ACSS is a non-feedback technology made with fully discrete amplifiers. Most people know the global feedback design can offer better specs in test measurements, and classic non-feedback can't do well in test measurements but can offer better sound for the human's ears. Here is a conflict of the classic circuits. But the ACSS opens a new field, it can offer a least coloration sound which is more neutral with very low distortion and high linearity. So it can retain the dynamics, detail and neutral sound but not sound bright or harsh.
Audio-gd's hjemmeside er her: http://www.audio-gd.com/Products-EN.htm

[FrederikS]

Skriger jo til himlen som ren marketing / snakeoil.

Alle outputs kan jo defineres som x mA og y V det er der jo ikke noget hokus pokus i. Langt de fleste har så smarte I/V converter trin som muligt, kan ikke helt forstå hvorfor det her skulle være anderledes end normalt eller mere snedigt for den sags skyld.

[LarsHP]

Det er i sig selv ikke nogen pointe, at opgive output i mA frem for V som et kvalitetstegn. Det er selve forstærkerkonstruktionen eller princippet, der er pointen. En af dem er netop, at med denne teknik undgår man helt I/V konverteringen, sålænge man kører CAST/ACSS.

Når jeg ser THD tallene på Audio-gd forstærkerne, så er de i mine begreber meget lave taget i betragtning, at der er tale om 100% non feedback konstruktioner. Når en af hifi verdenens absolut største navne indenfor high end forstærkere anvender dette princip gennem mange år, så er det vel tegn på, at det har noget for sig. Audio-gd har for øvrigt et meget, meget godt rygte mht. netop deres forstærkere og analogdelen i deres bedste serie. Eksempelvis John Darko (Digital Audio Review mv.) har Audio-gd forstærkere og DAC som reference i sit eget system. LC Audio forforstærkeren jeg havde blev KNUST af min Master-6. Eneste årsag til at jeg fortsat ikke har opgraderet mit ellers legendariske ZAPsolute effekttrin er, at Audio-gd's er 48cm brede, hvilket jeg ikke har plads til.

Har du over hovedet sat dig ordentligt ind i det her, før du kalder det markedsføring og slangeolje? Endsige hørt udstyret? Ja, undskyld mig, men jeg synes ikke, din kommentar tyder på det.

[Claus-DK]

Om det er salgsgas/snakeoil eller hvad man nu kalder det, tvivler jeg lidt på..

Det er ikke mit indtryk at King-Wa er typen der begiver sig ud i noget der ikke har hold i virkeligheden, han er nogen gange lidt for hurtig til at opgraderer, med lidt fortvivlende resultater, men salgsgas tror jeg ikke er noget han har en flaske stående af..