彙整 | 三月, 2008

HiFi 懷舊三十年 (五) 之 V-FET 之 三

21 三月

70年代係日本喇叭及放大器倔起的年代,不可不知,第一顆商用MosFet就是從Hitachi 跑出來,幾年後才有Siliconix 出 vertical 的MosFet。至於VFET,除了research paper外,旺記一直都看不到西方有出品,直到幾年前有所謂Power JFET,不過都EOL矣。

1975年,當時至敢言的發燒天書TAS曾 comment 過 Yamaha 的 B1。B1是Yamaha的頂班VFET amp,用自家的2SK70/J20。

Comments 頗為enteraining,姑且輯錄一些如下 :

“From the outset,I seemed to find serious deficiencies in the B-1. With all the speakers mentioned, there was a distinctly bright sound, which also was decidedly hard compared to Ampzilla and the Dual 76A. It really wasn’t pleasant to hear. Then I made a discovery: by switching from the Ortofon to the ADC cartridge the tables were turned completely. No longer did B-1 seem bright or hard; indeed , it just about wiped out the other two amps… with program material ranging from Mahler through Cat Stevens and Gordon Lightfoot to Broadway musicals, the B-1 kept wiping out the other amps in matters of definition in all frequency ranges…. Comparing Ampzilla and the B-1 on Dayton Wright speakers, the B-1 exhibited more air around voices and brass instruments, and less splattering of vocal sibilants, though with one record Ampzilla exhibited a low end that was a bit deeper and fuller than B-1." – JWC

另一寫手道:"…after spending a month listening to the B-1, I’ll have to take sides with JWC on this amp. I still feel that B-1 is the best overall amp on the market today." – PHD

然後,主編出 : " As for mid-range depth and focus, the B-1 , while exhibiting marginally more depth than, say, Ampzilla, still falls considerably short of the best tubed-type equipment. There is , unfortunately, little of Ampzilla’s ability to resolved detail. I  should mention that the B-1 sounds better on some speakers and worse on others. But under no listening circumstances has this amplifier even struck me as being anything special. Some may think this is because ‘it has no sound of its own’ but a sound of its own it does have, one I would describe as very smooth, so smooth, in fact , that it seems to soften all the angles of a musical performance." -HP

對不起,小弟覺得HP酸溜溜感覺溢於言表,無端端講乜野the best tube type equipment 呢,邊款 係 the best 呢 ?即係好似見到一個美女然後話,車,咪人一個。唔係人唔通俾個天使你。

Anyway 可以 provide 一下 Ampzilla的資料。Ampzilla 係我輩在70 年代至hot 的diy amp 之一,power 管係MJ4502/MJ802,Mot 記。

技術上,2SK70/J20在 linear region 贏bipolar 的MJ4502/J802 七七四十九條街。

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玩全音,歎壽司 (3)

5 三月

發燒友的 Common ground 祇有一項,就是傳真。不談傳真,就真的不知如何 benchmarking hifi高低了。但甚麼是傳真 ?可以試試問個錄音師給你一張傳真的唱片,他不是支吾以對就是爽快說沒有。道理很簡單,所有錄音都是後期調出來的,調出來的音色是錄音師的口味或捉摸市塲的口味,發燒錄音就是摸中了發燒友的口味。所以玩 hifi講 tonal balance,只算是口味的追求,找個 equalizer,或可以在 digital domain 加減 harmonic的調音台就可以玩得天昏地暗了。追求原音的人若曾玩過 analog或 digital equalizer,唔多唔少會泛起一陣空虛,心中暗問 : what is truth ?

Leo Fung 十多年前就在雜誌上講過,何為 原音 ?在玻璃房和石屎房錄的 violin 是完全唔同聲的,聽慣石屎房 violin的人會說在玻璃房錄的 violin好假,但其實卻是真嘢。Vice versa。

所以,旺記現在評價 hifi 的 標準只有一瓣,就是速度。訉息的波形 ADSR相對關係是改不了的,改了就是改變了訉息的基本形態,鋼琴可以變成貓叫,大概所有錄音師都不敢冒這個風險。