Pass Labs Aleph 1.7 開工

Alfred,

Your Pass  mosfet was matched to 0.5% already, that is the reason why it  sound so good....

[quote:187169c410="autumnleafcat"]愚見認為玩 HiFi 要動態, 要細節, 要分析力, 要大場面, 非原子粒機莫屬,
胆機只係贏味道, 胆機要用補品補到出血先可以有原子粒機既(部分)水準 ...
點選擇要視乎個人要求, 看來 alfcat 兄 已得道, 離 hi-end 不遠矣 ...[/quote]

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其實最重要是配合，無論是膽或是原子粒，好聲便是好機。

[quote:e1b9b51f8d="WINDWSS"]If i'm greedy, want 胆味道 and 原子粒機動態, 細節&大場面, do u think can obtain by using tube preamp and solid state power amp?[/quote]

Traditional wisdom tells us that it may be the way that you should go..... However, I change my opinion after using the pass Aleph P1.7. I would say you should try to use Mosfet pre-amp  and tube power-amp. you may be surprised.

Single end tube power amp is my favourite at the moment, To many people surprise, a small single power amp like 300B with 8 watt, with matching speaker can really drive some good dynamic while still maintain the musical character of single end of amp............


[quote:1152a0a830="autumnleafcat"]牌子廠 preamp 第一部係二手 Conral Johnson Premier 3, 連 phono 共 7 支胆,

CJ P3 中性得泥帶微甜但無 matisse ref 咁甜, 有齊 marantz 7 既真實樂器質感,

同 harmonic extension, 唔會刮耳, 動態極度龐大, 聽交響曲現場一樣 ...

個人最愛這 preamp, 令人黯然既係 phono 部分噪音好大, 以前 LP 係主力音源時,

不得不放棄 ...

跟住結婚發燒熱度不減, 只係就一就, 改玩 audion sterling EL34 單端合併機,

儘管只係14W, 聽 violin, vocal, 推 ProAc 1SC 漂亮得不可方物, 靜電喇叭級享受,

然而只係14W, 聽鋼琴細聲尤是可, 大聲就連鋼琴左手按低音鍵都拆,

動態大 D 既音樂又拆, 無理由只係聽 violin 同 vocal, 又唔可以大聲,

玩少同聽少咁多音樂, 又係不得不放棄 ...[/quote]

=D>  =D>  =D>  \/  \/  \/

聽君一席話，勝讀十年書.....

Even though the technical sides indicates that the output impedance is high, the amp itself is actually very dynamic, even more dynamic than my CLoned Matisse Reference . For the inpiut gain control, it is essential to match some CD which may have as high as 4V output on the balance level.




[quote:e8d014ade0="autumnleafcat"]A very special arrangement I noticed from the original design of Pass Aleph P preamp is the volume control is located at the output side.

Technically it would vary the output impedance on different volume level and also output impedance would be higher than normal preamp.

Moreover a gain switch is located at the input. this eventually reduces input impedance at maximum gain setting, that source usually dislikes.

The outcome would be reducing bandwidth due to the preamp high output impedance. Also the source sees a low impedance that would affect source itself distortion and dynamic characteristics.

Anyway these are only technical points of view. Most important is that you guys love the sonic signature of this legendary masterpiece.[/quote]

DO not  use iron casing, the better the conductivity  the better the casing, so  Copper better than -- > Aluminium better than-->  Iron.

You hum may related to wire and gounding, pay more attention to the how the wire is running, especially high tension (power ) and the heater. Beware that "resistor" is also some source of hum, do not use AB as loading resistor as they qre quite easy to introduce hum to the circuit.

Simple, Copper has a better conductivity than other metal so the machines will be sheild from other interference , so the background is quieter, more detail can be revealed by the machine and most importannce is the sound quality will be more musical. It is really strange.

The microphonics comes from the tube , not the case. You should change another tube to see the problem still exist. If yes, use some " tube cover" to reduce the microphonics. Like this one.

你唔加雲母，可能已經燒左。