Pass Labs Aleph 1.7 開工

這幾日做到傻傻哋 .... 都係忍唔住拿了套 Pass Labs 1.7 出來切吓．

見到有成８０粒電阻都有點頭痛, 有老花真係唔係一件太開心的事，哈哈．

工作了兩小時，完成了resistors + diodes部份，都係要休息一陣　．．．．

CAT

Good to hear alfcat playing new toy. Look foward your progress.

White CAT,

Support you!!!!


Also, DAC1955 :
144 pcs resistor
190 pcs capacitor
128 pcs diode, transistor, IC, socket, etc.

DIY PassLabs D MOSFET 要 matching ...

Dear Autumnleafcat,

MOSFETs need matching? Like capacitors type or ...

How do I match MOSFETs?

CAT

KK Sir,

If I know you guys TEN years ago, I will try this toy.

Now, ha..ha... I need to take a break of 15 mins after soldering for 20 mins.

CAT

dear alfcat,

These links I found on net about matching MOSFETs :

http://www.diyaudio.com/forums/showthread.php?postid=6632

http://www.altavistaaudio.com/MosfetMatching.html

Technically matching MOSFETs needs to prepare some test-jigs and instruments (variable power supply, multimeter, etc) which is a bit difficult and time consuming for home audio builder ...  :?

So you can check whether the MOSFETs are of same date code. The deviation within MOSFET samples of the same date code could expect acceptably small that matching isnt essentially required. But certainly this depends on your luck even same date code MOSFETs would give slightly higher deviation still within the manufacturer stated specification ...  :

With matching, however, the best match would drift within 2 - 4% deviation of each other after putting into circuit, due to physical environment change. But had been at a cost of buying over 10 pieces of MOSFET to obtain a match-pair ...  :roll:

One more thing could try is replacing normal rectifying diode to Schottky.

Dear Autumnleafcat,

你說的對. 可以轉為 Schottky. 但最初團購時是希望用一個平價錢去切部機.番咗來之後已先後upgrade 了電阻與電容 ... 加多了成千銀 ..... 都係聽聽先. 加上已大致上完了功 ...哈哈. :

CAT

cat sir

here is practiacl mosfet test ing for audio by Nelson Pass

http://www.passdiy.com/pdf/mos.pdf

can I to know where is you order holco resistor

DualXenon 兄,

Thank you

DualXenon,

Good information !

DualXenon 兄,

Holco resistors obtained from Sound Explorer in Yau Ma Tei.

CAT

Case work of Pass Labs is sexy. Do you have digital volume control,
selectors, displays?

Dear Autumnleafcat,

I will post the photos of the case and the others later. It should be a Pass Labs Aleph 1.7 CLONE. The case is around 6 KGs (bare).

CAT

Exciting project !

Getting close to have it done. However, there are still a few things that need to get.

1. Those Green wire connectors.
2. The wiring diagram ... just realised that I don't have it.
3. The RCA sockets; I mean the good ones.

CAT

PassLabs Case work 風雅的氣息真美 ...  


digital volume control / input selector 是否完成品, 還是仍需要自己 DIY ? ...  

是完成品, 唔使自己切 .... Just Assemble them into the Case.

The remote is not yet ready. Will be delivered later.

昨晚做完功課,把Aleph 1.7 所有的線事事但但地駁好了. 開一開,試一試 .... 嘩然! 果然好機!

感受上同我現在用的平價M7很不同. 對比是較為大, Details 較為多. 唔知係唔係未煲關係,D聲好似有少許Hard.

還有幾個電容和電阻未上... 上了後我相信音色會更好. 還要煲得100個鐘 ....

Cat sir,

This passlab is solid state amp right?

how much u pay for this kit?

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 ...

WINDWSS,

Please check your email

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]

-----------------------------------------------------------------------------------

其實最重要是配合，無論是膽或是原子粒，好聲便是好機。

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?

我第一部 preamp 係十幾年以前 DIY Marantz 7 連 phono amp 總共 6 支胆,

用大陸胆無 resolution , 然後換 RCA 胆聲音係快同埋動態大, 但 bass 潛得唔深,

跟住 DIY matisse ref 連 phono 總共 4 支胆, 動態都好大, bass 都潛得好夠深,

matisse reference 係帶少少甜少少厚, 係無 marantz 7 既清麗同中性,  

marantz 7 既優點係 right harmonic, 樂器質感真實, 但高頻去得盡容易刮耳,

matisse reference 既優點係 musical, refine, 但樂器質感唔夠 marantz 7 刺激.

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: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]

CD 降臨, 以 line stage 為主力, LP 進入黑暗時代, 發燒熱度上升, 第二部牌子廠

preamp 係 audio research LS 7, 這部胆 preamp 動態都好大, 但分析力一般,

樂器結像比例大所以音場感覺有好強高度感同深度感, 有胆香味, 無噪音靜如深海,

其實要求唔高可以玩過世, 但整體係要輸比以前, 心有不甘, 又換 preamp ...

今次係原子粒 preamp, 二手 Threshold FET 10 e line stage, 係分體電源 ...

... 漂撲半生, 終於找到安寧 ... threshold 雖然無胆既芳香, 胆既唯美  ...

但原子粒機容易(不費力)滿足一切 hifi 既客觀評價標準: 頻寬, 動態, 低頻, 力水, 平衡 ...

threshold 要動態有動態, 要細節有細節, 要分析力有分析力, 要大場面有大場面 ...

原來原子粒機既 neutral, 都可以精彩描述音樂 ... 無味精, 無添加 ... 好似重正 ...

今天我既 preamp 係 simaudio p5, power amp 係 threshold s/300e ... 係全原子粒,

... 大概有一天我會心思思玩返胆機 ...

accphoto,

The bad luck I got is that I always bought low efficiency loudspeakers which are problemic to tube amp. My previous speakers are AE1 (84dB), 1SC (84dB), Alon II (86dB), now d25 (88dB but I think actually lower) ...

一子錯, 滿盤皆落索 ... cannot play tube power amp ...

JM Lab is best match to tube SE amp ...

Pass Labs Aleph 1.7 終於完功啦!

頭頭尾尾都玩咗成個星期.... 因為唔係日日都得閑.

只有時間試了10分鐘, 但也覺得這部機真的不錯 ..... :wink:

有機玩, 一定要多謝大恩人 Accphoto 兄. 雖然忙到不得了,還幫我們四圍打點一切,配齊所有東西, 等我們可以開工 ..... Many Thanks AGAIN!

CAT

Dear alfcat,

Can the digital volume control and input selector accept balance (XLR) input?

以前係中環 "雅典" 聽 Metronorm T1i sig CD player, Passlabs X1.0 preamp, X600 power amp 行全平衡推 khama 力拔山河, 但改用 RCA 後效果不及 balance 時好, Passlabs 係全平衡 design, 用 balance 會發揮好 D ...

Dear autumnleafcat,

這部機是行 Balance 的. 我用RCA因為我無 Balance 的 source and Power Amp.

靜係個 volume and selector PCB 已經嘆為觀止, 遲 d 分享下個 performance.

Threshold 同 Passlabs 本屬一家, founder 都係 Nelson Pass, 儘管年代唔同, 然而線路同宗, 共勉之 !

autumnleafcat,

起初Accphoto兄建議我切這部機時,他說這部機好"中性", 用來做reference很好.

到現在聽了大約5-6個鐘,感覺Accphoto講的有道理...

完全check up之後,發覺音牆比我的M7闊,定位準,對比大,分析力好....細微的配樂,以前聽不到的,現在聽得到, 但又不會搶聲,好平衡.

我只聽了一年多Hi Fi,新仔一個 ... 只是切了(+聽過)6-7部前級...這部到現在聽過最好聲. 對我來說, 這個價錢, 有部咁既機,真是十分難得!

我相信如果行平衡輸入/輸出會有更大驚喜  :wink:

CAT

Dear alfcat,

恭喜你得一好preamp !

I have experienced both RCA and balanced mode in my hifi system.

In RCA mode, 比較有音樂感, 但頻寬, 動態, 低頻蝕少少, 分析力就唔比較聽唔出大分別 ...

In balance mode, 頻寬, 動態, 低頻, 分析力去到盡, 聽爆棚古典更明顯, 但 音樂感比較弱, 較冷感 ...

所以我最後 CD -> preamp 用 balance mode, 抓緊個細節, 分析力同動態 ...

preamp -> power amp 就用 RCA mode, ... 登番混個音樂感 ...


alfcat 你好幸運, 能碰上幫到手既朋友 (accphoto) 教路, 節省唔少金錢時間 !

Dear autumnleafcat,

你說的是. 我是一個信耶穌的人, 我感謝上帝有這麼多的好朋友在我的身旁. 他們都如天使一樣. 講真, 我只是傻瓜一名, 什麼都唔識, 問東問西問到人都煩那種 .... 但這些天使們從來沒有計較他們可得的利益來幫我 ... 相反好多時自覺慚愧, 因自己無什麼東西強, 可以幫回他們 ....

其實Hi Fi中有好多好人先先後後幫過我, 對他們萬分感激. 同事中, 我也有好幾個是上刀山, 落油鍋類 ....

父母教落, 別人的缺點不要記, 別人對自己的恩卻要記住, 有機會就要報 .... 所以盡管生命滿壓力與challenge, 還是樂觀的面對每一日 ....

CAT

=D>  =D>  =D>  \/  \/  \/

聽君一席話，勝讀十年書.....

每日聖經一席話, 祝福滿足過一生 ....

一樣嘢我要記得得多點做, 為我身邊的人多禱告... 求上主加倍祝福各人... 尤其在這場風暴日漸嚴重之時 ....

感恩 !

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.

Original manual of Pass Aleph P preamp.

I am still running in this toy.

For CD listening, it is very nice. However, I don't have any really GOOD LPs .... when I play LPs, the pre-amp expose all the "demerits" of the LP and the system.... ha..ha.

CAT

Frankly i really salute those who like to play LP.
For me it is cumbersome, need tuning, need cleanning..... wow need to do a lot work only can get good sound...... i surrender....

In my LP system, the sound depends almost entirely on the cartridge. I have three cartridges, two turntables and two phono amps.

Swapping between two tables can notice the difference on dynamic, extension and details. Same result on the sonic signatures of two phono amps. Maybe I use solid state phono amps, which is neutral.

Swapping between the three carts gives dramatic results. Dynavector 10X5 is sweet and good pace (令人興奮) but the lowest resolution.

Dynavector XX2 mkII has slight sweetness over neutral (陰柔), that makes every listening enjoyable, but a bit dim in high frequency.

ZYX Yatra (0.24mV) sounds as close as CD (剛陽). My friend audited it said that, if I didn't tell him, he believed that he was listening CD.

From the finding on ZYX cart, I have a hypothesis that the information of LP and CD are identical. Just most cart cannot retrieve the entire information from LP, or tune the sound under designer intention.

Could owners of Pass Aleph P preamp share their experience on using the preamp and the comparison to other preamps? What make it so special?

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]