- #19229 [Jp80mc], 23-07-25 01:46
- #19228 [Jp80mc], 23-07-25 01:43
Q值非常嚴重! - #19227 [Jp80mc], 23-07-25 01:42
嚴掌門,下午好,好文章好分享,昨日我也將對HF35拿出來保養一番,換了對.03 600V,缐性方面提升頗大 -
- #19226 [rcwy], 23-07-24 19:56(轉自小弟在 Fisher 同好會中一帖)
Mullard 5-20 = 用5支膽出20火 watt
記憶中,Mullard 5-20 設計特點:
1) 第一支膽採用5極高增益例如 EF86
2) 高增益後採用深度負回輸令膽機工作穩定,整體失真下降
3) 採用長尾分相 phase-splitting 兩支3極膽(即 ECC83 的兩邊)各自產生正/負半波強大推力,分別各推一支強放5極膽 EL34
4) 採用超線性 ultra-linear 輸出:EL34 強放功能回饋入 output 牛初端的 10-30% 抽頭,有效壓低5極膽 EL34 五極失真
5) 膽機輸出牛 output transformer 係膽機靈魂完美整合EL34 的正負半波成為美妙音樂!
所以,超線性膽機係好嘢嚟㗎。 - #19225 [rcwy], 23-07-21 19:49
。 - #19224 [rcwy], 23-07-21 19:44自給偏壓 self-biasing 就是靠一支 350 Ohm 電阻(灰白色水坭電阻)
作為兩支 EL34 的共用陰極電阻,在那 1950-70 燈膽生產的黃金年代,
燈膽大量供應,使用一定時數後便兩支 EL34 一起更換另一對佩對好的 EL34。
共用一支陰極電阻有一定的道理。
但是,時至今日,大家對擁有的古董 Mullard 膽珍而重之,珍貴啊!
因此,不同新舊程度,不同工作狀態的 EL34 膽,只要能通過到測膽機 tube tester
的基本設定測試,例如在涷膽時不閃光,不噴火,仍有些互導率 conductance
統統都拿來用。重新思考,把 EL34 共用陰極電阻一分為二,讓一支 有不良 自給偏壓
的 EL34 不至影響另一支 EL34 的自給偏壓,令有問題的一支 EL34 膽 更快更早地
被發覺到,保護了良好的一支 EL34,保護了古董輸出牛,也更為靚聲!
最後修改時間: 2023-07-21 19:53:41 - #19223 [rcwy], 23-07-21 19:10
HF—35(採用 Mullard 5-20 原設計自給偏壓,加大了三級瀘波電容來刪去整流 Choke 節省成本) - #19222 [rcwy], 23-07-21 19:05
EICO monobloc - Mullard 5-20 線路為基礎,
佩美國 Chicago 輸出牛,由 Mullard 原設計20W
輸出增至35W (HF-35) (自給偏壓),佩一對 Mullard EL34,
50W (HF-50) 及 60W(HF-60)(可調固定偏壓),佩兩支
鐵箍 EL34 特強燈膽,以美式測試準則,測出的數字或許有些水份,
但出力確實是增大了,音樂動態感加強了。
美式 Mullard 5-20 機,傾向於修改原設計,使出力更大,銷售點登更高的台階,
有別於英式 Mullard 5-20 機原裝設計。。原教主義者? - #19221 [rcwy], 23-07-20 16:20
If you like EL84-based power amp, Verdik 10 is a cheaper choice. 300 quits get an unrestored pair.
最後修改時間: 2023-07-20 16:20:37 - #19220 [rcwy], 23-07-20 16:10
I had Stereo 20 when I was in Hong Kong. The sound is great for it uses peanuts, EL84's. It is a smart knight. But still, in the LEAK family 12.1 is King. - #19219 [fotheringay], 23-07-20 04:51
When I took home the Leak Stereo 20 from Nick, EmporiumHiFi, he also gave me a very basic and low quality passive preamp to play with.
I have to say I was amazed with the pure quality of the sound from this combo.
It makes wonder what if I get some better quality passive preamp?
To cut the long story shop I bought two of them.
- #19218 [fotheringay], 23-07-20 04:40I heard of his but never got to visit his shop.
I am glad he is still around and has faith in this format.
What a fool, like me!!!
ha...ha.... - #19217 [rcwy], 23-07-20 04:08
- #19216 [rcwy], 23-07-19 00:24
喇叭拉闊少少,音場闊了多多。。。 - #19215 [rcwy], 23-07-05 15:21
記得!
一對 EICO HF-65 MONO 前級,殺低價格高它的眾多前級。 - #19214 [taimonsing], 23-07-05 15:03還記得當年Eico blind test劈低50C和馬一,這些年來只有缘接觸過HF85, 今日終於抱得美人歸HF-61大肥婆,有力量又有味道,蟹膏煲,正!
- #19213 [rcwy], 23-07-03 19:39
家居擺放方便使用 與 喇叭擺放提升音效
兩者都重要, 盡力而為吧! :)
最後修改時間: 2023-07-03 19:39:52 - #19212 [童虎], 23-07-03 11:08可以坐低,聽音樂,最緊要!現在也不太過著眼於音效。
- #19211 [fotheringay], 23-07-01 04:54
@19210..........
Indeed, that's the reason they are put away from the main house, in my garage.
See no evil, hear no evil, speak no evil.........
Infact, I wouldn't dare call my gears as " 古董機毒物".
Yes they are old and mostly relics from bygone years but they wouldn't bother people as my wife puts it "They are just junks!!!"
Very true as I have been junk collecting ever since I was young living not far from Duck Street in Sham Shui Po. - #19210 [rcwy], 23-06-30 22:11
(舊話新講)
作為過來人之一要講一句: 儲存老毒物太多搞到一屋都係毒物,
對自己及家人的心理健康及對家庭的和諧絕對不是一件好事。
唯有堅持只中小小小小毒(是點綴生命的小情趣),
唯勤 (勤力整機) 是岸(玩古董機發燒之道)! :)
(小情趣)
最後修改時間: 2023-06-30 22:20:07 - 下一頁 (5 of 965)
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有三粒IMP cap mix with good all