Lovely work and design! This looks like a great DIY build!

... excellent explanation and another awesome device made by you ... thank you...

很有心去做，解說清楚。

thanks!~

EL84單端輸出可出到3W，你可以設計到輸出1.5W，300B正常輸出是8W的，設計輸出7W的300B已是很保守了，我沒有見過有人設計出6W的300B，這不是珍惜300B，這根本上是浪費300B的能力，如果 300B識講說話，它一定投訴你！ 所謂強將手下無弱兵，設計師就是將軍，他設計出來的300B放大器就是兵，一個有能力有信心的將軍，怎會怕這樣驚那樣，最後設計出來的是一個怕死怕辛苦唱歌有氣無力的超級少爺兵！ 請改變你的想法，把這部輸出5W的300B改為輸出7W的300B吧，我相信會有更多人跟你做這部7W的300B.😊

@vincentfong4154

28 күн бұрын

多謝你的意見~ 設計EL84單端已經有一段長時間，如果我沒有記錯的話，當時算過五極接法輸出5.3W，三極接法輸出1.5W，已經算極限了。由於本人不喜歡五極的音色，唯有接成三極，所以輸出只有1.5W。 至於300B的輸出，的確有點保守，但是我在設計時參考了西電300B規格書的各項參數而得出的折中。在平衡功率和諧波的情況下，我決定採用西電300B的其中一項3rd harmonics較低的參數（個人不喜歡3rd harmonics）。 Plate voltage: 300V Grid bias: -61V Plate current: 60mA Load resistance: 3.4K Power output: 5.6W 2nd harmonics: -30dB 3rd harmonics: -44dB 由於輸出并非綫性，所以5.5W和8W其實相差并不是很大，反而輸出牛的功率比較重要。我做過2對300B，綫路基本上是一樣，輸出牛25W VS 35W，完全是天和地的差比，特別是低音和控制力。 最後，任何音響設計是應該留有餘量的，如果要强逼300B出盡力量（CLASS A）而此力量卻不能盡用的話（一般會使用attenuator 降低輸入信號），我寧願留些餘量，這樣300B才能從容不迫地唱出美妙的歌聲。

Although it's only the voltage difference across the regulator that is an issue, at switch on the full supply voltage will appear across the regulator circuit?

@vincentfong4154

11 ай бұрын

Yes, that's why there's a N-ch MOSFET before the regular IC

能不能用 LS3/5a 測試此單放大器?

@vincentfong4154

Жыл бұрын

我沒有LS3/5A，而且此單端沒有15ohm輸出，未能測試

Hi Vincent - these look great! Do you have a BOM available?

Bravo pour vôtre travail. Très belle réalisation. Je vois que vous connaissez votre sujet. Quelqu’un de bricoleur peut il réaliser ceci? Si oui avez vous dès lien ou nous pouvons réaliser ceci. Encore bravo et merci pour votre partage.

@vincentfong4154

Жыл бұрын

Thanks. I'm the one who made them. More details of my work can be found here: smp-gadgets.blogspot.com/2021/08/diy-300b-monoblock.html

@jameswarren1831

5 ай бұрын

@@vincentfong4154 I checked out the site but the Drive links are dead now. I was just getting ready to do point to point and I thought it was destiny to find PCB's but to no avail.

我有Marantz8B output 壞掉，如何換了它。

@vincentfong4154

Жыл бұрын

sorry不懂維修

請問輸出管300B係咪採用自给偏壓? 用家不用調整偏壓. 謝謝!

@vincentfong4154

Жыл бұрын

無錯

Vincent, are these for sale? Thank you!

@vincentfong4154

Жыл бұрын

Hi Carl, you're right. Just built another pair of monoblocks and would like to sell the old ones to save some space at home :⁠-⁠)

where can i buy it ? :) some kit diy

@vincentfong4154

5 ай бұрын

I'm afraid a kit is not available. Shipping fee is a big problem.

@radekpoboril374

5 ай бұрын

@@vincentfong4154 and is there option to buys schematics and lyaouts of pcb and wires?

@vincentfong4154

5 ай бұрын

@@radekpoboril374 I'm not sure. Because the calculation is based on the tailor made transformer, not sure if you can get the same from the market. By the way, this 300B tube amp is the old version, a new version comes with delayed soft start.

我想DlY砌你這台机，可否提供有關製作資料？

@vincentfong4154

7 ай бұрын

抱歉，暫時未有時間詳細整理教程，只有一個簡單介紹，希望可以幫到你： smp-gadgets.blogspot.com/2021/08/diy-300b-monoblock.html

@bigheros2078

7 ай бұрын

是否有空代裝一对最新版的胆机？

@vincentfong4154

7 ай бұрын

@@bigheros2078 做一對最少20小時，未計訂零件時間，恐怕今年內未有時間 你在香港？

@bigheros2078

7 ай бұрын

明白。但下载不到有關的，Schematic 和 Gerber file.

@vincentfong4154

7 ай бұрын

@@bigheros2078 因為我沒有上載