Andy師兄可以稍後安排，設計及製作此機对我來說係享受人生的passion rather than pure business. 現在我只是在自己朋友圈內少量制作，每一部機做了出來發到香港好快被拎走，PM你再安排可以幾時

恭喜Niceday師兄追這個post好耐,
請問會有機會試聽嗎？
Andy

多謝Welborne，依家當個project 咁樣去run，當搞到聲靚樣靚自己樂在其中

最後修改時間: 2026-01-16 15:32:56

niceday 兄，很漂亮和用心製作的機器，讃！

Hi Wilson, 有些人覺得Glass Metal Nano太多高頻寧願要高牌號Hi B，看口味，實際上Hi B或鎳合金出超高頻仍十分清晰而且較平衡，Glass Metal就有强調高感，所以看口味

Hi Eric,

我记得output 是Hi B

interstage 牛最後统一用Nano?

第三批蘭心，改用了强化玻璃

我心目中有個假設，市場上有邊部高級別單枝845 SE amp, 不論合併或是後級, 我都想去比較一下







最後修改時間: 2026-01-16 01:32:28

I have the same thermal run away experience with the EH and Gold Lion 300B's too. The bias voltage is approximately 6~8 Volts lower than the WE and LinLai's.

The EH and Gold Lion's are stable at around 350V B+ and 60mA. Once the idle current is higher, the current will get higher and higher. Of course I am using fixed bias for them. It is still safe using self bias.

Johnny

最後修改時間: 2026-01-09 18:56:07

可能我都好彩，我買超過70隻大陸300B 包括林籟，曙光，Psvane ，金音萊，暫時未有一隻係DOA, 超過九成半Transconductance同电流係within specification. 剩餘那5%仍可用只不過特性高咗或低咗，而且全部冇Thermal runaway. 反而我用WE300B, 俄國300BEH 同 JJ 300B試過Thermal runaway 而我係用fixed bias同埋grid bias 电阻用220K.

我試過大陸某幾款300B事實比WE300B更有肉地同動態，如果怕萬一大陸胆短路而做成燒牛，就要立刻採取保護措施例如加Fuse. 我經驗係胆屏short入栅/陰/燈絲係好少機會但仍然見過，而且唔係淨係大陸胆會咁，欧美日俄都有聽聞過，但只要輸出牛次級接地，对喇叭唔會俾部300B SE amp整壞

最後修改時間: 2026-01-09 15:06:27

曾經喺一位做機師傅度見到一盒曙光300B膽。就是圖中這款。隨手攞了兩隻返屋企試。一啲問題都冇，正常運作。可能我好彩。



最後修改時間: 2026-01-09 13:47:45

#5653

睇完你呢個經歷, 現在令到我有啲驚 :)

If you ask me about sound quality and sound quality only, I will tell you, 曙光 300B is a clear winner in my system.

Hi Johnny,

If safety is not a concern, I would actually choose 曙光 300B over my 1949 WE

I really like 曙光's sweetness and warmth, and it sounds more "human" than WE. Microdynamics is more abundant too, you can hear the vibrato of strings more clearly than WE.

But I really cannot rely on the stability of Chinese tubes. When I purchased my 曙光, I knew I had to bring my Amplitrex AT1000 tube tester in my backpack. Out of 12 tubes I tested, 4 had broken filaments, 2 had over current(internal short circuit or metallic gas poisoning), two had very low emissions (＜15%). I bought 2 with around 60% emissions and two with around 110% emissions.

The two with around 110% emissions developed some very bright spots on the filaments after using for a few hours. (you know that's a sign of impending doom) Now only the two with ~60% emissions are still working.

This means out of the 12 tubes that I tested, only 2 of them actually work.

Sigh........

Got it, meaning the risk is Chinese 300B potentially having quality issues

Again, nobody could predict when the tube would short it's plate to either filament or cathode. To protect the tube and OPT it is a good approach to use fuse in 300B cathode. Even Russian or European 300B could have such accident. I once tested a Tunsol USA 6550 also exhibited plate short filament.

For the fuse adversely affecting the sound quality, I audition one with and without, I cannot say I hear a big difference

最後修改時間: 2026-01-09 00:43:12

Hi Thanatos,

You are absolutely right in choosing the Western Electric 300B. When I got my very first 300B SE amp built, I used the cheapest EH 300B's. I knew it is not best but something I can afford.

No doubt that the WE 300B's are known with high reliability and good sounding. It would so nice having them fit in the system that people are so proud of.

Anyway, all I would say I have some other 300B's I tried. I am so lucky that they don't kill my speakers so far.

Cheers,
Johnny

The only risk we had talked about so far was a catastrophic meltdown of Chinese 300B

Hi Thanatos,

Maybe I got the meaning incorrectly because you pop up"Why risk?"，I re read your post only found you recommending WE300B being much safer. So I thought your risk indicated was not to use WE300B

So Why risk is referring what item?

最後修改時間: 2026-01-08 23:58:58

Johnny was talking about the comparisons between Chinese 300B and WE300B. I was just sticking to his context.

No other tubes were mentioned in the above discussions. I have not excluded other well-made tubes as far as safety and stability.

Saying that WE300B is safer and more stable than Chinese 300B doesn't imply that the only safe tube on earth is WE300B. There are tubes other than the above two.

Hi Thanatos,

Your previous advise was to use WE300B which is much safer. However most of the 300B users in the world may not really use WE300B, probably because of cost issue.

It is always good to put a 200mA fuse in cathode such that protection on tube and output transformer are guaranteed.

最後修改時間: 2026-01-08 23:43:36

Why risk?