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Budget 300b tubes recommendations

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#43
I was kind of set on the Electro Harmonix, basically because they're cheap and I don't hear anything bad about them. Now I came across these Shuguang 300BS-B. Most people I hear think the current Shuguang's are pretty good and I love the dome shape. Any info on these?

They have the 'mesh' plates, not a real mesh but perforated plates. Is there any reason why this would be a bad (or good) thing?
 
#44
Those mesh Shuguangs sound very nice. I have them.

Western Electric themselves used perforated plates on some of their tubes. It is not clear why they sound different.

But compared to true mesh, the perforated plates only lose 10% of their surface area.
 
#46
Is there anyone using 300b PP amps in an active biamping?

I have a pair of DIY c3m/300b monoblocks driving my Altec 515-8b/VOTT using an active crossover from 50Hz - 500Hz. Currently, I have a pair of Shuguang Treasures 300b in one channel and the other channel using JJ 300b. I am currently using Sylvania VT244 (5u4g) rectifier tubes.

Does the choice of 300b tube make a significant difference since it is only driving a narrow range of the frequency?
 
#52
Electro-Harmonix, EH Gold, Genalex, Mullard, Sovtek, Svetlana, Tung-Sol tubes (all New Sensor Corp. brand) made in Russia, Saratov in the old Reflector factory.

I prefer 300B EH Gold grid (tried several chinese, JJ, old russian, newer -normal- EH ones in the last decades), because I use it -sometimes- in A2 (FET source follower), and other brands tend to grow THD more in this range, than EH Gold.
 
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#54
I'd recommend the JJ 2a3-40s. You would need to use the 6.3V center tap it get a new 2.5V filament transformer. The are much quieter than the standard 5V model. They sound wonderfully lush and sweet. Better than everything else I've tried except some fragile mesh plates.
 
#55
In terms of "quietness" I would be using Rod Coleman's regs so I doubt that this would matter. I read a lot of posts about 300bs not lasting, and my understanding from Rod's posts is that AC stresses the filaments a lot more than the DC in Rod's regs. I therefore don't really pay much attention to reports of failures where Rod's regs or similar are not used.
 
#56
That would be one of many causes of longevity issues. I have worked on AC heated 300B amps from pre 2000 still running their original 300Bs that I didn't think were all that well made to begin with.

I have also worked on DC heated 2A3 amps with nearly new JJ 2A3-40s where the filament has peeled apart where it bends up and over the hangers up top.
 
#57
Funny how different things work out differently for each of us. That said, the regular JJs worked and sounded nice to me. Very durable as well. I only used the 2a3 version as I am heating with AC and so the hum is quite a bit lower. I have a set of Emission Lab mesh 2.5V 300b's on the way. But certainly not a budget tube.
 
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