I've yet to hear a 300B that I didn't like. They all sound good. It's a good thing that 300B are so cheap. Even if you don't like the sound, you can use them as regulators in power supply.
Cheap?? 300b has always been overpriced. I'd avoid all the Russian ones and go Chinese - they've all been pretty good for me over many years.
$30 for such a linear tube isn't bad at all. Yes, my JJ 300B and my Chinese 300B have never failed. DHTs seem to last a very long time. The RCA 45's that I'm using have been used since the 1930s and sounds amazing.
Joel, I can make pretty much all 300B sound similar to each other by adjusting the voltage, bias current, and taps on my output transformer (dampening factor). I'm using a Tubelab SE which has a strong low impedance drive and it negates the differences between various 300B tubes. If you're using an old school 6SN7 driver then the differences between tubes will be greater. Then the input capacitance of the particular 300B can affect the frequency response, etc.
I'd say get a cheap and reliable Chinese tube and just be done with it.
Very few 300bs cost $30!!! And I think you're being optimistic about lifetime. At stated operating conditions not exceeding the datasheet, they can go down to half emissions in a year of frequent use - like listening most of the day. I've stopped buying ebay ones stating "light use" because they're usually halfway through their lifetime. I wish they lasted longer, but in frequent use they don't - unlike good rectifiers or small preamp tubes, for instance.
Quote: I'd say get a cheap and reliable Chinese tube and just be done with it
With Chinese tubes we have to be lucky, because some are reliable and some are not.
The reason is that some Chinese workers are good, with years of experience in mounting tubes, and others are novices without the ability to do a good job.
For this I prefer Russian Military tubes.
I've had several pairs of JJ 300B purchased around 2000 that have many thousands of hours of use, and still have one pair that I will use in another amplifier project (sold old 300B stereo amp, offer was right). These have been unfailingly reliable and still tested very good the last time I checked them on my Hickok 539B tube tester. In use the bias almost never has to be adjusted with these particular tubes. A really good 300B should give you something like 10000 hour service life based on experience, although very few modern ones will.
I am not sure about the quality of current JJ 300B, but I have former clients who have purchased current production in the past couple of years and report no issues to date. They appear to be the same, and unlike many of their beam tubes have been consistently OK wrt to build quality.
I recommend anyone buying 300B buy them as burned in matched pairs - should save a lot of grief and has worked well for me.
No experience with the Guigang tubes. My recollection is that Guigang was a short lived start up, ran out of money and was recently acquired by someone else. (The people behind ps**** ?)
TJ and Sophia made dhts have been pretty nice IMLE so another few to check out.
According to what I read in another forum, Guiguang went out of business and its people formed a new company called Psvane. I can't find any user feedback on their entry level 300B tubes yet.
Seems Guiguang has taken by the hi priced audiophile PSVANE brand in October2011.
So Shuguang factory no more made the PSVANE tubes, which is a good thing for Psvane tubes.
An announcement: Who was GuiGuang? | Psvane Audio Tubes, Caps and Amps
So Shuguang factory no more made the PSVANE tubes, which is a good thing for Psvane tubes.
An announcement: Who was GuiGuang? | Psvane Audio Tubes, Caps and Amps
You mean the company who spams this forum (and the LinkedIn groups) repeatedly? My confidence in their integrity is something less than zero.
In quantity in 1998 - 2001 time I was paying far more than $30 for a Valve Arts 300B wholesale, not sure where you are getting your pricing from, and good ones are a lot more. I think with very careful shopping you might get a serviceable pair for a little less that $200 shipped from China.
I still have a wholesale account with a major U.S. importer, even in huge quantities they have nothing that comes close to the prices you quote.
I still have a wholesale account with a major U.S. importer, even in huge quantities they have nothing that comes close to the prices you quote.
- Status
- Not open for further replies.