I need advice on a 300b tube
Here is my issue...I bought a pair of almost new Linlai 300b B-Z treasure tubes from a person who said that one of the 300b 's had developed a humming noise after 5 hours of good (no issues) use in her amp. She claims that she heard a humming noise coming from her amp and so she put in her old stock 300b's and this noise stopped and then reappeared upon reinstalling her new Linlai 300b tubes. The noise she claimed followed into one of the 300b tubes..(I have no idea what that means by the way. How can a noise originate from her amp and then somehow get into her new tube? I do not think so at all and she merely got a tube that suddenly went bad.) She asked her friends can anything be done as her return window was already expired on these tubes. They said just leave the problem 300b in her amp and let it 'burn in' for 48 to 72 hours and see if it restores itself. She got scared though and sold both of the 300b's cheap (ebay) and here I enter in. I thought she selling the exact treasure tubes I wanted and at half price? ($99 plus tax) With her people's advice that might actually mean only a small and temporary setback on one these tubes? So I grabbed for it. What do you think? Probably a really dumb move on my part right? (This is not the first time I have done this by the way).... Yet I am new to tube amps (not solid state though) and recently purchased a Willsenton 800i 300b /805 from china hi fi...a 100 lb. beast ....(and just to let you know this thing really puts out some serious music.... fidelity, sound stage, its all there and most of all is the ease of listening ....absolutely no fatigue whatsoever. But to the tubes---
I initially thought to myself I'd take a chance so I bought these tubes. Yet now perhaps I should not have done so. I am thinking could this faulty 300b tube somehow pose a risk to my new Willsenton 800i tube amp and if not I might wind up with only one good Linlai 300b from the purchase. I then thought should I buy another Linlai 300b B-Z treasure to make for a restored pair how would I know if it was a match to the original ? What do you think? I know an impulse buy is many times a stupid choice but maybe one of you might have experienced a noisy tube that can repair itself as was suggested by these sellers' audio friends..... I called a person where I live and he has many years experience in audio and he has never heard of a noisy tube repairing itself in this manner....What do you think? Is there a way to fix a noisy tube? (Also this is off topic--but I have been a member of audiogon for years now and all my correspondence as in all entries in the forums and any of my buys---- all of it is gone. This happened a number of years ago as well. Has this happened to any of you?) I just looked on my site and I have only one entry from a year ago.) I have not given my password to anyone ...this is a mystery to me.
That tube is dead, do not use. Also, tubes don't repair themselves, may only cause harm to your amp if continue to use. Most humming, popping, many types of sudden distortion are tube related issue, always replace suspect tube with known good tube to confirm tube is indeed the problem.
I've been member here since inception, yet shows I've only been member since 2012. Everything prior to 2012 disappeared, don't know why this happened, just never thought to ask. First noticed this some years ago. |
By “the noise follows the tubes” means as the tubes were swapped the noise switched channels. Showing it is tube caused.
I agree with @sns … do not use the tube. They don’t self correct and it could damage the amp. You will just have to purchase another one. There aren’t so many hours on them it should make a difference. |
You could try reflowing the solder in the tube pins (how to videos on Youtube), but you would then want to test the tube in a decent tube tester (NOT the amplifier). I my old Audion DH/SET 300B amplifier and my current Bottlehead DH/SET 2A3 amplifiers the power tubes do not need to be closely matched. This said, I generally run matched pairs as I have them on hand.
DeKay |
I really appreciate your advice and what to do with this tube ( sns and ghdprentice). I will not take a chance with using this noisy tube on my new amp. Though I will at least read up on a possible way to fix this tube (thanks dekay). Maybe since the seller has not yet sent this tube out for delivery I can cancel the sale otherwise I will have at least one good tube left and then decide if I want to chance making a pair with another replacement. |
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