Burned Out


I recently got caught up in the tube swapping craze. I have a tubed amp and preamp. I researched things as well as I could for only having access to the internet and forums like this. I also was in contact with the owner of a very well known vintage tube dealer. I bought two tubes from eBay from dealers with a long history on eBay and high customer review rating. Both tubes from eBay were for my preamp, one  was a Brimar and the other Melz 1578 6sn7 tubes manufactured in the 50’s or 60’s. The Brimar only played through one channel and at first dealer tried dispute the fact that it malfunctioned and then contacted me saying he was now having the same issue. The Melz red plated on me and was very microphonic. The dealer is in the Ukraine so I’m waiting to see if I will get my refund. And, last but not least one of the most reputable dealers recommended a tube RCA and has stated he stands behind his product. But, what happens when his product causes damage to your preamp? My preamp now plays only through one channel. When I called up the dealer about the noise the tube was making, I was told follow the instructions regarding microphonics and that there was no way the tube would damage my equipment. There was a recommended break in period of around 48 hrs. Well long story short, my preamp is not functioning and has to be sent back to manufacturer and as of on out $115 for the tube. So my question is are NOS tubes worth all the risk? Are the newer tubes that bad that I have to sacrifice the working condition of my gear for a possible sound improvement? I would like to know your thoughts. Are tubes the Shuguang Black treasure, Northern Electric, a safer risk. I’m venting right now, but looking for answers
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Mistake 1 - Buying tubes on ebay
Mistake 2 - Buying tubes from the Ukraine on ebay

Sellers I would recommend are Jim McShane, Brent Jesse, and Vintage Tube Services (Andy)

I hope your future experiences are better.
Thirty years of tube amps, here’s what I think about tube rolling. If diodes were on the outside and could be as easily swapped that would make a lot of sense. These rather inexpensive little parts can make a huge difference in image depth and liquidity, far in excess of anything I have heard from swapping tubes. But diodes are inside. You need a screwdriver and solder. Too much trouble. Plus nobody calls them diode amps, even though a tube is a diode. So they have the name recognition all wrong.

If caps were on the outside and could be swapped as easily, same thing. Caps make as huge a difference as diodes. Way more than tubes, that’s for sure. But again, screwdriver. Solder. And the image thing. Caps and diodes are for "tweakers" and "modders" lower forms of life not like the sophisticated respectable tube rollers.

Transformers, now you’re talking! The transformer easily has the single greatest impact on sound of anything in a tube amp. All the output, all the music, goes out through the transformers. They must be of the highest quality or dynamics and details suffer. Unfortunately, if you think caps and diodes are hard to change, you ain’t seen nothing yet! The transformer is literally a black box, impenetrable, nobody knows really what one is, how it works, or which one is better or why. I’m talking about audiophiles. Top guys in amps know perfectly well. It’s us who are clueless.

So clueless in fact that of all the things we can change for the better, the one we pick to do the most is the one that makes the least difference and costs the most and nobody knows which one is any good or indeed if it will work at all. Clueless don’t even begin to cover it.

You think the people making tubes don’t know this? They prey on your ignorance like, well I don’t know what but something greedy with a big appetite.

You want to play with tubes? Do it right. Get yourself a Raven. Dave Thompson has a huge selection of some of the world’s best NOS tubes. Knows them like the sommelier in a fancy French restaurant, or a John Wick movie. https://youtu.be/aZnVM3THZSg?t=13

Seriously, that is the way to go. Anything else likely to be a big waste of time and money. As you seem to be in the process of learning.
Tell us how your tube amp was damaged.  Did it work correctly with any of the tubes?  Give us more detail on how your preamp went downhill, tube by tube, and ended up not functioning. Maybe we can help you out.