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
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.
Nos or so are sometimes living hell.
It appears that you hit the sometimes with propably shorted tubes but if you have used paypal i guess you are covered for a refund.
Unfortunately buying old tubes in case of malfunctioning you are not covered for your gear, whoever the seller is, unless you buy replacements from your gear manufacturer.
Best is to check any old tubes after purchasing and before installation on a tube tester.


+1 jperry
I have paid a bit extra to get tested tubes with dealers who stand behind them. I've had flawless luck with Jim McShane, Brent Jesse, and Vintage Tube Services (Andy). Good advice, MC. Little odd it has to conclude with yet another plug for Raven. Are you on retainer?
I'm sorry to hear of your troubles, that's got to be disheartening.

I also have had excellent results from Brent Jesse.

Personally, I would not pay for NOS.

I bought some 6sn7's from Brent. Didn't like them as much as the ones I was used to. He first had me break them in for 60 hrs, then, still didn't like them, I returned them, tried a different, less expensive one, they sound great, and he refunded me the difference in price.
So, my dad owned a TV Repair Shop from 1946 - 1980.  He got sick and after he passed, we started to break up the business.  I was left with a wall of tubes ... all types ... roughly half were TV only use tubes, the other half were Radio and Audio use tubes.  I thought I hit the proverbial NOS jackpot.  Not to be.  Easily more than half were duds.  Had the late, great Art Dudley over to the store and we tested tubes together.  No dealer would take the tubes, even for free, because of the time and effort involved to catalog and professionally test this wall of tubes.  It would have taken me years.  To the City Dump they went, life is way too short.  

The morale of the story ... you couldn't give me a NOS tube.  Strictly new production for me.  There are enough good new production tubes out there.

No need to question MC's plugs.  Because of MC, I discovered Raven Amps.  Admittedly, that will probably be my first purchase, once I retire from the 9-5 in the next year or so.  I am actually glad he continually mentions Raven Audio.


I’m not going to complain and put down someone’s business, but the dealer was one of the first rate sellers. I contacted him when I thought there was an issue(I’m somewhat new to tube rolling). I followed his instructions and kinda let my guards down thinking I was being too cautious and he had to be right. I learned the hard way, no one cares about your gear as much as you, and no one knows everything about every single amp or preamp and how it will respond to something new in your system. Sure he’ll probably replace the tube, but I’m stuck with the repairs and shipping.

Do not buy tubes on ebay or without making sure your gear is voltage compatible with NOS tubes many times the voltages are wrong in the old tubes for modern tube gear I would suggest trying andy's tubes. I have bought some of his graded tubes and they are absolutely wonderful and trouble free.
I would buy from Ukraine only what was made in Ukraine, or made in USSR. Looking at the list of Soviet valve factories, I see some 30-40 names, 7 in Ukraine. No idea which tubes they made. What was not made in Ukraine, was made in Russia, or on rare occasions elsewhere, and could be in Ukrainian stockpiles, esp. military valves like 6С33С, etc.
But I noticed that none of the Soviet factories had name “Brimar”.
— Why on earth a dealer in Ukraine (or Russia, or Poland, or my native Latvia) would have a sizeable stock of NOS valves made in Western Europe, or in the States, available at so competitive prices they can re-export them?
Wherefrom?? They were not close to the sources, they did not have spare money to buy up surplus stock.
Given that - what are the chances of counterfeiting? Rebranding local NOS stock, re-branding new local or Chinese or Russian production... I for one most probably could not tell the difference.
I’m sorry to hear about your burnout, but the sellers didn’t test the tubes before they sent them to you. My guess is that they have a large enough volume going out that they can afford a few pissed off customers.

I had a "nos" 12ax7 rca blak plate literally implode on me in my conrad johnson mc55. That was a real b---- to get out. Lesson learned.
There is nothing wrong with NOS tubes as long as they are tested beforehand. If they test good, then they will likely run ok. I don’t mean testing on a mutual conductance tester, those are crap and you would find those in drug stores in days past. I’m talking real Mu testers that test at actual operating voltages.

If you can find a seller that does that, then you are pretty much guaranteed to get a good tube. If not, then you will be playing Russian roulette. I had a very good looking st 6v6 blow the fuse right off the bat on me because it was shorted. Unless the glass is broken and the getter has gone grey, you can’t tell that a tube is bad or not. Hence the testing....
Tubes will be tubes - even new production tubes can have an issue.

First learn what makes the sound - sound the way it does.

Miller - diodes eh, resistors yes capacitors yes - transformers chokes yes but it comes down to the design  DHT, point-to-point wiring, AC filter chokes, capacitors and resistors all have an impact.

Best advice - learn to solder!

I built a preamp with a rotary switch where you can simply change out the resistors on the fly.  Now that was fun to show people the differences especially all those who told me that they would not be able to hear the differences..

I have also built cost no object components and just recently build a few to various price points.  Some of these are getting very close to the cost no object builds because we have figured out what parts make the best sound - at least to our ears!

Happy Listening.
Another thread with a vague or misleading title. The clickbait epidemic continues.
Buy a nice solid state amp , then focus your refinements of tubes On that . It gives a great combination.used by many Audiophiles.
...enjoyed the J. Wick clip...pity equipment isn't presented in the same matter of fact fashion. *L*  But even gun shows flaw prey to testes...

It'd be an interesting option, if one could swap out caps, diodes, even xformers much like the way computers can be 'modded'.  Not as likely to be pretty, and one would have to 'pop the top'...a warranty 'no no'....

One can change mbo's, cpu's, mem sticks, drives (hard or ss), cards....
My soundcard allows me swap IC's to vary its' performance.
One can opt for cooling options for overclocking that rival what one can find in racing vehicles...

I run fans on my amps already.....*shrug*
I believe the OP said the Melz 1578 came from a Ukraine dealer. The Brimar came from a well-known US dealer.

Based on my experiences buying Melz tubes from Russia
I doubt they have been tested.

The short story is, it was a rca vt231 gray glass tube. Highly recommended. Placed the tube in my preamp, which only requires one tube. Right away I had some concerns about the noise. Called the dealer who advised me how to deal w the issue and that I couldn’t do any damage to my system. And, the rest is history the noise continued and my preamps volumne can’t be increased without the a deafening static like roar. And, yes I removed the tube in question and placed the original back in and got the same result. Manufacturer of preamp has to inspect for location of the damage. No more tube rolling with NOS tubes for me. 
this is an opening for me to repeat my advice, buy a simple tube tester, test them when you receive them. Verify bad when a problem occurs, verify good, annual check .... take it to your friend's house, loan it to those you trust.

Not big high quality one, just a basic one.

My basic one always agrees with my big Hickock, I don’t even bother with the big one anymore. It’s good, no short, has more than enough strength, and if I bought ’matched’ the same strength as it’s twin? Yes!

my simple one, with original instruction book


some simple testers do NOT have sockets for some less popular tube types, you can ask seller if your tubes are listed in the manual, or, if you can return it, no big risk.

also get a tube substitution book

mine is downstairs, something like this, has english #s also

I spent some time in Odessa, Ukraine. I don’t know if I’d buy products there unless I went through someone I knew personally. I’ve seen shops there that lasted only a few weeks before they either moved or disappeared altogether. Most folks in Ukraine are struggling to buy food though of course there are some who have some wealth but buying from Ukraine isn’t like buying from the UK or Germany. That aside, I do love Ukraine. Anyway, I bought about $350.00 worth of NOS military grade Telefunken’s on eBay for an HH Scott FM Multiplex and they transformed the tone and musicality of my tuner but the seller was here in the states. He even made sure I got a matched pair and swore they were all tested. I can’t remember the name of the tube tester but it was the Rolls Royce of testers. I’m sorry your pre amp was damaged. I would try to have it repaired and then look for a seller here in the US. 
The Raven PR dept does not know the difference between an Opamp and a FET. Use caution when selecting a guru. I only gush about gear I have actually heard...at length or own....

Andy at Vintage tube has serious test gear. You really should name the dealer in USA as you have slighted all 3 named by others.

Finally, RAM tubes are fantastically graded.Roger Modjeski ( RIP ) knew his way around tubes. He also hand wound his output transformers.......
Andy Bowman is serious about selling quality tubes and customer satisfaction. Every tube I've bought from Andy has been cream of the crop. 


The downside is the wait time for an order is now a few weeks.

Well, my preamp designer has always been very helpful, he repaired my preamp for free. He makes his equip himself, so as long as the parts were moderately priced he had no problem doing it for free, three hundred for shipping is what I came out of pocket. I replaced all my NOS tubes(6sn7) with some Black Treasures and they sound great and very quiet(so far). No more experimenting w NOS tubes for me. There’s no guarantee’s with anything we do, but after 3 times at bat and 3 strike outs I’m done.