This guy is selling bogus tubes ...

[JMP/HBE]

https://www.ebay.com/itm/165512429640?hash=item26894f4048:g:JXsAAOSwOzpez9Xm&amdata=enc%3AAQAHAAAAoFLamJO%2B6lztSebU0LgP%2FGvtd%2FC83b69pgkgg4fn9zkWhqVL4e1Wb6yI3NIt1smMGAOHnjrXy%2BVN0EL1MKDvQATCqsVPKWCtN7xVeFG8TBrvVWDGSQwwX0SwBGfxgr0JTbYrhoa0UZXvE%2FiHWd0KpfGlDIW3kmxXSVhySNKrYg1ylwkS%2FGry0BPZYTwrNGRu46Fd255spff9aSjYNZpUpFI%3D%7Ctkp%3ABk9SR5qA0P_-YA

I bought 2 quads since the Ukraine war, ive dealt with him for years no issues. The tubes bought last six months bias too hot. [over 80% max plat dis ]
Ive had the same amps no problems for 20 years and i have other tubes that bias fine.
I asked for a return and different brand he sells and he told me to "take it to Mike Matthews.
Buyer beware.

[trevorus]

Can’t you set the bias on the amp? Some tubes run a little hotter, you have to give them a little mor negative voltage to keep them under control unless I am mistaken.

[JMP/HBE]

Yes Bro i can bias an amp, its not the amp its the tubes.
Take what you want and leave the rest.

[ErikH]

Wow. Even says. "30 day returns | Buyer pays for return shipping" and the bottom of the ad itself says "All tubes carry the 90 day factory warranty against defects from date of purchase."

Report that to eBay. They'll make him accept the return.

Telling you to take it to Matthews is a crap answer. Though he does own the company that makes these. You may end up having to go that route.

[JMP/HBE]

Wow. Even says. "30 day returns | Buyer pays for return shipping" and the bottom of the ad itself says "All tubes carry the 90 day factory warranty against defects from date of purchase."

Report that to eBay. They'll make him accept the return.

Telling you to take it to Matthews is a crap answer. Though he does own the company that makes these. You may end up having to go that route.

I have to be fair i bought the last quad in July and i didn't put the tubes in til yesterday so im 19 days over the 90 period. Ive bought from this guy for about a decade and never had a problem so i assumed the tubes were good however there is something different about the 2 quads i got the last 6 months.
I will be going back to more reputable tube vendors that value customers more than money.

[hamerfan]

Oh, the good days are gone, when Groove Tubes sold those kind of tubes as ‘selected’ and extra hot with an markup to the next customer.

[trevorus]

Yeah, if there’s a return policy and he’s not honoring it, that’s shady. Sorry for your issues!

[Securb]

It must be pretty easy to bootleg tubes. The only thing you need to manufacture is the boxes, which are cheap. You have the worker wipe off the original logo on some cheap tubes with solvent and screen print on a new one. There are also probably bootlegs going out the backdoor of some of the Chinese tube companies with Russian logos on them. Either way, it is probably very lucrative for the scumbags doing it.

[beaubrummels]

I think the first clue something was different would be the 7500 mhos transconductance stated right on the box. I believe for EL34s that should be around 11000 mhos.

[Ewizard]

While I won't speak to the level of matching quality, you most certainly can bias the tubes down. They may red plate at what is supposedly 80% of the expected dissipation, but all that means is the tubes are colder than average and require more ( negative ) bias voltage to keep them in their sweet spot.

This is kind of along the lines of Mesa's numbering system. They test their tubes and give them a number. The idea is that if you replace your current tubes with the same number, then you should require no bias adjustment. If you buy a hot set of tubes and you have a fairly cold bias, the tubes will sound horrid. Conversely, if you have a COLD set of tubes, even a modest bias will have them burning up.

A tech's standpoint on biasing is ALWAYS bias the tubes, regardless of the bias topology. Fixed, or cathode biased, you always check and set the bias. Some tubes will happily run at over 100% of dissipation ( max dissipation is a theoretical number really ), while others will not run up to max dissipation happily. The 70% rule, is only a rule because it sets so close to a happy medium, that it is considered safe for 99% of tubes. If you bias to 70% of dissipation, you can generally be assured that the tubes won't go into meltdown, or be so cold that crossover distortion is abhorrent.

So the question is really a matter of, will the tubes bias at all and not have crossover distortion, or do they just not bias to the theoretical number you are shooting for? 25 watts per tube is not necessarily an actual number. Some small percentage of tubes will not quite bias to 25 watts, while others will happily produce above 25 watts happily.

Not all tubes are the same. Some people like colder tubes because they break up sooner. Some like hotter tubes because you get more punch and volume.

[NegativeEase]

I find the OP thread title unfair.

Bogus means fake, and I do not think the seller in anyway is selling fake tubes, nor are selling hot tubes unusual -when you dont buy 3rd party rated tubes, and buy ones only tested at the factory -it's a risk anyone takes.

I agree will the seller, your issue is with the manufacturer not him. He had a return policy and you missed it.

He cant run a business being liable for unsatisfied customers for a perpetual duration -especially when it's not gross negligence on his part.

[JMP/HBE]

My bogue may not be your bogus check yourself. What would be nice is if i could just buy a couple extra quads of tubes ive been using for 10 years from a seller ive been using w/o yanking out the tubes thats are working great to test the new ones when they arrive to see if they're wonky YES that would be great but i guess i can't do that anymore and there was a time & place that i tested everything when it was delivered.
Guess i gotta go back to that ------------------- BUT YOU GOTTS ADMIT THERE HAS BEEN SOME CRAZY TUBE SH*T GOING ON THE LAST 6 MONTHS.
Seems sh*t still rolls downhill.
I likely got some factory seconds or something not surprised. I call it like it happens. The seller could have cut me slack but he didn't and i could file a PP claim but not gonna but im done forever with the seller.
I broke out the Mullard / Amperex XF-2's for the JMP tired of F-ing around. Likely never have to change those til i die.
Mike Matthews and Russia can blow me --->

[beaubrummels]

I don't know why you ever took the Aperexes out. If I had a matched quad of Amperex, I'd be done for the next 10-20 years.

[NegativeEase]

My bogus may not be your bogus check yourself.

As you requested, I have successfully checked myself, and the word Bogus still doesnt mean how you are using this against the vendor. But neither here nor there, we can move on.

BUT YOU GOTTS ADMIT THERE HAS BEEN SOME CRAZY TUBE SH*T GOING ON THE LAST 6 MONTHS.

No doubt there! What me to pick you some good ones when I am in the non embargo European countries in November?

[JMP/HBE]

I don't know why you ever took the Aperexes out. If I had a matched quad of Amperex, I'd be done for the next 10-20 years.

Well ya know there is a backstory to those Amperex EL-34's i snagged them off Reverb at a lower but fair price from just a regular swinging Richard and i had little to none info cept "the guy i got them from said they were good" yada so i had them in that JMP for about 6 months. Incredible sounding tubes cept i was getting strange electrical anomalies noises with the band that seemed to continue no matter where i played. So thru trial & error deducted that the tubes were bad and i pulled them.
Was going to throw them away buy could not im a packrat so i stashed them again.
Come to find out some of the strange noise was coming thru the power the PA & I were sharing, 2 i was getting RFI thru the wireless so i took care of that and finally the older Furman PF Pro i was using the oil caps inside went bad making the line voltage all wonky up & down.
So earlier this week i thru the XF-2's in my JCM-DSL 100 and they bias absolutely spot-on perfect thru the new Furman voltage regulator.
Then i had trouble with the new Svetlana's so i took a chance and rebiased the JMP with the Amperex and they are again spot-on perfect and AMAZING in every way.
AND with the new Furman AR 1215 voltage regulator quiet as can be i just jammed the JMP over 30 minutes and the amp wasn't even hot just slightly warm on top.
Sure am glad im a packrat.