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Vacuum Tube Snake Oil Salesmen

Just a mini rant to complain about vacuum tube suppliers (not all but most) and their false advertising.

I ordered a set of 4 matched 2A3 Acme tubes direct from PSVane for my Woo Audio WA33 as an upgrade. They cost close to $1k all together.

When I got them I checked on my MaxiMatcher2. The boxes said 65mA but with correct operating voltage and bias set on the tester I could only get 2 of them up to 43mA. One other read 39mA. And the last one was an internal fault short which could have damaged my amp had I not checked them.

I asked to return one "Matched" set for replacement. The PSVane customer service would only offer to send me one tube and not a matched pair. They would not pay return shipping to return one set. Instead they demanded I smash the bad tube and send them a picture. Has anyone ever smashed a large vacuum tube with a hammer and seen where all the pieces of glass fly to? I said no way. I will throw it out or return it but I am not going to risk cutting my hand doing that. So they refused to send a replacement. 

While I had the Maximatcher out I decided to go thru some other tubes I had in my spares box to check them (purchased before I had the tube tester). I could not believe the results. Some tubes matched by well known vendors were off by as much as 30% from each other.

It is really a good investment to get a tube tester if you will be a regular user of tube amps. 

If you must buy PSVane then get them from Amazon and not direct so you have some safety to return them.

 

calieng
invalid
1,378 posts
 

@devinplombier  

I'm sure if you measured the transistors in an amplifier you would find deviations in those as well. These tube testers are not that accurate like people think they are.  The best way to match or test the performance of a tube is in the circuit they will be used in. 

pcrhkr's avatar
pcrhkr
332 posts
 

I think the company ripped you off. They apparently do not care about losing customers. I learned in retail many years ago. It's better to lose money on one customer and gain a reputation in an industry as giving top notch service. That one customer you lose money on will redeem when that customer comes back again. Not to mention free advertising with all that persons audiophile friends. Sorry for your bad vendor experience.

calieng OP
203 posts
 

Not to beat a dead horse - but I was getting low on 12AX7s so I ordered some Mullard reproductions from Vivatubes. Given what has happened recently I decided to get 2 matched pairs of Psvane Horizon 12AX7 from Amazon to compare.

Vivatubes rated each matched 12AX7 in the 96.5 (plus or minus a couple tenths) for gain as marked by hand on the box. All results were unique.

Psvane were simply stated tubes as matched with no test results marked on the box.

RESULTS with MaxiPreAmp II:

Vivatubes average reading 97.5 (plus or minus a couple tenths) with either side of the tube within a couple tenths of each other. All exceeding the 92 target gain.

Psvane tubes ranged from 84.2 to 91.7 for gain. None met the 92 target. None were well matched for either side of the tube or for the pair in each box.

For what it is worth...Vivatubes appears honest and accurate (deviations due to different test equipment). Mullard reproductions are either much better made or much better QC than a competing brand.

I will thank Amazon in advance for their good customer service in accepting back the Psvane 12AX7s.

marco1's avatar
marco1
709 posts
 

@calieng. Funny I had the exact opposite experience with some 6sn7’s purchased from Viva.  It’s been a while so I don’t remember how the test results were noted, but suffice it to say the tubes did not match.  Viva also took the tubes back without question. Moral to this story, test the tubes yourself no matter who you buy from, which really doesn’t speak too well to this part of our industry.

audition__audio
1,776 posts
 

Well gain is different than transconductance.

Remember that the vast majority of these testers only test a tube at one operating point and these point vary from tester to tester. 

Apples to apples only if the seller uses the same tester as the consumer.

The thing to ask yourself is if you would pay much more for tubes which were matched using numerous operating points from a vendor willing to spend the time and money to do it correctly.

Most, I think, would not.

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