Shootout of Nos 6sn7 tubes

@lowrider57 that's a bummer. Seems like a bit of a crap shoot.

Is everyone ordering their 1578 from the same eBay seller?  Seems to be a lot of poor quality and noisy tubes being sold?  Some Ukraine and Russian sellers have been known for selling QC rejects. 

@testpilot
This subject was mentioned on another forum. All the best tubes went into service with the Russian Military and QC standards were high during the Cold War.
The tubes in question are from 1980 and QC had slacked off by then. The Military still got the highest rated tubes, others were sold to the public. These do have the OTK inspection stamp.

Sounds like a plausible explanation.

I have three pairs of 1578 two made in 1980 and one in 1983.

Two of them had been bought from persons in US.

One of them is bought from Russian dealer.

The one from Russian dealer had been working fine so far for 30 hours.

if you have problem with it, contact the Russian dealer, it seems that Olga is cooperative with request.

Recently I had run into terrible Ebay dealer located in US.

I will post his case in more detail later today.

I ordered Kenrad vt 231 tube from Ebay dealer " vascotube " or "tube tech" on June 5th Thursday.

Most Ebay dealer ship the item on next day or following day.

But this guy did not show any shipping information by Saturday.

Thus i sent request to give tracking information.

But no response from him.

After going through his measurement " TUBE1) 90/112TUBE2) 100/120 ", I got the impression that this tube is not matched well.

Thus on Sunday I sent him to cancel this order if it had not been shipped.

But no response from him either.

On Monday, I gave him final ultimatum, if he does not respond to his reply, then I will leave negative feedback on him.

But I got no response by 6PM eastern time, thus I left negative feedback on him at his Ebay site.

Then he contacted me and asked me to start return process instead of his cancelling unshipped order.


I started return process but he refused to agree to return proceedure unless I change the feedback on him.

I told him that you had not responded to my three inquires for more than 48 hours.

Thus i can not change my feedback   out of my conscience.

He then found out that I am an Asian and gave me racial slur against Asian.

I had tried to resolve this case peacefully.

I told him that if he give me sincere apology about racial slur and cancel the order from his unshipped item, then I will close the case.

But no response for more than 10 days.


I had bought lot of things including Nos tubes in Ebay, but had not had any problem with anyone except this guy.

Most other dealers gave response to my inquiry within 12 hours.

But this guy did not respond to my three inquiries for more than 48 hours.

And then he made a racial slur against me.

I am going to file racial discrimination suit against him.

Stay away from Ebay dealer " vascotube "


Thomas