One or more GENUINE NOS 1578 MELZ tube (6N8S, 6H8C, 6SN7) metal base hole plate

Hello! You're bidding on a genuine NOS 1578 MELZ tube – premium vintage long-life tube.

 Tubes were tested at Ua=250V, Ug=-8V, Uh=6,3V. Every tube has a sign on top and we will give you testing results.

You can pick any tube that you want. Information is updated after every sale (2 pcs. are sold, 5pcs. left).

Tubes have no sign of use and we guarantee, that every tube has a "1578" stamp on it.

(According to datasheet, min (65% of NOS) is Ia=4,5 mA, S=1,8 mA/V).

1578 is a very special tube from a large 6H8C/6SN7 family, and it was used in the control devices of USSR nuclear stations. 1578 tube has a unique design - its perforated “hole” plates reduce electrical capacitance of the tube and improve thermal balance inside of the electrode system (decrease the influence of the heat emitted from the cathode on the control grid). 

1578 tubes were selected for identical triodes, low microphonics level and lifetime about 5.000 hours (at Ua(max)=275V and Pa(max)=1,5W). These supreme tubes were made only of the best materials; they went through the circles of tests at their limits, special regime of thermal-cycling and military QC.

I'd like to explain where do all those “1578-plastic-base” and “1578-non-perforated-plates” have come from. USSR had a planning economy. When the plan wasn't fulfilled properly or not enough tubes were produced for an urgent order, MELZ manufacturer did take ordinary 6N8S (sometimes metal-base ones, sometimes not) and get them through tough tests, thermo-cycling and so on. If the tube has passed all the tests, it was labeled 1578. The only advantage of these 1578s – is that the tube was selected and tested/hardened. But its sound is similar to cheap ordinary 6N8S. It is not a genuine 1578! Don't be fooled!

Real 1578 must have both characteristics: special construction with perforated plates and “1578” stamp, as a sign of selection and hardening. Our tubes have both!

So, don't miss a chance to get a genuine vintage tube!

Please email us with any questions before you bid!

Thanks for viewing my auction, and happy bidding!

Payment must be received within 3 days. You will get exactly what you see on a picture. Actual photos.

Buyer is responsible for all the taxes. You will get it marked as "a gift" and we will declare any cost if you want.

 We will ship worldwide with REGISTERED / EXPEDITED AIR MAIL! You will get a tracking code to check it’s delivery status.

It will be packed and wrapped carefully.

Delivery time is about 2-3 weeks (for Italian customers – up to 4-5 weeks, due to Italian custom).

Item is guaranteed! Due to item's age and detailed description of the lot - returns are accepted only for technical reasons or mistakes.