valve info? NEC 30M-P25

[planet10]

I picked up a small Sony R-R that used this tube in an SE output stage (and a 3rd one in the head driver amp?). I'm guessing it is one of those rarish single manufacturer Japanese tubes... does anyone know anything about them. Of primary interest is what the likely primary would be on the OPTs.

It also used 6267s on the front end -- i gather this is an EF86 variant.

dave

 

[fdegrove]

Hi,

Dunno about the NEC tube but :

It also used 6267s on the front end -- i gather this is an EF86 variant.

Yep. The direct equivalent would be the EF806S which is the SQ version of the EF86/6CF8?

The Soviet equivalent is the 6(shh)23Pi.

Cheers,😉

 

[AV8R]

30M P25

I will have to dig through my old stuff, but from memory it is a 30 volt heater pentode made by Matsushita. Sony machines tended to use low volts HT so out impeadance about 3 K Ohm. 2 watts output.

 

[planet10]

Re: 30M P25

I will have to dig through my old stuff, but from memory it is a 30 volt heater pentode made by Matsushita. Sony machines tended to use low volts HT so out impeadance about 3 K Ohm. 2 watts output.

That jives... the HV tap on the trafo is marked 140V IIRC. And 30+30+30+6.3+6.3 = 102.6 V -- pretty close to what you'd expect for a series string

3K 2 W would make it suitable for 50EH5 or 50C5 spud amp.

dave

 

[AV8R]

30M P25

All I can add from my last post, is that I made a mistake, it's not Matsushita but Nippon Electric Company(NEC) and I could not find data save that it is a B7G base Power pentode with 30 volt heater. 35C5 is nearest relative. 50C5 is taller and more power.