12hg7 vs 12hn7a

[nhuwar]

Hi all,

I'm looking at a amp that uses a 12hg7 as a driver, but all I can find is the 12hn7a. In you opinion is the 12hn7a a good tube for audio?

Thanks for the help,


Nick

[Tom Bavis]

Do you mean 12GN7? The 12HG7 and 12GN7 are considered equivalent and many were marked with both numbers. The 12HG7 was often found in the large (1 1/8") bottle - 12HG7 is usually the standard 9-pin size.

[nhuwar]

OOps typo, Ya I might the 12gn7. As far as I could tell by the data sheets they looked pretty much the same, just wanted to ask though.

Thanks Tom



Nick

[richwalters]

I'm using the 12HG7/12GN7 as a substitute for the pricy 12BY7A, configured as a triode for driver. The GE spec sheet shows gain in triode practically double to other tubes. Both are good high gm line video tubes specially for the old TV and broadcast markets. The slight drawback of the 12GN7 is the high g1 capacitance and limitation to input volts and no attention to microphony. They aren't screened and will readily self oscillate with bad layouts.
The sibling european EF184 is smaller, screened and plentiful.

rich

[vitalstates]

Pete Millet used a 12hg7 to drive 813 in 2 stages if thats any help. Google should find it, or failing that if you mail me I will send you circuits.

Ed

[nhuwar]

Originally posted by vitalstates
Pete Millet used a 12hg7 to drive 813 in 2 stages if thats any help. Google should find it, or failing that if you mail me I will send you circuits.

Ed

Thats what I'm building LOL

Nick

[Brett]

Originally posted by nhuwar



Thats what I'm building LOL

Nick

I've used them as drivers in PP for 813 and they were excellent.