High gm version of 12AU7

[ruffrecords]

Is there a tube which is basically a high gm version of a 12AU7? In other words, 12V heaters, B9A base, preferably same pin out, similar mu but higher gm.

Cheers

Ian

 

[DF96]

ECC804? Also known as 6/30L2, possibly sometimes sold as 'Mazda 6CG7'.

 

[rongon]

12BH7A

12FQ7 (if you can find 'em)
--

 

[316a]

Is there a tube which is basically a high gm version of a 12AU7? In other words, 12V heaters, B9A base, preferably same pin out, similar mu but higher gm.

Cheers

Ian

ECC99 perhaps ?

316a

 

[jgf]

12BH7A

Yes, then ECC99 beyond that

 

[ruffrecords]

I should also have said the same physical size as the 12AU7!

Cheers

Ian

 

[ruffrecords]

ECC804? Also known as 6/30L2, possibly sometimes sold as 'Mazda 6CG7'.

THat'sdefinitely in the right direction. Thanks.

IAn

 

[DF96]

I realise you did specify 12V heater. The ECC804 has only 6.3V heater, with a screen on pin 9.

 

[45]

I should also have said the same physical size as the 12AU7!

Cheers

Ian

I would try the 6N1P-EV. It's cheap and very good. The EV version is long life. It was designed as a true low frequency voltage amplifier. It is 6.3V though with pin n.9 connected to a screen between the two halves. Amplification factor is 35 and average gm 4.5-5 ma/V at 150-180V/6-8 mA. Input capacitance is higher than 12AU7 though.

 

[TonyTecson]

6gu7

 

[jane]

7044

B9A basing, mu = ~20, gm = 10 ma/V

 

[famousmockingbird]

The 7044 looks like a great tube until you see the plate curves, not that great looking to me. I am curious to how it sounds for audio use.

 

[ruffrecords]

7044

B9A basing, mu = ~20, gm = 10 ma/V

Looks a bit like the ECC99 and like that tube it is much taller than the 12AU7. I need something no taller. And its price is crazy!

Cheers

Ian

 

[kevinkr]

The 7044 looks like a great tube until you see the plate curves, not that great looking to me. I am curious to how it sounds for audio use.

Lots of ARC amps have used them in balanced driver circuitry. Used to have bunch of Amperex ones which I unloaded when I realized what they were worth.

 

[Hearinspace]

I haven't used this for a few years as it doesn't work on a Mac, but if I remember correctly it would be perfect for this search.

 

[jane]

Looks a bit like the ECC99 and like that tube it is much taller than the 12AU7. I need something no taller.

What about 5687?
Same height as the 12AU7 but with a slightly different pinout.
Vh= 12.6 V, mu = 17, gm = 8 ma/V

 

[Shef]

And what is 12AU7's gm in mA/V ?

 

[famousmockingbird]

3.1mA/V

 

[rongon]

New age of insane prices on tubes

If the bottle has to be the same size as a 12AU7, then I think 5687 is going to be the best choice. Unfortunately, it looks like prices on those tubes have gone a bit crazy. They used to be a $4 tube, now it's $15 and up.

Then again, I see people selling 5814 (industrial 12AU7) for stupid crazy prices these days. So maybe the 5687 is still something of a bargain at "only" $15 each.

Possible problem is that the 5687's pinout is different, and its heater takes double the current of a 12AU7.

 

[Ketje]

This one ? TDSL Tube data [ECC813]
Mona