use of 12ax7 and 6v6 as 6T9 alternative?

[armstrom]

I've read that the 6T9 is very similar to half a 12AX7 and a 6v6 in the same envelope... At least at lower voltage in the 250-300V range. Unfortunately, the only datasheets I can find for the 6T9 don't include any graphs so I can't compare them directly. I really would like to build the stereo 6T9 amp from spare time gizmos but the lack of availability on the 6T9 compactrons has me leaning toward using more readily available tubes. I know cathode biased SE amps are pretty forgiving... could I simply substitute a 12ax7 for the driver stages (one triode per channel) then use one 6v6 on each channel for output? Could the rest of the component values remain the same?

Here's the schematic: (I plan to use the ultra-linear modifications)
6T9-UL-Tube-Amp-Schematic.png (image)

Thanks for any info you can provide!
-Matt

 

[Tom Bavis]

Yes same values should work, though the 6V6 might want a higher value cathode resistor - pick up the next few values (300, 330, 360, 390) when you buy parts. And the 330 pF feedback cap seems high, but value will depend on the output transformer.