TU-8500 12AU7 vs 12A??

[HarryY]

Originally Posted by HarryY

The 12AU7 has a plate resistance of 7,700 ohms
The 12AT7 has a plate resistance of 10,900 ohms

The 12AT7 is actually the higher of the two.

A better selection may be the 5751 with a plate resistance of 5,800 ohms.
That is if the TU-8500 can handle the higher filament current of
175 mA (at 12.6v) over the 12AU7 filament current of 150mA (at 12.6v).

Disregard this with the 5751 I read the plate resistance wrong

[paczeltf]

Originally Posted by HarryY

The 12AU7 has a plate resistance of 7,700 ohms
The 12AT7 has a plate resistance of 10,900 ohms

The 12AT7 is actually the higher of the two.

Victor may have meant the output impedance of the preamp.

[batty]

Has anyone tried different makes of 12au7?
What if any difference does that make?