by EWBrown » Mon Oct 20, 2008 11:04 am
This is basically a simplified version of the ST-35, without the two extra feedback paths that the original design had.
The 12AX7 should perform well in this circuit, and it is more easily obtained than 12DW7 or 7247. Though I am not sure, without running a simulation, what the phase splitter plate / cathode current might be, and if it would exceed the maximum 12AX7 ratings.
J/J does have a 12DW7 equivalent, the ECC832, so there is a less expensive alternative to the vintage tubes.
/ed B in NH
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