[gurevise]

Jim,

The standard version of 9-pin Cornet has value of R7 220 Ohms.
The octal version uses value 22 kOhms. There is considerable difference between these two versions of Cornet here. Why there is such a difference ( 220 to 22kOhms ), considering the rest of the components, in this time constant circuitry, are the same ( R7, R23, C8 )? Tubes are different, but 6SL7 has very similar internal impedance to 12AX7.

?

Thanks
Sergey

Another question: What's the purpose of R6?

[hagtech]

The 6SL7 is a bit different in plate impedance.  But there's more to it.  I chose different operating points for each tube.  I run the octal at higher current.  Also, without cathode bypass, plate resistance goes way higher than data sheets (about double in this case).  As a result, plate load resistor changes, as does equivalent R for the combo, which sets EQ turnover.  The 22k was added resistance to get it just right, without having to change capacitors.

jh