12BH7 optimization instead of 12au7
Posted: Wed Oct 17, 2012 7:23 pmHi to optimize a ST 70 driver board For 12BH7 would R18 need to be changed .
Mark
Mark
diytube.com
new registrations are closed at this time
http://www.diytube.com/phpBB2/
12BH7 optimization instead of 12au7
Page 1 of 1
Posted: Wed Oct 17, 2012 7:23 pmPosted: Wed Oct 17, 2012 9:38 pmDepends.... whose ST-70 board?
Posted: Thu Oct 18, 2012 12:49 amPosted: Wed Oct 31, 2012 6:03 amJust ran the sims via John Broskie's TubeCAD. No change is necessary for subbing a 12BH7 as the long tail phase splitter. The bias voltages remain unchanged in this arrangement.
But using a 6DJ8/6922 doesn't get the right voltages as the LTP, and it's lower max voltage rating is a problem. The bias is more suited for small signals as a voltage amplifier. Unfortunately, it doesn't have suitable gain for a simple sub in the diytube ST70 driver.
Shannon
But using a 6DJ8/6922 doesn't get the right voltages as the LTP, and it's lower max voltage rating is a problem. The bias is more suited for small signals as a voltage amplifier. Unfortunately, it doesn't have suitable gain for a simple sub in the diytube ST70 driver.
Shannon