When looking at the 12ay7/6072a valves for my phono amp, I have kept looking for a datasheet that suggests a maximum grid resistor size.
The only one with a value is the GE one that suggests a typical value of 0M1, significantly smaller than other 9-pin valves that can be in excess of 2M0. http://tubedata.milbert.com/sheets/093/6/6072.pdf
Also I looked at the 6072-based AN M10 schematic I have attached. In the two instances where grid resistors are employed, they are only 50 and 100k respecively.
This would have to be considered as part of my RIAA calcualtions so:
Do I need a grid leak resistor?
If yes, is 100k max reasonable or might something much bigger be possible such as 1M0?
12AY7/6072a Grid Resistor
-
- Old Hand
- Posts: 693
- Joined: Sun Nov 09, 2008 2:06 pm
- Location: Manchester
#1 12AY7/6072a Grid Resistor
TD-125/RB250/MC25FL & 'Snail' phono, NAS/SBT with CS4398 DAC, 41MP pre & MoFo Power, still messing with OBs.
- Mike H
- Amstrad Tower of Power
- Posts: 20189
- Joined: Sat Oct 04, 2008 5:38 pm
- Location: The Fens
- Contact:
#2
1 Meg is a design maximum, otherwise it's whatever the circuit needs, just provided it doesn't go over the design max. Your circuit is OK as it is.
Apart from having no grid leak resistor at the input socket
47k ?
Apart from having no grid leak resistor at the input socket
47k ?
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."