I think this is more a power question hence here.
Tube amplifier with B+ and B- from the same PSU, I assume that if we have PSU noise then it would occur on both B+ and B-, thus using both in a push-pull means the output has +noise and -noise along with the signals amplified and therefore cancelling out?
I've not seen this done as much in pre-amp stages from a lot of the schematics - is there any reason for this?
Tube amplifier with B+ and B- from the same PSU, I assume that if we have PSU noise then it would occur on both B+ and B-, thus using both in a push-pull means the output has +noise and -noise along with the signals amplified and therefore cancelling out?
I've not seen this done as much in pre-amp stages from a lot of the schematics - is there any reason for this?
> if we have PSU noise then it would occur on...
All voltage on a point is relative to some other point.
Relative to what??
Normally "V-" is defined as "zero", our ideal reference; and all power noise appears to be on B+ (re:B-).
The other thought: small signal stages are low-current stages and normally trivial to filter clean-enough.
All voltage on a point is relative to some other point.
Relative to what??
Normally "V-" is defined as "zero", our ideal reference; and all power noise appears to be on B+ (re:B-).
The other thought: small signal stages are low-current stages and normally trivial to filter clean-enough.
So the back story is I'm looking at the designs for a 6SN7 front and a 6AS7 output - the 6SN7s typically run higher voltage, thus the noise that appears on the lines would I suspect be larger so I was just curious why this wasn't used (perhaps more difficult to get a balanced response or GNFB may do the job).
I'll keep googling but I've not seen a definitive statement hence asking 🙂