Regarding the power supply design... If I need roughly 25v for the lm1875, and 9v for the jfet preamp stage, what is the best way to design the power supply? I was thinking using an 18v transformer for the 25v power amp voltage, and then having a linear dc regulator that draws off of the filtered +/-25v dc and drops it down to about 9v and putting a capacitor filter network right after the linear regulator, which then goes to the preamp circuit... or i could use a 6.3v transformer for the preamp and keep both power supplies completely separate... any thoughts? 18v A/C rectified and smoothed is about 25v D/C and 6.3v A/C rectified and smoothed is about 9v D/C.
If I use a linear DC regulator, I could save on the amount of ironware I would have to buy, and also need only one rectifier. The main question I keep thinking of is: Will a linear DC regulator introduce noise into the circuit, even if I filter its voltage output with caps before connecting to the preamp circuit?
I'll add for reference the regulator type I'm thinking: http://www.ebay.com/itm/DC-DC-4-2-40V-to-3-3V-5V-6V-9V-12V-24V-Buck-Step-Down-Converter-Linear-Regulator-/322365124189?
If I use a linear DC regulator, I could save on the amount of ironware I would have to buy, and also need only one rectifier. The main question I keep thinking of is: Will a linear DC regulator introduce noise into the circuit, even if I filter its voltage output with caps before connecting to the preamp circuit?
I'll add for reference the regulator type I'm thinking: http://www.ebay.com/itm/DC-DC-4-2-40V-to-3-3V-5V-6V-9V-12V-24V-Buck-Step-Down-Converter-Linear-Regulator-/322365124189?