First amp build, Please help?

[nat-han]

I'm building a Tweed Princeton (5F2) and I'm kinda confused on a couple things.

The first thing is the capacitor orientation. The schematic shows a difference between the polarized and the non-polarized capacitor. So I know which is which. If I'm correct I have the polarized highlighted in an orangish color and the nonpolarized in blue. My problem is I don't know which side of the polarized capacitor is + and which is -.

The second thing is the kit (mojotone smallparts) gave me two 22k resistors a 1/2 watt and a 1watt. I assume the 1watt goes next to the 10k 2watt resistor (pink).
thanks, Nate

[JHow]

Regarding the 22K resistor, put the higher power one in the power suppy and use the 1/2watt for the nfb loop.

Regarding the polarized caps, the oriention is pos. to the cathode of the tube and the neg. to the circuit common. Think about the voltage drop in the circuit across the capacitor, which side is more positive? In this case you have about 1.5 volts on one side and zero on the other - the 1.5V side gets the positive end of the cap (12ax7). The polarity of the cap is marked on the cap itself, on axial caps the "crimped" end will be positive.


Just an afterthought, on the power tube you will have a greater voltage difference , around 19 volts, at the cathode.


Have a look at the orginal fender version of the schemo:

http://www.kbapps.com/audio/schemati...ceton5f2a.html

[nat-han]

Thanks JHow! That makes alot of sense.