Finished my HiFi Amp Project

[beedoola]

I'm not sure what you mean here. The input resistor that is there should be fine. Bypassing the TC circuit will give it more gain and distortion, if that's what you like.

For instance, a lot of Fender's use a 68k and 1M at the input jack - the 68k then going to the preamp tube. The 1M going to ground at the input.

[guitician]

OK, that series resistance is used when multiple inputs are tied to the same tubes grid and provide for differing input sensitivities. It can also be a limiting resistance in case of a tube short to protect the device connected to the input. And 68k is typical, I've seen 47k and 100k as well.

[beedoola]

Yeah, the frequency response of an audio amp is around 20-20000 hertz and playing six string guitar through it can have too much bass. But, that is why I said play it first, because the old amps really lack bass to begin with. And the frequencies that the tone controls are designed for are not the same as they use for guitar. Bypassing gives the amp more room to breathe and lets you tweak it from there.

I removed the tone stack.

I also removed the wiring from the selector switch, but I'm wondering if this is correct.

In the photos below:

Input jack goes to a 68k and then those wires all meet

That big yellow cap goes to pin 7 on V1 - 12AX7. A resistor goes from pin 7 to ground - I didn't add nor alter the resistor going from pin 7 to ground. nor did I add the cap to pin 7.

The blue wire goes to a resistor that then goes to ground.

Green wire goes straight to Pin 2 of V1.

The stripped wire goes to the Lug 1 of the Volume pot.

Again. The blue, green, yellow cap and stripped wire all meet at the 68k, which goes to the input jack...

[guitician]

The 12ax7 is two amplifiers in one tube. You can see in this data sheet the diagram of the pins. That orange disk is a capacitor too and it is another output and the green wire is the input for that stage.
You have the output going into the input by connecting the 68k resistor to the blue and stripped wire. The stripped wire should only go to the blue. And the yellow cap and 68k need to have a 1M ohm resistor to ground connected to them.

[beedoola]

[ATTACH=CONFIG]27810[/ATTACH]

The 12ax7 is two amplifiers in one tube. You can see in this data sheet the diagram of the pins. That orange disk is a capacitor too and it is another output and the green wire is the input for that stage.
You have the output going into the input by connecting the 68k resistor to the blue and stripped wire. The stripped wire should only go to the blue. And the yellow cap and 68k need to have a 1M ohm resistor to ground connected to them.

Does the 1M go right from the input jack to ground, or after the 68K with that yellow cap?

I'm getting a lot of ground noise. I used a shielded wire for the input. I'm not sure if that is it, or the power cords proximity to the hot wire for the speaker output jack I added. I used the original selector switch so choose between the different impedances of the OT.

Definately a lot more gain. Any way to reduce the amount of gain?

Also. One of the EL34s seems to react more to playing dynamics than the other tube. For instance, when I pick hard you can seem the tube sag whereas the other EL34 doesn't do that.

[guitician]

Yeah, right at the input jack is where the 1M resistor goes. If your running one stage right into the other without a control between the stages your going to have too much gain. EL34? you must mean EL84, and they are a push pull pair that work together. Both tubes should be identical for the best performance, although mismatched tubes will work OK for guitar. About the noise, these old amps used a ungrounded chassis and you have to flip the AC plug to ground the chassis which should have a capacitor to the line input, referred to as the "Death Cap". A better thing to do is upgrade the cord to a three prong grounded type. I've used ones from old electronics like computers/printers.