Shielded cable

[mbach72]

Sorry for the dumb question, I usually lurk around enough to find answers I need without posting, but not in this case.

I'm in the process of building my first amp. I'v done some effects pedals, and wired a few guitars, but no amps. I believe that I should be using shielded cable from the input jack to the grid of my preamp tube(with a 68k resistor in between). I have two lengths of shielded cable, one apparently has a solid core, the other is stranded. Neither has a very big core. I know that there is not much going through this cable, but the ones I have seen in other amps look bigger to me. These both look equivalent to the shielded cable used in guitar wiring.

Do I need to be looking for a bigger size, or is what I have sufficient?

Also, my understanding is that the braid stripped, then twisted and grounded on the tube end, and just left intact on the junction with the 68k resistor. Correct?

Thanks for the help. Sorry for the newb post, but I'd like to this right the first time.

[MWJB]

Chances are that the conductor is adequate, as long as you feel that it is mechanically up to the job, it's really just a continuation of your guitar cable which may have a centre conductor of 7 strands of .2mm wire and cross sectional area of .22 sq. mm.

The important thing is to just ground one end to avoid loop hums, usually they are grounded to the input jack ground/buss wire, but no reason why you shouldn't ground at the tube end.

Heat shrink the ungrounded end so that the sheild & jacket can't slip down and short the centre conductor, turning off your tube.