Grounding of Input Connectors on a Gainclone

[saabie22]

First, let me apologize for asking what's probably a trivial question. I was unable to find an answer by searching the site.

I'm building one of Brian's Gainclone kits.

I'm confused as to whether or not I should insulate my input jacks from the chassis. The input connectors that I have mount through my aluminum back panel and will therefore be grounded.

Should I make a plastic bushing to isolate these from the chassis? My thinking is that I might be building a ground loop since the wire shield will connect to signal ground on the amp board.

Thanks for your help on this and countless other questions that I've found answers to in this forum.


Mike

[troystg]

Hi-

It is better to have the RCA's insulated and then connected to the chassis ground through a 100 Ohm resistor.

However, it is easier to just grnd them at the mounting point and if you pick up a grnd loop or noise to go back and enlarge the hole for an insulator.


Troy

[carlmart]

Originally posted by rabstg
It is better to have the RCA's insulated and then connected to the chassis ground through a 100 Ohm resistor.

100 ohms is too high. 10 ohms should be a better value, but most people here are just doing the star and only joining signal and supply ground there. No resistor.

What you should do is use a small ceramic capacitor, with very short legs, 10nF or so, right at every RCA connector, soldered between connector's ground and chassis. That should take care of RFI. You are reading right: ground to ground.


Carlos

[saabie22]

Troy and Carlos,

Thanks for your advice.

I will insulate the connectors from the chassis and use the resistor and cap to ground.