How to ground pots?

[Oddvar R]

Hi. I was just wondering about the best way to ground the pots. Is the wire attached to back of each pot?

[pompeiisneaks]

I personally do not like soldering to the pot, it can cause damage to the pot. I know tons do it. I've had a few pots fail, and I'm not 100% sure if it was just my noob soldering or the technique or just the pot.

Instead I've started running a grounding bus bar from the last pot's ground all the way down to the input area and then running a small wire from the pot's ground connection to the bar. I learned this from Sluckey I believe and it's worked great for me in every build since. I don't risk damaging the pots that way.

~Phil

[Oddvar R]

Do you mean like this?

[pompeiisneaks]

Similar yes, it looks like they bent the pot leads which works I'm sure but could weaken the leads over time? one bend probably wouldn't. I just run a small jumper wire from the pot leads to the bus bar.

Either probably is fine though.

~Phil

[xtian]

Best practices suggest, for lowest noise, grounding to a single point on the chassis only. If you solder to the backs of the pots, you have many points of contact with the chassis.

Also, consider how hard it is to replace a pot if obstructed by a buss wire--make life easy on your future self!

[Phil_S]

..consider how hard it is to replace a pot if obstructed by a buss wire--make life easy on your future self!

So much easier to run the small jumper. What makes people want to do otherwise? I don't see the advantage, though it looks pretty.

[wpaulvogel]

I always used a wire like Oddvar’s example until I did the Express amps. I did the Express like Ken except I ran a dedicated wire from the volume pot to the input jack and then to a lug bolted to the chassis. I split the buss wire between the bass control and presence control and grounded the presence pot to the phase inverter cap negative terminal. I was hoping that could eliminate a ground loop. Don’t know if it works for sure. I never used to use the chassis as a ground plane before building the Express amps. I did the Express that way to be correct and it works okay.

[Oddvar R]

Thanks for the info. There are some other issues I wonder about: Are the red wire I have circled attached to the same point as the blue wire? Or is it just passing by. And my transformer has a 50v bias tap, where does it go, if used?

[gktamps]

No, the red wire does NOT connect to the cap with the blue wire.

[wpaulvogel]

I wouldn’t use the bias tap. Just use the standard

[xtian]

No, the red wire does connect to the cap with the blue wire.

Missing word alert. No, the read wire does NOT connect to the cap with the blue wire.

[gktamps]

Missing word alert. No, the red wire does NOT connect to the cap with the blue wire.

My apologies, and thank you for catching my mistake, Xtian!
I've edited my post.

[M Fowler]

Another layout you can use.

Trainwreck Express Layout.pdf

[wpaulvogel]

Here’s a picture of one of mine.

[Oddvar R]

Looking good.