Larry Grounding scheme

[screamindemon]

All good, running like a dog with his butt on fire..
Calls are coming in faster than I can knock them down
Hows the amp coming??

Good to hear you are busy ! Amp is about done but now I am going to ad DC heaters so I got to figure that one out. MY power transformers doesn't have a tap for it.

 

[Smash]

I like running a bus bar above the pots and connect everything (most things) to that. But not soldered to the pot casings. Basically, what Soldano does in the SLO. And similar to what Ceriatone does in some of their amps, just instead of hanging off the turret board, I use the relevant pot lugs.

that is what rick does in wizards. it is hidden up there so a look at the chassis looks like he didn't ground much.

 

[RedPlated]

Good to hear you are busy ! Amp is about done but now I am going to ad DC heaters so I got to figure that one out. MY power transformers doesn't have a tap for it.

Which amp are you trying to put DC heaters in?

 

[screamindemon]

Which amp are you trying to put DC heaters in?

My Marshall build from the Larry thread. 100 watt Mojotone British. It’s a it’s a 2 channel 3/4 gain stage plate driven tone stack.
Will be powering 3 5 volt relays , 2 12AX7s and 3 LEDs for the foot switch. Would like to go with a 6 volt power supply .

 

[screamindemon]

Was getting ready to start a post about adding power supply for this. Would appreciate your help with component selection if you don’t mind.

 

[screamindemon]

https://www.jameco.com/webapp/wcs/s...-1&catalogId=10001&pa=102163&productId=102163

Thinking about running this transformer ? If I am correct I calculate 348 milliamps of draw from the above. Should give me room to spare.

 

[screamindemon]

Sorry that should be 804 miliamps.

 

[RedPlated]

Was getting ready to start a post about adding power supply for this. Would appreciate your help with component selection if you don’t mind.

I’ll shoot you a PM

 

[SpiderWars]

Resurrecting this thread. I'm about to resume building a 18W Liverpool that I back-burnered and was reading about grounding again. I found this old @novosibir post from 2011 interesting. I also found a picture of a gutshot of an impeccably wired Larry Wrecky 35 (Express clone) and it clearly had Larry grounding and not star. So that sort of meshes with what @FourT6and2 said, either one works when done correctly. Really the only difference is the 'sub-stars' are connected to chassis at strategic points instead of the star.

"joey" referenced in the quote below is SLOclone forum joey. He knows his stuff too. The quote is from Larry.

By principle and theoretically joey is right - the best grounding scheme is:
- each stage does have its own filter cap
- all grounds of every stage are connected to their corresponding filter cap negative (sub star)
- all sub stars are routed together in the order, as the circuit is running (ground bus) - still isolated from the chassis (!)
- the ground bus is connected to the chassis at only one point