JazzGuitarGimp wrote:I've never encountered the 'brass plate' grounding system. I assume the plate is connected to the chassis by virtue of bring sandwiched with the chassis at the pot shafts and input connector? I didn't see anything on the weber layout that suggests a ground wire to be soldered to the brass pate at one end, and then connected to a chassis screw at the other end. Are all of the pots and input connectors tightened securely to the chassis?
Yeah, that's exactly how it works. It's squeezed against the chassis at the inputs/pots. I have the power section grounded to a lug of the PT and the grounds from the inputs and board going to the chassis/plate near the inputs. Inputs and pots are secured.
Just to make sure I'm not making a rookie mistake, which grounds exactly should be at PT and which grounds should be grounded near inputs to prevent the grounding loop?
On Fender amps, the brass plate is typically soldered to chassis near the power amp end (just to make sure). But your problem is not an issue of where the ground is located. Lou has been giving you good blind advice, but a few pics would probably do the trick.
Firestorm wrote:On Fender amps, the brass plate is typically soldered to chassis near the power amp end (just to make sure). But your problem is not an issue of where the ground is located. Lou has been giving you good blind advice, but a few pics would probably do the trick.
Firestorm is right; around here, a few pictures are worth darn near a thousand posts. I am a bit concerned about the wandering GND measurement you took at C13+. But the fact that the bias supply won't get you more negative than -18V is a show-stopper for 6L6's, so we need to get that figured out before you can move forward. As Firestorm points out, where a particular circuit is grounded won't have any effect on static DC voltage measurements. As far as DC is concerned, GND is GND, so long as the connections are solid enough to carry the current being asked for by the circuit.
Alright! Vacation time kicks in this week. I'm ready to dedicate serious time to this thing. Here are some pictures. Let me know if you would like to see pictures of anything specific. I have a camera handy now.
Firestorm wrote:On Fender amps, the brass plate is typically soldered to chassis near the power amp end (just to make sure). But your problem is not an issue of where the ground is located. Lou has been giving you good blind advice, but a few pics would probably do the trick.
I have a camera readily available now. What specifically would you like photos of?
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