Need help determining best grounding points for my amp

[Mike_J]

I have attached the layout for my amp.  I circled in red the ground-to-chassis points that I currently have planned for this amp.  I reversed the layout so the inputs are on the left when the tubes are pointing up.  This has caused me some confusion.

I have made quite a few amps with the grounds attached the way they are shown here.  However, the HT caps, screen caps, rectifier and relay power supply board is placed on the opposite side of the amp from where I normally place it.  I normally place this ground point where the red X is.  In all the amps I have done this way they are very quiet when not being played.

I need to make a decision in how I am going to do this because it may involve countersinking a screw so it can be placed under the power transformer.  I am thinking it would be best to place the grounding point where the red X is.  I would place all of the grounds on the tree the 6.3V @ 1A will connect to the indicator lamp and the relay power supply board.  The 6.3V supply would use the top two connections of the tree and the grounds would take the bottom connection.  I have attached a picture of the tree so you know what I am talking about.  (Will require a separate reply to show this.)

I would then run a single larger wire over to the other side where the red X is.  If I do it this way I am very confident if the amp has any noise it will not have been caused by the grounding scheme but would be something else that would need to be tracked down.  Does anyone see this as necessary and know whether placing the 6.3 volt power and the grounds on the same tree will cause problems?

Thanks
Mike

[Mike_J]

Here is the tree I was talking about in the initial post.

Thanks
Mike

[sluckey]

I normally place this ground point where the red X is.  In all the amps I have done this way they are very quiet when not being played.

So why change it now?

[Mike_J]

I normally place this ground point where the red X is.  In all the amps I have done this way they are very quiet when not being played.

So why change it now?

Sluckey

That is kind of the way I was headed.  The only question is how I am going to get there.  Do you see any problem with me tying the ground on the front of the amp to that tree and sending a wire over to the other side?

This may actually be the last unresolved issue on this amp.  From here I can complete the build.

Thanks
Mike

[sluckey]

Do you see any problem with me tying the ground on the front of the amp to that tree and sending a wire over to the other side?

What do you mean? Ain't the amp just simply a mirror image from the way most of us would do it. So just mirror your other successful ground schemes.

Is your 'tree' gonna be bolted to chassis in the vicinity of your PT?

[Mike_J]

Do you see any problem with me tying the ground on the front of the amp to that tree and sending a wire over to the other side?

What do you mean? Ain't the amp just simply a mirror image from the way most of us would do it. So just mirror your other successful ground schemes.

Is your 'tree' gonna be bolted to chassis in the vicinity of your PT?

The tree is bolted right next to the PT however it is not in the path I think it should be in.  I would think it would be best to have a somewhat linear path for the grounds from the preamp ground to the OT ground to the cathode grounds to the power tube grounds and then finally the 120 volt ground.  That way the likelihood of a loop hum would be reduced.  That is why I know I should move it to where the red X is.  I have always done it this way and it has always worked. 

What I couldn't remember is how close I could get a 6.3 volt wire to ground but in retrospect many people run their heater wires flush to the chassis so I guess there was probably no reason for my concern in having them close together on the tree.

I will look at my grounding points on my other amps and make sure I am copying them.

Thanks
Mike