Bogen 110 Conversion

[Willabe]

PT HT ground preferably links to first filter cap neg lead, so that the charging current pulses do not flow through chassis.

Preferably use a single link from secondary 0V to chassis - such as shown next to input socket.

https://www.valvewizard.co.uk/Grounding.html

[angelodp]

PT HT ground preferably links to first filter cap neg lead, so that the charging current pulses do not flow through chassis.

Preferably use a single link from secondary 0V to chassis - such as shown next to input socket.

https://www.valvewizard.co.uk/Grounding.html

I believe I have the first recommendation correct - the HT PT is grounded with the first Cap -


On the second suggestion, on my Marshall 100 Lead I took the speaker ground to the presence ground (Larry ground)
Here would it be better to ground the output over to the input ground?


Right now I have four nodes for ground


1. Input
2. Power rail and Power tube cathode
3. Mains ground
4. Output


Are you suggesting I eliminate the output ground?

[Willabe]

You should read the grounding link I posted from Merlin.

I believe I have the first recommendation correct - the HT PT is grounded with the first Cap -

If #4 is the PT CT, then this is wired wrong. CT and 1st filter cap ground only go together, then a wire is run from there to the chassis ground or other grounds. You have everything grounded together like a star ground.

On the second suggestion, on my Marshall 100 Lead I took the speaker ground to the presence ground (Larry ground)

Here would it be better to ground the output over to the input ground?
No, the OT secondary ground lead has the most current in the amp. It goes with the power amp ground.

Are you suggesting I eliminate the output ground?

The OT secondary ground lead has the most current in the amp. It goes with the power amp ground. The presence pot ground goes with PI local star then is run with a wire/daisy chained back over to the power amp star.

I passed a kidney stone and I'm on pain meds, I can't do this until I feel better.

[angelodp]

Ouch, sorry to hear about your health issue. Appreciate your taking time even with .....


I have read Merlin's grounding many times. I can say the quietest amp I have (most are) is the Trainwreck Rocket which is a single point ground. Then the Dlite is star ground and very quiet and many others that are variants. My 100w lead is star Ala Larry's.  Let me try what you suggest.


Best A

[Willabe]

With Merlin's grounding; each filter cap has it's own local star and those stars are then daisy chained to together.

You can then go with 2 chassis connections, power amp and preamp. Or you can do the single chassis ground.

The noisiest ground connection is the 1st filter/PT CT. And the speaker ground has a lot of current, so it can be a problem. 

With a true star ground you end up with wires all over the place, very messy. 

I have no idea who 'Larry' is.

[angelodp]

So - Larry Novisiber - came up with a grounding scheme used widely, here I think and at Metro and TAG.


Thanks for the intel.

[Willabe]

No thank you on Larry.

I would never do my grounds like that. Never.

And if you've read the Merlin grounding link several times, like you say, and understand it, you wouldn't use that grounding either.

[Willabe]

No thank you on Larry.

I would never do my grounds like that. Never.

What I mean by this is, you can get a grounding layout to work on a certain amp, but that doesn't mean it will work for any/all amps.

Merlin's and KOC's will work with any amp. There are reasons they ground what with what and where. 

[angelodp]

Yes understood. I am mapping out my options. I know I am over-thinking this whole project, but for me it's a hobby and I am taking my time and want to make it great. I'll post a new upgrading grounding scheme soon. Work is now getting in the way...




Thanks.