Brass Plates To use or not to use ??

[crunchman]

Just wondering if you are not using the plate should you use "shorting" jacks or what,

not sure what the significance of the plate is exactly.This pertains to a new 5E3 build......Thanks, crunch

[Enzo]

The brass plate is a lot easier to solder to for a ground connection than the chassis itself. SInce the plate is pinched to chassis by the jacks and controls, it is electrically ground.

[Tom Phillips]

The use of shorting jacks is not really related to the brass plate. You should use shorting jacks as indicated on the schematic with or without the brass plate.

My opinion is that the brass plate was used by Fender as a convenient grounding “buss” that was relatively easy to solder to. However, the brass plate really isn’t a buss because it touches the chassis in multiple places. The fact that the brass has lower resistance than the chrome plated steel chassis is really insignificant in the application. If you are doing your own build you will be better off by improving the grounding scheme used as has been discussed in many threads and in the published books. That will result in less hum than you will get by duplicating the original Fender layout and/or using the brass plate.

Cheers,
Tom

[Enzo]

Indeed, if you don;t plan to solder anything to the chassis, then the brass strip has no purpose.

[crunchman]

OK, I recall reading a post where someone used a length of romex that ran from a PT bolt to the inputs (have to search it again)

I guess I also wanted to know if its smart to use isolation washers on the inputs and where to get them, I don't see them over on the Hoffman

page, I was under the impression that shorting jacks accomplished the same thing as isolation washers. I will prolly just follow the triode layout

which I guess is star grounding (input grounds to local chassis and filter cap grounds to PT bolt) , the PT 40-18016 has no center tap so I need to go

virtual and elevate using the cathode of V4 I think.Just trying to hash out the different scenarios, it's been a while.......Thanks

[loudthud]

I guess I also wanted to know if its smart to use isolation washers on the inputs and where to get them, I don't see them over on the Hoffman page,

They are on this page near the bottom:

Tube amp Screws - Nuts - Washers

Depending on front panel thickness, they can be too thick for the threads on the jack. Sometimes you have to sand them down on a belt sander.

[crunchman]

Thanks LT, I was looking under the jacks section ! At .16/ea. I better find some other stuff Doug has that I need, shielded cable !!

I found a really neat build pictorial in flixr that demonstrates a wooden build jig that I may incorporate with mine, seems it would make soldering

alot easier, really nice work too.See it hear, thanks again !

5E3 Tweed Deluxe Build by Joeyvelour - a set on Flickr

[Bruce / Mission Amps]

5E3 Tweed Deluxe Build by Joeyvelour - a set on Flickr

HA ha ha... talk about MASSIVE over kill!!

[hasserl]

The use of shorting jacks is not really related to the brass plate. You should use shorting jacks as indicated on the schematic with or without the brass plate.

My opinion is that the brass plate was used by Fender as a convenient grounding “buss” that was relatively easy to solder to. However, the brass plate really isn’t a buss because it touches the chassis in multiple places. The fact that the brass has lower resistance than the chrome plated steel chassis is really insignificant in the application. If you are doing your own build you will be better off by improving the grounding scheme used as has been discussed in many threads and in the published books. That will result in less hum than you will get by duplicating the original Fender layout and/or using the brass plate.

Cheers,
Tom

In my experience this isn't true; my suggestion is to just use the brass plate and be done with it, if your amp isn't quiet it's not because of the brass plate, it's due to something else you did (or didn't do).

[JoeM]

I used the brass plate in my 5F6A clone and the amp is dead quiet.

[crunchman]

HA ha ha... talk about MASSIVE over kill!!

LOL, I like the build fixture idea ! I'm gonna use that part of it.I googled a bunch of 5e3 pics for follow for lead dress !

[divineamps]

5e3 build

Indeed, if you don;t plan to solder anything to the chassis, then the brass strip has no purpose.

I am building a kit from the triode electronics schematic. My question is I decided to use brass grounding plate. I have the grounds run
under the board as shown. Also ran grounds from the ground side that goe to pins 3 and 8. Will this cause an issue, seems I am double
grounding? Should I just scrap the brass plate and stick to the schematic? thanks
karl

[loudthud]

Grounding is frequently the problem when a new build by a novice builder has objectional hum. It's a lot of work to have to remove the eyelet board because improper ground wires need to be removed from the back of the board. Opinions vary on how grounds should be connected. It's a good idea to leave your options open so if changes need to be made after you get the amp working, you don't have to rip the whole amp apart to make changes. Check my profile to find links to threads on fixing hum problems.

[divineamps]

Thanks for your help. I decided to go with the original layout, I know it is not the best way, but being my first build just wanted to have something to
follow. I did run into something perplexing however.
The layout from triode electronics 120v w40 -18021 power transformer. It shows blue and brown wires coming from o/t, footnote says they are not used.
Since the transformer does not have those colors thats good. question is what powers the plates? Im thinking pin 3 is the anode? correct?
Do I just leave as is?
Thanks

[Tom Phillips]

Thanks for your help. I decided to go with the original layout, I know it is not the best way, but being my first build just wanted to have something to follow…

That’s a good plan. Although I said in my post #3 above that that grounding could be improved there is some risk in deviating from the Fender layouts unless you already have the experience to successfully complete an alternate grounding scheme. After following several other discussions where builders ran into trouble I’m pointing out that things can get worse if the builder uses a combination of different grounding schemes. One common upgrade for the 5E3 that I believe all kit suppliers follow is to use a two wire balanced heater circuit.

I did run into something perplexing however.
The layout from triode electronics 120v w40 -18021 power transformer. It shows blue and brown wires coming from o/t, footnote says they are not used. Since the transformer does not have those colors thats good. question is what powers the plates? Im thinking pin 3 is the anode? correct?
Do I just leave as is?
Thanks

Sorry. That’s very confusing and I can’t determine exactly what you are asking. Can you re-state the question? And when you say “Do I just leave as is?” What exactly is “as is?”

Regards,
Tom