Frankenstein Vintage Hi-Fi into 5E3 build...IT LIVES!

[Lonely Raven]

Sounds really good, what a great project!

[Structo]

Sounds good and should work great for your country licks!

I was going to say that with 6V6's the OT primary is usually between 6K-8K on a 8 ohm load.

Sounds like you got it working good, congrats!

[bastardbus]

I am looking at the dates of your posts......
How fast did you build this.?
That amp is AWESOME looking. Sounds great with your Tele. I am sure it sounds even better/warmer in person.
Well Done......!

Once I had the parts on hand maybe a couple evenings. I am into old `50s RCA tube hi-fis and have done quite a bit of recapping and rebuilding of old tube units so the amp itself was pretty easy and really fun for me. I probably spent most time finding parts, testing the transformers and figuring out if they would be compatible with this design. The hardest part was coming up with the best way to lay out the circuit as you can tell this is nothing like Fender did it so it was from scratch so to speak.

That video was recorded with a tiny digital camera....not even a proper video camera so you can guess how much better the amp just sounds in real life. It is one of those amps that you just want to sit and doodle with finding all the different nuances it has and next thing you know 2 hours have gone by!

Thanks for the kind words btw.

[bastardbus]

I have been playing this amp and it sounds great. I do notice a bit more hum then I would like as well when I dime the amp to 12 it wants to oscillate a bit.

I did some reading about ground loops and how this will cause these issues. I planned on doing a star or buss type grounding schematic separating the different sections of the amp. I have read about the brass plate under the pots and input jacks and how it is essentially a star ground set up.

I was wondering how this brass plate is mounted in the original 5E3 Fender amps. Is it isolated from the amp chassis or does it just sit on top of the chassis? Does the brass have a lower resistance and why current takes the path of the brass and not the chassis? Since the amp I built is not the common Fender design I need to find out how that brass plate originally functions to use it or something similar in my amp.

If anyone has any info or even pics of the brass plate and mounting that would be great to see.

T

[Structo]

Depending on the amp, I like to ground my sections in roughly two areas.

The power filter caps near the power transformer on it's own screw with lugs.
Make sure the paint or anything is bare under this.
I usually use a start washer against the chassis here to make a good contact.

So just about every thing from the AC inlet to the power tubes gets grounded here.
Like the power tube filter caps, power tube cathodes and anything else in the power section.

The preamp cathode grounds, preamp filter cap grounds and pots all ground near the input jack.
That is the quietest place for sensitive grounds.

So I take a piece of bare buss wire and bend it to a L shape.
The short side goes down to a ground lug by the input.
The the long side goes above the pots, I use small pieces of wire to connect the pot lugs that need to be grounded up to this buss wire.

Be sure to have the earth ground wire from the power cord goes to it's own dedicated ground lug near the power cord inlet.
Do not ground anything else to this lug, it is a safety thing.
Some say to make the ground wire longer than the hot or neutral in case the power cord gets yanked on, the the last wire to be connected is the ground wire which keeps the hot supply off of the chassis.