Hey,
It is perfectly OK to ground the speaker ground to the chassis star ground bolt.
If you look at Doug Hoffmans layout and follow this method it works perfectly. I have built 3 Tweed Deluxe amps and all came out perfect. I did add another 1 meg pot to my Tweeds so I can adjust both sides of the V1, hi/lo and mix them with a pair of 220K resistors. In other words the 3 pot Tweed Deluxe volume tone works out kind of strange to me. Sounds good but limited. 2 volume and 2 tone pots works very well for these amps.
Most of the time hum is caused by the heater wires and the V1 tube picking up the 60hz AC hum and amplifying the signal. You could have the wires twisted out of phase from V1 to V2. Unplug it and check with a meter and make sure all of the heater wires are in phase. Pin 9 V1 must also be pin 9 V2 etc. Pin 4-5 must be pin 4-5 both V1 and V2. If one gets out of phase it can induce hum.
Center tap on the heater wire coming from the tranny must be on star ground. Very tightly also and get good contact to the chassis for all grounds. Also the heater wires have to be twisted carefully and very tightly so the hum is cancelled out. Its all in a careful wiring layout and make sure you have space between all the wires coming from the board to the tubes or anywhere in the wiring scheme. I use a stiff wire so it is bent to stay in place away from other wires etc.
I do not really like the soldering wires to the pots method. I make up a solid wire ground buss and solder grounds to the buss wire and suspend it rigidly and attach the grounds starting at the inputs and work right to left in a flow. Even though I used the 12A Switchcraft jacks which do ground to the chassis at the input this is totally quiet and the ground loop has no effect as far as noise.
I have also built up 5 Marshall 2204 builds successfully which are much more finicky that the Tweed Deluxe builds. These are very hum sensitive.
I also have found after building near 20 amps that Mallory Caps have better tone than the Orange Drops. I have used Mallory, Sprague, Sozo, and about to try out the Mojo Dijons.
Anyway you need to solve the hum problem and I have been there and try out checking the heater wires and their twist and location and distance from other wires and phasing and see if that solves you hum issue. You could also have a bad preamp tube, haha.This happens a lot.
Good luck
Thanks DCbluez. Thanks for the great advice, Actually the 5E3 has hardly any hum now that I rewired the grounds and separated the signal and power grounds. I don't know why the original layout on Triode showed a buss connecting the signal cap to the power cap. So i but that one and installed two grounding points.
I think it is the guitar picking up signal now because when it is unplugged there is no hum and even with the volume turned all the way up. Before this separation I think I remember trying it without the guitar plugged in and there was really a lot of hum.
Ah! Yes! I was worried about that before about the heater wires not being from pins 9-9, 4-4 to 4-5 etc. I didn't know but now I do. Thanks for the info on that! I wasn't sure so I ended up rewiring it so that 9 went to 9 etc. I should have used different wires haha.
You also mentioned that you can check with a multimeter if it is out of phase? How do you check that if I may ask. Sorry, I am still new at all this.
As for mods, I looked some up but I found it might be hard for me to do these mods at least for me. The spaces are too tight on the 5E3 and I would end up breaking wires etc. hahah because of my clumsy hands. But maybe I will do those later. or need some kind of prototype amp to test it out first before I make some wiring and soldering done.
Topic: 5E3 build log! Criticism and suggestions welcome!! (Read 11806 times)