Schem wiring question

[FunkyE9th]

I think what you need to do is redraw the schematic so that the cap is to the right of pin 8 of the rectifier.

[C Moore]

Well I hope you guys can sleep comfortably tonight; after the way you beat me up over this chassis and made me cry.....
Regarding Phil's point about that Long Orange Wire for the PI cathode cap/resistor....What if I use a radial cap (with resistor) and go right from the Cat Pin on the tube, to one of those ground tabs on the tube socket.?
Thanks

[Firestorm]

You don't want grounds in random places. Preamp grounds go near inputs (preamp filter cap grounds, too). Power amp grounds go as far away from the inputs as you can. Safety ground usually goes over on the power side, too. If some leads have to be long, make them the plate leads. If a grid wire has to be long, shield it. Cathode leads have signal on them too, so watch where they're routed. Pay attention to which leads are in phase with each other and which are out of phase. In-phase leads from different stages can couple if they are too close.

[C Moore]

I moved that 100/50 cap. It is on Pin 6 of the PI (the middle of the 3 pre sockets), and then to ground on the term strip. It is grounded on the far left term strip, just to the left of that Sozo cap.

[Firestorm]

When you get far enough along, shoot some more pix and we can criticize you some more.

[Phil_S]

When you get far enough along, shoot some more pix and we can criticize you some more.

I think you must mean, "so we can help you some more."

[C Moore]

I never did show you guys the trem circuit I have on the other side of the chassis. At first I thought I could squeeze it onto the 2 un-used tube sockets, but there was not near enough room.
I put the front panel and metal case on so you guys have a better idea where things go. I have to make a new back panel, and I am in the process of doing that now.
I am still working in the output section. Do you think I will be OK if I glue the 10 watt cat resistor to the chassis where it is, and then run that blue by-pass cap from the tube socket to ground.?
I thought about attaching the cap to the 10 watt resistor, but I was un-sure about heat issues....
Would it be better for the forum's server if I delete my original 2 pictures.?
Thanks

[Phil_S]

Do you think I will be OK if I glue the 10 watt cat resistor to the chassis where it is, and then run that blue by-pass cap from the tube socket to ground? I thought about attaching the cap to the 10 watt resistor, but I was un-sure about heat issues

Conventional glue and hot glue are both no-no's inside an amp. That cathode resistor will get hot. Whether it gets hot enough to burn the glue, I don't know, but it will surely soften it enough to make a gooey mess of it and it won't be doing its intended job while its temperature is elevated. If you must use something like that, use automotive grade silicone.

I'd recommend against any sort of fixative for the cathode resistor. Actually there is no reason why it can't rest on the metal chassis, and there will be a modest heat sinking effect.

As for the bypass cap, if it fits across the sandblock resistor, I'd put it there. It need not go over top. I think I'd put it along side. Make sure it isn't touching. I might cut a small bit of cardboard to use as a temporary spacer until it was all assembled and soldered, to assure that you'll have a gap.

The green wire near the cathode resistor is a potential problem. Make sure there is no contact between the wire insulation and the resistor. That green wire is the filament CT. As I said earlier, it should go to the same ground point as the other CT and the cathode R ground. Move that wire now and you will fix two problems at once.

Grounds all over the place don't generally work right. Creating the ground scheme is a systematic thing and there are "rules".

[C Moore]

Hey Phil -
I was not sure is It was a good idea to have the heater CT and the HV CT grounded to the same terminal. I guess they are both on the secondary side of the PT, so that should be fine....not sure why I thought it was a problem. The heater ct does not carry any current, is that correct.?
Thanks

[Firestorm]

I thought about attaching the cap to the 10 watt resistor, but I was un-sure about heat issues....

The "rule" about output tube cathode bypass caps is they should be away from cathode resistors because of the heat issues. Some amp builders did it that way, most did not. Supposedly, the heat derates the voltage rating on the cap, so if you have to put it somewhere near the resistor, use a higher voltage rating.

[C Moore]

There is not enough lead length on the cap to run it parallel to the resistor. Would it be a sin to run it from the tube socket to ground like it is.?
Thank You

[Firestorm]

It wouldn't bother me. You've got the grounds in the same place. What is the voltage rating on that cap? It looks small.

[C Moore]

It wouldn't bother me. You've got the grounds in the same place. What is the voltage rating on that cap? It looks small.

The schem shows a 25/25 cap. I am using a 22/25. I do not think I have any experience with a 2 x 6V6, cat biased amp. So I have no idea what the voltage will be there. Well that is not true, I have a Fender 5E3, but I cannot remember what kind of cat voltage I have measured. Are you thinking I should get a 50V cap.? Although, relative to what I have done on this chassis, changing out that cap if needed would be about the easiest job in the whole amp.
Thanks

[Firestorm]

Oh yeah. 6V6. 25V is probably fine, but it depends on so many things. Even amps with cathode-biased 6L6s tended to use 25V caps. I usually use 50Vs, but if you don't have any on hand it's probably just fine.

[C Moore]

I have gotten a bit further with this. This chassis had two lights powered off the heaters. I do not have to use them, but at the moment I have one wired to V1 and the other light wired right to the heater supply of the PT. If you think something looks bad, go ahead and tell me now....
Thank You