Options for adding circuit nodes after the fact?

[mirage_indigo]

Ive fabbed up and installed my main power supply eyelet board but I find myself needing to add a couple nodes for a rework. Anybody have a good solution for adding wiring points to an eyelet board or chassis once it's already installed. Right now the best solution I can think of is one of those point to point solder lug strips along the back wall?

Any ideas?

[xtian]

Photos mean everything. Can't envision a solution without seeing the problem.

[TUBEDUDE]

I'm sure space is an issue, but the closer to the associated circuit the better, since your off the card anyway. Pics always critical for best advice!

[T Wilcox]

terminal strips work or you can cut a piece of FR10/Garolite to a small board with just the amount of eyelets you need. Either way you need to add another board bc even if you could fit more eyelets on your existing board you'd need access to the bottom side to crimp the eyelet. Been here a few times. usually a terminal strip does the trick

[Travis_HY]

Photos mean everything. Can't envision a solution without seeing the problem.

This is spot on. Pictures could give some sense as to what you are working with and what you need to accomplish. Without them, it can be hard to see what the goal might look like.

That being said, there a few ways I go about adding power supply nodes in amps. The most simple would be something like an additional gain stage (or a two gain stage channel for that matter) that is added at a later time. A prime example would be adding an additional filtering stage for the Normal channel on a Fender black panel amp. Granted, this is not an added set of gain stages, but rather it is a channel that most folks likely don't use.

First I will remove the B+ jumper that is connected to the Normal channel's plate resistors from the Vibrato channel plate resistors. Then at the apex of the plate resistors for the Normal channel I will solder the positive end of whatever filter cap I intend to use (generally 10uf or 22uf) and ground the negative end on one of the cathode resistor grounds. I will then solder an additional dropping resistor (anywhere from 1k-47k depending on the circuit) at this apex point where the filter cap was just soldered with the unconnected resistor end sticking straight up. Then I'll connect the previously disconnected B+ jumper to that upright resistor.

And there ya have it: additional B+ node. If you can use this method while building (and if you have the chassis space) you can really clean up the layout, particularly if you want to try some more complex circuits in the power amp section.

Hope that helps!

[SoulFetish]

When space is an issue, one option is installing insulated terminals using available chassis space. Often you can get away with adding a couple of these types of terminals and using existing terminal contacts to accomplish what you need to. I've found it to be pretty efficient, and keeps a nice clean layout, depending on how much additional circuitry you need to install.
These are a couple of photo examples that I could find quick, but I've installed these after a "complete" build as well. The green terminals are 2-56 thread and fit nicely into the this gauge aluminum chassis. But ones with a threaded inset work nicely too.
One nice thing about standoffs with the threaded stud is that if you have a bottoming tap, you can fit them in locations where you can't get to the other side of the chassis (ie. transformers or other hardware)

isolated standoffs.jpg

isolated standoffs2.jpg