Help replacing Kustom 1-L inputs - With Photos!

[Hobojangles]

Hello everyone,

This is my first post here in the forums, and I'm seeking counsel on an issue I'm having with my Kustom 1-L head.

I took it out of an old 1-L combo, the speaker was dead, but the head was not so I decided to test it on a spare 2x12 cabinet, and it had an amazing tone, so I've been using it with that ever since.

I've got some experience with electronics - I've done some soldering and made a few guitar cabs before, so I have some idea of what I'm doing. My issue is that the inputs I'm trying to use to replace the old ones are completely different to the ones already in the head. They have the same amount of pins, and they contact the tip and sleeve in the same way as the old ones, so I figure it should work - I just don't know which connections to solder where. Essentially what I need is a diagram that points out which pins on my new inputs are equivalent to those on the older input. I'm planning to reuse the capacitors already in the head.

Here's some pictures to give you guys a better idea.

[joecool85]

Best way to check what goes where is to plug in a guitar cord and use a DMM set to "diode" and check which pin makes it "beep" when touching the tip, sleeve etc.

[phatt]

Won't work,,Wrong type of socket.
The socket you are trying to replace is a special purpose switch setup.
Probably switches some FBack tricks when the second speaker jack is inserted.

If it works don't mess with it.
Phil.

[J M Fahey]

Best will be to get the same exact ones, for minimum fuss.
They will also fit in the original holes.
The plastic ones are somewhat thicker and will force you to enlarge them.
http://www.hoffmanamps.com/MyStore/perlshop.cgi?ACTION=enter&template&thispage=JacksPlugs&ORDER_ID=!ORDERID!
You need the
Switchcraft 12A jack
1/4 phone jack with ground switch. 7mm thread length
Used for amplifier input jacks.
Price each = $2.60
If your front panel is too thick, buy the one below it, the "L" version, with longer threads
If you want to use the plastic one anyway, remember this: jacks come in 1000 different ways, but *Plugs* are always the same, so under a good light you put a plug there (then pull it) and watch which contact does the plug tip touch, "follow" it to see which lug it's connected to, check which extra contact (switch) touches that tip connection when unplugged, and ceases touching when plugged, and so on.
Same what happens with the ground (plug body) connection.
Only when you are *sure* as to what leg on the plastic one matches which leg on the metallic one can you replace the jack and be certain that everything is as God (ok, Kustom ) intended.
Here "form" will be different, "function" must be the same.
If you want, draw a diagram of what the original connection is, for us to check.
It will be easier if you get the original jacks, of course.
Yours have an extra unused (so unnecessary) extra switch, activated by a small plastic (insulated) disk which is touched by the plug tip wnen inserted, you don´t need it, the Hoffman jack does not have it, but the rest looks about the same.
Beware it might be mounted in a different way (right is left and viceversa), what´s important is what does each plug part touch.

[phatt]

Whoops,,, yeah don't mind me I'm at the wrong end of the Amp. LOL
I assumed those where speaker outputs.

OK they are input sockets.

In which case it looks like the stock 68k/68/1 meg input found on nearly all Valve Amps from years past.
Maybe look up the fender schematics for clues as to how they wire up.

Meantime here is one of mine that might help get your head around it.

You do need switching sockets and as Mr Fahey made note the plastic jacks will need a bigger hole and I add you will also need a new ground wire.

The metal sockets (by design) ground the sleeve,, but plastic sockets need an extra wire to go back to circuit common/ground.
I've circled the parts that are important.

It may look tricky for the novice so google *fender wire up* or similar comment for clues.
As I'm sure I saw a neat pictorial of how to wire up these inputs a long time ago??
Hope it helps.
Phil.

[J M Fahey]

Hi hobojangles.
We all seem to having been mistaken by Mr Ross (Kustom´s designer) design choices.
I´ve been searching some of his old, yellowing paper (really !!) schematics, and he seems to have used the "useless" switch after all.
99.99% of other designers don´t, and don´t need them, but, well, I guess he wanted to be "special".
I´ll wire a couple plastic jacks since that seems to be all you have available (including the grounding ring phatt suggested) and post some picture or drawing, but I remind you you´ll have to enlarge those holes.
The sensible option is to buy a couple of those Hoffmann metallic jacks, and wire an *equivalent* input circuit.
Those original complex switches *are* still available, but they will probably ask too much for them.

Best option: buy a couple Hoffmans, post a couple close up pictures from different angles, and I´ll suggest how to wire them.

Good luck.

PS: are you sure those original jacks don´t work any more?
What are the symptoms?
"If it ain´t broke, don´t fix it"