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I'm just about done my Plexi build; just at the horrible confusion stage of figuring out the cliff jack wiring and the coax stripping. The instructions from Trinity are leaving me confused....

Any advice or clarifications?

That post above is for a combo but would work for a head if you flipped the one set of jacks around.

What problems are you having?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

More in understanding what exactly is happening with these jacks. If I understood that a bit better, I'd probably be less confused with the wiring. As it is, I'm using the link above, rolled the TMB jacks to match, and just adjusting for the Hi and Lo inputs.

So, what I'm trying to figure out...

What is the wire jumper crossing the hi and low jacks is for? Is it just to blend signals between what's gone through the 1M resistor and what hasn't? i.e. On the normal channel, if you're plugged into Hi, you'll put the signal through the resistor and then split it through both the hi and lo jacks and send to the V1? And if you're plugged into low, both sides ov V1 will get the signal without having passed through the 1M resistor?

The shields on the coax are tied to ground at the jack. Why?

And... why are there 4 lugs on a jack? From the way that they are wired, it would seem that they are not connected in pairs or anything like that...

I see what you need. Let me whip up something to peruse. We don't go into this in the manual, we just show you how to make it work. Actually, the layout is good enough to make it work.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

True enough; a monkey with a good attention span can build off of the drawings.... the problem is is that I actually am trying to understand what's going on and how things are actually working....

http://www.google.ca/url?sa=t&rct=j&q=& ... Wc&cad=rja

The jack is a mono jack so it's got a tip (hot) and a sleeve (ground generally). The other two contacts on the jack are also the tip and sleeve. The two tips and two sleeve connections are tied together, when you insert a cable into the jack it breaks the connection between the two contacts. Switching jack...

Read the PDF above, it may help.

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That PDF is sort of helping. Thanks.

Your sentence re: the jacks.... let's see if I've got this... The jack has 4 lugs, split into two banks. Each bank has a hot and a ground. Lets call the banks left and right to match up with the drawing in the link earlier in the thread... If nothing is plugged into a jack, then the hots are jumpered together and the grounds are jumpered together. If you plug something into the jack, it breaks the jumpers allowing the left and right bank to operate independently. I'm wrestling with this concept..hope its correct, because there is a lot text coming that is based on this....



So... on the NORMAL channel...

You plug into the LO input... the right bank on the LO input becomes active. The ground is jumpered over to the HI ground, right bank, which is tied to the ground shield of the coax and tied to the ground lug on the chassis (in fact, if my hypothesis on how the banks are jumpered is correct, all of the HI input goes to ground). The signal (hot) goes to V1 where the full signal goes thru a 68k resistor. The signal goes to the tube socket and part leaks flows thru the tube socket and to the other 68k resistor which runs back up to the high input which dumps it to ground.

If you plug into the HI input.. the right bank on the HI input is active, and the LO input banks are jumpered.

The ground is jumpered over to the left bank where its spliced with the grounding shield of the coax and they're jumpered to the ground lug on the chassis. The hot is jumpered over to the LO left hot bank, which, being jumpered to the right bank, sends signal down the LO coax. The signal is already on the HI coax. The signal on each passes thru 68k reisistors and join up again on the tube socket.

I'm not going to wrestle with the TMB side of this until someone can confirm that I've got my head correct on the Normal channel

That's a very good article that explains the details.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Correct

The two hot or two ground connections are either connected or unconnected based on whether or not a cable is inserted.

The co-ax (shielded) cable is only grounded at one end to get rid of hum. Grounding it at both ends could introduce hum.

The TMB and Normal channel have their jacks wired the same way. So once you understand one you understand the other as well as any other dual input amp (Fender, Marshall, Hiwatt, Vox, etc.).

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