Hey RG, the FCB group guy is right, a TRS <> TRS should work but "only" if plugged into Sw1 (Sw2 isn't wired the same). The ring of Sw1 is connected to the tip of Sw2 "if" nothing is plugged into Sw2 "and" a TRS plug is in Sw1. But you still have to assign a FCB button to each Sw (relay) as each button can only toggle on/off. This is the same as using a TRS > TS/RS (insert) cable and plugging each mono plug into either Sw1 or Sw2.
A "Y" cable and an"insert lead" are not the same thing (sorry if you know this already). A Y cable joins 3 mono jacks together so you can split one signal into 2 (or vis versa):
T
1____T
2 |
-----T
3 S
1____S
2 |
-----S
3
An insert lead connects the tip of a stereo plug to the tip of a mono plug and the ring to the tip of another mono plug
T
1______T
2 R
1______T
3 S
1______S
2 |
------S
3 If you look at the FCB diagram (doc) you attached, the Ring of Sw1 either connects no where (mono plug) or connects to Sw2 Tip (stereo plug). However, if you have a plug in Sw2 it breaks the connection between Sw1 ring and Sw2 Tip.
So a TRS <> TRS cable plugged into Sw1 (and nothing in Sw2) AND 2 buttons assigned, one to Sw1 (relay1) and one to Sw2 (relay2) you can use just the one stereo cable and the 2 buttons should work the same way the Peavey FS works.
If you use an insert lead TRS <> TS/RS and plug each mono plug into either Sw1 and Sw2, the mono plug connected to the TRS Tip will toggle clean on/off and the mono plug connected to the TRS Ring will toggle Ultra/Crunch. However, if Clean is toggled On, Ultra/Crunch is bypassed so that the Ultra/Crunch Sw will do nothing until Clean is turned Off.
Now you could get cleaver/complicated (warning this may do your head in LoL) and assign 3 FCB buttons to the FCB Sws' (relays) so each button will select a specific voice rather than toggle. So say you use Btn3 = Clean, Btn4 = Crunch and Btn5 = Ultra. To make this work you need to have each Btn do a couple of things when selected (turned on) including turning On/Off the other Btns:
Btn3 On = Sw1 On (will select clean regardless of Sw2 setting)
Btn4 On = Sw1 Off and Sw2 Off (will select Crunch)
Btn5 On = Sw1 Off and Sw2 On (will select Ultra)
So to do this (I'm assuming this is possible with you UNO SW):
Btn3 On - assign to Sw1 normal On/Off When selected, Btn4 & 5's On/Off state shouldn't matter, it will select Clean. However, if you turn Btn3 Off, then Btn4 & 5 state does matter as what they (i.e. Sw2) are currently set to will be selected by turning Btn3 Off. So if you make Btn3 On also turn Btn4 Off and Btn 5 ON, turning Off Btn3 should revert to Ultra (because Btn4 Off = Sw2 On (using reverse ON/Off for Btn4)). If you prefer to revert to Crunch then make Btn3 On turn Btn4 On and Btn5 Off.
Btn4 On - assign to Sw2 Off (use the reverse Btn On/Off feature maybe to do this?) and ALSO turn Btn3 Off and you may need to/should also turn Btn5 Off
Btn5 On - assign to Sw2 On and Also turn Btn3 Off and Btn4 Off
Anyway after writing this I suspect this may possibly make your head spin.
But hope it helps and you get it to work.