bordonbert Posted June 14, 2016 Share Posted June 14, 2016 I'm new to the Line6 Variax, I've just bought a JTV59. I know that the footswitch which you have to buy separately acts as a combined A/B unit and passes on power to the guitar from the external supply. But what does it send where? Am I right in thinking that it is the simple logical system you would expect? +9V direct to the Ring and Sleeve when connected, with the signal on the Tip and Sleeve, signal fed to the switch which then sends it on to either the 1/4" jack or XLR connection as outputs? If so, surely it should be a piece of cake to actually make one of these from a converted standard footswitch and the correct 9V/200mA supply. Can anyone point out where that is wrong? Has anyone done this? Quote Link to comment Share on other sites More sharing options...
snhirsch Posted June 14, 2016 Share Posted June 14, 2016 Almost, except I believe it's +7V on the ring. Quote Link to comment Share on other sites More sharing options...
bordonbert Posted June 15, 2016 Author Share Posted June 15, 2016 Well if that's the case it's about £10 to get a cheap any name FS-1, a +9V 2A+ supply, and put a standard LM317 type regulator unit in the footswitch to give the stabilised +7V and Bob's your Mummy's bro'! Surely? ;) Quote Link to comment Share on other sites More sharing options...
snhirsch Posted June 15, 2016 Share Posted June 15, 2016 I think that would do the trick neatly. Quote Link to comment Share on other sites More sharing options...
bordonbert Posted June 16, 2016 Author Share Posted June 16, 2016 Errrmm! For anyone interested here is an update. You know what I said about a cheap LM317 regulator? Now where is that 'embarassed' emoticon......... Have a look at the attached pic. It shows both sides of the internals of that footswitch. I have to take my hat off to Line6, that's something comprehensive for what it does. It certainly isn't a simple regulator and switch is it? And the build quality is first class. Glad I had a look as it seems I have demonstrated to myself that it was money well spent. Quote Link to comment Share on other sites More sharing options...
snhirsch Posted June 16, 2016 Share Posted June 16, 2016 I suspect the smaller devices are to facilitate pop-free audio switching. The power supply does appear to be a simple TO220 package regulator with some bypass caps. Quote Link to comment Share on other sites More sharing options...
Charlie_Watt Posted June 16, 2016 Share Posted June 16, 2016 There is a rectifier there too because Line6 used an AC supply for these. I have a couple of these - never use them though. Quote Link to comment Share on other sites More sharing options...
bordonbert Posted June 16, 2016 Author Share Posted June 16, 2016 I don't think that can be all that is going on there GH, there are about 8 or 10 transistors and 5 or 6 surface mount chips in there too. It doesn't take active devices like that to make switching pop free. You're right with the regulator chip, though the code number had been wiped as is common on this type of device. There will be a balanced line driver for the XLR out which will either take a dedicated chip or a few opamps, and maybe an unbalanced driver for the jack out. Heaven knows what the rest is for, sensing of whether the guitar is attached, sensing of the TRS plug inserted into a two pin socket so the power on the ring is shorting? And Charlie has to be right too, the power supply is AC so rectify it. I would have chased it out but as it was surface mount it would have taken an age and maybe not even given any hint as to what some parts were doing. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted June 16, 2016 Share Posted June 16, 2016 The XLR is for going into mixing consoles and recording gear the use balanced inputs. A/B is for switching between the XLR and 1/4". Recommend not engaging phantom power on the mixer when using the XLR output on the XPS. Otherwise, use the 1/4" signal line. Quote Link to comment Share on other sites More sharing options...
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