3DPT switch on a TS-5

[moandj]

Warning: Newbie Post

I'm trying to mod my TS-5 for true bypass and relocate it to a more durable enclosure.  I'm using a 3PDT switch and I've rewired the LED.  I've been looking at the picturesue True bypass diagram in the beginner's forum.  The LED works, bypass works, and battery works so far.

I'm having two problems at this point:

1. My DC jack must be wired incorrectly because when I plug in the adaptor, no power at all and it cuts off any power from the battery.

2. FX in/out is not working.  When I switch the effect on, I get no sound.  When I switch it off, the signal bypasses with no problems.  I've done plenty of googling about this and I've found that it is the input and output buffers.  I know that I need to take the FETs out and put in jumpers.  But, which ones do I take out (there are several)?  I know the ones in the input and output buffer need to be taken out.  I've read that Keeley article about converting a TS-9 to TB and he mentions that the 510K resistors need to be taken out.  Which FETs and resistors do I need to take out?

I get the feeling that I need to bypass the input buffers to get to the real effects input.
Here's a link to R.G.'s tubescreamer analysis: http://www.geofex.com/Article_Folders/TStech/tsxtech.htm
Here's the Keeley article I was referencing above:  http://www.musicianshotline.com/archive/monthly/pedal_power/0704.htm
And here's the schematic:

[cd]

Referring to this schem (apologies to RG):



Remove the parts circled in RED.

Remove the part circled in GREEN and replace it with a jumper wire.  The jumper wire should run from the drain to the source of the old 2SK30A.  If you're looking at the 2SK30A with the flat side towards you, the pins go S G D.  So you need to jumper the outer two holes and leave the middle hole alone.

[cd]

DC jack should be wired like this:

http://www.smallbearelec.com/Detail.bok?no=93

[moandj]

Thanks for the speedy replies.  I'll work on it tonight (hopefully with much success).

I know this isn't ideal for a beginner project but I had already taken the plunge.  It looks like building these from scratch would be easier than to try and "renovate" an existing PCB.

[mrdorbe]

Is there any chance you can upload these photos again please?

[Mark Hammer]

Thanks for the speedy replies.  I'll work on it tonight (hopefully with much success).

I know this isn't ideal for a beginner project but I had already taken the plunge.  It looks like building these from scratch would be easier than to try and "renovate" an existing PCB.

What people tend to forget is that FET-switched pedals can't just have  an external switch added, and work.  They need to have the electronic switching circuitry nested in the pedal disabled.

This is the nature of cd's comments.  The 2SK30A (which probably just says K30A on it) is being used to block/enable the distortion signal to make it to the output.  In a stock TS-5, stepping on that foot treadle would turn the k30A on, turning it from a "blockage" to the distortion signal of many megohms, to a pathway of well under a few hundred ohms.  Adding the external switch does nothing to that FET, and leaves it in its "off" state...which is why you get no effect signal but get a nice bypass signal.

What CD suggested involves bridging the "in" and "out" pins of the FET (more precisely, the source/drain pins), so that it always behaves as if it has been turned on permanently...or more precisely, as if it wasn't even there to block or permit the distortion signal to pass.

Note that there will be two such FETs, and several other transistors on the board,  One of the K30As is used to enable the clean signal to come through, and the other is for the distortion.  When one is turned on, the other is turned off.  You need to bypass the one in the path of the distortion signal, and disable the one in the path of the clean signal.  This site may have some useful info or pics: http://www.planeteleven.net/tubescrmr/

[Gus]

If you are going to rehouse it you could use a bigger case mount switch like what is in the TS5
Wire the monetary switch to the pads of existing PCB mounted switch.

TS5s sound fine stock