SergeModular

I am noticing that there seems to be a voltage bleed when I touch the second
touch resistor on my TKB. The first resistors LED lights up and the pot for the
first stage slightly affects the voltage output of the second stage. Is there an
internal trimpot that adjusts the sensitivity of the touchpads? Might I need to
send the TKB in for service. It functions normally as long as the second
touchpad is not pressed. Thanks in advance!

Ben

--- sydilaxe <sydilaxe@...> wrote: > I am
noticing that there seems to be a voltage bleed

You shouldn't need to send your TKB in for service. There are two
trimpots on the back of the board and they usually have to be
adjusted because we all have different body chemistry and the
surrounding atmospheres of your studio and our shop are different. I
adjusted these to my fingers in Hartland. blah, blah, blah...

OK Here's how to trim the TKB. The best tool to use is an actual
trimming tool used to adjust trimpots, but a small jeweler's
screwdriver will do the trick in a pinch.

I don't have a board here with me so I'll describe the procedure as
best as i can. There are 2 trimpots on the PCB. There is one on the
pads side of the board (???) labelled press, or pressure or something
like that. It's best to leave this alone.

The trimpot nearest the jacks, i think, is markes sens, or
sensitivity, or something. This is the one to tweak. Do not force
the trimpot when you adjust it, you could break it. It moves pretty
easily. You have to have the TKP powered up and adjust the trimpot
so that the desired response is achieved. A bad adjustment will make
just about all the LEDS light up, so it's easy to tell when the TKB
is properly adjusted.

I hope these directions are clear, but i doubt they are. If you
want, you can email me at nick@... privately, and i
will call you on monday when i have a TKB in my hands. Then i can
talk you through it.

The first stage affecting the voltage of the second stage is just one
of the quirks of the TKB. It's analog, and it's not perfect, but it
gets the job done.

If i'm totally wrong, then Tim will have to slap me in the face, but
i've built several TKBs so far, so i hope i remember what i'm doing,
so i don't look like a total moron. :-)

hope this helps,
Nick Liebrecht

Hi Ben -

Yes, what you're dealing with is an adjustment issue. We adjust the sensitivity at the shop before a TKB ships but a number of factors influence it that we can't adjust for - everything from climate/environment to the pH balance of the user's skin.

If you open up the TKB (assuming it's a current generation TKB it's the three top screws and the two bottom black hex screws) and get access to the PCB, there's are two trimmers, one of which is marked (you guessed it...) "Sensitivity". You want to adjust this slightly.

At the far extreme all of the pads light up. At you back it off you'll get the condition that you're experiencing now - interaction between pads 1 and 2. Back it off just slightly to where this no longer happens. You might want to try it out again after putting the chassis back together but before screwing everything back down - the temperature difference can have a slight effect.

If you need any more help with this, feel free to email me,

Tim

sydilaxe wrote: