Boss tremolo TR 2 rate led mod

[oddman]

Hello there,

I am doing some mods on my Tr-2 and building it in an other enclosure.
What I already did is: added a volume pot, made it true bypass and added a switch that sets depth to max.
What I also would like to do is to include a blinking LED in the LFO circuit.
But I'm kinda stuck with this one ..
Here is the schematic, can someone help me?
http://www.schematicheaven.com/effects/boss_tr2_tremolo.pdf
I thought it was somewhere on R29 ..

Thanks for the help

[jimmychung82]

hi, ive modded my tr2, but not like that!   do you think you could share how you made it true bypass? 
also, what size enclosure did you use?
what value pot did you use for the volume?

maybe i can muster the guts to try your ideas..

[oddman]

Hi,
To make it true bypass I just removed Q7, it's part of the fliplfop schematic, by removing it the pedal will always be in the on state.
If you then wire it up with a 3dpt or dpdt (without led) it's true bypass.
The enclosure I used was a 1590BB Hammond enclosure.
I have replaced R9 with a 10K pot. (the lower the resistance, the higher the volume)

To be honest, I also removed C4; it gives it a little bit more sprankle (high ends)

Witch mods did you do?

[slacker]

You can probably add a blinking LED by taking the signal from either pin 1 of IC3A or pin 7 of IC3B. Pin 7 of IC3B might be easier as you could attach a wire to pin 3 of the depth pot rather than trying to solder to the board. Feed the signal to a high impedance buffer to stop it loading down the rest of the LFO and hook your LED and current limiting resistor up to the output of the buffer.

[oddman]

Thanks for your help.
So can it be something like this? Or will this invert te blinking?

[slacker]

You need to remove the ground connection from the output of the opamp. Just attach the resistor to V+ then to the LED with the cathode of the LED going to the output of the opamp. Like that the LED will be out of phase with the signal from pin 7.
If you want it in phase then attach the resistor to the output of the opamp then to the LED with the cathode of the LED to ground.

[modmod]

hi guys,i tried that with a TL071 but it doesn't work,do i need to connect the vcc+(pin7) and vcc-(pin4) of the TL071 as well ? thanks in advanced

[modmod]

finally i make it work ,but it's out of phase blinking,tried slacker's method for in phase but it doesn't work, any hints guys ? thanks a lot

[ppatchmods]

take the negative to ground and the positive to j3 and it will give the rate even in bypass