Double Flush Tremolo

[Sleazexx]

Hi guys,

I've build the double flush following this doc

http://www.madbeanpedals.com/projects/DoubleFlush/docs/DoubleFlush.pdf

However, pedal doesn't nothing, volume pot works, I can raise and lower the level but the other 3 seem to not work, the vactrol I've used is that of the image



They've sold as VTL5C1, but I think that it is not, could this be the problem? LED does not work, check the connections, there's no bridge or bad connections, the values are correct and already build 3 different PCBs and the same problem happen.

Any suggestions? do the same thing happened to someone?   

[madbean]

Which LED is not working...the one after R13? If so, the LFO seems to be the issue and your vactrols might be fine. You should take some voltage measurements on IC2 and IC3 to see if they are operating correctly.

[Sleazexx]

Which LED is not working...the one after R13? If so, the LFO seems to be the issue and your vactrols might be fine. You should take some voltage measurements on IC2 and IC3 to see if they are operating correctly.

Yeah, that led after R13 .... I've taken some ICs measurements and these are:


Supply : 9.28 V

LF351 (IC2)

Pin 1 - 3,2v
Pin 2 - 2,2v
Pin 3 - 2,38v ~ 2,47v
Pin 4 - 0v
Pin 5 - 0,05v
Pin 6 - 1,64v
Pin 7 - 8,4v
Pin 8 - 7,39v

TL062 (IC3)

Pin 1 - 2,9v ~ 3,2v
Pin 2 - 0,65v
Pin 3 - 2,4v
Pin 4 - 0v
Pin 5 - 2,4v
Pin 6 - 2,4v
Pin 7 - 2,4v
Pin 8 - 8,4v

In pin 3 of IC2 and pin 1 of IC3 the voltage varies between those two values

[madbean]

Are you sure the LED is conencting to ground? Also, the voltage on pin3 of IC3 is looking fairly low. With a measured supply of 8.4v it should be more like 4v, not 2.4v. So, have a look again at R22, 23 and make sure they are right. If so, pull IC3 from its socket an remeasure pin3 without the IC to see what you get.

[Sleazexx]

Are you sure the LED is conencting to ground? Also, the voltage on pin3 of IC3 is looking fairly low. With a measured supply of 8.4v it should be more like 4v, not 2.4v. So, have a look again at R22, 23 and make sure they are right. If so, pull IC3 from its socket an remeasure pin3 without the IC to see what you get.

Yes, is connected to the ground, but I've measure the voltage between R13 - Led+ and the voltage is 1,9v

I've measure pin3 in the socket of IC3 is 2,6v , the same voltage in R22 - R23 (I've measure again)

[Sleazexx]

Are you sure the LED is conencting to ground? Also, the voltage on pin3 of IC3 is looking fairly low. With a measured supply of 8.4v it should be more like 4v, not 2.4v. So, have a look again at R22, 23 and make sure they are right. If so, pull IC3 from its socket an remeasure pin3 without the IC to see what you get.

Yes, is connected to the ground, but I've measure the voltage between R13 - Led+ and the voltage is 1,9v
I've measure pin3 in the socket of IC3 is 2,6v , the same voltage in R22 - R23 (I've measure again)

[Sleazexx]

Are you sure the LED is conencting to ground? Also, the voltage on pin3 of IC3 is looking fairly low. With a measured supply of 8.4v it should be more like 4v, not 2.4v. So, have a look again at R22, 23 and make sure they are right. If so, pull IC3 from its socket an remeasure pin3 without the IC to see what you get.

I've building other pcb and now the effect doesn't tremolo effect but if the volume pot is high in my amp, I can hear the sound from the oscilator, but the tremolo effect doesn't appear, could be the vactrol ? I've reflow again and I've checked bridges and both is ok.

[AntKnee]

I ran into a similar problem on a different tremolo, and I found I had a 100k resistor in place of a 100 ohm resistor. This is an easy mistake to make, even when you have already checked them you might not notice. I didn't find it until my third check on the resistor values.