Building the Echo Base PCB

[1878]

It's VERY distorted. I'll get the audio probe on it tonight & I'll post some voltages too. I'm starting to worry I've broken something

[Kill Switch]

I just finished this build and I'm happy with it for the most part. I also get noise at long delay settings. I added some resistance to limit it to about 500ms. where it still sounds ok. Another issue is the self oscillation makes a bee line for higher frequencies. Rather shrill sounding and won't maintain any lower frequency oscillation. Everything else works ands sounds right though. 

[Taylor]

I just finished this build and I'm happy with it for the most part. I also get noise at long delay settings.

True - this is the nature of the PT2399 chip. They only rate it up to 300ms. Everything past that is "lagniappe" in New Orleans parlance.

Another issue is the self oscillation makes a bee line for higher frequencies. Rather shrill sounding and won't maintain any lower frequency oscillation. Everything else works ands sounds right though. 

This is pretty much how it sounds, however I find that limiting the feedback to only the area right after oscillation makes for softer, more mid-rangey oscillation. As you go past there, the diodes clip more which makes the feedback more shrill. You could try the diode lift mod, or else just limit your feedback by changing the 20k coming off of the feedback pot to something bigger.

[1878]

Since sound qualifiers are relative, when you say it's distorted and muffled, you know that the repeats in a working Echo Base are not super-clean like a Boss DD-7 type delay, right? A certain amount of distortion and filtering ("muffled" sound) is normal. So are you get much more distortion and filtering than is normal with a PT2399 delay?

Probe 4066 pin 10 and let us know what you have.

Just put an Atari Punk Console through it and probed pin 10 of the 4066. It sounded better than the normal signal. I put the meter on the same pin and got a reading of 06.8. Also, the rate of speed for the modulation doesn't go slower than approx 100bmp. I think I've done something bad to this.

I've been looking on Youtube and mine sounds nothing like it should.

[Taylor]

okay, now probe pin 1 of the 4066. If sound is good before that switch, see how it sounds after the switch.

[Poste]

I built this the other day, and am having some problems, I have read through this thread and some of the other one, however still cannot work out whats going on.

I get clean signal, the led lights up when the pedal is engaged, and I can hear a ticking noise when engaged, but I cannot hear the signal. The middle pot changes the ticking rate so I think that is working. I checked and the the output is not grounded.

Can somebody point me in the right direction as to what I should be checking.

[Taylor]

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[badblock]

Hey everyone! I built my echo base today, the delays sounds great and stuff, but the modulation doesn't work (LFO). The depth knob acts like a finetune of the time knob, and that's it. The LFO switch is fine. I built my unit with the shape mod (with the pot that blends square and triangle). Can anyone help?

[slacker]

Hi

Does the LED flash?

[badblock]

Thanks for the reply!

No, is it supposed to flash when the lfo is engaged?

[slacker]

Yes when the LFO is on the LED should flash at the speed set by the speed pot. If it's not flashing but just turns on and off when you bypass the effect, then it means the LFO isn't working and the depth pot will act like you've described. First thing I would check is the wiring to the LFO kill switch, make sure you haven't accidentily shorted out the 2 pads that this connects to and that the switch is working, maybe disconnect it and see if that helps.

[badblock]

I checked for continuity with a polymeter between thw lfo sw solder pads. The switch acts as normal, when in "lfo on" position, the pads do not short, when switched, they get shorted. I guess the switch wiring is ok 

[slacker]

Ok, it's not that then, next thing I'd try is disconnect the waveshape pot just in case you've wired that wrong and see if that makes it work. You can just remove it, you don't need to rewire the depth pot properly, the LFO will work with neither of them connected.
After that if you've got a meter measure the DC voltage between all the pins of the opamp and ground and let us know what they are.

[badblock]

I tried disconnecting the shape pot, nothing changed, measured both TL072s and these are the results:

[slacker]

The opamp on the right is the one used for the LFO. The pin that is at 1.97 volts has something to do with the problem, but I can't think what could be causing that.
I would double check that the resistors down the left hand side of that opamp are the correct values and that all the solder connections are good with no blobs of solder shorting anything out. Also check that the speed pot is correctly wired.
If you've used sockets you could swap the opamps just in case you have a bad one.

[glops]

I've finally "finished" my echobase.  It's pretty great so far.  I did all of the mods detailed in the PDF and the extra stomp for the D Mad/Modulation toggle arrangement.  Everything seems to be working just right except that the led isn't flashing but I am getting different ranges with the LFO knobs.  I did everything according to the build instructions, the only thing I did differently was to tie all the grounds to the input jack ground sleeve (DC jack ground to output ground - output ground to input ground - and Board ground to input ground).  I read in the thread that the star ground should be at the DC jack.  Would that make a difference?  I am going to go ahead and swap out the LED because I was testing some of them and I think some of the same clear ones weren't lighting up cause they are infared ones.  Maybe I mixed them up?!?!  I started to the outboard wiring last night and got about 75% done and gave up cause the switching was confusing me.  Decided to sleep it off but actually was never able to fall asleep.  Got outta bed at 5:30 this morning and fired up the iron!  I'll check the LED in the meantime....

Thanks,
Richard

[Taylor]

Where you star ground won't matter as far as the functioning of the pedal. Theoretically it might effect noise/ticking, but I doubt even that would be a noticeable difference in most cases.

Does your LED light at all?

[glops]

Led won't light at all.  Solder connections looks solid.  I desoldered the led and tested it and it works.  I've decided to not have the blinkie and am just going wire it as an on/off indicator.  Must be done with this machine.  Great project!  I need to get the OC 2 now.  Got any new stuff in the works?

Thanks
Rich

[bassesofdeath]

Just wondering about the point where the clean kill mod is. Has anyone used a A10K pot instead of using the 10k and a switch?

[jimmybjj]

I've made a drill template for Taylor's arrangement of components. It is meant for 125B enclosures, but with some alterations you could use it for the BB enclosures:
http://www.pjpedals.com/projectfiles/EchoBaseDrill.pdf

Enjoy!

Can someone please repost this, the link seems to be dead.

Thanks, Jim