Echo Base not echoing....

[StereoKills]

Finally got around to building the Echo Base on Taylor's beautiful PCB. Got it all wired up tonight and plugged it in. I'm not getting any repeats or modulation although the clean signal is passed beautifully whether the effect is on or off. When I turn the level up past 75% I can hear a ticking noise that isn't affected at all by any knobs other than the level. Also the led is pulsing (didn't think that was supposed to happen). I can take some voltages in the next day or two, but it's late tonight and I'm bushed. Hoping someone could point me in the direction to look. Thanks!

[Taylor]

Does the LED pulsing change speed when you turn the LFO rate knob?

More importantly, have you built an audio probe?

[StereoKills]

No the pulsing speed does not change at all. I haven't built a probe yet, but it looks like now is a great time!

[Taylor]

Strange. So we know the audio TL072 (far left) is working, and the LFO TL072 (far right) is oscillating, but the speed pot is not affecting it. I would trace through with the probe and see where the audio problem lies first. Your delay chip may be dead.

[StereoKills]

After two weeks I finally got the time to sit down and trouble shoot this bad boy. I opened it up and got my multimeter ready.....and noticed the delay chip was backwards (facepalm moment). Soo.......yeah works great now! Awesome sounding circuit and I must say that you did a really good job on the PCB Taylor, thanks again!

[Taylor]

Thanks, and I'm glad you got it sorted out. If an "experienced" DIYer tells you he never fired up a board, couldn't get it to work, and after hours of cursing, realized he had a chip in backwards, then he's either not experienced, or a liar.  

This is one reason why I go to great lengths to put all orientation-specific parts pointing the same way on a board. I don't like PCBs that have electros, ICs, diodes, etc pointed every which way. Diode pairs are the only forgivable exception.