Building the Echo Base PCB

[edd29]

Very nice, what does Room/Hall do?

the room is  i can turn the repeat contol fully clockwise with a nice room sound
and the hall is just about haftway turn and its double the sound
basicly i add another cap to pin 9  and 10 of pt2399 with switch so ican turn on and off
it does give boost or hall sound.

[Ultrakd]

I cant find a 50k resistor, would using a 51k resistor be ok?

[slacker]

Yeah, absolutely fine, the 50K is only for the LED so it's not critical. Depending on your LED you might want a different value anyway.

[parra]

Hi, i've just built the echobase and the delay itself sounds really nice, and the tails function is the best but, i have no modulation at all...

the led is on but it doesn't flash with the lfo, and when i turn off the LFO the led is brighter, but still no modulation...
when i turn the depth and waveshape knob the delay time changes, but the speed knob does nothing...

i've read all this thread, tried changing the tl072, 4066 and bc560, reflowed some solder joints but without any luck, so if someone have some sugestions firem up.

Thanks

[Taylor]

The far right of the board is where the LFO is, and it sounds like your oscillator is not oscillating. Check to make sure that the LFO SW pads are not shorted to each other or anything else, and post the voltages from the pins of the rightmost TL072 if you can.

[snarblinge]

also check you power source, flattish batteries will cause the same, I had this, and don't reccomend batteries for this build.

[parra]

i've took out the lfo sw and it still doesn't oscilate, and i'm using a 9v power supply, not a batery. when i get a new multimeter i'll post the voltages, cause my old one broke a few days ago, but in the meantime i'll keep trying to see if i could find the problem because this pedal is to good to be wasted like that, even the delay by itself is great....

today i even bought a new 1M speed pot thinking that the other one was broken but no.....it's strange that even with a super bright led i only get a little bit of light, almost can't see it......damm

thanks for the replys anyway

Edit: i've tried to short between the depth knob and the tl072 with a led and i get oscilation in pin 7, so the oscilator is working but not modulating the delayed dignal....f#@k

[claytushaywood]

You might want to check out the cave dweller over at mad beans

completely different style delay... ive done some research and trial and error and have found that just putting one cap on a switch with 2 other values (3 way toggle) you can get three very useable levels of darkness on the delay repeats- havent tried this on the echo base but it uses the same capacitor off the pt2399- the mad professor deep blue delay actually uses a 15n cap (i believe it's like pins 13 and 14... probably wrong-cant remember exactly) but the DBD has very netural sounding repeats that are interesting- I like 37n and 62n as darker settings

Has anyone figured out how to add an effects loop to the echo base?  that would be ultimate!
I was also curious about adding diodes to the repeats knob to prevent self oscillation from getting super loud- I beleive the skreddy echo has something like this.  if you put some diodes across maybe the effect level or the repeats pot when you crank the repeats pot you will get all the oscillation goodness but it wont get super loud... and you can leave it going to get an awesome wash of delay- I love that feature of the skreddy

anyone point me in the right direction?

[slacker]

Has anyone figured out how to add an effects loop to the echo base?  that would be ultimate!

There' s various way's to do it, depending on what you want, here's a schematic with 3 different places to try http://www.eskimo.plus.com/fxstuff/echobasenotes.png

A. The first repeat and all subsequent ones are affected, but each repeat only goes thorough the pedal in the loop once so subsequent repeats don't get more and more affected.
B. The first repeat is clean but every subsequent repeat goes through the pedal in the loop, so the repeats get more and more affected.
C. The first repeat is affected by the pedal in the loop and every subsequent repeat goes through the pedal in the loop, so the repeats get more and more affected. To add the loop here you would need to add buffers before and the FX loop and maybe move the 20k resistor and 4n7 capacitor to after the Loop.

I was also curious about adding diodes to the repeats knob to prevent self oscillation from getting super loud-

Already has this.

[samblam]

So I've built an Echobase but it doesn't work 

I'm only really concerned with troubleshooting the delay part of this as the LFO section was never a priority, if I can get the delays going I'll be happy... I've already tried resoldering a few of the connections around the troublesome pots but here is what I'm facing:

With Level at maximum the delay volume is still pretty quiet, this may be related to the other problem though:
The feedback knob at maximum only produces 4 audible delays. No self-oscillation.

The only different parts I used were a BC109 instead of the 2N5089 and a 2n3906 instead of the BC560, and an a100k pot for time instead of b50k (I like long grungy delays though, which is what I thought I'd get with this pot substitution).

Any help?! Thanks in advance.

[slacker]

Is the dry signal OK? It should be the same volume as plugging your guitar straight into your amp. If it is but the delayed sound is quiet then the problem is probably to do with the resistors connected to pins 13, 14, 15 and 16 of the PT2399, check their values carefully, and make sure you haven't accidentally switched any of the 10k and 47k resistors. Also check for blobs of solder or anything else that might be shorting the signal to ground.
The feedback problem will probably go away once you have the volume problem sorted out so I wouldn't worry about that for now.

Your part substitutions will be fine.

[shoud]

hi !
do you know where i can get a PCB (or two... yes, definitively 2 would be better) of Echo Base ?
i wrote to musicPCB (unavailable till 08/22 ... and we are 09/03), but yet no answer.
Thanks in advance for your answer .

[Taylor]

Hi Shoud, I do have the PCBs, however where I live, we were just hit by a big, slow hurricane, so my workshop does not have power, and there's no mail or shipping service right now in the city. I should be back up and running this week and I will put the PCBs back on the site and be ready to ship boards out.

[shoud]

 
hope everything is fine for you, and your shop ...
we're lucky in europe, we don't have hurricanes.
i'll check the website

[Taylor]

Thanks for the kind words - everything's fine, just a little wet! We're pretty used to hurricanes here so while it is an inconvenience, we'll make it through just fine. But I might just try to move to Europe one of these days!   

[hxc]

Hi, some quick, stupid newbie ( ) questions about the pots to be used for the EBase:
In the BOM, I guess the A in A110K is for "Alpha", the "B" (B50K) for "Bourns"?
Also, should the pots be log or lin? My gut feeling says probably log for all?
Thanks  

[lespos]

"A" - audio or log pots
"B" - linear pots
"C" - reverse log pots

So  A110K (really 110K not 100K? ) is log 100k pot, B50K is linear 50K pot.

[hxc]

"A" - audio or log pots
"B" - linear pots
"C" - reverse log pots

So  A110K (really 110K not 100K? ) is log 100k pot, B50K is linear 50K pot.

Ah, thanks. Makes sense .
And yes, 100k of course. Bad typo .

[DrKoester]

I've got a near-complete build but before I finish I wonder how you would wire a LED to pulse with the delay time, whether or not the pedal is bypassed.  Any thoughts?

thanks, Tom

[Taylor]

To do it you'll need some extra logic chips. IIRC you have to divide the clock signal down by some arbitrary number. Somebody posted a layout to do this long ago in the main Echo Base thread, but unfortunately it would be tough to find. I would try using google like so

clock divide "echo base" site:diystompboxes.com