Building the Echo Base PCB

[hoyager]

The dry kill mod is included in the pdf Taylor has setup for the pcb build, i think the link is further up the page

Ok, I've paralleled a 47k and a 39k (beside pin 5 of LH opamp), 100k was too much, its louder and has pushed it closer to clipping but its also added like another dimension to the delay, its like a noise booster, which sounds a bit rainy and quite pleasant..

I've made some AB comparisons between the Echo Base and an Ibanez AD150 (mn3005) with a rhodes and a polysix

http://hoyager.posterous.com/delay-ab-tests

The ad150 seems to have alot more low end response, which contirbutes to its smeary warmth i think. Also it seems to have twice as much headroom? Its delay level is at half to get the same level from the echo base. The combo is really good, echo base after the ad150, it really starts sound space echo-ish with the modulation

Is a linear pot a good idea for the feeback too?, on mine its useful range is all up at 8 and 9

Andy

[slacker]

Before changing the pots for linear ones test if the volume of the delays is about the same as the dry signal when the Level pot is on maximum and that the pedal will self oscillate when the Feedback pot is on maximum. If it doesn't do either of those things then I think there is something else wrong not just the reduction in volume that you get from lowering the 47k resistors to 22k.
If those two things are fine then, yes I would try linear pots for Level and Feedback. Next time a do an order I'll get some linear ones and try it with my pedal.

If you want more bass, less treble then try making the 15n cap just before the Feedback pot bigger. Sorry I don't know which one that is on Taylor's board.

[Taylor]

It's the one right below the feedback pot. Thanks for helping with these questions Slacker! I don't know how you still find time to help people with their EB builds, but it's very kind of you.

[jimmybjj]

I ordered the wrong regulator. would there be anything wrong with using this aside from the obvious size?

http://www.futurlec.com/Linear/7805K.shtml      to-3 package

thanks for any help.

[Taylor]

I don't see anything in the datasheet that makes it look like it has different properties. You need to ground the case though as it has no ground tab.

[MojoFilter]

i think this crudely pieced together diagram shows what i need to do to have the diode lift, clean kill, dual purpose footswitch, waveshape knob, and momentary bypass. can someone verify, please?



also, the tl072 chips that i got say "TL072CP" will they work in this and the tap tremolo board?

finally, is there an easy way to add an effects loop to this?

thanks!

[Taylor]

Your diagram looks right to me. TL072cp should work just fine.

I haven't added an effects loop diagram to my PDF yet. There was a lot of talk in the main Echo Base thread on how to do it, but searching that thread is hard. I'd try a Google search for

"effects loop" "Echo Base" site:diystompboxes.com

That should give better results than using this forum's search button. There are a few different ways to do a loop with different results, so you'll need to figure out which you want.

[MojoFilter]

awesome! thanks!

i'd love to be able to switch the loop from before the delay to inside the feedback loop to after the delay, but i may be livin' in Dreamland. i'll do some more reading and try google instead of the forum's search function

[Haberdasher]

TL072cp should work just fine.

Hi Taylor.

I have some NJM072BD chips here.  Any reason I shouldn't use those in the place of TL072's?

[slacker]

Yeah they'll be absolutely fine. The are just a different manufacturers version of the TL072.

[Haberdasher]

Excellent, thank you slacker.

I also have another question.  In the pdf it gives both the diode lift and the resistor sub (22k's for 47k's) as solutions to distorted humbucker sounds.
I'm planning on subbing those resistors out and also using the dual purpose footswitch for modulation/dub madness.  I remain confused as to whether or not I need to also do the diode lift.  If it is not recommended, I'll use the extra toggle switch to kill the clean signal.

Thanks in advance for your advice.

[slacker]

I think the diodes are really a matter of personal taste, I've never tried mine without them so I can't say if it sounds different or better without them, I mostly use single coils though.
Probably the best thing to do is build it without the diodes and see how you like it, then if you want to try the diodes you can just temporarily connect then between the middle pin of the feedback pot and ground, that's probably easier than soldering them to the board and then trying to remove them. Then if you like them you can solder them to the board or decide if you want the diode lift switch.

[hoyager]

Its funny how the just act of asking for help can solve the problem. *solved* and thanks!

[MojoFilter]

i got my board yesterday. [thanks, Taylor!] i just finished putting it together this morning and it doesn't quite work right.

the feedback knob does nothing. i only get one repeat unless i hold down the dub madness switch, and then it only goes into oscillation if the level knob isn't all the way up.
also, with the level knob all the way up, the delay is a little quieter than the clean signal; i'd like it to be able to get at least a little bit louder than the clean signal.
and it makes a whining sound with the lfo depth and delay time knobs down even if i switch off the modulation.

does anyone know what the problem may be?

[Taylor]

Did you use board-mounted pots or offboard wiring? At least with your feedback pot, it sounds like you've got a bad solder joint in that area and audio's not passing through. If your feedback works with the dub switch on, the problem would be fairly localized around the feedback pot itself.

[MojoFilter]

it works!!!!!!




i was poking around and i tried attaching the 27k resistor to the middle lug of the feedback pot and it worked! i ended up adding a little jumper on the back of the board



still needs knobs and i get ticking in many settings but besides that it sounds great

thank you so much, taylor and slacker and everyone else who helped!

[Taylor]

Wow, that's awesome. Love that case.

Ticking? Weird. I have never experienced ticking on an Echo Base, even perfboarded ones. There's a 2u2 electro in the LFO section that I assume is there to stop ticking. You might try reflowing your solder on it?

By ticking are you talking about a tick that changes speed along with the LFO? Or just weird clicks and noise when the time is set long? Because the latter is just a function of the chip, especially if you use a pot bigger than 50k.

[slacker]

That looks great, nice work. I can see why you had the problem of only getting one repeat though, it looks like you didn't put in the 20k resistor that connects to the middle lug of the feedback pot. Without that the feedback pot has no connection back to the input of the delay so it won't work and you will only ever get one repeat.
If you do the "dub madness" mod you still need that resistor, the extra resistor and switch don't replace it.

[MojoFilter]

it looks like you didn't put in the 20k resistor that connects to the middle lug of the feedback pot.

that's what it was. i did think that the resistor with the dub madness switch replaced it. i guess i should have posted a picture earlier. i'll have to fix that soon, but i'm really happy to have it working.

and the ticking is in time with the lfo but it's less apparent with my real amp than with the little amp i was testing it with.
i'll put that missing resistor in and remove that jumper in the next day or two and report back if it changes. then maybe i'll post some clips

[funkbass187]

would subbing 22k for the 20k resistors cause any major problems?