Building the Echo Base PCB

[cyklopljud]

Cool, glad you got it working.

Thanks again Taylor for your extended help.
Looking forward to the next PCB.

O.

[Taylor]

My thanks as always to Slacker for helping out with these questions - since he designed the circuit, and is far more clever than I, he knows it more intimately and can pinpoint issues quickly, as in this case.

[Berger]

Has anyone done a drill template for the Right Angle PC mount pots?

Aaron

[kristoffereide]

built the EB a couple of days ago (the PCB). Wonderful PCB! best quality pcb i´ve ever seen.

THe build was nice, though the distance from hole to hole for the resistors were a bit short, however if they were bigger they wouldn´t fit my box

very good pedal, i did the diode-lift to remove the distortion (just removed them completely) and for the 47K combo, i made one 22K and one 39K to make it sound right in my ears. I use this in an FX-loop and before I changed these it made significant cut in my rig-volume. Now it´s fine though.

Love this, and will try Taylors other PCBs.!

[Taylor]

THe build was nice, though the distance from hole to hole for the resistors were a bit short, however if they were bigger they wouldn´t fit my box

True, attention needs to be paid to lead forming with these PCBs, as they are very compact and I absolutely hate resistors on end. I find it pretty easy to bend the leads with my fingers the way you normally would, just closer to the body of the resistor.

Thanks for the kind words and I'm sure we'd all like to see your build if you get a chance.

[kristoffereide]

Thanks for the kind words and I'm sure we'd all like to see your build if you get a chance.

unfortunately Im not big on graphics, and mostly do colours and a text on a white BB to distinguish one pedal from the other, so it´s not much to look at

[jcwillow777]

I'm having trouble finding a couple of 15nf capacitors. I have all of the other parts. What could I substitute that would be a fairly easy find, or where can I find some?

Thanks

Never mind, I found some.

[kristoffereide]

Hey again.
Just built another one of thiese, but now I only get a buypass-signal and no echo. Any thoughts about what I did wrong?
Thanks,
Kristoffer

[Taylor]

Hmm, could be anything in the delay portion of the effect, really. Use an audio probe to see if you have sound at pin 16 of th 2399.

[kristoffereide]

no, actually I don´t. Tried swapping the chip, no difference

[Taylor]

So if you follow the schematic, if you have no audio at pin 16, it's somewhere between the input and there. So the delay chip is not the problem. Check through with your audio probe at the inputs and outputs of the TL072 and the pins of the 4066 as noted in the schematic. I'm pretty sure I followed Slacker's pin numbering so you should be able to locate the issue that way with your audio probe.

[kristoffereide]

I seem to have modulation at pin 13, if that tells you anything. I´ll check later, now I have other studd to do Thanks!

[Taylor]

You want to check out the other TL072 on the left, this one has the audio.

[tombola]

Just built my Echo Base PCB in one evening (after quite a few more evenings ordering parts!) Fantastic board, thanks to Taylor (and Slacker)
Now I just have to decide which of the 5 mod switches to keep, then box it up!

[Parsa]

I like checking datasheets before I build, and I noted that the 2N5087 has to be put on the PCB in reverse of the BC560 when used as a substitute. The collector and emitter are reverse. I did a forum search, and it was mentioned in the main Echo Base thread, but since that's getting to be a mighty tome, you may want to mention this fact in the built PDF.
[BC 560 Data Sheet (pdf)]  [2N5087 Data Sheet (pdf)]

I've heard good things about subbing the 2N4403 in music circuits. For instance in this article. Any thoughts? I can get that tranny for pennies at Jameco. (It would also need to go into the PCB in reverse.)
[2N4403 Data Sheet]

Lastly, I note you have  1μF poly film cap with a Mouser part number. Looking at the PCB, it's a 5mm spread on the leads. I'm assuming I could use this part from Jameco instead: Capacitor 1uF 50 Volt/30VAC PLYE 5%

Steve

[Taylor]

Indeed, when substituting transistors, it's necessary to check the pinout before putting parts in. But if the E and C are reversed, why not just flip the part around instead of putting it on the back of the board?

The BC560 is not used in the audio section - it acts as a voltage controlled resistor to cary the delay time of the 2399 chip. I don't know about the one you linked, it might work as I don't think this is too critical in any case. But the 2n3906 is supposed to be confirmed for that, and it's plentiful.

That cap should be fine.

[Parsa]

But if the E and C are reversed, why not just flip the part around instead of putting it on the back of the board?

That's actually what I meant by reversed... just flipped around so the flat side of the transistor points the other way.

So I can just use a 2N3906? So noise is not really an issue in that part of the circuit....That's good, since I have a bunch of those standard transistors.

[Taylor]

 Right, noise won't really matter as this is just controlling the frequency of the internal clock of the PT2399.

[Ginsengbob]

Hello
Can anyone tell me what the holes under the pt2399 and 4066 are for?
Also, This may sound stupid but where do you wire the ground from the audio input and output.

thanks

[Taylor]

Hello
Can anyone tell me what the holes under the pt2399 and 4066 are for?

They are called vias. Their purpose is to connect a copper trace on one side of the board to the other side of the board. You don't need to do anything with them or pay attention to them at all.

Also, This may sound stupid but where do you wire the ground from the audio input and output.

thanks

Connect the grounds from the 2 jacks to the ground tab of the power jack.

Welcome to the forum.