Build Your Own Clone Message Board

I hate to bring this up after such a long delay. You know... life happens.
Anyway, I did what was suggested and built an audio probe. I tested this and it works perfectly. I recorded into my looper and then fed that into the input of the Echo Royal so I'd have a consistent source to test with.

I connected to ground and used the probe end on the "mix" connection on the board and I can hear my dry signal in my amp.

So, now, I'm trying to trace backwards through the circuit and try to detect where the problem is; to see if I can find the repeats / wet signal somewhere and determine where it's getting cut off.
I'm struggling a bit with figuring out where to test. I'm trying to use the images from the instructions to determine the physical traces/path and also using the schematic to try to match up the signal flow through components. I'm a n00b so it's been a struggle. (see image)

Can you give me some advice on some key connections to test where I SHOULD hear the wet signal?

I'm figuring things out.

I started with the MIX pot. (looking down at the pot dial left to right are pins 1, 2, then 3 if that's right). Pin 3 has a clear clean signal as long as the mix isn't all the way up. Pin 1 has a very low volume clean tone - like 10%. Pin 2 has an even quieter clean tone than that. I'm assuming it's clean because I have the repeats cranked and there's only a single tone.

Next I looked at the SA571 chip as that has the result of the delay processing. According to the schematic (http://byocelectronics.com/echoroyalschematic.pdf) it looks like pins 10, 14 and 15 feed in the delay input and then pins 2 and 3 have the delay output and the signal passes through pins 6 and 7 to go on to the mixer.
- I can hear the tone WITH modulated echo on pin 10 but it has a lot of static. Sounds like it's 40% volume and like through a megaphone/old radio. Pins 14 and 15 have the same thing.
- input pin 11 has almost no sound... I think I can hear the signal at like 1-5%. I'm confused about this because it seems to be the main input for the wet signal.
- Pins 2 and 3 have nothing. (this SHOULD be the delay signal)
- Pins 6 and 7 have no sound as well... which makes sense if there's nothing coming in on pins 2 and 3.
- Pin 12 is connected to the repeat pot, but I hear nothing there either.
Seems really weird. Seems like there's an issue elsewhere

TL072 is being used for some kind of amplification or something before the SA571. Pin 6 is the input and I can hear a faint dry signal there.
Pin 7 has a much amplified version of that clean/dry tone.
It seems like pin 7 is the main amplified input used for everything (including the dry mix signal) and it seems to be good at this point.

The PT2399 chips are used for the repeats and are between some pins in the SA571 (inputs/outputs).
- pin 9 has a clean tone followed by a modulated echo with a lot of static just like on the SA571.
- pin 10 and 11 have nothing
- pin 12 has a clean tone and modulated echo on the chip closest to center and the edge chip has a modulated tone with a modulated echo (2nd phase delay I'm guessing). Both with static in the signal and low output.
- pin 13 has nothing
- pin 14 has the same signal as pin 12 on the center chip (clean tone with modulated echo. pin 14 on the edge chip sounds the same as it's pin 12 (modulated tone with modulated echo) except with a low pass filter or a bunch of treble removed.
- pin 15 (main inputs) sounds the same as pin 14 on the center chip. The edge chip sounds the same as pin 14 and 15 on the center chip (ie without the low pass filter effect that's on it's pin 14).
- pin 16 has nothing.

Seems like something is wrong with the signal before the PT2399 delay chips but after the TL072.

I'm done for the night.
If this was helpful, let me know. If it wasn't, let me know what I can do / test to provide information that may be helpful.
Thanks!!!

Let's work forward instead of backwards. Do you have signal at:

1. pin 7 of the TL072
2. pin 11 of the 571
3. pin 10 of the 571
4. pin 14 of first PT2399 (closest to the center of the PCB)
5. pin 14 of second PT2399
6. pin 2 of 571
7. pin 6 of 571

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

1. pin 7 of the TL072 - loud and clear clean signal
2. pin 11 of the 571 - VERY faint signal barely audible. could be clean signal
3. pin 10 of the 571 - slightly quieter clean tone with modulated repeats and lots of static
4. pin 14 of first PT2399 (closest to the center of the PCB) - just like pin 10 of 571 but with a low pass filter effect on the static
5. pin 14 of second PT2399 - modulated initial tone with modulated repeats. Again, sounds like another layer of low pass (less treble)
6. pin 2 of 571 - sounds the same as pin 14 on second PT2399 - modulated tone with modulated repeats
7. pin 6 of 571 - nothing

Hello,

I would like to report a similar problem - the Echo Royal appears to work, however the bypass switch changes only the LED status, the effect seems always enabled.
The MIX knob only changes the volume of the effect, dry signal is always present.
I too have a kit with four J111 JFETs.
Should I do the same tests as suggested previously i.e. remove the FETs and bridge the drain/source pins, or can we just assume it's a bad batch of J111s?

A question to people who have changed over these transistors - did you pull everything out of the enclosure before doing so? The wires I have connected to the DC connector, jack sockets and switches are all rather short, and it looks like it's going to be a PITA to get everything out before de/resoldering.

An image of my build can be seen here:
https://i.imgur.com/howdMi2

Cheers

100% I took the board out of the case. You sometimes have to access both sides of the board especially when you have to desolder.
I left my wiring long on purpose because I just assumed I might have to take things in and out. The part that really annoys me is the power connector with the nut on the inside so I can't fully remove the connection from the case without desoldering the wire. You might want to consider replacing the wires with longer lengths at least short term.

Contact sales@buildyourownclone.com and request 4x J113

You don't need to "desolder" in so much as you're not trying to salvage the old J111. It's pretty easy to remove them if you're intention is not to reuse them. Clip the head off the J111. Then you can simply heat the solder joint and pull the remaining lead out with a pair of tweezers or pliers. Once you have those out of the eyelets, you can use some desolder braid or a solder sucker to remove the solder from the topside of the PCB.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Did the 7 tests above narrow down the issue?
Any more tests that I should do that would help identify where something might be wrong?

I'm sorry. I didn't see your previous post come through my feed. Yes. That helps. I would assume you've got a bad 571. Please contact sales@buildyourownclone.com and request an replacement.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

No problem, will do.
Is this based on the "bad" signal on pins 10 and 11 on the 571 or missing signal on pin 6?
I will remove the 571 and re-flow the solder on those connections tomorrow and see if I get a different result and then contact sales.

Thanks.

Well, the signal at pin 7 of the TL072 should be the same at pin 11 of the 571. So maybe you're having problems at Q3 still. You did replace that with a J113? But the fact that you have signal at pin 2 of the 571 and nothing at pin 6 suggests a problem with the 571.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

I replaced all 4 JFETs with the replacements sent to me. They are marked with JCJ-113-N22.
I don't see Q3 marked on the schematic, but I do see a Q reference at the JFET between the TL072 pin 7 and the 571 pin 11 (between C6 and C9). I will check things over again.

Thanks - I have contacted the sales address. I have already been able to remove the board, sacrifice the dead J111s and remove the leads/solder and clean up the through holes.

Cheers