Home

[brach]

So that’s good that the FET fixed the no signal issue.
Now it sounds like something is wrong with the high frequency signal path. We need to know if the problem is with the digital control (as in the high optocoupler’s led isn’t lighting up) or if the problem is in the audio signal path.
With the depth knob at 0 (fully counter clockwise) what DC voltage do you get on the square pad of the high side optocoupler (opto1)…from ground (black lead on ground, red lead on the square pad)? It should be about 1.8V dc.
-Brach

[brach]

Yes, that would do it. Good job noticing it was backwards. That is a FET (field effect transistor) which is responsible for momentarily muting the audio signal while the relay is switching to keep the relay click out of audio path. Since it’s backwards it might be constantly keeping the signal muted, so that’s why everything is really quiet.
Email us at info “at” zeppelindesignlabs.com and we’ll explain how to get a new FET.
-Brach

[brach]

Scooter,
The good news is that you are getting at least some sound to pass through the circuit, so we know it seems to be working on some level. This problem sounds like a bad connection somewhere…like a bad solder joint in the audio path. The volume knob is off in the counter clockwise direction…is it behaving that way? I suggest you re-flow your solder joints again to make sure everything is connected the way it should be. Another possible cause could be the signal is partially shorting out somewhere, possibly against the back of one of the pots when the circuit board is installed in the chassis. Make sure the pieces of paper don’t have any holes in them and nothing is poking through.
Good luck.
-Brach

[brach]

Hi Kit…
I’m trying to get back to working a few hours here at the lab. I’ve been out with some family health issues for the past several weeks.
I’m sorry about your Quaverato trouble. Since you are getting continuity to ground on the round pad only when power is on, this tells me that your microcontroller probably has been damaged so you may need a new one. You can try reflashing it to see if it can be salvaged, but if you don’t have the means to do that then your best bet is to get a new microcontroller.
If you want to inquire about getting a new microcontroller, you can contact us at info “at” zeppelindesignlabs.com
Once again, i’m sorry about this trouble…and sorry it took so long for us to get back to you about it.
-Brach

[brach]

Bob,
I’m glad to hear that’s it’s working the way it should on a real amp. I’m not sure why it was behaving that way with the Pod…i guess just keep using the real amp.
Good luck.
-Brach

[brach]

This is an odd symptom. I’ve never experienced this before. But it has to be something simple, like a bad connection or solder joint…there’s not much after the volume pot except the output jack. It’s hard to say much without hearing it myself. If you could send me a cell phone video showing me this problem i might be able to have some more insight.
Before you send the video tell me what circuit board version do you have? 6.x or 8.x?
If you have board version 8.x then see what happens when you remove (or lift one leg of) C17.
If you have version 6.x then proceed with the video.
Our email is info “at” zeppelindesignlabs.com
-Brach

[brach]

That’s great!

[brach]

You have a short somewhere. The first thing to check is your distance sensors…is one or both of them plugged in backwards?
The next thing to check is your solder joints. Are there any solder bridges? Is there any loose solder pieces on the board that could be shorting together 2 solder joints? Look carefully. You may want to re-flow the solder joints just to be sure.
Let me know what you find.
-Brach

[brach]

Thanks for asking.
Believe it or not, I actually designed the Percolator intentionally using these caps…the decision wasn’t all about cutting cost. I could have used a few types of cheaper film caps, but I chose the Panasonic because I like the way they sound in the amp. The cheap 470pF ceramic caps probably seem like an odd decision but I am intrigued by the way they distort…distortion in these types of caps is a function of the voltage across them, they tend to impart more odd order harmonic distortion as the signal through them is bigger. I didn’t have a particular reason (other than cost) for using these particular electrolytic caps.
I fully support and encourage tweaking your amp with different parts. But I wouldn’t change any components until you hear the what the amp sounds like with all the stock components. Then if you do want to change out parts, it will give you a baseline for how the sound has changed.
We get our transformers from a supplier overseas and from a company here in the US called Edcor.
Thanks for the questions. Let me know if I can answer anything else.
Good luck with your build.
-Brach

[brach]

Andy,
I’m sorry to hear about your Quaverato issue. By the symptoms, it does sound like the microcontroller is damaged. You can try to re-flash it if you can borrow a PC, but if the microcontroller has been badly damaged it may not be flashable anyway. Otherwise, you can either get another microcontroller from us (contact us via email: info “at” zeppelindesignlabs.com). If you are into building electronics, you may have another atmega328p around, which you can flash with our software…if you can borrow a PC. If that sounds like too much of a headache, contact us and we’ll sell you a new microcontroller.
Once again, sorry for the trouble.
-Brach

[brach]

Mike…
Sorry, i’ve been out of town. I just responded via email.
-Brach

[brach]

By your symptoms, i’m assuming you have an older version of the Quaverato, which had a relatively low input impedance. Try putting a buffer pedal before the Quaverato…basically any non-true bypass pedal should work…even a Boss pedal that’s not engaged. That should help dive your Quaverato better. Alternatively, you can adjust your tone trim pots to your taste while it is in your pedal board. This may be a better option if you don’t want to put a buffer pedal before it.
-Brach

[brach]

I’m glad your build went well, but i’m sorry about the ac hum. If everything works well with your bench supply, then there must be an issue with your radio shack power supply. Try a different power supply or a battery to see how it goes. Possibly the filter cap(s) may be old/dried out in your ratio shack supply. You could check the ac ripple under load from your supply with your voltmeter.
Thanks for the suggestions. We are currently in the process of designing the Macchiato MKII which will have several improved features. I”ll take your suggestions into consideration when we make the assembly manual for it.
Thanks and good luck.
-Brach

[brach]

Make sure the rate pot is soldered properly…just re-flow those joints to make sure. Check the voltage on the corresponding microcontroller pin (pin # 25) to ensure voltage is getting there…it should be between 0 and 5 volts depending on how the knob is set. If all that looks good then it may be that your microcontroller fell victim to a static discharge somewhere along the way. This happens sometimes which causes the ADCs on the microcontroller to not function anymore.
-Brach

[brach]

Mike,
I’m not sure that the noise you are experiencing is the same kind of noise as jrg320. Would you classify it as a “high pitched whine” associated with the rate knob setting, that can be minimized by lowering the depth knob?
If not, then you have an unrelated issue…how would you characterize the noise (a video might be helpful)?
No matter what kind of noise you have, it is important to make sure you followed all the steps in the assembly manual…otherwise you can end up with a broken or noisy pedal.
Pictures would help after I’ve seen video of your pedal and heard what kind of noise you are experiencing…so i know what to look for in the photos. Our forum is annoying in that you have to have a web link to post a photo. So use google drive/photos or another upload site. …actually email may be best (if the files are small enough): info “at” zeppelindesignlabs.com
-Brach

[Author]

Posts