Messages

okay I will try that. thanks!

Out of curiosity, do you have a set of instructions if you do have an oscilloscope?

Alright, got the voltages for the ICs.
Vin: 9.6V
15V: 15.14

IC1:
1-7.52
2-7.53
3-7.52
4-15.06
5-7.52
6-7.52
7-7.53
8-7.51
9-7.52
10-7.52
11-0
12-7.51
13-7.52
14-7.52

IC2
1-0.91
2-1.78
3-1.78
4-0
5-1.79
6-1.78
7-4.97
8-1.78
9-1.78
10-4.74
11-4.74
12-1.78
13-15.1
14-1.78
15-1.78
16-0.916

IC3
1-15.01
2-7.49
3-3.89
4-3.89
5-0
6-7.51
7-5.77
8-1.042

IC4
1-15.01
2-7.51
3-5.24
4-5.24
5-0
6-7.51
7-6.61
8-1.067


IC6
1-7.23
2-7.76
3-7.82
4-15.1
5-15.1
6-15.1
7-0
8-0
9-0
10-7.5
11-7.5
12-0
13-7.27
14-15.12

I will get voltages later tonight, I don't remember anything being weird about them when I was first building it, but it would be good to get a second set of eyes on this.

the pedal is delaying. It's doing things, so that's cool.
However, it doesn't oscillate. And the clock frequency doesn't go higher than 9.5khz.

I've tried an NE570, and an v571d, and different MN3005s and different CD4047s.

Hoping the symptoms are something someone has seen before. thanks!

Interesting. Alternatively you can increase R25 to 100k. This will increase the charge up time on the anti lock circuit. So, at power up pin6 will see the 2k2 to ground then as the transistor switch is powered it will reduce to the total resistance to its minimum.

Okay, will take note. After changing back to 100 ohms, I was unable to make the lockup state occur again after multiple power disconnect/reconnects with discharge time in between. But I will probably do this if it occurs again, that sounds like an easy fix to make that boot up time happy.

I think that one PT2399 was definitely unhappy in the circuit, but maybe the TL062 also helped? In any case, my coworker seems happy as his first pedal works now!

An update, I put in another PT2399 and the high current draw state has been fixed. Current draw is 37 mA when it is working properly.
However there are still issues where the chorus effect does not happen. I'm going to revert R24 back to 100 ohms.

Something is sinking a whole lot of current but I'm not sure if it's your particular PT2399 or the anti-latch circuit. Using the TL072 for the other is fine - shouldn't have any effect.

Try removing the two TL072 and check the current draw again on power up and see if you get the same result. Check for any pins on the PT2399 having continuity with ground that shouldn't (on pins 3 and 4 should).

One other idea: try powering it up with IC3 removed to see if you have the same issue. Maybe let us know if the LFO is causing an issue.

Pic of the top of the board, too, please. And, report any other voltages that are out of line with the build doc.

to be clear, when I probe pin 2, the current draw drops back to 40-50mA, and I can get chorus tones out of it again. So that's why I think the current draw may be related to the lockup issue. Only pins 3 and 4 are connected ground, as we would expect.

This is something my coworker built, his first pedal, so I'm helping him debug it. I've attached a photo

I have a Ballast Junior here where sometimes there is no chorus effect occurring.
Now, I think this is related to the "lockup" issue of the PT2399. When I power it with a bench power supply, i noticed that it is drawing an unusual amount of current. around 135-140. But when I probe with a multimeter Pin 2 to see what's happening, the current draw drops and the effect begins working again. And the voltage at Pin 2 looks normal after this (around 2.5V)

Currently toying with the "anti-lockup" circuit (Q2 and its neighbors) but nothing yet. I tried the older value of 47 ohms for R24 just to see, with no luck.

One difference is that I have TL072s in both positions, as I didn't have a TL022. Will be trying a TL062 for IC3 tomorrow.

Should I also try swapping PT2399s? Any other fix ideas?

I would double check your resistor values if you have motorboating. A wrong value in a couple key places could cause that (too much gain). Specifically, check R7-R9.

Maybe post a clear picture of the top of your board too so we can also double check your resistor values. There are other places downstream where a wrong value could produce that result, as well.

I took a quick look, and I think everything is in order? Maybe I'm missing something though.
Don't mind the paralleled resistors, I didn't have 43k on hand haha.
Overall though, I like this style of board. The connectors and bypass would be really easy for less experienced DIYers.

This is an issue madbean documents in the build doc, but I'm having trouble beating it.
At higher gain or bass settings the motorboating goes nuts. Lower gain settings seem fine. It works up to like 75-80% of the gain knob.

I tried toying with some cap values, increasing the decoupling on Vb to 220uF. No luck. Any tips?

Missed out on the Expandora, but I'll get it next time it is in stock. Thanks for all the cool projects!

February should be pretty off the hook. It's going to be phaser city up in here, and some of them will have tap tempo/waveform options.

Phase 90 based?

Really looking forward to the new designs.

I removed C12 and reduced C10 to 470p.
[soundcloud]https://soundcloud.com/secretrogue/return-of-the-pearl-octaver[/soundcloud]
Description from soundcloud:
"Tweaked my Pearl Octaver clone, very satisfied with it now, gonna be back on the board, no need to buy an Octron.
Forgive the hum, I was using my Strat on the middle position, and I'm plugged in the high gain input of my VTM. With the coil tap on, it's the beefiest position on it, but it's got a bit of noise.

Here are my settings:
normal signal: 25%
octave up: 100%
octave down: 50%
two octaves down 25%

recorded on my iPhone."

Low voltage threshold diodes for D1 and D2 should just let it rectifiy lower level signals.

Okay ya, I was using that one, but if I use the same pad size as all your other parts, they overlap, if I place it on the lines that the part has laid out. But your Weener Wah doesn't have overlapping parts.
So I was wondering if the Eagle Part's pinout is the right spacing to fit both Fasels and Whipples? Your Weener Wah looks like the pads are farther. So should I do something like that? I just want to make sure both kinds of inductors fit haha.

Hey madbean, I was making my own wah layout, using your library in eagle. I was curious about how you did your Inductor part. The pad spacing is different than your library. I can't use the default pad size without some overlap. I'm okay with that for my single sided etches.
But I was wondering, should I space my pads like yours? Does it allow both Whipples and Dunlop Fasel inductors to be used?