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Even in calibration mode there is still no low frequency sound?…after turning up the trim pot? Keep the depth knob fully counter clockwise all the way off when you test the calibration mode.
I just got done rechecking this. Enter calibration mode by holding both buttons down, disconnect power, reconnect power while holding buttons down, both LEDs flash, when they stop release buttons. At this point effect is bypassed so press bypass button to engage effect. Depth control is full counterclockwise, harmonic mix full counterclockwise, no sound. This is after adjusting low trim pot 20 turns clockwise, green light (low optocoupler LED) is visible, however it is not pulsing but on steady.
I am tired of screwing around with this, it doesn’t work and I’m not certain at this point if it ever will. I have asked Amazon to return it and they say it has to be approved by you. I have tried for four days to work this out with you and then you just blow me off with no explanation. As far as I’m concerned the bare minimum that I am owed here is a complete refund including shipping, and that doesn’t in any way compensate me for the 20 hours or so I have wasted here. You should give me a pedal that actually works.
I’m just now seeing your post from the 12th. I’m sorry that I haven’t been more available to help you. I’ve been so busy with trying to get a new product released, taking care of a very sick 6 year old, and staying up with my baby who’s not sleeping well that i haven’t had time to help you (or anyone else that i’m currently in the process of helping) troubleshoot anything for the past few days. I’m sorry that you took my busyness as “blowing you off”. We are not obligated to help our customers build their kits, but we do it because i have a passion for helping people understand their gear. When someone gets a kit (instead of a ready to play product) part of the process of building it is troubleshooting, which takes a lot of patience. I will do my best to help you, but i can’t guarantee anything because a lot has to do with your skills and knowledge. In our previous posts i think maybe i was assuming too much…I’ll try not to assume anything.
Now, let’s get on to troubleshooting…
I don’t want to assume anything or be condescending, but it would be helpful for me to know if you can read and understand the schematic in the back of the assembly manual. And (also not to be condescending, but) if you don’t understand anything i’m asking of you please just let me know and i’ll explain…we’ll save a lot of time and frustration that way.
The high frequency signal path works, but the low frequency path doesn’t. We’ve narrowed down that the digital side of things is working…the low opto led is lighting up. So we know the issue is in the analog path. You said you corrected the jumpers and now they are soldered correctly. To be sure of that, (with the power off) please test the continuity between pin 1 on U2 (the TL074) and TP3 (they should be connected, test them with your meter’s beep test). Also test the continuity between TP4 and R5 (the pad closest to R19 and R20). These tests will tell us if the jumpers are soldered correctly. Sometimes when the jumpers are heated up too much one of the little rectangular pads can come off the board.
Please make those tests and let me know what you find.
I am sorry you’re having personal problems, but so is everyone else. As far as standing behind your product, that would be your personal choice. I certainly can read a schematic. Assuming that pin 1 on U2 is the one with the square pad, then there is continuity between there and TP3. There is also continuity between TP4 and R5. I had already checked this but I’m not convinced it means that either OPAmp “A” or the LDR in the low Opto is functioning correctly.
You can test if the LDR is working by unsoldering the jumpers (JP3 and JP4) and measuring the resistance across TP3 and TP4. Keep the depth knob off and the resistance should be relatively low (when the power is on). But you should have already done this when you calibrated the pedal, so I would guess that it’s still working.
When you measure the resistance between R15 (the pin of R15 closest to pin 1 of U2) and pin 3 on U2, what do you get (with the power off)?…I’m wondering if S5 is working properly.
Also, what DC voltages do you get on the pins of U2A, pins 1,2, and 3?
OK R15 to Pin 3 of U2 is off the scale with power off. DC volts on pins 1,2 and 3 of U2 are all 4.47 V. Yeah I was kind of wondering about that whole assembly (resistor bank and dip switch). I found a couple of questionable solder joints there and resoldered all of that. I checked across the resistor plus switch (on the solder side of the board) I got the appropriate readings, but when I try to read from R15 to pin 3 of U2 I get an off scale reading.
Ok good, that must be where the problem is. Test for continuity across switch 3 on S5 to see if the problem is with that component or if it is open somewhere else…i’m assuming only switch 3 is on currently. If the pins of switch 3 on S5 are not connected flip on switch 4 or 2 just to see if you can get signal through the LPF. You may have to re-adjust the low side trim pot.
EDIT…i just re-read your post and it seems like you tested across the switch already. If so, test from R15 to R21/22/23/24…it should be connected. Then measure the resistance across R22 to see if it is really 18K. Then test across the switch (switch 3 should be the only one connected, do it again for good measure). Then test to see if the other side of S5 (the opposite side from the resistors) is connected to pin 3 of U2. …just figuring out where in that signal path it’s not getting through. My guess is S5 because that’s the only component with moving parts.
I don’t know what to think. I have checked all four switches and they are all working. I still can’t get any reading from R15 to pin 1, but I also can’t get any reading on any of the bank resistors R21 thru R24, I keep thinking maybe I’m having some kind of meter problem, but then I check some other resistor and it’s OK.
As you can probably tell from my last, I’ve got myself so confused I don’t know what I’m doing I meant R15 to Pin 3 but I think I was measuring Pin 1, I did eventually get 18 K ohms from R15 to Pin 3, so I think I’m going to take a nice long break from this.
I have decided that I have spent as much time on this as I can afford to at this time. It is semi-operable and I will have to settle for that for now. I may have time to look at this again at some time in the future. Thanks for all your help.
Alright. I understand the frustration and needing to take a break. It can be very confusing working on the solder side of the board where nothing is labeled. But I do think we are close to figuring this thing out. When you are available to look at it again start by checking over the signal path from R15 to pin 3.
Take care.
-Brach
