Thanks in advance for for any help here. So I've messed around with some veroboard and PCB stuff before, but this Kingslayer is an order of magnitude beyond anything I've previously attempted. I've had this Kingslayer board sitting around for a couple of years (It's the 2012 ed.) and I given that I don't have the time for hobbies I wish I did, I've put it together slowly over the last year or so.
Anyway, I finished it, it lights up and the switch seems to work in that it turns on and off. But there's no sound -- I am getting a hum. Things I've done -- I double checked the wiring, cap and diode polarity, component values, inspected the board for soldering issues. (I recently won an Amazon echo in a raffle; and it has an app that lets you read resistor band colors out loud and it will tell you the value. How cool is that?) I slept on it, and checked it all again. I've swapped out the two ICs one at a time for different ones of the same value and tested it to no avail.
Some known issues with the build -- I put in the wrong component (IIRC, it was a resistor) and had a whale of a time getting the desoldering gun to work and really did number on one of the pads. I was worried that it wouldn't work, but once I got the right part in there the my multimeter, which FWIW I barely know how to use, confirmed it was working and registering the right value. In general, the board and especially the switch is kinda sloppy. I forgot to do all the flat components at one time, a mistake I don't plan on making again. And in terms of soldering, impatience and inexperience are a bad combo -- I'm working on it! -- but I think the soldering is adequate. I've never used these plastic stereo jacks before -- possible grounding wiring issue there? And I have only tested it on battery power, haven't plugged it in yet.
Anyway, here are some pics and a copy of the old build doc. Since I'm self-taught from the internet and have no technical background, I'm hoping that there's something really boneheaded I'm just not seeing. Yes, I know, rock it before you box it, but I just put the switch and jacks in to make it easier to put cables in and out to test it. And yes, my experience with this Kingslayer means that building a testing rig just rocketed to the top of what-to-build-next.
Again, thanks for any help. I aspire to be the guy here providing advice rather than begging for it.
With input jacks like that, both have to be grounded, since they're both plastic, the out put jack won't ground through the enclosure.
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Forgive my noob-ishness, but what's the best way to ground them? What lug -- tip, ring, sleeve -- would I solder? And to where? Just to the enclosure? Or somewhere else?
And thanks!
Solder the two sleeves together and to the dc input jack.
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Thanks much. I'll give that a try when I get home from work.
Ok, I soldered the sleeve from the output to the sleeve from the input, which was already grounded. Now there's no hum, but still no sound. Would be grateful for more ideas about what might be wrong. Thanks!
the soldering looks good to me. Next thing to do is check voltages. Please measure voltages of all IC pins and post them here. Did you by any chance apply 18V, because that would fry the charge pump.
Quote from: m-Kresol on May 31, 2016, 09:22:07 PM
the soldering looks good to me. Next thing to do is check voltages. Please measure voltages of all IC pins and post them here. Did you by any chance apply 18V, because that would fry the charge pump.
The potentiometer soldering looks lacking to me, each joint should look like a silver Hersey's Kiss. Where did you get your diodes, and did you test them before you used them.
I got my diodes either from Mammoth or Tayda. And no, I did not test them. Yes, I will test and or socket them in the future.
Yes my soldering isn't great -- I'll work on it and look closer. But from my vantage point, I think it's solid enough I don't think contact with the pots is necessarily the problem? (Man I hope my judgment doesn't prove totally wrong on this.)
Anyway, I did measure the ICs with my multimeter. Please bear in mind I'm just learning how to use the thing, and for some of these the voltages were jumping around a bit. For the measurements I started with the corner (the square soldering pad and worked my way back, and for the second row I returned to the front and again worked my back again.) Many thanks for all the help.
IC1 TLC274
.258
.265
.025
3.85
.021
.063
.519
.523
.520
.448
.125
.176
.177
.516
.519
.054
IC2 TC1044SCPA
3.65
.65
.016
.326
3.52
1.81
1.62
.420
I asked about the diodes because the glass ones from Tayda are a crap shoot, they might work and they might not. Are you using a battery? If so, it looks like it's about dead. I mentioned the soldering because more often than not, reflow in and making sure you have enough solder fixes the issue. I've been at it a long time and I still have solder bridges from time to time and have to reflow occasionally, we're all human.
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Thanks, I'll go over the pots again and see what I can do to improve things. Yeah, I'm using a battery - though it was unused until I plugged it in a day or so ago. (Multimeter says it's pumping out 9 volts FWIW.) It's been in my basement for a year or so, I wouldn't have thought it would lose a charge that quickly. I'll see if I can't plug it in and retry the multimeter.
Quote from: heminator on June 01, 2016, 01:45:12 AM
Thanks, I'll go over the pots again and see what I can do to improve things. Yeah, I'm using a battery - though it was unused until I plugged it in a day or so ago. (Multimeter says it's pumping out 9 volts FWIW.) It's been in my basement for a year or so, I wouldn't have thought it would lose a charge that quickly. I'll see if I can't plug it in and retry the multimeter.
Oh, if the meter says 9v, then you're good. Definite power issues on the circuit itself.
I know this is of no help but I'll be damned if I ever use another greeny cap. I hate those little crappy things. Ugh.
Well, battery might be an issue after all... I plugged the pedal into the power supply on my pedal board and IC readings look pretty different.
IC1 TLC274
.520
.485
.003 (if it registered at all?)
8.93
.104
.520
.520
.520
.520
.448
.098
.520
.136
.513
.513
.104
IC2 TC1044SCPA
8.91 (Interestingly enough, touching this pad with probe caused red LED in PCB to light up)
8.93
.000
.516
8.93
7.60
5.08
-8.76
I've only used those neutrik sytle 1/4" jacks a couple of times but I recall having to run jumpers from lugs on one side of the jack to the lugs straight across on the other side of the jack (at least on one particular occasion). I cannot remember why at the moment but I'm guessing someone else can elaborate on what circumstances make this necessary. I do suspect it may be your problem.
Jon
Quote from: Stomptown on June 01, 2016, 04:40:04 AM
I've only used those neutrik sytle 1/4" jacks a couple of times but I recall having to run jumpers from lugs on one side of the jack to the lugs straight across on the other side of the jack (at least on one particular occasion). I cannot remember why at the moment but I'm guessing someone else can elaborate on what circumstances make this necessary. I do suspect it may be your problem.
Jon
Oh my god! How could we've missed that! You've used switched jacks. So one of the rows on the jacks are the switch lugs (which will connect to the other row when nothing is inserted). However, you've used the top row on both jacks, which is when oriented the same way not the same contacts! So one jack is good, one is connected to the switch pads instead.
Figure out which ones are the regular pads (the ones that are directly connected tap that moves upon inserting a plug) and solder to those (tip and sleeve on each jack). Or just run a wire from the pads directly across to link switch and regular pads.
voltages with the battery are indeed totally off. maybe it draws to much power. You should have -8.76V on the negative power pad of the TL074 (pin 11 if I remember correctly) with the power supply though. maybe measure those once more. The charge pump looks good though.
Fixing the switch wiring should give you bypass at least!
Ok, thanks so much for all the help. I ran jumpers across the jacks and now I do get sound. Progress! However, when the pedal is engaged I still seem to be getting the bypass sound. Turning the pots, flipping the switches seems to have no effect. I should also add that there's a slight hum. I'm off to work now, I'll try remeasuring the ICs later. Thanks again.