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I built a Civil War Muff’n with several of the upgrades, including the Tone Bender switch, 3 way Diode clipping selection, and the Tone TwEQ. The tone TwEQ seems to be working properly, but neither of the mini toggles(Tonebender and Diode Clipping selection) seem to be working, and there also doesn’t seem to be very much gain for a Muff pedal. Any help would be greatly appreciated, thank you!
Isaac, it may not be what you want to hear, but you’ve got quite a few mods going on all at once here. It might be best if you worked from a known-good place, add a mod, verify that the gain levels are working correctly, etc, and then make the next mod. Does the Tone TwEQ provide the same gain level in as it does out, if the knobs are in the middle? If you disable the “bender” feature, does the Muff get louder? There should be a significant difference in the volume level of the muff with different clipping options, as an LED has a forward voltage much greater than silicon diodes. On the diode selection switch, check continuity of the switch between the end lugs and the center lug in each position and make sure it’s working correctly. Make sure that the LED shape matches the PCB the way they are mounted. If they are both backwards from the screen print, it’s okay, but if one is right and one is wrong, you will need to fix that.
I am sure some of the other guys here have some ideas as well.
Bruce, thanks for the info. Should I try to go through and undo the mods? How do I check the gain levels, specifically before and after the Tone TwEQ? Nothing changes tone wise or volume wise when I flip either of the mini toggles(the “Bender” or the Silicon/Off/LED clipping selector switch). I just checked the continuity on the diode selection switch, in position 1 I have continuity between lugs 1&2, 2nd position has no continuity, and the 3rd position has continuity between lugs 2&3.
It sounds like the switch is working fine.
If it were me, I’d de-couple the 2 boards and work each one working with the simpler mods, one at a time, starting with the built-in diode selection switch, and once the Muff is done, and the Tone TwEQ is verified separately, couple them back together.
If you have a 150k resistor, you can replace the Tone TwEQ and the built-in original tone section with a 150k resistor, just during troubleshooting, and make sure that the output level issue is not the Tone TwEQ (instructions in the build document on this).
I would not undo the Diode Selector mod. That’s very well known and is fairly simple. I can’t tell whether one of your LEDs is flat on the visible side to match the silkscreen on the PCB. Please verify.
I just compared the Civil War values in the build document, which aligns with what I sent you, and everything looks good in that regard. I did not look at every color code on every resistor on your build, determine the value, and make sure it aligns with the specified value. Your image is also not in great focus across the entire thing, so it’s difficult to read capacitor values, etc. I know you’ve done some other builds, but a picture of the solder side is usually requested to make sure you have good “Hershey Kiss” shaped solder joints and that the soldering is not the issue.
I don’t want you to jump all over this next comment, because I don’t think this is your fix, but…
In regards to the gain level, I will tell you this–The R25 resistor was added to reduce the gain a little bit, as many of the modern transistors were “too hot” and started to cause some self-oscillation on some rigs when the effect knobs were turned up. This resistor helped bring the circuit back down to earth, but it may be that this resistor could be replaced with a jumper if you’re finding that you don’t get enough output. We saw the issue with 2n5088, which is about half the gain of the Civil War’s BC549C transistors, so I suspect switching this to a jumper may introduce issues, not resolve any. You could try it. You could probably tack-on a jumper on the solder side of the board which could be easily removed later if needed.
Lastly, if you are going to be building combo builds, I strongly suggest you build yourself a test rig, similar to the Beavis Board. You don’t need the voltage sag feature, but basically something with jacks and a footswitch and terminals that you can connect/disconnect a circuit board to test to make sure it’s working without wiring up the circuit into an actual enclosure.
Thanks! I do not currently have a 150k resistor, any other way to bypass the Tone TwEQ and not install the removed resistors and capacitors?
It looks like the LEDs are facing the proper way, one left, and one right.
I will get a couple better pics and post them.
How would I go about building a test rig? That sounds like a fantastic idea!
I accidentally labeled the Volume and Sustain reverse on the enclosure, that’s why those 2 pots are not directly wired to the PCB
I removed the Tone TwEQ, and reinstalled all of the jumpers, resistors, and Capacitors on the Muff’n circuit, and it is still not working properly. Neither mini toggle changes anything, amd I hardly have any gain or volume. Any help would be greatly appreciated!
Isaac, the transistors all need to be inserted backwards from their current orientation. I just looked up the data sheet for both the BC 549 and the 2n5088 and the pinout is reversed between the two. There is a note in the build document about this, and unfortunately I didn’t really think about it when reading this thread the other day. Give that a shot and report back please.
Bruce, thank you very much!! That did the trick, and it is all working perfectly now, except the Diode Selector Switch doesn’t change the tone very much at all. Should it? There’s no volume difference between LED, Off, and Silicon. And I thought you had mentioned there should be. Thanks again for all of your help!
Also, should the Diode Selector work with and without the “Bender” engaged?
When the Muff Bender switch installed at J2 is open, the clipping diodes at D5 and D6 are disengaged. That eliminates those from the circuit. With the SUSTAIN pot fully clockwise, you will have the maximum signal reaching the diode clippers at SW1. The switch needs to be a ON/OFF/ON type SP3T switch wired as shown. In the center (OFF) position, no clipping diodes are engaged and there should be no change in the signal level. In the other switch positions, you will engage either LEDs or other diode pairs. The signal level will be clipped (distorted) and reduced. If you are not hearing a change when switching, the switch or its wiring may be faulty or the LEDs/diodes may be installed incorrectly or may be faulty. Check these items and report.
I did a continuity test on the switch, and it seems to be working correctly. I took a pic of testing the correct spot(the middle spot on the SW1 set), the other probe to ground. I was getting .743v in all 3 settings(LED, Off, and Silicon). Was I checking this properly?
Not sure. Continuity setting on your DMM should have a diode symbol and read 0 volts for continuity and infinity for an open circuit.
What setting should I have my DMM on when checking the signal? And am I checking the correct spot for testing the diodes? Thanks for your help!
It sounds like you need to back up a bit and start with reading the instructions that came with your particular DMM. That will help with your unit. Then, go to the GUIDES page on this forum and scroll down to see several helpful guides that cover the information you need to build pedals. That will make it easier for you to get specific information about each project.
We’re here to help!
I’ve been doing quite a bit of reading, and hopefully some learning about my DMM and taking readings. Please correct me if I’m wrong, but it sounds like I almost always have the DMM in DC Voltage when taking readings, except when checking Capacitors, Resistors, and Diodes. Make sure the Black probe is to a good ground. Most of the time to take readings at the pins of ICs and Transistors.
So to check the Signal level(To see if the Diode Selection switch and Diodes are working). I would put the DMM in DC voltage, put the Black probe on a good ground, and the Red probe on the “Collector” of the Q2 Transistor(blue circle in pic)? And check that in each of the 3 switch positions?
Thank you very much for your time and patience, it is greatly appreciated!
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