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I just built the Cupcake. Everything works but I have a few questions:

1. Is the 10K pot supposed to be at 0 volume at it's lowest setting, then peak midway, then return to 0 volume when at its highest setting?
2. I am getting wild squeals with the trimpot in most settings (persistent, throughout notes being played) that change pitch and intensity if you roll the guitar volume/tone up or down. What is going on?

Now I admit - I ordered my IC from Tayda and they did not have something called JRC4558, but "NJM4558" (which has 4558D / JRC / 0058T). That is the IC I am using and getting these weird results. There is a setting I can reach where there is no squealing, but it seems to not be doing much as a compressing effect. Again, the volume is at 0 when the level pot is at 0 and returns to 0 when the level pot is maxed.

I also bought another "4558" IC from Tayda - the TJM4558CN - do not know what kind of difference this will make. It's tough to desolder ICs. Any pointers on that, while we're at it!?

Josha

I built the Runt previously and housed it in a temporary enclosure. Now I decided to finally try and get it into the 1590A and have run into a few issues. I basically followed the baby build guide step by step. I got it to all fit. I checked the bypass which seemed to work. I installed the pots and connected up IN/G/OUT at the bottom of the board to the 3PDT switch, 9V and G at the top to the DC jack and fired it up to no great success...

I switched out C1 with a 2u2 electrolytic, and I believe I have the polarity correct (can this be tested with DMM?) - currently negative lead is connected to R1. I had it the other way around originally and was getting no signal.

I am fuzzy on the resistor that completes the LED circuit, but have attached a photo to show my interpretation of the baby build procedure.

I am getting a loud buzz when I turn up the volume, so I'm assuming this is a grounding issue, but I don't know where I went off.

OK, second build, Cave Dweller, super fun build, I got it all to fit into a maybe 4" diameter can. It looks like a spaceship!

My problem is with the echo function. The echo, or slapback sound is not a direct echo of the input sound. That is to say, when I play a note, the note is colored with this "pfft" or "pptthh" kind of fuzzy sound. This only takes effect in the last 1/3 of the echo pot. The first 2/3 of the sweep are clean.

I replaced socket C3 with a 3n3 cap, and also have a 1uF tantalum cap in C10. Polarity on C10 is correct.

I have not tried any problem solving yet, as I am quite new, and am more so "assembling" pedals at this point than "building" them. Anybody have any ideas?

Built the Runt. Sounds great. First build ever (still unboxed). Had a blast. BUT...

I originally used a 3mm blue LED for a power indicator. I noticed when I touched one of the LED leads when it was powered, it glowed slightly, although the pedal was off. I then turned the pedal on, and after a minute or two of playing through it the LED apparently died. I replaced it with 3mm green. It began blinking when I turned it on and played, and died very quickly.

I am using a CA3130EZ instead of the LM308. Also, I am using an electrolytic capacitor for C9, however the polarity is correct.

Any idea what's frying my LEDs? This was really fun for me and I'm eager to get it into a box!

I am trying my hand at my first madbean build and I have some electrolytic caps of certain values to use where film may have been more convenient. How can I tell which direction to place the +/- leads when it is not specified on the build docs?

Thanks from a 1st time builder...