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Your second issue is supposed to happen,they all do this. Helps tremendously when you're testing it. But even my BYOC pedals stay on when powered with an adapter and not a battery. Glad you got this first issue straight,it's a heavy pedal. I built one and now why I know it's called a chunk chunk,cause that's the sound the pedal makes for sure!

Yea its a great pedal but no where near as chunky as my Zoom driver pedal. I was hoping the Chunk Chunk was going to be its replacement so I could retired the poor old thing. Oh well!

Sorry for taking so long to reply but I figured out the main issue.

Due to a skechy borrowed muti meter the trim pots were set at to high of a voltage. Got them set at the right voltage and it works great.

Still have the 2nd issues though where the unit doesn't power off when the input cable is unplugged.
Heres a picture of the wiring if anyone can see the issue.

Yep

First, check your wiring against Madbeans Standard wiring diagram. Next, check all your solder joints for any cold ones. After that, check (and double check!) your component values, check for solder bridges etc... If you want to narrow down the options, first read the Rules For Getting Tech Help, and then re-post add to your post accordingly. Good luck!

Paul

When wiring it up I followed the Madbeans Standard wiring diagram and Ive checked that several times. I normally as a rule go over all of my solder joints as I go then check them again ones Im completely done, but Ill go through them again and also check all of the values ( Sorry I read the rules when I first started here but forgot about checking the values).

Check your resistor values, you may have gotten a batch of mislabeled. Secondly are you powering from battery or adapter. You still get power with no cable with an adapter but not with battery. Off board wiring is correct?

Jimi the Chunk Chunk is not wired for a battery but the other pedal that Im having the same problem with is wired for both and has the issue on both.


Thank you both Ill come back when I have more info.

Ok I got my Chunk chunk finished but Im having a couple of problems:

First issue is the biggie I get a bypass signal but when I engage the unit I have a very weak signal and hardly any distortion. Turning the lvl up to max doesn't even reach the amps volume. I followed the BOM and didn't change any part values, didn't do any mods and all of the trimmers are around 4.5 v.

Im not a tech so Im looking for a place to start or if some knows what the issue is right off that would be awesome.

Second issue is that when the input cable is removed the unit still has power. Ive never ran into this issue so Im not sure what it could be. I now Ive 2 pedals that have this issue. Ive double checked the wiring (both pedals are wired differently).

Thanks in advance

1.- You could just use any combination that reaches 30n, like 22n and 8.2n, or 18n and 12n, 3.3n and 27n, or just use a 33n and leave the other empty.

2.- the bias @ 4.5v is a starting point, it depends on your transistors, and other component values, as well as your power supply, if you are @ 9VDC you could start with 4.5v on all trimmers and then moving it up a little, maybe the first stage with a couple more mV, and the rest at 4.5v.

On mine (running it @ 12vDC) i have the first two stages a little higher than the other two.

Use your ears to taste.

Hernan.

Thank you for answering my questions Hernan, but it just raises more. I leave those for now and get back to building this beast.

Im building a chunk chunk and I ran into a bit of a problem. Well while Im here I might as well ask a couple of questions.

1: I messed up when I was ordering my parts I needed to order two 15n caps but I only ordered one. I don't have anything local that resembles a electronics store other than radio shack  and they don't carry that value. On the board these go in c18 and c19 they are in parallel to add up to 30n. My question here would be can these caps be subed for different values and what difference would it make?

2: The doc for the chunk say to bias the trimmers at 4.5 volts. Ive seen others that say 5 to 6 volts. What are the differences?

Thanks in advance for your help.