diy pedals making slappy sound

[richreynolds]

Hi, this is my first post here.  I've built two pedals so far, the lovepedal woodrow and the lpb-1. They both have the same problem. They make a very slappy and trebley sound when playing the low strings. I cant figure it out. Any ideas as to what would cause this?

[Kipper4]

Hey buddy welcome to the forum.
Why  dont you post up a sample so we can see or rather hear what it is your dealing with.
the descriptions a bit vague

[richreynolds]

The sound is most noticeable while palm muting. It's very very trebly when muting the low strings.  Sounds similar to muting the high e string but on the low e. Both pedals do it.

[artifus]

this sounds like extreme compression or limiting artefacts. signal's being slammed somewhere and the effect you are hearing is recovery.

[richreynolds]

How can i fix this artifus?

[artifus]

reduce gain

[richreynolds]

So a transistor with less gain? Can resistors affect the amount of gain also?I'm still very new to building effects

[aron]

Are you sure it's not your amp?

Aron

[richreynolds]

Fairly certain it's not the amps. I use many effects through an Orange Rockerverb and Marshall JCM 800 and the other effects all sound fine.  Could it possibly be in the 3pdt switch wiring or maybe the soldered connections on the veroboard? I've heard this could possibly be a grounding issue also.

[richreynolds]

when i put my finger across the C1 and ground row it seems to sound fine. This is the layout i used for the lpb1.  http://diy-layout.com/diyl/25/render 

[pinkjimiphoton]

sounds to me like your input cap is off by a factor of 10,000 or so...

what size input cap to the circuit?


make sure you didn't put in say, 1000p (.001u/1n ) where it should be 10,000p (.01u/10n ) or 100,000p (.1u/100n).

i can't tell what you built from the link you put up to diylc, but the input cap could be anywhere between any number of ranges.

it sounds to me like your input cap is way too small, and you're rolling off most of the bass... and that would account for the extreme bass cut.

ESPECIALLY since ya say when ya bypass c1 with your finger (which also happens to be a capacitor, for all intents) it sounds "normal"

i just looked at the thread a little closer, and yeah, i bet your input and/or output caps are way smaller than they should be... check it out, and hollah back!

[richreynolds]

The input and output caps are .1uf

[pinkjimiphoton]

not to sound like a douche, but you're SURE they are both right?

i often find components mismarked, and if ya use say, ceramic cap, you have up to an 80% tolerance..

[Jdansti]

What are the markings on your input caps? 

[richreynolds]

The markings are 2a473j

[Jdansti]

2a473j would be a 0.047uF (47nF) cap.

[artifus]

that should be fine for guitar. next.

[Jdansti]

>The input and output caps are .1uf

It may not be the problem, but your input caps are ~1/2 of what you said they are.

Quick check: You might want to use some alligator clips or some other way to temporarily place another 0.047uF cap in parallel with the one on the board and see if that helps.

[pinkjimiphoton]

that will also cut about half the bass, making it more of a high mid booster than a full range booster.

i still say that's the problem, especially if input and output caps are the same. the output cap not so much,
but if putting a finger across the input cap makes it sound "right"..
i bet jdantsi just posted the "cure".  remember...just cuz the cap is marked 47n, doesn't mean that that's the value of the cap, or it isn't mis-marked.
it could be off by a pretty huge factor.

try a second in parallel... if it suddenly sounds better, that's your problem.. i've built this circuit with up to a 10 u input cap. i don't reccomend that, as it's too much low end and becomes unstable when cranked. but it sounds "normal" even that big.. it passes all the guitar frequencies, and sub harmonics.

a 47n cap is gonna roll off a LOT of the low end. in a fuzz not such a big deal, but in a booster, it's half way to treble booster imho

someone like gus, aron, mark or rg could probably explain it way better than me.

[Paul Marossy]

a 47n cap is gonna roll off a LOT of the low end. in a fuzz not such a big deal, but in a booster, it's half way to treble booster imho

I kind of have to agree...