Farty compressor

[Karma Police]

Hey everyone.

I got a Guyatone ST-2 compressor, and it's in my effects loop at the end of the chain. I really like that it tightens up the strings, especially as I have to do some chords and a lot of very busy playing.

However, I notice it's causing a "farty" sound, mainly with the open E string (well, tuned to Eb or Db) but it is audible on the other strings on occasion, when they're played open. BUT what is strange is that I can replicate the farty sound without the compressor, but its much much quieter, and only happens when I really pump the low Db hard.

I guess what I'm trying to say is that it seems to be..."amplifying" that noise - but I like what the pedal does to the other three strings.

I played it at band practise and it wasn't super noticeable, I get a pretty growly, aggressive sound. But it is bugging me!

My gear:

Ibanez RB950 Roadstar 2 (four years older than myself) > EHX switchblade > Gallien Krueger Diesel Dawg > Boss GEB7 > EHX Small Stone > Guyatone ST2.

All powered by a T-Rex Fueltank Jr.

Is it the noise it's supposed to make? Is it overdriving my amp? Is it ****ed?

[Karma Police]

And I suppose it helps to know that my amp is an Ashdown MAG300, into a 410t cab, into a Carvin RL118.

[bongomania]

If the sound happens without the compressor, the compressor is not the source of the sound. Yes it makes the quiet sound louder, that's one of the things a compressor does. But it's not the comp's fault. It's another pedal, or even the bass itself, getting clipped- and the sound is just amplified relative to your peak sounds by the comp.

[Gearhead43]

Farty sound? Just pretend you have an Ampeg.

[improvpwnd]

I had the same problem. Try turning down the output gain on the compressor a little....even if its at unity.

[Karma Police]

Thanks, I will try that. As far as I could hear everything sounded great last night at practise, but I'm fussy and like to know exactly whats happening in my chain haha.

I was worried it was perhaps a speaker problem, but then I realised that would mean it happened all the time...and also wondered if it was something loose inside, but it would appear not.

[bongomania]

Turning down the output gain on the compressor would just mean that the distortion (which is almost certainly happening somewhere else in the chain) is not being amplified as much- but then neither is the rest of your signal. So you turn up your amp more to be heard, and there it is again. I could be wrong of course, I'm not there to hear/test it myself, but this sort of thing is pretty easy to test for.

[Swift713]

Is there any input level control on the compressor? Maybe you need to turn down your bass signal into the comp.
It sounds like you're describing my bass with a low battery. Is yours active?

[dannybuoy]

The only 2 pedal comps I've ever had (EBS Multicomp and Diamond Compressor) both distorted when digging in on the low E string. The distortion was coming from within the pedal. I fixed it on the EBS by turning down the internal trimpots, and on the Diamond by running at 18v instead of 9v. So it's possible that your bass is just too loud and the pedal can't handle it!

[Fawkes007]

I had this problem with the Demeter Compulator while playing my Roscoe (with the demeter pre, no less). I turned the trim pot all the way down, and it still happened. I sold the Compulator.

[cheapbasslovin]

I'm with Bongo. If you can replicate the noise without the compressor, then it's happening before the comp and the comp is bringing it closer to the volume of the rest of your signal. Unless the Guyatone is a buffered bypass and you're overloading the input (I don't know what kind of bypass it is, or even if this is likely), the noise is happening earlier in your chain.

[DannyWBassMan22]

Does anyone know how to resolve this issue? I have had some distortion in my signal when picking the low string harder. I have taken my compression pedal out of the signal chain and am still getting it so it is obviously not the problem (I had already used the trim pot to reduce the gain as much as possible on the pedal)

I did not have this issue until I had to reduce the battery on my active bass, I had tried another 9v but still have the same problem. Is there any other way of reducing the output on my bass? I heard somebody mention an 18v battery could be a possible solution?

[donstrenz]

Does it still happen when you turn the bass down? If that fixes it, you might be able to compensate by lowering the pickups. My high output Gibson humbuckers were overdriving my EBS MultiComp like that but the Fenders didn't.

[GGman]

A compressor should be on the front end, not the last unit. It raises low levels, and lowers high levels to within a smaller range and then has output gain to make up what may be lost. I use a compressor all the time on bass. I worked in studios engineering and producing for many years. What I like is that I can now play very easily, but sound is big. All the notes and strings play the same with some added sustain. It also makes the sound punchy, especially low E that tends to get flubby without it. But, to each their own. Some may not like the sound of a compressor. Start off with very little until you start to hear and feel a difference. Back of a little if it is too thin sounding.

It is the key to why you hear the bass so well in recordings. It allows it to cut through the mix equally of all the other instruments.

GG

[bongomania]

Originally Posted by DannyWBassMan22

Does anyone know how to resolve this issue? I have had some distortion in my signal when picking the low string harder. I have taken my compression pedal out of the signal chain and am still getting it so it is obviously not the problem (I had already used the trim pot to reduce the gain as much as possible on the pedal)

I did not have this issue until I had to reduce the battery on my active bass, I had tried another 9v but still have the same problem. Is there any other way of reducing the output on my bass? I heard somebody mention an 18v battery could be a possible solution?

Wait, wait- let's be clear here: You're getting a farty sound when you dig in and it has nothing to do with the compressor. So you have to ask yourself exactly what is distorting- and then you have to examine how to improve its headroom. Headroom is how much higher your signal can get without distorting. I.e. if you are at the max of your preamp's signal-handling abilities and then you dig in on a spiky low note, the preamp will distort.

There are two common ways to resolve the problem- the easiest is to lower the level of the signal going into whatever is distorting. For example, turn down the volume knob on your bass a bit. If that concept is unfathomable to you (it seems like a lot of people are horrified by the idea) then you can put another pedal, one that can cut signal levels, in line in front of the distorting device.

What a lot of people don't realize is that you can easily set up an amp/preamp to reduce its own headroom too far, making it susceptible to easily distorting at various points other than the input. Boosting the EQ too much is the most common example, but also "enhance" and "ultra-low" and other voicing switches/knobs which scoop the mids and boost the lows will almost always set you up for unintended distortion if you aren't careful.

The power supply is always a question, because many (not all) preamp/effects will distort easily if the power supply is inadequate. A low battery is most common, but a wall-wart or 'brick' supply with not enough total amperage available for everything plugged into it will also cause this sort of problem. As danny mentioned above, some pedals will have higher headroom when run at a higher supply voltage. I've even read that the Alesis 3630 will distort less if you use a wall wart with higher available amperage than the stock supply it comes with, so make no assumptions. You can always safely use a power supply with a higher amperage rating, but with voltage you have to check with the manufacturer about any specific piece of gear to be sure it can safely handle higher voltage.

First step, though is process of elimination. If you get the farting sound when going straight from bass to amp with nothing in between, then the problem is in the bass (battery, pickup height, bad electronic component, even a bad solder joint) or in the amp (EQ settings, gain staging, bad component/solder joint).

Depending on your results, then you would add one pedal at a time back into the chain, or adjust one EQ/voicing control at a time, and continue from there. Good luck!

[bongomania]

Originally Posted by GGman

A compressor should be on the front end, not the last unit.

Welcome to Talkbass! Since you have plenty of experience with compressors, perhaps instead of telling us what a compressor is, and making blanket statements about where it goes in the chain, maybe you have some advice for the posters asking how to reduce clipping (farty noises) in their pedal compressors?

[DannyWBassMan22]

Thanks for the opinions and information.
I managed to try using the amp today with another active bass, the amp had no issues at all with regards to the distortion (the bass I tried out was a 6-string and the amp could handle the B-string without any issues).

I also tried lowering the volume as much as possible and just using the eq from my amp rather than the bass but to no avail.

Since I know that the problem is with the bass I managed to get hold of a local tech who said he would have a look at it, he advised that it may require that the pickups be lowered to resolve (as somebody else did mention on this thread).

Thanks for the feedback and I'll let you know the outcome!

[JanusZarate]

Hold on just ONE second. You're running them through the effects loop? There's your problem!

I'm surprised no one else has addressed this yet.

Most pedals don't work well in the effects loop of your amp. It's usually intended for rack effects.

The problem is this: The effects loop produces a much higher output, often close to or at line level. Such output is great for rack gear, but is often too much for most effects pedals. The result? Fartiness and other less pleasant overdriven sounds.

It doesn't harm your pedals at all, but it usually causes your signal level to drop much lower than it normally is, and it just doesn't sound all that great.

Try running your pedals in front of your amp, into the amp's input, instead of using the effects loop.

However, if you still get that fartiness, then I would look to the output of your bass. You can try turning down the volume on your bass, lowering the pickups, adjusting the onboard EQ, or lowering the input level on the amp.

If that solves your problem, you could try putting the pedals back in the effects loop and re-assess how they do in the loop compared to how they do in front of the amp.

On a side note... a lot of guitarists use effects loops, and some bassists do, too. The main reason often is because of how the preamp is being used. Guitarists usually push their preamps into distortion, and most prefer modulation after distortion. The effects loop allows them to place effects after the preamp, but before the poweramp.

[Inverness]

So I have a tangential question here. Is it more beneficial on bass to put your modulation effect and what not before the distortion? Because as I'm walking down my effects path, the only thing I've got between my bass and my amp (besides a wireless unit sometimes) is a Russian Muff and the Polish Love. I've potentially got a Yamaha SPX-990 on the way, which is of course a rack unit. I've got a dbx compressor up there in the rack, as well. Should I be re-thinking this?

[bongomania]

That's totally up to personal taste.