Weird Farting/Distortion in AMP

A setting of 6 on the volume control corresponds to a clockface settting of 1 O'Clock on the LH500. I am not familiar with this amp, but many amps are well beyond their clean power limits when the volume is turned up this high.

I could be wrong, but I suspect the rig is just at it limits when turned up to 4. I'll try to explain: The level of the volume control only tells you how much of the amp's potential gain you are using, not how much headroom you have left. The control on your amp goes from 0-10, but it's a mistake to assume that setting the control to 5 will give you half of the amp's potential volume. The level of the input signal must be considered as well. Turn down your bass's output and you can turn the amp up more before it distorts. Basically this entails reducing gain in your bass's preamp and making up for the difference in the amp, but the totally gain remains the same. Unfortunately this will not allow you to play louder and once the amp hit's it power limits it will begin to distort, regardless of where the volume control is set.

So I suspect your probably need either another speaker and/or a bigger amp. If you have an 8 ohm 410XL, the LH500 only makes 350W. The good news is you can add a second XL410 and the amp will make more power (500W at 4 ohms) and you will benefit from mutual coupling between the speakers. The mutual coupling will give you bump in efficiency in the low end and fill out the sound.

Good luck:thumbsup:
Awesome response, thanks a ton. I just want to make sure I am understanding stuff correctly. In order to prevent the distortion, I should lower bass output and increase the volume of the amp? And doing this will give me the same volume? So I could have the output of the bass on like 1 and then the output on the amp at like 7?
 
Just found this too, and as you mentioned it's not a replacement for a good compressor, but it's probably a good idea to keep it on as a bit of protection for your amp and/or speakers.

"14. Limiter switch - This switch is used to engage the LH Series Limiter circuit. The LH Series Limiter is an automatic dynamics processors used to control the level from reaching clipping. Use the Limiter to even out the loud transients that can cause distortion. Using the Limiter will also help protect your speaker system"
 
Just found this too, and as you mentioned it's not a replacement for a good compressor, but it's probably a good idea to keep it on as a bit of protection for your amp and/or speakers.

"14. Limiter switch - This switch is used to engage the LH Series Limiter circuit. The LH Series Limiter is an automatic dynamics processors used to control the level from reaching clipping. Use the Limiter to even out the loud transients that can cause distortion. Using the Limiter will also help protect your speaker system"
Thanks. I have it on most of the times
 
Awesome response, thanks a ton. I just want to make sure I am understanding stuff correctly. In order to prevent the distortion, I should lower bass output and increase the volume of the amp? And doing this will give me the same volume?

Only if you are overdriving the front end of the amp. The first step would be to make sure you are using the active input, which will pad down the signal.

However, based on your description it sounds like you are overdriving the output of the amp. In other words you want the amp to play louder than it can. So turning down anywhere in the signal path will reduce the both volume and distortion. As I suggested earlier, you may need another speaker to achieve your volume goals.
 
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Only if you are overdriving the front end of the amp. The first step would be to make sure you are using the active input, which will pad down the signal.

However, based on your description it sounds like you are overdriving the output of the amp. In other words you want the amp to play louder than it can. So turning down anywhere in the signal path will reduce the both volume and distortion. As I suggested earlier, you may need another speaker to achieve your volume goals.
Thanks. Will turning down the EQ knobs on the shecter help as well?
 
Thanks. Will turning down the EQ knobs on the shecter help as well?

If you can run with less bass, you will probably get a bit more headroom so you can play louder. But since you are running the Schecter flat, I would probably dial down the bass control on the amp a bit. If the amp plays clean when you turn down the volume control, you are not overdriving the preamp.
 
If you can run with less bass, you will probably get a bit more headroom so you can play louder. But since you are running the Schecter flat, I would probably dial down the bass control on the amp a bit. If the amp plays clean when you turn down the volume control, you are not overdriving the preamp.
Alright so less bass on the shecter and amp can lead to more headroom?
 
Too low action is the most common reason for fret buzz in my experience, and raising the action (and/or adjusting the truss rod if called for) both have the effect of moving the strings away from the pickups. I'd do that first and see if that fixed it. Subtle adjustments to pickup height can make a big difference, a little goes a long way. Measure the strings-to-pickup distance after the relief, string height, and intonation are set up. It's pretty easy with most basses and can save some $ if you learn how. The right tools cost half the price of a setup and you can fine-tune any time you want once you learn how.

But I've never been disappointed with a good setup by a pro. You're on the right track, I'd bet. Get that fret buzz and pickup height dialed in and check back in to let us know if you're still having trouble.
 
Nope, not according to the manual. A HPF is a useful tool to help tame a boomy room, and can tighten up your low end by eliminating low subsonic frequencies that are not musical but can take a lot of amp power, which is then unavailable for more musical frequencies.
Thanks man. Would you still recommend using the compressor though?
 
I have the bass plugged into active. My eq is currently Bass 6.5 Mid 5 Treble 6.5. I do have my bass all the way up. And actually, I just got my battery replaced.

If I’m not mistaken, the LH500 has the Fender tone stack. Bass-Mid-Treble set to 2-10-2 is “flat,” work from that. Your settings are boosting bass and treble but starving your mids, TalkBass orthodoxy is “Mids are your friend.”

Boosting bass on both amp AND bass guitar doubles up on your fartyness potential while not increasing perceived volume. Work your way from both amp and guitar flat and I’ll bet you can wring a lot more volume out of that rig.
 
Alright so less bass on the shecter and amp can lead to more headroom?
Yes, decreasing the bass on the Schecter or the amp should give you a little more headroom. A high pass filter (HPF) would also help. An HPF limits the sub bass that you really can't hear very well.

A compressor could give you the impression of more headroom because it shaves off the peaks. Basically a compressor can give you higher average volume but not higher peak volume.