AX8 True Bypass Best Practice

Troy Kelly

New Member
I'm New to AX8. Using it as a front of amp pedal board only, in front of a Matchless Lightning 15 (no effects loop). I love the gain structure and tone and simplicity of the amp. I prefer having a loud amp behind me when I play, despite over a year of using a Helix with no amp on stage, only in my IEM mix, direct to FOH. I had to go back to a live Amp sound that I can feel in my chest, since the band does not use on stage monitoring at all, but strictly IEM.

I wanted AX8 to replace my analog pedal board. And mistakenly thought it had true bypass which is only in the FX8 apparently. My typical pedal board consists of Tube Screamer, delay, univibe, tremolo, etc.
First thing I noticed plugging the AX8 into my amp with no effects activated was a drastic change in tone.
The bass disappeared and the high end was off the charts not to mention a considerable hum.

What causes this drastic change in tone?
Is it the impedance setting? Is it one of the effects I've put in a block even though it's turned off?
With the Helix for example I found that setting the impedance to 1m and removing any reverb effects from the chain mysteriously fixed this and got me as close to true bypass as my ears can tell. Does the AX8 have a similar trick to save my amp tone and still use the AX8 as pedal board only? Is there a best practice to accomplish this?

I do play at least one gig a month where I have to use the amp modeler for a specific reason, which is why I chose the AX8 over the FX8. In the first day I found at least 3 amp model presets that blew away anything I found in the Helix after 2 years of playing with it.

I'm not a gear head, or an electrical engineer, I just want to play music.
Any advice is greatly appreciated.
 
I'm New to AX8. Using it as a front of amp pedal board only, in front of a Matchless Lightning 15 (no effects loop). I love the gain structure and tone and simplicity of the amp. I prefer having a loud amp behind me when I play, despite over a year of using a Helix with no amp on stage, only in my IEM mix, direct to FOH. I had to go back to a live Amp sound that I can feel in my chest, since the band does not use on stage monitoring at all, but strictly IEM.

I wanted AX8 to replace my analog pedal board. And mistakenly thought it had true bypass which is only in the FX8 apparently. My typical pedal board consists of Tube Screamer, delay, univibe, tremolo, etc.
First thing I noticed plugging the AX8 into my amp with no effects activated was a drastic change in tone.
The bass disappeared and the high end was off the charts not to mention a considerable hum.

What causes this drastic change in tone?
Is it the impedance setting? Is it one of the effects I've put in a block even though it's turned off?
With the Helix for example I found that setting the impedance to 1m and removing any reverb effects from the chain mysteriously fixed this and got me as close to true bypass as my ears can tell. Does the AX8 have a similar trick to save my amp tone and still use the AX8 as pedal board only? Is there a best practice to accomplish this?

I do play at least one gig a month where I have to use the amp modeler for a specific reason, which is why I chose the AX8 over the FX8. In the first day I found at least 3 amp model presets that blew away anything I found in the Helix after 2 years of playing with it.

I'm not a gear head, or an electrical engineer, I just want to play music.
Any advice is greatly appreciated.
How have you connected things? If you're just plugging into the front of the amp, you'll have some limitations in what effects you use... Or at least, the optimal placement in the signal chain.

Do some searching here for "4 Cable Method" (aka, 4CM) as well as Humbuster cables, which would help with noise.
 
Do some searching here for "4 Cable Method" (aka, 4CM) as well as Humbuster cables, which would help with noise.

The OP mentioned the amp has no FX loop so 4CM is not possible.

I'd start with an empty preset and just connect the input to the output block. Next adjust the AX8 output level. Does this still kill your sound ? Does it add hum ? If yes check your cables. Once these basics are fixed start adding blocks to the preset.
 
The OP mentioned the amp has no FX loop so 4CM is not possible.

I'd start with an empty preset and just connect the input to the output block. Next adjust the AX8 output level. Does this still kill your sound ? Does it add hum ? If yes check your cables. Once these basics are fixed start adding blocks to the preset.
Ah, yes... Reading comprehension helps ;)
 
The OP mentioned the amp has no FX loop so 4CM is not possible.

I'd start with an empty preset and just connect the input to the output block. Next adjust the AX8 output level. Does this still kill your sound ? Does it add hum ? If yes check your cables. Once these basics are fixed start adding blocks to the preset.

Thanks for the responses everyone. The cables are good and quiet. Both are dead quiet plugged straight into the amp. When I plugin the AX8 with empty blocks from input to output I get a hum that is acceptable (I guess). And basically my bass drops out pretty significantly and high end get's real high endy (as far as the ears in this forum would be concerned, granted the drunk guy groping the drunk girl in front of the stage probably won't know the difference). So I basically crank the bass knob on the amp to about 5'oclock (up from 2 o'clock) and the treble knob back to 12 o'clock (down from 2 o'clock). And I do have two identical matchless amps that I can quickly A/B next to each other and have sounding identical with nothing in the middle. Then I put my analog pedal board in front of one amp and the AX8 in front of the other amp.

Compensating using the bass and treble knobs on the amp get me roughly the same sound, and it's not like my analog pedal board doesn't have a hum when the tube screamer goes into action. But there is definitely a fullness and roundness to the overall tone that is gone. Ever so slight. I do use the gain structure on the amp extensively... From clean to hard rock dirty. I use volume to control the amount of distortion on most songs, but I also have 4 goto gain settings depending on the song and how much distortion I need when my guitar volume is at 10. I don't think the AX8 plays nice with my gain on the amp. Part of my challenge is that a lot of times I need to burst into a lead, but I'm on the other side of the stage and I do not have access to my pedal board. It actually sits behind a keyboard rig in the back of the stage unless I'm the only guitar player for whatever reason on a given night. I'm gonna give it a try this weekend on stage and talk to the sound guy and the other guys in the band see what we think.

Based on th eresponses here, I'm thinking ethe AX8 is going to do it's own thing and react a little differently with every amp and every gain structure. There's no magic sauce to get a neutral bypass from input to output.
 
When you say “empty blocks from input to output,” are you referring to having an empty footswitch page, or do you really have just a string of shunts between the input and the output? Those two situations aren’t identical.

With no blocks involved (shunts only), the AX8 won’t change your tone. What you’re describing sounds like a classic case of having a wah engaged without realizing it.
 
When you say “empty blocks from input to output,” are you referring to having an empty footswitch page, or do you really have just a string of shunts between the input and the output? Those two situations aren’t identical.

With no blocks involved (shunts only), the AX8 won’t change your tone. What you’re describing sounds like a classic case of having a wah engaged without realizing it.

Lol, I hear ya about the wah. No wah in this chain.
Shunts only... straight across from input to output. The footswitch page has the 8 empty slots, nothing selected. Nothing to select, I didn't add anything yet.

It changes the tone (the more gain I have on the amp, the more it changes). And the Shunts only config actually sounds identical to a full pedal board with everything switched off (Once I add phaser,drv,dly,trm without engaging them). On my Helix for example I found that the presence of the reverb patch I was using changed the sound quite a bit even when it was off.
When I deleted the reverb block (and changed the impedance) the tone sort of snapped into place.

I'll keep experimenting. If the band likes and the sound guy doesn't have an issue. maybe it'll just be my new sound. I dunno.
Thanks guys.
 
Lol, I hear ya about the wah. No wah in this chain.
Cool. I had to ask... :)


Shunts only... straight across from input to output...

And the Shunts only config actually sounds identical to a full pedal board with everything switched off (Once I add phaser,drv,dly,trm without engaging them).
That's a good sign. It indicates that the change in tone is coming from somewhere else.

The AX8 has a high input impedance; possibly higher than your amp. That could result in somewhat increased treble, but it could not affect the bass response, and certainly wouldn't make the bass "disappear." Something else is going on. Can you share a clip of the two sounds so we can hear the difference?
 
Cool. I had to ask... :)



That's a good sign. It indicates that the change in tone is coming from somewhere else.

The AX8 has a high input impedance; possibly higher than your amp. That could result in somewhat increased treble, but it could not affect the bass response, and certainly wouldn't make the bass "disappear." Something else is going on. Can you share a clip of the two sounds so we can hear the difference?

Is the impedance adjustable? Does it change based on what's in the pedal chain?
I mean the manual says instrument in is 1megohm and the output is 600 ohm. Whatever that means.
The hum is definitely related to the gain on the amp. Higher the gain the more hum, whereas it's dead quiet going straight in with gain maxed out. And it's not part of the signal chain, a gate does not affect it. Maybe something going on with my electricity at home and a combination of what's plugged into where? I'm no electrician, I'll see if the hum is there when I setup at the venue.But hum is not the main issue, it's quiet enough for live rock n roll, but enough hum that I couldn't record the AX8 through my amp in any serious way.

I've been avoiding the hassle of recording and analyzing the differences, but might be worth the effort.
 
Sorry, not native English speaker.

I thought he wants a TRUE true bypass.

An absolutely great thing about this forum is how people from all over the world come together to make our music sound better. What a concept! Appreciate all you guys who don't speak English as a native language making the effort to communicate in ours. More power to you. Mahalo, Arigato, Merci, Danke and so on.
 
Yells at others saying "what the hell does this have to do with the question being asked?"....can't read himself....
First off, I didn't "yell" at anybody.

Second, I misread 3 words, not a 6 paragraph post.

Third, I admitted my fault, which is more than many do.
 
Is the impedance adjustable? Does it change based on what's in the pedal chain?
I mean the manual says instrument in is 1megohm and the output is 600 ohm. Whatever that means.
The hum is definitely related to the gain on the amp. Higher the gain the more hum, whereas it's dead quiet going straight in with gain maxed out. And it's not part of the signal chain, a gate does not affect it. Maybe something going on with my electricity at home and a combination of what's plugged into where? I'm no electrician, I'll see if the hum is there when I setup at the venue.But hum is not the main issue, it's quiet enough for live rock n roll, but enough hum that I couldn't record the AX8 through my amp in any serious way.

I've been avoiding the hassle of recording and analyzing the differences, but might be worth the effort.

No, the AX8 doesn't have adjustable input impedance. The hum could be caused by a ground loop. Did you try the ground lift switch ?
 
Not used, bought new from Fractal. Ground lift had no effect. I’m not using XLR to go into my amp. Maybe a balanced cable would help? TRS? I was just using a regular instrument cable.

Too late to test now. Have to break out differentcables before tomorrow nights gig.
 
Is the impedance adjustable? Does it change based on what's in the pedal chain?
As @ChristThePhone said, no. That feature is available on the Axe-Fx, but not the AX8.


The hum is...not part of the signal chain, a gate does not affect it.
That indicates a ground loop. Make sure that your AX8 and your amp are plugged into the same wall outlet. Humbuster cables can help with ground loops. You might also find that disconnecting USB from your computer helps.


None of that resolves the fact that you're losing bass. Something isn't right. Are you running strictly guitar > AX8 > amp and nothing else?
 
Back
Top Bottom