Upgrading to Axe fx II

julindres

julindres

Member
Hey guys so I'm a happy axe ultra owner I have learned to get some really awesome sounds out of it. But my main problem and I tried a bunch of different settings and connections for the volume pedal which I use a lot and no matter what I tried I just cannot get a normal gradual sweep like a real volume pedal with a real amp. So I have been looking at the axe II and it looks great, but for the users out there and that frequently use volume pedal, including for swells and just volume control...Does the expression pedal work like a real volume pedal or is it still the same? Also would be great to hear from guys who have own the ultra and had similar problems with the volume pedal...

thanks!
 
Im using at the moment the Boss Fv 500L...Yes in the begining there is always a big dead spot and then right after the volume just jumps way high...I also tried a real volume pedal but it didn't do too good. I tried the expression pedal a bunch of different ways from using it with the volume block to using it in the fx loop...So is there a pedal out there that does not have this dead spots?

thank for the help
 
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the fractal EV1 doesn't have a dead spot. Volume block in the modifier section should have has many setting to help you tailor the sweep but there is not tricks to fix your dead spot. Such as taper type and you can adjust the curve of the sweep ect.
 
Make sure you are using an expression pedal with a linear taper. Volume pedals will almost certainly have a logarithmic taper since that is how the ear perceives volume changes. Expression pedals are changing a control voltage, not an audio signal level, so you want the pedal sweep to be flat and even. I think the Boss pedals have an expression jack on them that connects to a separate linear taper pot inside. Make sure you are using that jack and don't forget to calibrate the pedal's travel in the Axe as well.

f5P1V.png


See how the blue line has that bump in it's sweep. You want the linear response.
 
Thanks for the help everybody, the ultra does have the taper or linear options. On the pedal I do use the expression jack. I have tried different settings for the sweep that work well, but its just in the beginning of the pedal that it has a dead spot, once the volume comes on its already pretty high. I would say that around 1/4 of the pedals sweep is dead spot
 
No I'm talking about the physical taper of the expression pedal's internal pot. The taper settings in the wah and volume block of the Axe are different. Those settings change the way the control signal is translated to the the effect parameter being controlled. They do affect the way the parameter sweeps, but they are based on the use of a linear physical expression pedal. The Axe uses a control voltage to read the physical position of the expression pedal. Toe up is the lowest voltage (0%) and toe down is the highest (100%) With a linear pot, when the pedal is half way between toe up and toe down, the Axe sees about a 50% control voltage. With a logarithmic pot, the Axe would only see about a 10% control voltage (see graph above). That means that the first half of the pedal's travel does very little and everything happens in the second half of the pedals travel, hence the dead spot. Calibrating determines the start and end points for the control voltage, but the taper determines how it moves between the two. In the Axe II you can manipulate the shape of the response curve on the modifier screen to be anti-logarithmic (green line in graph above) and this can effectively counteract the use of a logarithmic taper expression pedal if needed. Not sure if the Ultra can do this or not. Best bet, use a linear taper expression pedal.
 
You might be able to adjust the position of the pot gear on the rack (little plastic bar with teeth that spins the gear) to make it rotate a bit further and avoid the dead spot at the very beginning of the pot's rotation. Many of the rack and pinion style pedal designs like crybabies as such are not able to rotate the pot it's full 300 degree rotation, so the manufacturers use custom pots that have a modified wiper range to compensate. If the pot is not set at the correct position relative to the treadle, you can sometimes get a physical dead spot at one end of the travel. You can usually push back on the rack bar and turn the pot one or two teeth in either direction to help get past it. Don't go too far and make the pot bottom out in its rotation though. You want the treadle bumpers to limit the travel, not the pot else you can break the pot wiper or shaft.

Edit: Scratch that. Just found that the Boss uses a different linkage to turn the pot. This does work for crybaby style pedals though.
 
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Yes I see, On the axe ultra I do get to use the setting to curve the pedal sweep on the pedal and it has helped, and like mr fender says with the normal straight line setting the first almost half of the pedal does almost nothing until about half way where it starts changing gradually. I do have a setting where it helps me with the beginning of the pedal but in the very beginning, I still get a dead spot. This no problem at home but when I play out at venues and the volume is much higher its very noticeable, Its almost impossible to do swells because from a very little space it jumps in volume all of the sudden
 
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