Cliffs tips about the 4-cable method

[dongrosh]

don´t miss that from the old forum:

Noticed a few posts with people getting noise using the 4-cable method. Couple things to note:

1. Proper gain levels are of paramount importance. Make sure your input level is set so that the red LED lights occasionally.

2. By default the FX loop runs at -6 dB. The Main slider will say 0.0 but it's actually 6 dB less than that. This is to prevent output clipping. For best SNR you want to increase this. Try 5-6 dB.

3. Set the Output2 Level knob around 1:00. This should be roughly unity gain.

I re-tested the method using a Mesa set to high gain and got a little hum but virtually no other noise. I threw a gate in after the loop to kill the hum.

CC

 

[jdurso]

good stuff man. i printed that out so when i finally get my Axe i can try that out with my Roadster. What Mesa are you rocking?

 

[Tone Jones]

There is still way excessive hum any time I engage the FX loop block with my head in the loop. It's so great it renders the 4CM useless. This very well could be my breaking point because if I can't use it in this configuration I'm forced to either use the AxeFx exclusively for effects and tone shaping or only in the loop of my amp which obviously won't allow pre-gain effects placement. This is not what I signed up for.

 

[javajunkie]

There is still way excessive hum any time I engage the FX loop block with my head in the loop. It's so great it renders the 4CM useless. This very well could be my breaking point because if I can't use it in this configuration I'm forced to either use the AxeFx exclusively for effects and tone shaping or only in the loop of my amp which obviously won't allow pre-gain effects placement. This is not what I signed up for.

You should be able to get rid of the hum by isolating it w/ an ebtech hum eliminator, ISO'd out of a buffer, or some other device that can isolate the input from out.

Some people additional are finding excessive hiss, but the hum should be easy enough to get rid of. I have had to deal with numerous problems like this using a multi- amp, mutil-effect rig. isolation transformers and buffers w/ ISO'd output are your friend in these cases. Plus careful cabling, isolating you rack from the rack and other rack items.

 

[acwild]

I'm getting excessive noise as well. Hey JJ, are you saying that it's AC hum (ebtech recommendation)? The noise that I have is present with my amp volume all the way down.

 

[javajunkie]

I'm getting excessive noise as well. Hey JJ, are you saying that it's AC hum (ebtech recommendation)? The noise that I have is present with my amp volume all the way down.

Sounds like a ground loop to me.

 

[acwild]

I'm getting excessive noise as well. Hey JJ, are you saying that it's AC hum (ebtech recommendation)? The noise that I have is present with my amp volume all the way down.

Sounds like a ground loop to me.

Looks like the ground lift only works for balanced cables too. I guess I'll order the Ebtech and give it a try, thanks!

 

[acwild]

I got rid of the hum by plugging my amp into the same socket as my AxeFx. Man, that was a simple enough fix. Now I just need to figure out how to get rid of the hiss.

 

[AlbertA]

I got rid of the hum by plugging my amp into the same socket as my AxeFx. Man, that was a simple enough fix. Now I just need to figure out how to get rid of the hiss.

Gate block

 

[acwild]

I got rid of the hum by plugging my amp into the same socket as my AxeFx. Man, that was a simple enough fix. Now I just need to figure out how to get rid of the hiss.

Gate block

No luck. The noise is just there. My Master volume has no effect on it, so I don't think it's a "sent" noise as much as an existing one. With a regular pedal, the effects loop is silent. :?:

 

[AlbertA]

Ahhh that type... Sorry...

 

[acwild]

Ahhh that type... Sorry...

Ha ha, thanks for trying anyway bud. I'm hoping that the Ebtech thingy that JJ recommended will do the trick.

 

[javajunkie]

Ahhh that type... Sorry...

Ha ha, thanks for trying anyway bud. I'm hoping that the Ebtech thingy that JJ recommended will do the trick.

Ebtech won't do a thing for his, only ground loops.

 

[acwild]

The hiss is gone! :mrgreen:
Using the four cable method, I had to max out the volume of Input 2 so that I could turn down the Output 1 volume. Apparently Output 1 was the culprit. By maxing out Input 2, I was able to turn down Output 1 to the point that the noise is almost inaudible.