4CM hissing

T

Tabs

Member
Ok restarting this from the old forum...

I'd really appreciate it if someone from Fractal could comment on this. If I'm doing something wrong I'd like to know what, as I think I've tried pretty much everything I know of, and if it's not something that can be solved I'd like to know so I can start looking into other options. I've had my Ultra since March and haven't even used it at a show yet because of noise problems between it and my amp. (ground hum first and now this hissing thing)

No matter what I set the Axe knobs to, iso boxes in the chain or not, I get a significant increase in hiss through my Diezel VH4 amp+cab when I'm running the guitar through the Axe-FX vs. direct into the amp. It sounds similar to what some lesser quality high gain amps (like a 5150) do. The VH4 is almost completely silent on its own unless you go to extreme preamp gain settings, which I'm not even close to doing.

I have nothing but an FXL block in the Axe's chain. It should just be cleanly passing the signal on to the amp, but some extra noise is getting in somehow and it's then being amplified by the VH4's preamp into the hissing I'm hearing.

Thanks,
Ryan
 
Hey guys, we had a 3 page thread goin on the old forum.

I'll try to make a video tomorrow to show exactly what's going on, but i am positive that all connections are correct and high quality cables are being used in Tabs' and my setup.
 
I've not connected the AxeFX to any other amp or preamp yet. I do know that using other digital gear with tube amps I've had some similar problems with increased noise. Does anyone know if the Out 2 is passed straight through as an analog signal, or does it go through A/D/A conversion? I am guessing it's the latter.
 
tubetonez said:
I've not connected the AxeFX to any other amp or preamp yet. I do know that using other digital gear with tube amps I've had some similar problems with increased noise. Does anyone know if the Out 2 is passed straight through as an analog signal, or does it go through A/D/A conversion? I am guessing it's the latter.
Click to expand...

You are guessing correctly.
 
I just hooked up my Egnater M4 in the loop of the AxeFX and got a pretty nasty hissing noise that was enough to be a problem.
I had a similar issue with setting up my Egnater M4 with a Digitech GSP1101.
The problem there was that the noise gate was BEFORE the loop where the external preamp was; so the gate in the unit was not eliminating any noise that the M4 generated.
The only way around that issue was to put a separate noise gate after the 1101 in my signal chain.
Seemed to be a big complaint about the GSP1101 that apparently Digitech is working on for an update available later this year.

Not sure if the same issue exists with the AxeFX - only had a few minutes to test it out tonight.
 
tubetonez said:
I've not connected the AxeFX to any other amp or preamp yet. I do know that using other digital gear with tube amps I've had some similar problems with increased noise. Does anyone know if the Out 2 is passed straight through as an analog signal, or does it go through A/D/A conversion? I am guessing it's the latter.
Click to expand...

Well it has to be converted - there'd be no point otherwise. The whole goal of the 4CM is to be able to have both pre and post effects routing all out of the same unit.

jimosity - the issue is really that my amp is silent when I plug direct into it, but hisses when running through the Axe-FX. Noise gate is a moot point the way I see it since the noise shouldn't be there in the first place... I think we've got the cause figured out in the other thread though after Cliff said that it's a Line Level signal coming out of Out 2 and not Instrument Level.
 
steveb said:
Javilynch said:
I have the same problem with my Cornford mk 50 on hi gain settings....tons of hissing!!!!
:?
Click to expand...

Do you have a passive DI box? Try this....

viewtopic.php?f=23&t=377
Click to expand...


The Reamp box website states this:

Question - Some people say I can use a passive direct box in reverse for reamping. Is this true?

Answer - – No. This would not work because of the large level differences between a microphone level signal and a line level signal. On the direct box the instrument input is designed for instrument level signals (-20dbm) and the microphone out is designed to give a microphone level signal (-60dbm typical) using a direct box in reverse would put a +4dbm signal into a –60dbm output and would cause extreme signal distortion before you even plugged into the amp.


The Reamp box look good but states it w/ only do the converstion for +4 balanced to instrument level (output 2 is unbalanced however):

http://www.reamp.com/


The same is true of the Radial remping device in the link above.
 
The Reamp FAQ also states this which releates to unbalanced connections:

Question - I use a computer with a sound card. Do I need a Reamp to send recorded tracks to a guitar amp?

Answer - Yes. Most high-end music cards (m-audio, lynx, aardvark) have +4 outputs on breakout cables. If your computer sound card has +4 outputs you are ready to go into the Reamp. Many consumer “off the shelf” computer cards (Sound Blaster type) are only –10 unbalanced. In this case, you will need to lower the output level another 10 to 15 dB, stay unbalanced and go directly into the amp without a Reamp. Don't call me if it doesn't works.
 
Another possibility is to run the signal from the mixer through a guitar pedal or preamp that has a buffered bypass. Passing the signal through the bypassed pedal will correct the signal's impedance. Obviously, a pedal with a hard-wired or 'true' bypass circuit won't be any use for this.
Click to expand...

This article would suggest a bs2 buffer splitter would be the way to go:

http://www.soundonsound.com/sos/jun04/a ... 0604-3.htm

It would also explain why I did not have an issue because my signal was buffered by the switchblade before going to the amp.

It would be easy to test. Throw a buffered effects pedal in between and see if it doesn't fix it.
 
javajunkie said:
The Reamp box website states this:
Question - Some people say I can use a passive direct box in reverse for reamping. Is this true?
Answer - – No.
Click to expand...

While they say that, in fact it does work quite well as I mentioned in the other thread I pointed to. Its MUCH better than just plugging the Axe into my Boogie. Lets not forget that Reamp is trying to sell something, but browsing other forums it's pretty common to use the DI in reverse trick for this type of thing. While the DI thing works, something like the reamp may in fact work a bit better, but at the moment the Reverse DI is working well enough for me that I'm not in a hurry to spend money on a reamp box when I already have a Whirlwind DI.

javajunkie said:
The Reamp box look good but states it w/ only do the converstion for +4 balanced to instrument level
(output 2 is unbalanced however):
Click to expand...

You can probably plug an unbalanced 1/4" TRS into the reamps 1/4" balanced in.. thats worked on every other piece of 1/4" TRS gear I've ever used. Once again, refer to the other thread I referenced before. Other reamp boxes may require a 1/4" unbal to XLR adapter, which are readily available.

However, caveat being I haven't actually tried a reamp box yet with the Axe, so YMMV.
 
javajunkie said:
This article would suggest a bs2 buffer splitter would be the way to go:
Click to expand...

A buffer will fix the impedence but not the levels, as the article says. With the reverse DI I'm using ( or presumably a reamp box) the Output2 control on the Axe is useable over it's entire range, rather than just the first tiny amount of it's travel.
 
steveb said:
javajunkie said:
The Reamp box website states this:
Question - Some people say I can use a passive direct box in reverse for reamping. Is this true?
Answer - – No.
Click to expand...

While they say that, in fact it does work quite well as I mentioned in the other thread I pointed to. Its MUCH better than just plugging the Axe into my Boogie. Lets not forget that Reamp is trying to sell something, but browsing other forums it's pretty common to use the DI in reverse trick for this type of thing. While the DI thing works, something like the reamp make in fact work a bit better, but at the moment the Reverse DI is working well enough for me that I'm not in a hurry to spend money on a reamp box when I already have a Whirlwind DI.

javajunkie said:
The Reamp box look good but states it w/ only do the converstion for +4 balanced to instrument level
(output 2 is unbalanced however):
Click to expand...




You can probably plug an unbalanced 1/4" TRS into the reamps 1/4" balanced in.. thats worked on every other piece of 1/4" TRS gear I've ever used. Once again, refer to the other thread I referenced before. Other reamp boxes may require a 1/4" unbal to XLR adapter, which are readily available.

However, caveat being I haven't actually tried a reamp box yet with the Axe, so YMMV.
Click to expand...

Just relaying the info. I got a lot of hiss the one time I tried using the reverse di box thing. The pedal buffer sounds like a more elegant solution if it works. Like I said, I don't have the issue so...

I agree about the balanced/unbalanced thing but having not tried it in this application, I can't say.
 
javajunkie said:
The Reamp box website states this:
Question - Some Just relaying the info. I got a lot of hiss the one time I tried using the reverse di box thing. The pedal buffer sounds like a more elegant solution if it works. Like I said, I don't have the issue so...
I agree about the balanced/unbalanced thing but having not tried it in this application, I can't say.
Click to expand...

Well, for me the reverse DI cut the hiss I was getting down by about 1/2, and then the ground loop switch on the DI took care of the rest. So it works for me, but of course YMMV for others with somewhat different rigs. I'll try an actual "reamp" box at some point, but I'm not in a big hurry to do so. :)

I also tried the radial "dragster" just for entertainment since I had one laying around wondering if it would change the impedence matching, but it didn't do anything in this application. I didn't really expect it to, but it was worth a shot. :)
 
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