4CM hissing

gigawatt said:
I can try the reverse DI idea, but wouldn't reducing Output 2's volume control have the same effect?
Click to expand...

I tried the 4CM with a Sansamp PSA-1 preamp and got the least noise by turning Output 2 as high as possible and reducing the PSA-1 gain. There seemed to be one noise component that was constant (with Out 2 knob all the way down, there was still noise hitting the Sansamp) and an additional amount changing with knob position. So whether it's reverse DI or just turning down a preamp gain knob, you might want to keep Out 2 pretty high. Check if the noise is there with Out 2 at minimum first though. If that can be avoided, turning it near max might not give the best results.
 
gigawatt said:
I can try the reverse DI idea, but wouldn't reducing Output 2's volume control have the same effect?
Click to expand...

When I used the reverse DI I think it was a combination of getting the gain level down making Out2 more useable, as well as being able to use the ground lift on the DI. For me Out2 was sending WAY too hot, and using the DI made the whole range of Out2 usable. The DI itself seemed to knock about 1/2 the hum out, and the other 1/2 was gone with the ground lift.

I used a Whirlwind Direct2 DI.
 
Ok guys. I have tested the X-Amp. I will cause more turbulence then ever.

I hooked up the whole thing with my Marshall JVM, checked all connections. Turned everything on. Dead silent.
That's good so far. Turned the volume up and.... nothing. Not a single note. :?
Checked everything again, everything seems fine. The amp works directly plugged in. If I set the FX Loop block off (signal through when bypassed) I can hear the delay block I have set up.
Checked the X-amp with Output 1, works fine into the front of the amp. On output2 nothing.
I took the X-amp out, just running output 2 to the front end of the amp. It sound, but if I engage the FX-loop on the JVM I get the usual Hum. Surprisingly I have to dime Output 2 to get a good signal. Strange.... it seems that on my Axe output 2 is instrument level, and simply the X-amp kills the signal converting it even down.
If I don't engage the FX loop on the JVM it is sounds fine.
Then I tried to set the FX loop to instrument level on the JVM, and the whole rig went dead silent.
Actually it sounds great and blending the real amp channel and an Axe amp in parallel is sonic heaven.
 
Thanks for trying man... I'm gonna sell my Ultra and wait for Cliff to release a new product that has a dedicated instrument-level 4CM/reamp out on it to fix this stuff.

I'll have it up on the For Sale forum soon.
 
That's a bummer man. I'm REALLY glad I didn't waste my money buying something else to fix the problem that can't be fixed.

I still love my Axe, even though I only use it after my preamp and I'm barely tapping its capabilities. When it comes time for the next Axe-FX I hope Cliff remembers this thread and incorporates whatever technology is needed to be noise free with the 4CM.
 
TimmyM said:
Smilzo wrote:TimmyM wrote: Thus it was a female XLR from the Axe to 1/4 inch jack. If the 1/4 jack is mono, this cable is called BAL-UN (balanced/unbalanced). One of the lead is connected, the other is disconected (ground).You are running unbalanced. I dunno It fixed it for me. I bought a normal guitar lead and put that from the unbalanced of output 1 to my effects return on my amp, and I was having to crank my master way past where it would normally sit. In that configuration I'd tried boosting things internally, but ran into clipping. Using an XLR to jack fixed it for me. I dunno. Might just be because of my amp.
Click to expand...

I also am trying to run 4CM with a Sherlock Fathead. (Great amp!) I have the hum issue that many have described.

Timmy, is the 1/4" jack end of your custom cable a mono or stereo jack. (I'm suspecting that it's mono and the differential signals from the XLR are wired to signal and ground on the mono plug, leaving the ground disconnected at the jack end). This would double the signal level. If the single ended (unbalanced) outputs 1 and 2 from the AxeFx are the same level, then the signal at the 1/4" jack of the custom cable which is going into the amplifiers effects return will be 3 dB louder than the signal from Axe Fx output 2, which is going to the amplifiers guitar input jack.

This would be a good thing, because the effect return level should be high compared to the guitar input level. I'm guessing that this is how you have solved the problem. I will try the same and confirm if I get the same result.
 
Nope, it made no difference. I tried a few configurations with the 1/4" jack. No reduction in hum :(

I ended up using a noise gate. Needed a high threshold. Not ideal, but it's ok.
 
Hiya Sandman,

Definitely a great amp. I ran the set up at a gig on the weekend and no hum. Sounded great. Not "guitar-cable-amp great", but very close.

Here is my set up explained as best I can...

I run the channel volumes of the fathead at 12 o'clock. I run all the channel gain controls pretty low (I'm not much of a super-high gain guy). This means the clean gain knob just comes on so its super clean (with the bright switch on). The Edge channel is run with the gain knob up a bit beyond where it just kicks in with sound and with the bright switch on and the boost switch off. The Rhythm channel is like the others with the gain knob just up past where the signal starts passing, and no boost or bright switch. I don't use the lead channel. Too much gain for me. The EQ on both channels has the bass at full, the mids up at 1-2 O'Clock and the treble is about 12.15pm. The master is wherever I set it and the presence on both is set just above zero (this is the best place for the presence to my ears - you don't need much in this amp). I run the effects loop in series with all of the send return volume controls maxed out.

On the axe - I set the front panel inputs to about 1.30pm and the outputs on both are maxed out. I use low-wound humbuckers and single coils to give me a bit of high end. My guitars are extremely well shielded and grounded and I get no hum when into the axe or into just my amps. They are a Belman Albatross Grande (plekked), a Maton MS500/12 Custom, a Gretsch G6120SSL.

Cable wise - neutrik and canare cables.
- 1 unbalanced guitar mono lead to Axe
- 1 unbalanced short mono guitar lead from Axe output 2 left to guitar in of Fathead
- 1 unbalanced short mono guitar lead from Fathead effects send to input 2 of Axe-FX
- 1 balanced mono neutrik/canare XLR to jack from the Axe balanced XLR output 1 to the 1/4 inch jack effects return of the Fathead.

No unwanted noise. No hum. No loss of volume. Check your guitars shielding and grounding. If you use single coils, it will hum. Mine hums when I split my coils. PLUS - the Fathead hums when I use more gain on the gain controls. It does this anyway, regardless of Axe-FX or not. I live under Snowy Hydro Powerlines and our House has shielding in the walls to reduce radiation. I also run my power supply through power boards with EM filtering so it reduces the noise.

I hope this helps - otherwise I must be in another dimension and my system works and yours doesn't. Sorry. Short of you coming to my house to hear it, I can't really say more than this. It works for me. Maybe you have better ears than me. I dunno.

TimmyM
 
I had nice results with a Marshall JVM setting up the 4 cable method no problems.
Today I have tried it with a Soldano SLO. Miserable failure.
It has an insane amount of hum, even without using the amp return and running the effects to powered monitors.
The only way I was able to get to normal noise levels is to tap the speaker output for a line level signal with a Weber Mass.
In that case a serious lag generated for the effects.
It seems the whole 4 cable issue is completely amp and loop specific.
(Anyway the SLO's loop is crap)
 
Hi,

I have this hiss issue with 4cm method also. I have AxeFx standard,Egnater M4 tubepreamp + VHT2/50/2.

Everything else works like charm and it's the best unit on effects / amps sims ever.

My setup / signal flow is guitar->AxefxFrontInput->AxeFxOutput2(left)->egnaterM4 rear input->EgnaterM4 left output->AxeFxInput2(left)->AxeFxOutput1 (unbalanced) -> VHT 2/50/2 -> speaker cabs

First I got hum issue. I got it solved in a minute by pressing ground loop switch on Egnater m4.
Now I got still hiss issue when Hi-Gain channels are selected.

I'm proposing two solutions (don't know if they work):

1. If it's possible to add one (additional) noise gate block to Axe-FX which can be put after the FX-loop in Layout menu. Don't know if this is technically possible.

2. I might buy ISP decimator prorackG. It allows you to put second noise gate after your preamp.
First noisegate takes away hum and noise that your guitar mic picks up. Second should take care of hiss.

I would like to know solution to this as I want to play with AxeFX live. It will replace my old g-major. Can't wait to put it in my live rig until I got this thing solved.
Now I'm using it for recording / home rig.

And yes after updating from 5.17 -> 6.06 my jaws dropped on floor.. Amp sims and cabs sound so good. This unit is the best.

BR,
Granny J from Finland
 
Jrm4 said:
I have this hiss issue with 4cm method also. I have AxeFx standard,Egnater M4 tubepreamp + VHT2/50/2.
Click to expand...

I had exactly the same results; I did this experiment a couple weeks ago,
four-cable method with M4, Axe-Fx, 2/50/2. Dialed all the levels to get the
least hiss. At the best level I achieved, I measured an increase in the
noise floor of about 10 to 12 dB.

I also tried using an EBTech Line Level Shifter to knock-down the
Axe-Fx output level. But I found that the EBTech lowered it too
much. There might a simple way to improve this attempt, but
I stopped trying.

After A/B comparing the Axe-Fx tones with the M4 tones, I decided that
the M4 wasn't worth the extra trouble for live playing anyway. For me,
the Axe-Fx tones are plenty good enough. It was liberating to
stop worrying about it, and just go with the Axe-Fx alone.

And you don't have the carry the extra gear.

Some kind of re-amping box or other product might make this work.
But I'm not sure what other people have found in this direction. I
know there were several tries.
 
Hum...


I'm trying to add the axe fx with the 4CM, yet I keep having ...HUM. Sounds like a groundloop, but I can't find it. Tried about everything to eliminate it, therefor I don't believe that's the case.

i've read a lot about the 4CM, the hiss and hums, and I've come to a few conclusions.

a) the balanced/unbalanced way.
I don't have any female xlr's atm, therefor I'd like to know your opinions on this.

2) ebtech hum eliminator
who's using this?

3) ...
anything else?
 
i'm trying to run the axe-fx into the front of my amp and i'm getting the same hum/hiss
i've also tried looping the axe-fx into my GRX4 (before the amp) and this problem isn't going away
The hum exists even when the axe-fx is bypassed in the GRX4! but if i disconnect the axe-fx, the hum goes away....

This sucks coz i'm using an amp with no fx loop so i want to run the axe-fx before the amp.
 
I also tried the 4 cable method with my Mark 4 rig and had major hiss issues. I would probably be able to deal with it but the gate has no effect to resolve the hiss. I am very disappointed with the outcome The axe sounds very good in the Mark's fx loop with no issues.
 
I have two amps that I have used as power amps (axe fx output to effects return). The Soldano has an annoying low volume hum but the Dual Rectifier is quiet. So obviously I will use the Rectifier head until my rack mount Mesa 50/50 arrives
 
Hi guys :)

About the hum - this did it for me : http://www.thomann.de/dk/ebtech_by_morl ... ator_2.htm

About the hiss: Regarding Cliff`s comment on raising the noisefloor each time you do a A2D & D2A conversion and the fact that putting the Axe before the preamp is much like adding a pedal/effect (that is always "on" as it is not real bypass) would suggest putting the first stage of the AXE into a midicontrollable looper( which you maybe already use anyway for pedals and stuff) and only turn the loop on when you turn on an effect in the first stage of the AXE.
The second stage of the AXE that you use in your amps effectloop does not give me any hiss problems but I do use a custombuilt gainstage for leveling send and return to give me unity gain - this might not be a problem with all amps but is with my Skrydstrup OD50.
This gives you the best of both worlds: you can use the AXE entirely for its superb post-effects( and add pre-effects if desired ) and actually switch between your own tube preamp and the AXE sim.preamps or mix both (via the AXE`s internal loop)

This works for me - might work for you too :)

Tommy Lui
 
I am still having no luck with the hiss issue.... HELP!!!!!

KINGSFAN said:
I also tried the 4 cable method with my Mark 4 rig and had major hiss issues. I would probably be able to deal with it but the gate has no effect to resolve the hiss. I am very disappointed with the outcome The axe sounds very good in the Mark's fx loop with no issues.
Click to expand...
 
Hi Kingsfan

Since you`ve had this problem for at least a month + I suggest you consult a technician.
Since there`s lots of people here having success with a simular setup, I am sure it can work for you too - I am the former owner of a Mk 4 and a bigger racksytem , using the 4CM and it worked fine for me(and I`m quite picky about noise issues :)

Or you might have a fellow guitarist with experience in this field - or maybe even a studio technician since there are some fundementals about, groundloop, hiss and setting up multiple units, that you also can have a lot of problems with when you are setting up a studio.

And guitarist loves GAIN and GAIN is the holy motherfucker of NOISE as it attracts whatever you put into it...

Amen

PS: Distant healing is sent out towards all AXE-FX`s in the hope for eternal CREATIVITY
 
I have never had a problem like this. Been using a rack set up for years and have always been able to figure out ground loops and such but this time I am stumped. The problem I am having sounds like running a D Box in front of a high gain amp. Now this only seems to be a issue with the lead channel of the mark IV, the rhythm 1 channel works perfect. It's not a ground loop issue, it's the HISS!! when I use the Axe through the Mark's fx loop is works like it should, but I want to use all of the features of the Axe along with my amp's pre amp..
 
Hi Kingsfan

In fact running a DI box in front of a higain amp is exactly what you do:

The first stage of the AXE (much like a DI box as it is an extra gain stage) in front of the leadchannel of a Mk 4 (really a highgain amp if you run the gain hard) will react this way.
I`m sure running any multi effect before the amp will have some amount of hiss (at least to my experience - TC G-force, Korg A3, Boss GT 8)

Sure a Noisegate would solve the problem but I`m not a fan of that - why I run the first stage of the AXE in a loop that I only activate when I use an effect in the first stage of the AXE.

:)

Tommy Lui
 
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