Using Helix with high gain tube amp - huge noise floor

[nhoven]

Hi there,

 

first of all, happy new year to everyone.

 

I'm having big issues with my Helix using it together with my tube amps. I got my Helix a few weeks ago, the plan was for it to replace my big a** FX rack. I wanted to use the Helix for FX only (in four cable method) while getting my base tone from my 3-Channel Tube Amp(s). That plan failed for now, because in the current state it's unusable.

 

When connecting the Helix to my Amps, a giant noise floor gets added. It can be barely heard using the first (clean) channel of my amps, but when using the 3rd (high gain) channel of the amps, the noise is so loud it makes the setup almost unplayable.

 

I have made a few tests in my home just now, with the following basic setup: A fresh, empty preset in Helix, all outputs set to instrument level, and a volume pedal block added before the output of path 1A.

 

No volume control in the Helix, be it in the input of the path, volume pedal block, the output of the path, or the big knob has any influence of the level of the noise.

 

Both stage amps I own show the same behaviour, so it is very unlikely to be a fault in one of the amps. Both amps are custom hand wired amps that I designed and built myself (before you ask, yes, I am qualified for that, and the amps are built to a very high standard, not some kind of botch jobs :) ), so no use asking for the amps' brand. Both amps have been on the road with me, playing reliably for the past years and working flawlessly with my, in terms of noise grounding etc. far more complex, rack system. Or so I thought...

 

Anyway. I am beginning to suspect that my Helix unit is faulty. Before I go through the hassle of returning the unit I wanted to ask if anyone here maybe has had similar experiences running the Helix together with a high gain tube (pre-)amp. I have attached a sample of the noise. I quickly recorded it with my mobile, as I don't have a recording setup at home.

 

In the sample you can hear the change in noise level when I plug the Helix into the amp's input jack. I held the mobile right in front of the speaker cabinet. First you hear some buzzing from the amp with nothing connected, then the click when I plug the guitar cable into the helix, and then I plug the other end of the cable into the amp's frontend. The amp was switched to its high gain channel, master volume set a little lower than stage volume. No guitar was connected to the input of Helix. As you can hear, the increase in noise is really huge.

 

Any help or suggestions are highly appreciated, I'm really frustrated.

Thanks, Nils

 

Edit: deleted sound sample to avoid further confusion.

[Joepeggio]

Ground loop(s).

 

It seems tube amps bleed to their ground. Hard not to with 400+ volts running around inside.

 

Experiment with Transformer isolating some of the connections, but not the guitar to Helix.

 

Example is players running stereo tube amp rigs often need to isolate one of the connections (amps).

[nhoven]

Thanks for your reply, but no, the issue is not a ground loop. Sorry I didn't make this clearer in my first post. I do a few Palmer isolation transformers and know how to use them, and the issue is the same with and without one.

 

I've attached another, better audio clip. What I'm talking about is this: Connecting Helix introduces some nasty hiss, as you can here while I'm connecting and disconnecting the guitar cable from the amp multiple times.

 

This hiss is really loud, and while it may not matter in a metal context, it matters in the context that I play, because in short breaks I can't kill that noise with the volume pedal. I would have to use an external pedal or noise gate, which really sucks :) .

 

Again, sorry for the confusion, I might have ben a bit overly tired when posting this morning ;) .

noise.wav

[jbuhajla]

If you turn on the gate on the input of one of your presets, do you still have the hiss on your high gain channel?

[nhoven]

Yes. None of the controls of the helix matter. Not the input gate, and not the output attenuation of the path output.

 

Edit: To me it seems like the noise is being produced in the analog domain after the D/A converter. So maybe it's "by design"? Is it the "normal" noise floor of the helix, which is being amplified by the huge amount of gain of the channel? That's why I asked for other amp users' experience... I can't really imagine the Helix's signal noise ratio is so... let's call it low that it gets cooked by a hot tube preamp. On the other hand, the primary design is for use with lower gain preamps (daw, FRFR systems), so I might as well be out of luck. Would like to know for sure.

 

For reference, it's a hot rodded 2203-design, so it has four gain stages, DC-coupled cathode follower, tonestack. There's always the possibility to use the Helix preamps, but that was not my goal. I love my tube amps :(

[ric1966]

For some reason I can’t load the sample noise you posted. When first connecting Helix to my Mesa 2:Fifty stereo power amp, I had a loud hum. It stopped when I plugged both units into my rack power conditioner, a Furman. Maybe a long shot for fixing your issue, but sharing my experience nonetheless.

[rd2rk]

"I have made a few tests in my home just now, with the following basic setup: A fresh, empty preset in Helix, all outputs set to instrument level, and a volume pedal block added before the output of path 1A."

 

Signal chain for 4cm:

 

Guitar->Helix Guitar Input

Helix Send 1->Amp Input

Amp Send->Helix Return 1

Helix 1/4" Left(mono) Output->Amp Return

 

Helix Preset needs a "FX Loop 1" Block (in this example).

 

IF this is how it's set up

AND you've swapped out cables (all should be shielded/instrument cables)

AND the amp and Helix are being powered from the same source

THEN maybe you should open a support ticket?

[shanecgriffo]

using helix just to the front of the amp or into monitors works fine tho?

[HillsideDeafener]

I put and ISP Decimator pedal in one of the loops and that worked like a charm. I was running a Mesa Boogie Tremoverb with the 4cm.

[nhoven]

"I have made a few tests in my home just now, with the following basic setup: A fresh, empty preset in Helix, all outputs set to instrument level, and a volume pedal block added before the output of path 1A."

 

Signal chain for 4cm:

 

Guitar->Helix Guitar Input

Helix Send 1->Amp Input

Amp Send->Helix Return 1

Helix 1/4" Left(mono) Output->Amp Return

 

Helix Preset needs a "FX Loop 1" Block (in this example).

 

IF this is how it's set up

AND you've swapped out cables (all should be shielded/instrument cables)

AND the amp and Helix are being powered from the same source

THEN maybe you should open a support ticket?

 

yes, thanks. I've got the 4CM-connections covered, that's how I do it, using Send 1 (Instrument Level) and Return 3 (Line Level) because the amp's loop is line level. For examining the problem I broke it down to the simplest form of connecting. And yes, of course I used proper cables. Different ones too.

 

 

using helix just to the front of the amp or into monitors works fine tho?

 

As I said, running the Helix into the DAW, active monitors or even the clean frontend of my amp is working fine. Running the Helix - even with everything off - into the frontend of the amp using the lead channel of my amp produces a high amount of hiss.

 

I'm trying to figure out if something is wrong with my unit, or if my expectations (of a pretty pricy unit) are too high, i.e. if that's the "normal" noise floor of the Helix that is being aplified the hell out of (which a high gain tube amp inevitably does). Although I must say, none of my other gear, analog or digital, is giving me so much hiss...

[nhoven]

I put and ISP Decimator pedal in one of the loops and that worked like a charm. I was running a Mesa Boogie Tremoverb with the 4cm.

 

using a gate or any kind of volume manipulating block in the digital domain does nothing for me, which leads me to belive the issue is somewhere in the analog circuitry of the helix, or at least outside of the DSP paths.

[Gritch666]

I have the same exact issue with Helix. I really think it's an adda converter issue or something. For sure, that kinda disappointed me, but for my use right now it doesn't matter so much. I'm using it with a Rivera knucklehead tré, who have a lollipopload of gain but is super dead quiet, so my noise isn't super bad. But with other hi gain amp, the Helix noise is just to hight. I thinking to set a stomp box noise gate between the amp front input and the Helix loop out.

[nhoven]

I have the same exact issue with Helix. I really think it's an adda converter issue or something. For sure, that kinda disappointed me, but for my use right now it doesn't matter so much. I'm using it with a Rivera knucklehead tré, who have a lollipopload of gain but is super dead quiet, so my noise isn't super bad. But with other hi gain amp, the Helix noise is just to hight. I thinking to set a stomp box noise gate between the amp front input and the Helix loop out.

 

Thanks for the confirmation. That really sucks. I mean, I'm suspecting that over the long run I might probably switch to using the Helix's preamps running into the power stage of my head, but not really being able to use is as a "drop in" for my FX rack makes thew transition phase really hard.

 

I've broken out the recording setup and prepared another audio clip, this time with some guitar as a reference for the "wanted" signal. I recorded the amp's preamp out straight into the DAW and applied some quick and dirty speaker simulation. This is the highest gain channel with the gain set at about 3 o'clock. Helix is running an empty preset, the 1/4" out is feeding the amp input.You'll hear (in order):

 

- noise floor of the tube amp without Helix

- me playing without Helix

- noise floor with Helix connected

- me playing with Helix connected

 

The clip repeats three times. If this really is the expected noise floor of the Helix, then this really sucks. Or I'm too picky, because my amps are pretty quiet even on high gain. But again, none of my other gear adds so much hiss.

noise sample with guitar.mp3

[Gritch666]

Mmm, this doesn't sound rights to me. Your playing with the Helix have way more gain to my ear. It's sound way more compress to and less dynamic. Are you sure you set your output to line level? If you are using the main 1/4 out in front, the unity gain is suppose to be at full knob volume.

 

And yes, I have the exact same hiss sound than you, just quieter probably because of my amp design.

[nhoven]

Yes, I noticed that, too. It's a bit less muddy, too, but I suppose that is because of Helix buffering the cable length and reacting a bit different to the pickups than the amp. I've checked the level settings and even re-did and reuploaded the clip before you answered. I've set the volume knob to only control digital volume so it's "out of the way" and can't be accidently turned down. I've rechecked that with a clean signal, knob full yields the same volume as full up, but Helix adds about 3 dB to the signal compared to straight into the amp. Unity gain seems to be more like 3 o'clock on the vol knob. Those 3 dB don't matter though. The noise increase is way more than those 3 dB, I think.

 

Edit: actually it makes matters even worse, because I'd have to attenuate the output to the amp to compensate for Helix pushing the amp harder, while the noise floor would stay the same.

[TB413]

This might be a dumb question, but have you completely ruled out a level increase through the helix as the culprit?

 

There are two reasons I ask:

1. If it is a 3 dB increase, I would consider that to be quite a bit and would expect your noise floor to increase notably.

2. I haven’t been able to find the input/output specs for the inputs/sends/returns/outputs so it’s possible that it’s not unity gain going from guitar in -> send 1 or from return 1 -> 1/4†out. I’m sure someone here can clarify...

 

Have you tried actually measuring the outputs to rule this out? If you build amplifiers I’m sure you have the tools. Just need a signal generator of some sort and a multimeter:

1. Measure signal generator output voltage at low (instrument) level

2. Connect signal generator to Helix input, measure Helix Send 1 output voltage. Is there an increase?

(1 and 2 only work if you can get an instrument level signal.. not likely with a phone app but maybe a dedicated generator?)

3. Measure signal generator output voltage at line level

4. Connect signal generator to Helix Return 1, measure 1/4†output voltage. Is there an increase?

 

If there’s an increase in level across the Helix then you know that’s your culprit and you can adjust either the send, return, or 1/4†output levels accordingly. Admittedly this is a pretty silly thing to have to do, which may not be necessary if Helix had meters...

 

If it were me I would probably just try turning the return and/or output levels down and see if I could match the tone. I’ve never been able to hook up rack gear in an FX loop at “unity†successfully without adjusting either my head’s send/return levels or the levels on the rack gear... maybe you’ve had better luck than me.

 

Long story short: while there may be some noise from the converters/preamps I would expect it to appear much more drastic if there’s any gain not being accounted for across the Helix or your FX loop. And if there is gain across the Helix, turning your outputs back down should reduce that noise floor and bring you back to unity.

[nhoven]

Good points. I was actually planning on measuring the level increase of Helix sometime this week. I think this is a secondary issue though. As I've found out so far, the added noise is not affected by any of the volume control measures inside Helix (which are all inside the digital domain, as far as I can tell), while the noise seems to come from somewhere in the analog domain, or at least outside the scope of the control measures in Helix. So while it's easy to adjust for the added level tone wise, this does not affect the added noise, which will stay at the same absolute volume, while the wanted signal will be reduced.

 

What I would have to do is to adjust that gain after the Helix with external gear to affect both the wanted signal and the noise. Which sucks of course, because I wanted the Helix to be the sole piece of gear to use :D .

 

That's what I've gathered so far anyway. I'm still investigating, but my impression: Meh, noise floor is kinda high for a flagship device :) .

[TB413]

I hear what you’re saying about the level controls being in the digital domain, but consider a couple of possibilities:

1. The noise is occuring in the head’s preamp but is being amplified by the Helix in effects loop. In this case, reducing the output level of Helix would bring that noise back to normal levels.

2. The noise is coming from Helix’s A/D and D/A converters. Using 4CM you are going A/D or D/A four times. Three of these occur before the output level control and would be reduced by turning it down.

 

In reality it could very well be a combination of both. If you’re getting any power tube saturation you would expect any level increase to change the amount of low-level noise more than the playing volume. If there’s enough added gain to affect your tone, it’s likely more than enough to noticeably raise the noise floor.

 

One other thing that may help locate the source is trying to isolate it to either the guitar->Helix->preamp or FX send->Helix->power amp sections. Do you experience the same noise with:

- Guitar -> Helix -> Send 1 to amp input, but amplifier FX loop bypassed (no 4CM)?

- Guitar -> straight to amp input -> amplifier FX send to Helix Return 1 -> Helix 1/4†output to amplifier FX return?

 

If you get noise separately with Helix only on the input side of the amp AND with Helix only in the FX loop then it seems more likely to be converter noise. Not an issue I’ve encountered with my Dual Rec but maybe you got a lemon..

 

If you only get the noise with Helix in the FX loop it seems more likely to be a level issue.

 

EDIT: It sounds like you have tried level matching with and without the Helix. Which level(s) have you been using to accomplish this? I’ve found it much easier to make precise level adjustments within the output block (volume knob unassigned) than doing it with the knob. It’s just easier to keep replicate small adjustments that way and see just how much you are adding or attenuating.

[nhoven]

At this point, I have long stopped to connect the Helix with the 4CM. It's just Helix - Cable - Amp input. That alone creates that hiss. Sorry if that wasn't clear.

[TB413]

Ah OK I may have missed that. Have you tried using the Helix 1/4†output (instrument level obviously) instead of the FX send? Just curious if it makes a difference.

 

Since it sounds like we’ve narrowed it down to the input side, the other thing you may try is adjusting the guitar-in impedance. It defaults to auto but you may find better results at a fixed value.

[nhoven]

Yeah I've tried both the main out and a send. Only difference is that the send produces additional ground loop noise and need isolating even in that simple config, main out doesn't. Also all my tests (except where I recorded guitar of course) were done without a guitar connected. Changing the Z from auto to 1M made no difference. Makes sense, as it's an empty preset w/o any fuzzes etc. Helix probably sets it to 1M anyway. Right?

[runesig]

Just out of curiosity, do you also have another cable like a midi or amp switch cable connected between the amp and the Helix?

[nhoven]

No, no other cables connected. To be honest, I've given up on that topic. Maybe I'm extremely picky, but for my needs, the increased noise floor is simply unacceptable. Adding to that the bugs with MIDI toggles and snapshots (my amps are MIDI controlled), I've concluded that the Helix isn't going to cut it with my amps.

 

Not all is lost though, I'm having loads of fun running the US Deluxe and Placater models into the amp's power section. Both sound amazing, so that's the route I will be going with. Silver linings.... sort of :) .

[zolko60]

Don't give up! Isolate a problem. If you are having fun in replacing amp tube preamp with Helix preamps, use passive loop switch and check how the noise and sound behaves while switching a real thing to emulation. I would be glad to read/hear what the comparission is (soundwise and noisewise) on similar (virtual vs analog) preamps.
Do the same with fx loop - I mean helix in your amps fx loop vs pair of cables. I am even curious how a pair of Helix AD/DA converters alone in the path compare to a pair of cords.
Please share - it can be important.

Yeah, I know such a "modular thinking" is not popular ;)

[LateratoR]

I use the Placater, L6 2204 Mod and ANGL Meteor amps most. For what I do live, I like the amp gain on most of these to be at around 7-8. 

My Helix Rack is connected with a single 1/4" out to my Legacy 3 Return - Eliminated 4CM because with the noise using multiple amps, never went away. Switching to this mode has improved the noise floor dramatically for me but using any of the four effects loops on Helix brings all of the white noise and hiss back. I could technically use a Voodoo Lab GCX to add the delays and reverbs that I'm using after the Helix 1/4" out and before the amp return but then I lose the ability to have my loops modular and levels controlled with snapshots. Kind of in a bind because while I can increase the noise gates and squash the "kshhh" noise, but I need sustain for my playing. 

 

I found that messing with the levels and mix in a SEND/RETURN block can take down the noise floor while still allowing the effect to come through. Not as strong, but enough for my Digitech FreqOut and Horizon Devices Precision Drive to still be effective. I've also experimented with three different types of isolated power supplies, sets of brand new cables, tried the Ebtech HE-2 in between multiple places and even run a higher end power regulator for everything (Furman M-8XAR). I made a video outlining some of my issues but since then I have even gone as far to take everything out of the rack and keep everything as separated as possible...eliminating proximity noise that I thought might have caused my issues. It has to be the conversion rates in Helix...HAS to be. Hopefully this helps...if anyone can help me, I'm all for it too! I'm close to the noise floor that I perceive as "acceptable" but am all for improving that if possible. 

 

[MikeDV1]

Using the Helix rack in 4CM with Triaxis and Simul-Class 2:90.  High gain patches on the Triaxis creates lots of noise as describe by other posters.  I did nothing as extensive as LateratoR to try and isolate.  I was moving my ancient GSP2101, and just 'cuz I hadn't heard it for a while, replaced the Helix in the signal chain setup with the 2101.  Same patches on the Triaxis, same cords, foot controller with about 10% of the noise floor of when using the Helix.  My simple test rules out everything else, so it's something in the Helix/outside world interface.  High gain modeled amps inside the Helix - very little noise floor at all.  I'm suspicious...  Anyhow, the noise isn't much worse than most when using high-gain amps, so it isn't a Helix killer issue, but it would be nice if it performed to 1990's level - in that area only, of course.  It has a couple of other attributes that are slightly better.

 

I use a power strip.  I've got a rack-mount Ebtech Hum Eliminator I'm going to try next.

[jmp22684]

I wish this could become a sticky with the amount of posts I see like this.

 

I run 4cm, amps I've done it with so far: Mesa TC50, PRS Custom 50 and my main gigging amp Mesa RoadKing series 1 212 combo. She's old and beat to hell! Quiet and reliable! I gig with this setup every week and am booked solid through the rest of the year.... needless to say, it needs to be reliable and QUIET (I don't need a Mic sending hiss to our FOH or IEMs):

 

I used to get crazy amounts of noise!

This is what I use, ebtech hum eliminator:

https://www.sweetwater.com/store/detail/Hum

 

Setup Helix:

-First I make sure everything in the helix menu is set to INSTRUMENT level, NOT line level.

-Then make sure that the volume knobs on the Helix DO NOT EFFECT ANY 1/4 output. If you're using the helix to replace an effects rack then let it do just that. You don't use effects racks to adjust volume, that's for the volume knobs on the amp. The helix needs to be unity otherwise you're going to over complicate things in your gain staging.

 

Setup the Amp:

-The amps effects loop must be series.

-The amps effects loop must be set to unity, on all three of the amps I listed above that was at 12 o'clock noon.

 

Wiring:

- Guitar > Helix input

- Helix send > Hum Elimimator > Amp input

- Amp send > Helix Return

- Helix 1/4 out > Amp Return

I have found no reason to use the second set of in/out on the hum eliminator and why add.

 

As far as routing in the helix:

- I simply drop a send/return block at the end of Path A and then send that to path B. I use path A for anything I want in front of the amp and Path B for anything after the preamp.

 

On high gain channels I use the helix input blocks noise gate, extremely modest settings.

 

Important:

If you split anything AFTER the preamp (send/return block) in the helix you'll get a volume discrepancy. Click on the merge block and reduce output by -3db.

 

I have found that I don't get great results (I enjoy anyways) using many of the distortion models. HOWEVER: Kinky Boost plays VERY nicely with my amps, it's been a godsend.

 

The wiring in my studio is HORRIBLE and ungrounded, new/VERY old house. Everything is run through a conditioner and that includes: Helix, RoadKing, computers, studio monitors, PA mains and subs, everything! If you're home wiring is worse than mine you should burn it down. If I can get it quiet using this setup and you're still having issues then there's something wrong with the amp.

 

I go into so much detail because I really am in a sub optimal situation when it comes to the power I'm being supplied, the age and condition of the amp I'm using, and the sheer amount of load I'm putting on a single ungrounded outlet.... If I can get it quiet with this setup and do it with little to no tone change with the helix in 4cm so can anyone!

 

Just buy the hum eliminator

[jmp22684]

^^^ Excuse anything caused by this being writting on my cell during my first cup of coffee.

[HonestOpinion]

...

 

I used to get crazy amounts of noise!

This is what I use, ebtech hum eliminator:

https://www.sweetwater.com/store/detail/Hum

 

...

 

I wonder if the Behringer model is basically the same thing as the Ebtech for a fraction of the price? I only ask because I got a Behringer cable tester a while back that was literally exactly the same as the Ebtech at 1/3 the price. They were either the same device rebranded or a perfect job of reverse engineering. Here is the link to the "Behringer Hum Destroyer": https://www.sweetwater.com/store/detail/HD400?gclid=EAIaIQobChMIxPri4Jm32QIVyIizCh0FFwm6EAQYASABEgITKfD_BwE

[nhoven]

It's not that easy, I think you might be missing the point, at least for my case. Hum is not the issue, so "just guy the hum eliminator" is not going to fix anything. And yes, I do own a high quality isolation transformer, just not the Ebtech one.
 
Feeding the tube amp's input from the sends of the Helix introduces nasty hiss and what sounds like digital noise even before I start thinking about 4CM. Using the Helix's noise gates proved as completely useless as the noise is produced outside the DSP domain.
 
Not trying to offend you, but saying that if I can't get a low noise level, then the amps that do have that problem are faulty is plain ignorant.
 
I have no idea why some people don't have that problem; I have it with three different amps. Maybe not everyone is as susceptible to noise or used to the noise high gainers produce (and there are some VERY noisy amps out there). My amps are very quiet even on high gain settings, and I can't stand the noise the Helix produces.
 

I wish this could become a sticky with the amount of posts I see like this.

I run 4cm, amps I've done it with so far: Mesa TC50, PRS Custom 50 and my main gigging amp Mesa RoadKing series 1 212 combo. She's old and beat to hell! Quiet and reliable! I gig with this setup every week and am booked solid through the rest of the year.... needless to say, it needs to be reliable and QUIET (I don't need a Mic sending hiss to our FOH or IEMs):

I used to get crazy amounts of noise!
This is what I use, ebtech hum eliminator:
https://www.sweetwater.com/store/detail/Hum

Setup Helix:
-First I make sure everything in the helix menu is set to INSTRUMENT level, NOT line level.
-Then make sure that the volume knobs on the Helix DO NOT EFFECT ANY 1/4 output. If you're using the helix to replace an effects rack then let it do just that. You don't use effects racks to adjust volume, that's for the volume knobs on the amp. The helix needs to be unity otherwise you're going to over complicate things in your gain staging.

Setup the Amp:
-The amps effects loop must be series.
-The amps effects loop must be set to unity, on all three of the amps I listed above that was at 12 o'clock noon.

Wiring:
- Guitar > Helix input
- Helix send > Hum Elimimator > Amp input
- Amp send > Helix Return
- Helix 1/4 out > Amp Return
I have found no reason to use the second set of in/out on the hum eliminator and why add.

As far as routing in the helix:
- I simply drop a send/return block at the end of Path A and then send that to path B. I use path A for anything I want in front of the amp and Path B for anything after the preamp.

On high gain channels I use the helix input blocks noise gate, extremely modest settings.

Important:
If you split anything AFTER the preamp (send/return block) in the helix you'll get a volume discrepancy. Click on the merge block and reduce output by -3db.

I have found that I don't get great results (I enjoy anyways) using many of the distortion models. HOWEVER: Kinky Boost plays VERY nicely with my amps, it's been a godsend.

The wiring in my studio is HORRIBLE and ungrounded, new/VERY old house. Everything is run through a conditioner and that includes: Helix, RoadKing, computers, studio monitors, PA mains and subs, everything! If you're home wiring is worse than mine you should burn it down. If I can get it quiet using this setup and you're still having issues then there's something wrong with the amp.

I go into so much detail because I really am in a sub optimal situation when it comes to the power I'm being supplied, the age and condition of the amp I'm using, and the sheer amount of load I'm putting on a single ungrounded outlet.... If I can get it quiet with this setup and do it with little to no tone change with the helix in 4cm so can anyone!

Just buy the hum eliminator

[jmp22684]

I personally can't vouch for that. No experience with the behringer unit.

 

The last behringer unit I owned was a mixer that failed, I haven't had the urge to dip into that brand again.... although I do own an M32r, sooooo.... ; )

[nhoven]

I wonder if the Behringer model is basically the same thing as the Ebtech for a fraction of the price? I only ask because I got a Behringer cable tester a while back that was literally exactly the same as the Ebtech at 1/3 the price. They were either the same device rebranded or a perfect job of reverse engineering. Here is the link to the "Behringer Hum Destroyer": https://www.sweetwater.com/store/detail/HD400?gclid=EAIaIQobChMIxPri4Jm32QIVyIizCh0FFwm6EAQYASABEgITKfD_BwE

I would suspect that they save on the quality of the transformers. I have no idea what transformers are used in the Ebtech device, but the transformers used by Lehle or Palmer are pretty high quality and thus rather pricy.

[jmp22684]

It's not that easy, I think you might be missing the point, at least for my case. Hum is not the issue, so "just guy the hum eliminator" is not going to fix anything. And yes, I do own a high quality isolation transformer, just not the Ebtech one.

 

Feeding the tube amp's input from the sends of the Helix introduces nasty hiss and what sounds like digital noise even before I start thinking about 4CM. Using the Helix's noise gates proved as completely useless as the noise is produced outside the DSP domain.

 

Not trying to offend you, but saying that if I can't get a low noise level, then the amps that do have that problem are faulty is plain ignorant.

 

I have no idea why some people don't have that problem; I have it with three different amps. Maybe not everyone is as susceptible to noise or used to the noise high gainers produce (and there are some VERY noisy amps out there). My amps are very quiet even on high gain settings, and I can't stand the noise the Helix produces.

 

What is the make and model of the isolation transformer you are using?

[nhoven]

I'm using the Palmer BALUN PLI05.

[jmp22684]

Hrm.... and where in your chain did you put that.

 

Trying to see how this could be happening. Is everything else setup the way I posted? Palmer between the helix send and amp input only and everything else on the helix setup correctly and the amp.

 

Not really one of those things that's left to interpretation (leave that to the poets and artists) this is electricity and pretty much an exact science.

 

I gotta get to work. I'll take another look through your post and get back later.

 

Good luck!!

[nhoven]

I've been through everything and spent countless hours investigating. Empty preset (apart from a send block), send set to instrument, feeding the input of the amp via the isolator - noise unaffected by any means of volume control or gate inside the Helix. Doesn't get any simpler.

[jbuhajla]

 

I found that messing with the levels and mix in a SEND/RETURN block can take down the noise floor while still allowing the effect to come through. Not as strong, but enough for my Digitech FreqOut and Horizon Devices Precision Drive to still be effective. I've also experimented with three different types of isolated power supplies, sets of brand new cables, tried the Ebtech HE-2 in between multiple places and even run a higher end power regulator for everything (Furman M-8XAR). I made a video outlining some of my issues but since then I have even gone as far to take everything out of the rack and keep everything as separated as possible...eliminating proximity noise that I thought might have caused my issues. It has to be the conversion rates in Helix...HAS to be. Hopefully this helps...if anyone can help me, I'm all for it too! I'm close to the noise floor that I perceive as "acceptable" but am all for improving that if possible. 

 

Check to see if your Furman is properly grounded. Technically, the metal housing of the Furman should act as a shield for the electromagnetic stuff going on inside the unit. However if the unit/housing is not grounded, it may not be shielding properly. 

 

EMI is a huge issue, and I think it is starting to rear its ugly head with all the new devices on the market that make is easy to add loops and loops of various components. There are so many AD/DA conversions and amplifier circuits in these modern devices. It makes is much more difficult to troubleshoot these issues and pinpoint where noise is coming from. I wonder is we may start to see the use of shielded cable being implemented on our meager little guitar rigs in the near future...

[bigbazz86]

I've got this same issue with the unit. If I want to use it for the compressor/OD pedals into the front of an amp it adds a decent bit of background noise that I can't get rid of. And this is just by default of plugging into the unit, without any effects on. This is not an issue with my traditional pedalboard of stompboxes, no noise is added from them but the Helix gives some headaches.

 

Send outs - If I use this instead of the main out to the input of my amp (set at instrument level) we get a considerable amount of noise even with an empty preset and the out set to the 1/4 (so send isn't even outputing) it's making noise, it's unusable for this purpose. This is annoying because the send is putting out the right level without me having to mess with the volume knob on the unit, but it's unusable due to the added noise.

 

1/4 main out - If I use this at instrument level I get a lot less noise than the Send (even at line level this is less noise than send) but still considerably more noise than just plugging into the amp, noise that my normal pedalboard does not add. What's worse is that this output is connected to the volume knob, which means I'm now playing guessing games as to where to set it, it never sounds the same as just plugging into the amp.. Again not a problem with normal pedalboard, and if there is a solution to that particular issue I haven't found it.

 

Until now I've only been using the unit for modelling, straight through to a PA system and it has been fine. This is the first time I've used the unit into an overdriven amp with the intention of using it for boost.

 

Edit : To add more detail : Amp was a Cornford Hellcat (35w 4x EL84, 2x12).

 

Helix connected to PC via USB at the same time.

 

Guitar > Helix > Helix 1/4 out > Amp input = Lots of noise, more noise than when not connected to USB.

Guitar > Helix > Helix 1/4 out > Amp return = No added noise, or insignificant enough to not matter.

Guitar > Helix > Helix Send > Amp return = More noise than 1/4 out, additional low frequency hum, disappears when USB is disconnected and is then equal to the 1/4.

 

 

Edit 2 : Helix was not plugged into USB for these tests - Added a 2nd amp = Peavey 5150 into a Marshall 4x12.

 

Amp 2 : (5150) - Guitar > Helix > 1/4 out > Amp return = Very audible thick low level hum. Seems more to do with the amps FX loop itself, so I will give the Helix a pass on this.

Amp 2 : (5150) - Guitar > Helix > 1/4 out > Amp input = Same issues as amp 1 but worse, noisy.

 

Edit : Added a 3rd amp, Marshall AVT150 (1x12 hybrid combo, solid state power amp)

 

Amp 3 : Helix 1/4 out into Return = Same as Hellcat, no or insignificant noise added.

Amp 3 : Helix 1/4 out into amp input = Some noise added, marginally less than the Hellcat but a clear to hear hiss.

 

[krisjohnson22]

I've had the same issue with a helix I've only had for a short while. I have a complicated multi-amp setup with 4CM, but I began patching everything together piece by piece to try to eliminate previous noise issues since I was rebuilding my whole rig anyway.

 

I didn't get past step 1. Plugging the helix loop send 1 into the front of my soldano HR100 was incredibly buzzy. I fixed that with either a radial transformer isolator or an ebtech power scrubber (the name escapes me but it basically filters noise out of the ground pin on the power source without disconnecting it completely like on widomakers). I decided to use the power scrubber to avoid using a transformer that affects tone mildly and save it for possible use later once more stuff gets connected. With this problem solved, I flipped to the overdrive channel and that wretched hiss I hated from my pod HD pro was there being amplified to unusable levels by the preamp. My Mesa Roadster has the loud hum too but not nearly to the same extent as the Soldano.

 

My signal chain at this stage doesn't get any simpler than effect into amp input. I tried all the different outputs, instrument vs line level, guitar connected or not connected, volume knob in and out of the equation, volume pedal/gate in an effects block turned all the way down, the noise stayed steady and didn't fluctuate one bit. It's obviously the noise floor from the DAC stemming from the signal level being set quite low relative to Full Signal in the DAC making the noise floor quite strong relative to the anemic instrument level signal. They've provided an extreme amount of headroom on their outputs that makes no sense to me except....

 

I have a theory. When I switch the outputs from line to instrument and vice versa, I don't hear any kind of relay clicking inside or anything and the noise level doesn't change at all, leading me to believe they set it up with the extra headroom so that an active guitar signal being sent out line level doesn't clip the DA. The problem seems to lie that instead of having a relay or physical switch step down the signal level to instrument level and take the noise floor down in level with it, it attenuates the signal digitally, utterly decimating the signal to noise ratio on the output in the process. Horrible gain staging practice on Line 6's end. I've used other products that either have a physical pad switch that do not seem to suffer from anything resembling this issue.

 

In the past, I had used a Digitech GSP1101 with hacked firmeware running "around" my pod HD to both attenuate a boosted signal from my pod back to instrument level to get rid of some of the his as well as act as a gate on the main outputs with it's sidechain input, the signal detector part, in the input section before the pod's input as the noise coming out of the pod would make the gate have to be set way too high to work. It was kind of like having 2 ISP Decimator G-Strings running side by side in stereo. Even with 2 more stages of ADC/DAC (4 total) in the signal, the noise level was much lower this way running a 4 cable method inside of another 4 cable method. Fortunately, this at least also provided means of running a midi controlled volume pedal for each amp that didn't eat up 2 of the limited effects blocks or reset every time i changed patches.

 

I had really hoped after reading reviews and evaluations that line 6 had figured out how gain staging is supposed to work (look at the Axe FX as an example) and release a product that worked properly for the 4CM without needing to use my GSP1101 again and the extra headache in ground loop control that entailed. I was very disappointed to learn that they had not and I was going to have find a work around again. At least I don't need the GSP for the volume pedals with the Helix.

 

What I'm going to attempt to do is to jack up the signal on the output either by setting it to instrument or using the send level control or both and then pad the signal back down to go into the amp input at a proper level at unity gain. Fingers crossed that this will work.

[phil_m]

16 minutes ago, krisjohnson22 said:

I've had the same issue with a helix I've only had for a short while. I have a complicated multi-amp setup with 4CM, but I began patching everything together piece by piece to try to eliminate previous noise issues since I was rebuilding my whole rig anyway.

 

I didn't get past step 1. Plugging the helix loop send 1 into the front of my soldano HR100 was incredibly buzzy. I fixed that with either a radial transformer isolator or an ebtech power scrubber (the name escapes me but it basically filters noise out of the ground pin on the power source without disconnecting it completely like on widomakers). I decided to use the power scrubber to avoid using a transformer that affects tone mildly and save it for possible use later once more stuff gets connected. With this problem solved, I flipped to the overdrive channel and that wretched hiss I hated from my pod HD pro was there being amplified to unusable levels by the preamp. My Mesa Roadster has the loud hum too but not nearly to the same extent as the Soldano.

 

My signal chain at this stage doesn't get any simpler than effect into amp input. I tried all the different outputs, instrument vs line level, guitar connected or not connected, volume knob in and out of the equation, volume pedal/gate in an effects block turned all the way down, the noise stayed steady and didn't fluctuate one bit. It's obviously the noise floor from the DAC stemming from the signal level being set quite low relative to Full Signal in the DAC making the noise floor quite strong relative to the anemic instrument level signal. They've provided an extreme amount of headroom on their outputs that makes no sense to me except....

 

I have a theory. When I switch the outputs from line to instrument and vice versa, I don't hear any kind of relay clicking inside or anything and the noise level doesn't change at all, leading me to believe they set it up with the extra headroom so that an active guitar signal being sent out line level doesn't clip the DA. The problem seems to lie that instead of having a relay or physical switch step down the signal level to instrument level and take the noise floor down in level with it, it attenuates the signal digitally, utterly decimating the signal to noise ratio on the output in the process. Horrible gain staging practice on Line 6's end. I've used other products that either have a physical pad switch that do not seem to suffer from anything resembling this issue.

 

In the past, I had used a Digitech GSP1101 with hacked firmeware running "around" my pod HD to both attenuate a boosted signal from my pod back to instrument level to get rid of some of the his as well as act as a gate on the main outputs with it's sidechain input, the signal detector part, in the input section before the pod's input as the noise coming out of the pod would make the gate have to be set way too high to work. It was kind of like having 2 ISP Decimator G-Strings running side by side in stereo. Even with 2 more stages of ADC/DAC (4 total) in the signal, the noise level was much lower this way running a 4 cable method inside of another 4 cable method. Fortunately, this at least also provided means of running a midi controlled volume pedal for each amp that didn't eat up 2 of the limited effects blocks or reset every time i changed patches.

 

I had really hoped after reading reviews and evaluations that line 6 had figured out how gain staging is supposed to work (look at the Axe FX as an example) and release a product that worked properly for the 4CM without needing to use my GSP1101 again and the extra headache in ground loop control that entailed. I was very disappointed to learn that they had not and I was going to have find a work around again. At least I don't need the GSP for the volume pedals with the Helix.

 

What I'm going to attempt to do is to jack up the signal on the output either by setting it to instrument or using the send level control or both and then pad the signal back down to go into the amp input at a proper level at unity gain. Fingers crossed that this will work.

 

 

My Bogner Atma is dead quiet when connected via the 4CM... I honestly don't get any sort of extra noise, even on the highest gain channel. A lot of this comes down to how the loop in  the amp is designed.

 

As far as changing from signal to line level, really, it's the effects returns that are changed, and they are definitely using a relay or some sort of switching. If you hook up a meter to the returns and change them from instrument to line level you see the input impedance changes from 10MOhm to 10kOhm.