H9 Hiss in front of amp – Video

[mafromusic]

What's going on here?

https://www.youtube.com/watch?v=kCi-BGEK1UY

[nickrose]

It could be a hardware fault, but is more likely to be gain settings on the guitar,  pedal or the amp. 

Try setting the input gain (see UM) so that the peak led flashes on very loud notes, and adjust everything else accordingly.

[SucKamc]

The vid is me. I changed the input gain to the proper amount a long time ago. Also, I'm not even playing during that part of the vid and my guitar's volume is on 0. But in any case, the input gain adjustment did nothing to address the veritable Timefactor's worth of noise coming from the unit.  🙂

[nickrose]

If you are convinced that all your gain settings are reasonable and that the unit has a hardware fault you should contact support@eventide.com

[SucKamc]

I'm not convinced there's a hardware malfunction. I do wonder if (like the Timeline apparently has) there is a design issue that makes them all a bit noisy in a situation like this. I'd love to hear a video of a rig where a semi-clean amp is used, a little hiss or normal, day-to-day, modest amount of rig noise is already present on the video, and then the H9's bypass is changed. Notice that the effect isn't even ON at any time in my video. The H9 just has a higher-than-average amount of hiss. 

I do HOPE that mine is merely broken (same with the others who've reported this problem). I do really like plenty of the effects. In particular, it's a reverb juggernaut. 

[nickrose]

I'm not going to be telling you anything you don't know, but there are always potential noise issues with any digital product.  A combination of low output guitars in front, high gain amps afterwards, and incorrect gain settings makes this sometimes unavoidable. The TimeLine will face the same issues.

All H9's current go through audio analysis testing, and must have a signal to noise ratio in the 90-100dB  range to pass. So, we believe (apart from rare hardware problems) that these products have an entirely good noise performance, and reported problems are usually as described above.The H9 also has better noise performance than the TF, MF and PF.

It is our belief, that, when set up properly, the H9 has no significant noise issues, as shown by the large number of users who have no problems.

[SucKamc]

I'm not a tech guy, and I have adjusted the input gain, but would the input gain setting be relevant when it's a guitar on 0 plugged into an H9 (stock adapter) into the amp? I may misunderstand its relevance in that particular situation.

[SucKamc]

I'm playing mine at the CMA Fest tomorrow. I'll run it by some Nashville friends and get their opinion. I know the Timefactor wasn't well-received by them due to this issue, but I do believe you that the H9 bench tests better than the TF. It just seems like, at the very least, MINE doesn't (and the others who've reported the same problem). I'd just love to know if I need to mail it back, because that's kind of a PITA given the ole schedule. May have to rush ship it; I'd just love to avoid the process altogether.

[laurent-fr31]

This conversation is a bit old, however, I received my H9 max a few weeks ago, I am plenty satisfied in the effeect loop but yesterday I decided to test the H9 in front of the amp for the wah mainly. I must say I am experimenting exactly the same hiss problem as afore mentioned and described. In the effect loop, no noise at all, all is perfect, but, when I try it in front of my (high gain) amp, even with no other pedal nor effect loop connected, only guitar + H9 + amp (so with no risk of ground loop beween front and effect loop), I have that strong hiss.
It does not come from the guitar (I tested with several) nor from the cables of very high grade (evidence audio). And I tested with different input levels in the H9 but it is not linked to that. I use the provided power supply (just with a plug US/EU adaptator as I am in Europe) could there be a link ?
Any idea of what I could test ? Else I will continue to use it in the loop only, not a big issue, anyway…
Thanks in advance for any idea 😉

[gkellum]

laurent-fr31 wrote:

Any idea of what I could test ? Else I will continue to use it in the loop only, not a big issue, anyway… Thanks in advance for any idea 😉

Well, as Nick mentioned above, the H9 must have a signal to noise ratio of 90 – 100 dB to pass our quality control routines.  What this means is that if your guitar signal comes in loud enough that it's close to clipping when you play then the noise floor is 90 – 100 dB quieter than this.  And that's a big difference.  The problem is that if you have a quiet guitar which you are plugging straight into the H9 you may have a signal that peaks at say -60 dB.  That means that you have only a 30 to 40 dB separation of your guitar from the noise floor.  If you put this into a high gain amp and say you boost your guitar by 30 dB to compensate, then you are boosting both your guitar and the noise floor by 30 dB.  If you instead put a boost pedal before the H9 and boost it there by 30 dB, then you're going to have 60 to 70 dB separation of your guitar from the noise floor, and if you raise the signal a bit more in your amp, you're going to be less likely to hear any hiss.  And that's effectively what you're doing when you run the H9 in your effects loop.  Your amp is boosting the signal to more or less line level before it goes into the H9.  So, you're getting a better separation of your guitar from the noise floor.  If you want the same quality of sound when you put your H9 in front of your amp, then you'll want to put a boost pedal before it (when using quiet guitars).

[nickrose]

The situation is probably more complex that Greg implies. Most of the noise comes from the input load resistor – if this is lower, the noise level drops, but so will the tone. This means that a booster which will improve the level without changing the tone will be hard to find.

 

Depending on your guitar and your ears, you may be able to find a solution, but this is not guaranteed – a low level output from a guitar is hard to use with digital inputs.

 

[laurent-fr31]

Thanks a lot for your quick answers. I tried with a booster but this does not solve the problem. And my guitar has strong pickups (gibson sg standard with 498T humbucker) which allow to reach the peak in the input signal.
I tried several configurations, in pre, post configurations as well as ‘normal’ and with the booster but each time it is the same: no noise at all when inserted in the effect loop, a superb sound, and a floor noise when in front of the amplifier (an ENGL ironball), in dsp mode or when activated (no noise in true bypass) and of course this is clearly more noticeable with the amp high gain channel. I definitely think it could come from an impedance issue between the h9 output and the input of the amplifier. Or maybe the power supply of the eventide (which has no ground pin contrary to the amplifier…) ?

[SucKamc]

I think that the ESSENTIAL issue here is that, regardless of if Eventide’s staff is correctly describing WHY such noise can happen, the people who are experiencing the noise with the H9 and Factor pedals just don’t experience that noise with other pedals. 

The vast majority of other pedals (including digital ones) don’t seem to have this problem in these rigs. 

[nickrose]

Please be so kind as to give us an example of another digital pedal that does not have noise problems with your guitar, when simply connected guitar-pedal-amp.

If you will do this, we can buy one and test it. But, I do not expect to find a difference.

 

[SucKamc]

Are you saying pedals that produce NO noise whatsoever? Or the level of noise that an H9 or Timefactor produces?

[nickrose]

No noise at all would be nice, but unlikely.

What I'm looking for is aspecific example of a digital effects pedal that, when used with the same named guitar, produces significantly less noise than an H9 when connected guitar-pedal-amp,

Given that these are "the vast majority", this should not be too difficult.

 

 

 

[nickrose]

It's my belief (and I know things) that the real noise performance of our pedals is pretty much the same or better than most other pedals.

But, there is one proviso. Some pedals have a noise gate on their output which cuts off the noise when there is no signal. That is why I was keen for people to name "quiet" pedals. So far no-one has.

We did not add a gate because its operation can usually be heard, either a breathing effect or cutting off decay tails. In addition, it does not cut the noise while you are playing – that is always there, but is masked by the signal.

But, maybe people would prefer this….

 

[laurent-fr31]

To be honest I have not had many digital pedals (and all were sold when buying the H9) and they were all used in the effect loop so I did not detect that noise in front of the amp. But I still own a digital T-REX TAPSTER (Tremolo), and I have just tested right now in front of the amp.

And I confirm Nick that you are right. When used in this configuration, the pedal produces some hiss/noise when activated. Possibly lower than the H9, anyway typically the same kind of noise we are speaking off in this topic and which is particularly unacceptable to my ears…

So, I accept the explanation that it is linked to digital pedals in front of the amp (I didn’t noticed in the past becasue using only analog effects in front of the amp). This being said, even if it is common to all digital effects, any ideay of how this kind of noise could be removed or at least very very reduced ?

Thanks 😉

[nickrose]

Alas, there is no magic answer. You can try some or all of the following:

1) Use an effects loop where possible (my guess is that this is why people use them).

2) Keep the input signal level as high as possible – then you can turn down the gain, reducing the noise by the same amount.

3) Maybe use a noise gate (or a pedal with one) just before the amp if you can find one that is not too noticeable.

[SucKamc]

The effects loop did the trick for me. It’s dead quiet back there. Sounds killer, too, of course.

 

As for pedals with which the noise wasn’t a noticeable issue in my rig: Strymon Timeline (which also gives the opportunity to swap bypass settings; both were quiet), Pigtronix Echolution 2 Deluxe, Line 6 M9 (again, I believe a bypass toggle is available in the menus, rather than comparing, e.g. an active drive model to true bypass…also, the M9 is not w/o its problems, and I still prefer the H9 to it in most respects),. FWIW, the TC Nova had a similar noise issue. In all of these cases, I’m talking about WITH the stock adapters. That should aid in research. (Obviously, those using 1-Spots should be corrected and/or banished from public life.)

 

Others could chime in with pedals that worked fine for them vs the H9. I know my co-worker Larry Rolando (Nashville session guy…same with Andy Most) had to yank his Timefactor for the same reason. I could find out from him what he replaced it with, if we’re conducting an honest search for a solution here, and not something else. FWIW, I still think they’re fantastic sounding products. I have another H9 tied to my recording rig for use with every instrument (and that, in addition to an old H3000). I know HRI and TGP had some threads about TF noise in front of the amp. I will say, I don’t think (and maybe you guys aren’t saying this, so do correct me if I’m unfairly representing your responses) that one’s using vintage-output pickups and a lack of clean boosts on one’s pedalboards is quite to blame for these noise issues, particularly given the ubiquity of that type of rig and (if it’s true) that other pedals don’t tend to have as much noise.

 

But I’m definitely in the camp who is interested in a solution. I love the sound of the TF and H9, even though these reports have been out there in the forums for years, now (I think it’s fair to say–though I’m definitely open to being wrong–in greater number than those reports vis a vis so many other pedals….the 1-Spot users, notwithstanding). 🙂

[nickrose]

I know the Line6 DL4 has a noise gate – we'll have to look at the others you mention.

Note that some amps have an excessively hot effects loop, so this is not always the solution.

 

 

[danisev2001]

I’ve done some tests. I did a couple of things and the hiss was reduced:

1. I adjusted the H9’s input level. I increased the input level (around +17 dB)

2. I placed a Ep booster before the h9 (minimum gain level)

The hiss is still there but things are getting better.

I think that the situation would be even better with something like this before h9:

http://lehle.com/IT/Lehle-Sunday-Driver-SW

A noise gate always have aneffect in the signal, I wouldn’t use a noise gate in my rig.

 

 

 

 

[SucKamc]

Apparently, among others that people used with greater success than the TF, there’s the El Capistan. That’s according to this thread (page 5):

 

http://www.hugeracksinc.com/forum/viewtopic.php?f=1&t=74966

 

Might want to add that one to the list of pedals to test. Some also said that Eventide tech support maintained that there was no problem and/or that the problem was actually that the player chose to not use high output pickups, no clean boosts, etc. This was 4 years ago. Y’all have been hearing about these issues for years, now.

[danisev2001]

I found out something interesting. The hiss is only noticeable when the pedal is in pre/post configuration. I mean when inputs and outputs 1 and 2 are used. Otherwise the hiss is gone. If I put h9 in front of my amp in normal configuration (using only input 1 and output 1) I am not able to hear the hiss using all my amp channels. 

I realized that in this pre/post configuration the hiss is gone when I swicth off the effect loop

 

Maybe there is a bug or something you could fix with an update….

 

What do you think?

 

 

[nickrose]

Can you describe how your unit is connected ? I'm thinking that you may have some kind of feedback going on which is causing/increasing  the hiss.

[danisev2001]

This is the scheme:

 Guitar –> Input 1 

Output 1 –> Amp

 

Send –> Input 2

Return –> Output 2

 

 

[nickrose]

I'm now thinking that you have some kind of ground loop. You say that the hiss goes away when you kill the effects loop, so maybe this is where it is coming from.

 

Are you able to lift the grounds from the cables going to first input 2, then output 2, and see if this makes a difference ?

 

It's very likely that this has a hardware cause specific to your setup – Pre/post wiring can be difficult, and there is no one-size-fits-all solution.

 

 

[danisev2001]

“Are you able to lift the grounds from the cables going to first input 2, then output 2, and see if this makes a difference ?”

What you mean?

How can I do this?

 

[nickrose]

Presumably you have 4 cables going from the the H9 to and from the amp. This means that there are 4 ground connections, which may be too many.

My guess is that if you unsolder/cut one or more of the grounds going from the H9 to the amp, this may fix it.

But, to do this, you would have to be moderately technical, and I don't wish to assume that you are. Do you have any technical friends who can help ?

Otherwise, keep the cables as short as possible, and the same length. Ground loops more commonly cause hum, but they can have other effects.

 

Lest you think that this issue only applies to our pedals:

http://www.thegearpage.net/board/index.php?threads/strymon-mobius-pre-post-function-can-cause-ground-loop-hum.1482152/

 

[Alancarl]

I am finding this is a very interesting thread! I want to add my experience of trying to use a non- gated digital device in front of my Fender Super Champ(not set to a very high gain. My mind goes wild imagining all of the potential of being able to utilize flexible DSP algorithms in front of my tube amps whether the digital devices were hardware or software based. Imagine the tweak-ability especially for a tweak head such as myself! What I found was that All of the devices and their DA converters did raise the noise floor somewhat. Of course the higher the amps gain the greater the noise. Now these devices are all very high quality and expensive as if price really matters:-)
It’s just the nature of the beast I have found. I like to think of it as a tube guitar amp input is an acid test for ANY digital device because of the often times higher gain settings that most of us like.
Basically I prefer to use time based effects in an effects loop ir in a Twp amp wet/dry rig so at line level signals the hiss issue is not an issue.
I do like my ProCo in front of my amp though/-)
My 2 cents.
Thanks,
Al

[danisev2001]

Sorry…

I was completely wrong. The hiss has nothing to do with the effects loop. It appears when the h9 is in front of the amp that’s all:

-If h9 is in normal routing the hiss is there..

-If h9 is in pre/post routing (no matters if the effect is pre or post) the hiss is always there…. 

 

 

[matt_stutts]

I know this is an old thread but it was the only one I could easily find that contained the same issue I’m finding in my Space pedal (already sent an email to support, just waiting on a reply.)  

 

I have sw version 5.2.06 on the pedal.  I’ve tested this in every way I can think of.  My guitar is a PRS Starla.  I’ve tried all sorts of configurations including:

guitar > space > audio interface

guitar >space > vox ac15 (clean)

guitar > rig (presense of other pedals, on or off, make zero difference) > ai or amp

Even just tried plugging nothing into input 1 of the Space pedal and the output going to my AI and listening through headphones, either monitoring the signal after going through my daw or listening to the signal coming out of the space itself.

 

At the end of the day, I’ve discoverd that it doesn’t matter what is before or after the space.  What matters is the bypass setting.  In Relay, it’s nearly quiet.  In DSP or DSP+FX, there’s a considerable amount of noise/hum.  It’s mostly in the 3-4.5K Hz range, as I’ve played around w/some eq settings in my daw to try to isolate it.

I’m not sure using Relay mode is ideal for my situation, and I don’t have an effects loop as others have used.

I’ve powered this unit in multiple manners.  I typically use an isolated power supply (1 spot cs-12 brick), though I’ve also used the wall wart it shipped with.  I’ve tried multiple outlets in the room…multiple rooms, even.  

I’ve run the same tests in the same manner using a strymon Timeline as well as an El capistan.  No noise with those pedals.  So, I’m reasonably sure it is (if not caused by then relating to) the bypass mode setting in the Space.  

I’m not sure how to resolve this.

[Honch]

This is what bugs me off pretty much, with H9 Max and most other digital pedals that has 600K ohms (mono or stereo) input. If you should put your guitar in there, it isn’t the 1 mOhm that is required. Now what on earth has this to do with hiss, and such things? Well it has. Strymons are better at it. If you should put a guitar into any input it must have above the 600 KOhms that Eventide has. IF YOU’RE GOING INTO A FRONT OF ANY TUBE AMP. Otherwise use the fx/send and return.So you have to use a Lehle Sunday Driver or something else that can convert the signal first, before going into the Max H9. This applies just as well to other digital pedals, and is not of any faults of Eventide. Then we have all this +4 db input and -10 db. On top of it all. +4 db are used in mixer and professional studios, and that value has to be the same throughout the chain. -10 db are consumer products, and regardless of that you have this on guitar lead, or not it must stay the same throughout.

If all these things are stuck together, you’ll bet you *ss you have hiss problems and noise problems when in front of the amp. Regardless of that the amp input is at 1 mOhm doesn’t make sense since the Max H9 turns it down to 600 K Ohm anyway. That’s why you have to use a Lehle in front of everything that can bring it up to 4 mOHms if you like, and have a crisp, clear high end without noise. Gain structure matching and keeping it all through the chain is almost impossible, hence the use of buffers.

To balance the Strymons hype bit, they have other problems such as aliasing and heterodyning. Let’s not go there. But by and large, it has to do with some pedals put in front of TimeLine,Big Sky, Blue Sky that has a charge pump built in. To ramp up the voltage to 18v inside. On certain dirt pedals, it has a peak frequency above human hearing range, around 22 Khz. And the filters doesn’t track this or filters it out, so if you use downsampling or any pitch shifter it gets downshifted to within the human hearing range, and since even 17-18 Khz can’t really be heard by us old blokes either, it may very well turn out just as … “hiss”. It is heard as whining when you use shimmer settings on the Strymons. Alas, thinking a tube amp wouldn’t see these frequencies, they pass though fx/send in any amp as well.

[nickrose]

Here's a bit of mathematics:

1000000.0 Ohm resistor at 25.0 °C within 20.0 Hz to 20000.0 Hz frequency band will have :

Noise Spectral Density = 1.283185e-7 V/√Hz or 128.3185 nV/√Hz

Noise within desired bandwidth = 1.813790e-5 V or 18.1379 uV

Dynamic range re 1V RMS = 94.8 dB    (thanks to http://www.audio-perfection.com for maths).

This shows that a 1M resistor by itself has about a 95dB noise figure relative to a typical guitar. This is without any other electronics. Beyond that, the following fet or opamp will have a noise voltage, and a further noise voltage due to its noise current, which will be directly proportional to the input resistance.

An H9 has a dynamic range of about 92dB, including all electronics, so it is pretty good.

Obviously we could easily put a 20M resistor at the front end, but the noise performance would be reduced proportionally. It is a tradeoff.

Our feeling was that with most guitars there is little to be gained by increasing the input resistance above its current value. In fact, some people find it too bright see our FAQ Q: The H9 alters my tone, adding brightness to the signal. Why?.

Some pedals use a noise gate to reduce the percieved noise. We are considering this, but are concerned about "breathing" effects and cut-off of effect tails.

So, it's all a trade-off. If you can hear a difference and are prepared to put up with a bit more noise, by all means use the preamp of your choice.

[danisev2001]

suckamc wrote:

The vid is me. I changed the input gain to the proper amount a long time ago. Also, I’m not even playing during that part of the vid and my guitar’s volume is on 0. But in any case, the input gain adjustment did nothing to address the veritable Timefactor’s worth of noise coming from the unit.  🙂

Hi suckamc, 

Do you have  a defectiv unit or is it normal?

I have exactly the same problem that you describe.

 

Regards, Daniel.

 

What did you do?

 

 

 

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