Noisy H8000FW

[ThreeFingersOfLove]

Hi all,

Can you please load preset 3910 and try it once at 96KHz and once at 48KHz? Do you notice anything?

I notice that it's very noisy at 96 KHz and less noisy at lower sampling rates. At 48KHz for instance, my TC M-3000 is dead silent to the point that I often wonder if it's turned on – and it costs 1/10 of the Eventide. It's freaking me out and I think there must be a serious issue with the converters. In fact the only way to get rid of this noise it to bypass the unit entirely. Selecting the thru presets (which effectively mute the DSPs) doesn't work.

I told this to another person who has an H8000FW and his is noisy at 44,1KHz (with the same preset) and dead silent at 96KHz.

Of course I have contacted Eventide's support and still wait for an answer.

Regards,
Yannis

[nickrose]

I see that I replied to your previous post on this topic in 2009. It is a reported bug. Obviously it got missed in the V5.5 release. Apologies.

My guess is that it is affected by the settings and/or the input source. Make sure that the "plex fdbk" is not too high.

If this preset causes you problems, please do not use it until it is fixed.

[ThreeFingersOfLove]

Hi Nick,

It has nothing to do with input sources. When the same input sources are fed to a TC M3000, I have absolutely no noise at all. I got in contact with another user who has an H8000FW and he tried the same preset and he told me that while there is noise at 44.1 when he switches at 96 Khz, all noise disappears. Both units have 5.5 so I don't think it's a OS issue, either.

You mentioned about the plex feedback… well it has nothing to do with the plex feedback either because even if I set this to zero, there is still noise. The funny modulation pattern disappears when the mod-depth is set to zero, at which point there is still a lot of noise. Changing presets doesn't alleviate the problem, selecting the Thru preset for both DSPs doesn't alleviate the problem either. The only way to get rid of the noise is to just bypass the unit.

This is extremely frustrating and I just can't live with it. I have to get rid of this noise in Izotope RX, after recording enough noise so that it knows what to remove – and the results aren't always satisfactory because Izotope cuts a few highs and so I have to equalize the recordings again. I am not sure whether I can live with having spent so much money on a machine that is praised for its excellence – but fails to deliver in this respect.

[ThreeFingersOfLove]

Is there any any particular reason why switching to 96KHz makes my H8000FW noisier? Should I have my unit evaluated?

[nickrose]

If the noise is, as you say, only a feature of certain specific presets, it is probably not a hardware problem.

[ThreeFingersOfLove]

All presets have a little bit of noise, some more than the others. #3910 additionally has this funny mod patern because obviously the H8000FW cannot recognize an audio signal from noise.

The thing that worries me most is that switching to 96 KHz this noise becomes unbearable. So, my question is simple: Is this behaviour normal, yes or no? You guys have plenty of units over there. Just switch sampling rates. Do you notice that the background noise is increase?

Thanks, Yannis

[nickrose]

Is it possible that you are not giving the unit enough signal level ? They typically have about 110dB dynamic range – this means that if you can hear the input noise, full level would be deafening.

What input are you using (XLR/jack  balanced/unbalanced) ?

What led meter reading do you get with a typical signal ?

Does it give you this noise with a "Thru" preset ?

Do you get the same noise level with channels 1/2 as 3/4 ?

[ThreeFingersOfLove]

Hi Nick,

1. inputs and outputs are Vovox cables, balanced
2. I typically see 1 LED being lit
3. This noise is also present in the Thru preset but not that loud
4. Noise is present in both 1/2 and 3/4 channels

[nickrose]

ThreeFingersOfLove:

2. I typically see 1 LED being lit

I think this is your problem. Assuming you mean the bottom led, this means that your input is about  40dB too low, meaning that you will get 40dB more noise than you should.

You need to adjust your input levels, either at source or by the [LEVELS] menu so that ALL the leds (except the top red ones) come on for high level signals. Then reduce your output gain to match.

This change will significantly reduce your noise level and distortion. It will also improve the performance of pitch shifters and dynamics processors.

[sean.e]

deja vu

http://forum.eventide.com/cs/forums/p/5014/21157.aspx

[ThreeFingersOfLove]

Hi again, lol

The level on my Minimoog Voyager is set to 10. Voyager is going into a Manley Massive Passive which boosts an additional 2.5 dB and there is still only one LED lit. If I use the H8000FW's preamplifiers then I have more LEDs lit but the problem persists. Do I need to use an external preamplifier maybe?

Also, how can you explain that the noise at 96 KHz is considerably louder?

Regards,
Yannis

[nickrose]

Are you using 1/4" jack connectors ? If so, it is possible that you are connecting an unbalance input to the balanced inputs of the H8000. This will give you low signal and a lot of noise. Sounds like you need to look at your connections.

It looks like the Minimoog probably gives out about +4dB at full shout, so this should light about the bottom 3 leds. If it does not do so, it would again indicate some kind of connection problem.

Lest you wonder, the reasons that I am so sure that the problem is at your end are as follows:

1) Our gear is pretty quiet.

2) Even if there were a hardware problem, it is unlikely to occur simultaneously in both audio boards. It could be a mysterious power supply problem, but this would probably have more dramatic symptoms.

3) If it's only lighting the bottom led on the meter, it's going to be noisy.

There is little value in discussing the nature of the noise until we are sure that you are giving the unit a good signal.

[ThreeFingersOfLove]

The output connectors of the Massive Passive are balanced. I use TRS (from the Manley MP) into XLR on the Eventide. Either way it's a balanced cable. I really don't think there's a problem with the connectors, they are all very high quality… even if the signal is low in level, how does that explain the noise even when NO signal is present? Even more how does that explain more noise in higher sampling rates?

You say that the converters have something like 110 dB dynamic range. I have no trouble believing that but firing up a frequency and spectrum analyzer on the Eventide's output shows a level of approximately -70 dB, which means that there's something like 40 dB of noise!!! So you see I wonder why I have so much noise without even a signal being present. Just switching on the H8000FW makes a considerable difference. When I play something this noise is masked of course, but when the signal fades to silence, the noise is still there.

Nick, when you switch on your H8000FW and you have no signal that feeds into it, is it noisy? If you switch sampling rates, does the noise gets louder?

[nickrose]

Yannis – you have to start believing me. Unless you can get most of the leds lit on a high signal, you will get noise. Whether a signal is present or not.

This applies to all equipment, analog or digital, not just ours.

My system is not noisy, because I operate it with the correct signal level. You'll probably find the problem in time, but if not, you should get someone in to look at it.

[t_tangent]

Hi Three fingers,

I dont know if this helps or not. I havent had time to try it out at 96khz yet either, but if preset number 3910 is called Drum-O-Tronic which it is on my H8000FW, then at 48khz I can hear no noise at all. However this is via the ADAT I/O. I tried it out a bit earlier after remembering this thread. I will try to run it again via analog I/O and will set that to 96khz as well to check it out when I can. In the meantime I hope you manage to resolve it. Maybe try connecting it to something else just to see if that changes anything. I also have a Massive Passive that I can try to hook up one of my analog synths via and then into the Eventide to see if I can replicate it. Will let you know.

cheers

t_t

[ThreeFingersOfLove]

OK, given the fact then that everything is pushed to the max and that I use very high quality cables, does a preamplifier between the Massive Passive and the H8000FW is going to solve the problem? Please enlighten me if there is any other way to boost the signal to hit 4-5 LEDs. I know I am tiresome, but it's important for me to solve this problem.

[nickrose]

You'll understand it's hard for me to know what is happening without being there. What you have should be enough, but for an unknown reason it is not.

Do you have access to any other equipment that has a hot line level output on XLR that you could try ? Make sure that LEVELS/inputs/Pre A/D Gain is set to 0dB.

[ThreeFingersOfLove]

I have another unit that has a hot line level on XLRs and I am going to try it today. All levels (inputs, pres, outpus) are already set to 0 dB.

This is gettting really frustrating because I got in contact with another user who uses synth –> H8000FW and he sees something like 6-7 LEDs.

There must be something awfully wrong with my H8000FW 🙁

[nickrose]

I'm afraid that, much as you may not believe this,  it is most likely to be your connections. If it were a problem in the H8000, it would probably not apply to all channels.

But, if you haven't already, try a CLEAR SETUP to make sure something is not set wrong.

[ThreeFingersOfLove]

…the cables that I use to connect to the 3/4 inputs of the H8000FW are balanced but the synth's outputs are not. This cable probably makes the volume drop by something like ~12 dBm, no? Maxing the synth's output (and with the same TRS/XLR cable), I got something like 5 LED on *some* loud patches. I had to reduce the H8000FW's 3/4 outputs by ~10 dB because after that there is a RME Fireface 800 and because they don't have the same headroom, it kinda freaked!

We are getting somewhere. It's still noisy but not as much.

…What if I a). use a TS cable from the synth into the H8000FW's analog ins, b) have the output levels back to 0dB and c) lower the inputs on the RME FF800 so that it doesn't clip?

[nickrose]

ThreeFingersOfLove:

It's still noisy but not as much.

When the gain settings and connections are right, it will not be noisy.

ThreeFingersOfLove:

…What if I a). use a TS cable from the synth into the H8000FW's analog ins, b) have the output levels back to 0dB and c) lower the inputs on the RME FF800 so that it doesn't clip?

Sounds promising – connect the TS cable from the synth to the 1/4" input of the H8000, not the XLR. Or, if you want to us the XLR, make sure the cable is wired pin 2 to tip, pins 1 AND 3 to sleeve.

[Author]

Posts