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Roland VB-99 V-Bass System => VB-99 General => Topic started by: Martin Turner on December 29, 2018, 01:45:30 PM

Title: VB-99 wild interference
Post by: Martin Turner on December 29, 2018, 01:45:30 PM
I play a VG-99 while my wife plays a VB-99. The VG-99 is quite well behaved, but we get some wild interference on the VB-99. We've tried swapping all the power supplies and GK cables over, but the VG-99 still never picks up the noise and the VB-99 does. It's intermittent, like the sound of a mobile phone occasionally polling. We've tried getting everyone to turn off their mobile phones, but, of course, you never know what's going on in the next room.
I've tried lifting the Ground and unlifting it.
What is the next step to tracking this down?
Title: Re: VB-99 wild interference
Post by: Martin Turner on December 29, 2018, 01:55:57 PM
I should add — we get this interference even when no GK cable is plugged in and no instrument connected.
Title: Re: VB-99 wild interference
Post by: ElliotG on December 29, 2018, 02:06:36 PM
Id suggest putting a ferrite choke on the power cord, or try replacing the power cord.  See if swapping the power chord of the two devices makes a change?


https://youtu.be/LuMlM8zWQFk
Title: Re: VB-99 wild interference
Post by: Martin Turner on December 29, 2018, 02:10:34 PM
Thank you — we already have ferrite cores on both the power cable and the GK cable, and we've swapped them around.

Would adding an extra ferrite core help at all?
Title: Re: VB-99 wild interference
Post by: ElliotG on December 29, 2018, 02:32:09 PM
Quote from: Martin Turner on December 29, 2018, 02:10:34 PM
Would adding an extra ferrite core help at all?

Adding an additional ferrite core could help. I'm not optimistic given that swapping power cords did not fix the problem, and one device has the issue the other one doesn't.  It suggests there is an issue unique to the  VB99.  You could give it a try.

Make sure the case is screwed together tightly with no missing screws.  I'm not familiar with the VB99 construction, but you could also check the case to make sure the shielding in the case is all connected.  Check all the corners, and where the bottom attaches.
Title: Re: VB-99 wild interference
Post by: Martin Turner on December 29, 2018, 02:38:01 PM
Thank you — I will take it to bits and see if there's any loose wires. I will report back.
Title: Re: VB-99 wild interference
Post by: admin on December 29, 2018, 03:21:31 PM
Quote from: Martin Turner on December 29, 2018, 01:45:30 PM
I play a VG-99 while my wife plays a VB-99. The VG-99 is quite well behaved, but we get some wild interference on the VB-99. We've tried swapping all the power supplies and GK cables over, but the VG-99 still never picks up the noise and the VB-99 does. It's intermittent, like the sound of a mobile phone occasionally polling. We've tried getting everyone to turn off their mobile phones, but, of course, you never know what's going on in the next room.
I've tried lifting the Ground and unlifting it.
What is the next step to tracking this down?

Verify you are connecting the short 1/4" guitar cable between Bass 1/4" output and GK-3B 1/4" Input

I assume you are using a GK-3B bass GK pickup?

Or what type GK 13 pin Bass?

This should reference the Bass instruments string earthing ground to the GK13 cable large round Ground Shell at each end of the GK13 cable

On the GK13 pin input side. There is only one Ground for everything (analog Audio per string, DC control voltage and EMI/RF sheild

Review the GK13 cable FAQ

https://www.vguitarforums.com/smf/index.php?topic=19481.0

and GK-3B installation manual
https://www.roland.com/us/support/by_product/gk-3b/owners_manuals/207a4e60-75ef-4076-a611-c20e477806b4/

https://www.roland.com/V-Guitar/gk3b-requirements.html


Im concerned when you say you removed the Ground and nothing changed
If you mean lift the AC Mains Ground, may not alter things much.

Suggests you do not have a proper instrument earthing ground via the GK13 cable

Find an ohm meter
Title: Re: VB-99 wild interference
Post by: admin on December 29, 2018, 03:28:49 PM
Quote from: Martin Turner on December 29, 2018, 01:55:57 PM
I should add — we get this interference even when no GK cable is plugged in and no instrument connected.

Change patches on the VB99

The GR300 COSM Analog GR Model patch on the VB-99 will make a lot of self noise - even with nothing connected to the GK 13 input jack on the VB-99

And turn the VB-99 Master Volume down

Also try removing all cables

Connect the Roland Power Adapter to AC Mains

Connect Stereo  Headphones to VB-99

Identify with headphone monitoring which VB-99 patches exhibit the most noise ( with nothing else connected

At the end of the day, you may be experincing tyipcal ACMains switching power supply white noise - due to an AC Mains ground loop between the VB-99 Sub XLR outputs and your Bass Amp/ PA Cab/ Mixer

https://www.vguitarforums.com/smf/index.php?topic=2078.0
Title: Re: VB-99 wild interference
Post by: gumtown on December 29, 2018, 04:44:40 PM
Save your settings and patches and try a Factory Reset?
Title: Re: VB-99 wild interference
Post by: Martin Turner on December 30, 2018, 02:06:45 AM
Thank you everyone.
We are using the built-in version of the GK-2B on a Warwick Bass. We had no problems of this kind while using the V-Bass, only on the VB-99.
The unit makes the noises even when no Bass and no GK cable are connected.
By Ground Lift, I meant that I had tried the Ground Lift switch in the back on both positions.
The sound is very intermittent: it is about 3 seconds of RF type interference, and then there will be nothing for five minutes.
It is not affected by turning the unit down, so the noise is most noticeable when the unit is turned down, because then the noise to signal level is much higher.
I hope this additional information may spark something with someone.
Title: Re: VB-99 wild interference
Post by: admin on December 30, 2018, 06:41:09 AM
Quote from: Martin Turner on December 30, 2018, 02:06:45 AM
Thank you everyone.
We are using the built-in version of the GK-2B on a Warwick Bass. We had no problems of this kind while using the V-Bass, only on the VB-99.
The unit makes the noises even when no Bass and no GK cable are connected.
By Ground Lift, I meant that I had tried the Ground Lift switch in the back on both positions.
The sound is very intermittent: it is about 3 seconds of RF type interference, and then there will be nothing for five minutes.
It is not affected by turning the unit down, so the noise is most noticeable when the unit is turned down, because then the noise to signal level is much higher.
I hope this additional information may spark something with someone.

Read the link provided for possible cures/ corrective actions

https://www.vguitarforums.com/smf/index.php?topic=2078.0

Might be a local source of EMI emissions

( wifi router, smart meter to local utility, etc)

Try the VB-99 in a different room/ building
If it persists - it might be indication of a failure of the internal power supply filtering - and requires service

The VB-99 production run is now 10 years old


(https://static.roland.com/assets/images/products/gallery/vb_99_back_gal.jpg)
Try adding an  Earthing ground wire to the Earth Ground Screw on rear panel ( far right)
- see VB-99 owners manual
Title: Re: VB-99 wild interference
Post by: fokof on December 31, 2018, 10:10:56 AM
You are hearing the noise through what ?
Maybe it's your amp/monitors....

If you unplug everything : USB , SPDIF , 1/4 , XLR  . really everything  , do you hear the noise through headphones ?
Title: Re: VB-99 wild interference
Post by: Martin Turner on January 01, 2019, 05:00:51 AM
Yes, we hear the noise through everything. We've tried it in three different countries (UK, Belgium, Netherlands), through headphones, USB, sub-out and main-out, with just the unit on and no GK cable or other input plugged in. We've also swapped out the power supply, the power supply cable and the connecting cables. On the sub-out we have tried with ground lifted and not lifted.

As an update, I've taken it to bits this morning and checked there are no loose connections, and cleaned all the contacts.

I've also done a full factory reset: no improvement.

I've ordered an RF/EMI suppressor power cable, which should be arriving on Monday. The only thing I have not yet tried (next on my list) is to connect an earth separately.

Today, experimenting, I discover that if I change the patch on the front panel, the noise goes away for a short time. It doesn't matter which patch. That would suggest to me some kind of capacitance effect which is dissipated by physically changing patch.

I will keep you all posted.
Title: Re: VB-99 wild interference
Post by: sixeight on January 01, 2019, 06:34:55 AM
The short silence on patch change is normal for the VG and VB99. This would suggest the problem is on the GK side. It could be a bad solder joint on the GK connector board. There is a lot of strain on that connector.
Title: Re: VB-99 wild interference
Post by: Martin Turner on January 01, 2019, 06:55:46 AM
Hi — this is with nothing plugged in at all. It's not a momentary silence, though — it breaks the interference. It returns later on (like, a minute or so later).

I've spent the morning working on it. The result seems to be entirely independent of the output volume control, so we are able to mitigate it to some extent by turning the physical output knob right to the top, thus giving a much stronger signal in relation to the noise. It's not really a long-term solution, though, as the signal would then be too hot for a lot of inputs.

I've also tried adding a second earth/ground using the screw on the top right of the rear output panel. This doesn't seem to make any difference at all.

I've also tried turning the noise suppression right to the top on the patches, but this doesn't seem to make much difference of any kind.

The sound is definitely RF: it has that characteristic RF sound which we used to hear on long speaker cable runs, and it comes in and goes away again. It is somewhat reminiscent of a Phaser — ie, as if a resonant filter was in operation somewhere.

Leaving the box plugged in and powered up for a few hours seems to reduce the number of times the interference comes back per five minutes, making me wonder if something somewhere is damp, and the heat is drying it out.

I'm expecting an RF/EMI shielded power extension delivered on Monday and will report further then.

Thank you for all your helpful directions so far.
Title: Re: VB-99 wild interference
Post by: admin on January 01, 2019, 10:01:03 AM
Perform a system Reset

(after backing up patches)

Then seek a Roland Repair Center , with luck the syptoms are repeatable on the repair bench.

I would start by replacing the 9VDC  PSU external  power brick
Title: Re: VB-99 wild interference
Post by: Martin Turner on January 01, 2019, 10:38:38 AM
Thanks — we've done the system reset and replaced the PSU.

I'll let you know what the result of the RF suppressor is, and then possibly talk to a Roland centre. Our previous experience wasn't great, though.
Title: Re: VB-99 wild interference
Post by: admin on January 02, 2019, 01:12:16 PM
There is a known  phenomena of Power line transmitted  / conducted EMI/RF signals which could be the source of the intermittent RF static noise - which could get through a defective AC Power brick which still works as a 9VDC power source, yet now transfers conducted RF static from the AC Mains power source

https://www.sweetwater.com/store/detail/PSB120--roland-psb-120

https://apps.fcc.gov/kdb/GetAttachment.html?id=REAJXgAL22bcKwWcnSL%2FQA%3D%3D&desc=174176%20D01%20Line%20Conducted%20FAQ%20v01r01&tracking_number=34866
https://www.electronic.nu/2017/09/08/emc-filters-design-selection-and-installation-of-power-and-signal-lines-filters/

Remember,  we live in an era of "smart devices" and many of these "offend" by periodic interdevice communication via any means, often using the AC Power mains 

( explains why i avoid owning new appliances (LG, Samsung) as most of these new "smart" appliances always generate random bursts of EMI/RF noise

https://www.techradar.com/news/networking/powerline-networking-what-you-need-to-know-930691

Using an AM Radio to Detect EMI

https://youtu.be/lXPJvSU8MwI
https://youtu.be/jVZrLLMHh8k
(https://m.media-amazon.com/images/S/aplus-media/sota/33573a4b-3150-4950-8cb4-da6842a5bb63._SR970,300_.JPG)
https://www.amazon.com/Sony-ICFP26-Portable-AM-Radio/dp/B012F0DGYE/ref=pd_lpo_vtph_23_lp_t_3?_encoding=UTF8&psc=1&refRID=K0VAE9EJM47B8F5


https://www.amazon.com/Greenwave-Dirty-Electricity-Filters-Individual/dp/B01M6XNTO9/ref=pd_day0_hl_23_2?_encoding=UTF8&pd_rd_i=B01M6XNTO9&pd_rd_r=0e2baea4-0ed4-11e9-8165-45849ee12971&pd_rd_w=ZSoxK&pd_rd_wg=KfG0l&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=M5J3QQ5YGDJF2DTQ4PPA&psc=1&refRID=M5J3QQ5YGDJF2DTQ4PPA
Title: Re: VB-99 wild interference
Post by: Martin Turner on January 03, 2019, 02:56:38 AM
Thank you, that's very helpful. I've got a filter arriving on Monday. If that doesn't fix it, I'll order a new PSU.
Title: Re: VB-99 wild interference
Post by: Martin Turner on January 11, 2019, 11:29:18 AM
So, I wired up an extra earth, installed additional RF chokes and put the power through an EMI/RF filtered power trailer.

Still not achieving the silent performance I have on my VG-99, and Noise Suppression / Noise Gate isn't helping.

I've done a full factory reset, swapped all the cables and power supplies over.

Will now look at purchasing a new power supply.
Title: Re: VB-99 wild interference
Post by: admin on January 11, 2019, 11:35:06 AM
Noise Could also be due be dying internal electrolytic capacitors  - which can occur if the unit was exposed to extended heat  ( like stored in a outdoor shed ) 

Id have it looked at before it dies.
https://proav.roland.com/global/support/service_repair/service_centers/


Belgium / France / Holland / Luxembourg

Roland Center Europe NV
Houtstraat 3, B-2260, Westerlo(Oevel),
BELGIUM
TEL: +32(0) 14 57 58 11

Title: Re: VB-99 wild interference
Post by: Martin Turner on January 16, 2019, 03:17:29 AM
Update: had a good conversation with Roland service, and will try out a couple more things they suggested. It is apparently not a known problem.
Title: Re: VB-99 wild interference
Post by: fokof on February 23, 2019, 02:36:54 PM
Have you found the problem ?
Title: Re: VB-99 wild interference
Post by: Martin Turner on February 23, 2019, 03:18:03 PM
We're back to using the V-Bass right now live. Sometimes you have to work on a problem to a particular point and leave it for a while.
Title: Re: VB-99 wild interference
Post by: Antonuzzo on April 18, 2019, 08:44:05 AM
I've had similar problems with the VB-99, but it's more evident when using the GR-300 emulation. For some reason, the VB-99 is really sensitive to earth interference.

The only solution that I've found is taking a 1/4" cable from the CTL 3,4 port and running that to earth via a clip. The downside is that you can't use a footswitch.
Title: Re: VB-99 wild interference
Post by: admin on April 18, 2019, 08:55:57 AM
Don't forget that RMC does make a subsonic filter specifically for the VB 99 which really helps  the gr300 emulation  and many other tones to eliminate unwanted noise

it has different EQ cut off points tailored for bass contact RMC pickups
Title: Re: VB-99 wild interference
Post by: admin on May 14, 2021, 11:52:05 AM
As always,  keep cell phones away from your guitar pickups

Else you will pickup EMI/RF noise

https://youtu.be/PqmuMQJ4xGg
Title: Re: VB-99 wild interference
Post by: gclev on March 11, 2023, 09:18:33 PM
Curious if you tried different power supply. I had a similar issue with an Alesis iodock. Turned out it was the power supply.