running oscillator

[jgams]

Just picked up the MB at Long&McQuade and I love it. Sounds great and is a joy to play with.

Just wondering if anybody else can hear the oscillator running quietly even with all the settings turned down (mixer, envelopes, filter, volume, and headphone knobs)? The gate source is set to KBD but it's still making noise after the key is let go. Pressing a key or turning the fine tune knob affects the pitch. -Quietly-

Thanks
-j

[Worlock]

Mine seems to do this too though I don't find it noticeable until I have the MB run through a distortion pedal.  Then you can hear the sound clearly, even with both volumes off.

[dalasv]

Check to see if you have the Amp LFO anywhere other than exact 0.

[jgams]

Hi dalasv.

The Amp LFO is set to exact zero, but even if it's changed from the centre value the tone remains. The only thing that affects the tone is playing the keyboard - the tone will match the key pressed and remain after the note gate has silenced - or turning the fine tune knob or the pitch bend wheel. This is with ALL knobs and sliders zeroed or centred- master volume off, headphone volume off, filter off, mixer and envelope faders off, etc.

*Added*
I just checked again and it seems the tone is 2 octaves below the key pressed (sub osc?). I can hear it in the background running parallel to the other waves when any of the osc mixers are turned up very little and of course the envelope is opened to allow the waves through.

[diabolik!]

mine is doing this now as well.  its starting to drive me crazy.  any news?

[Bruno@arturia]

Hi
If you can hear, with master, and headphone volume to min position, it looks like a ground issue.
In my opinion few possible solutions:
 * the other machines you use, don't have clean ground (Worlock: do you still hear it if the pedal is battery operated?)
 * a ground loop is made somewhere in your setup
 * Cable shield/gnd connection is faulty
 * The internal grounding between the two PCB, is not good enough: you can try to tighten the three black screws on the back panel.

Bruno

[Worlock]

Im having troubles duplicating this again.  I may have had the LFO on or something.  I think when it was doing this, I had the volumes up anyhow.  I don't have an adapter so the distortion was running off a battery.

[jgams]

Hi Bruno,

I've only been using the MB with headphones so far and now I've also tried another pair as well as different power bars and outlets around the house. I also tried to tighten the screws on the back but they were in there pretty well. The sound is still there. It's not an urgent issue for me as the synth functions perfectly otherwise and sounds amazing but I worry that it might get worse in the future.

Thanks
-j

[circfine]

Hi, all!!

I reside in S. Korea and bought MiniBrute last week.
I'm learning a lot about true analogue experiences and it's a musical delight.

However, there's one thing very curious.
As some people mentioned above, my MB also has a same problem.
Running oscillator at Master Volume (including Phone) knobs at Zero position.

No ground problem, no wrong connections, everything is clean as informed.

But I can hear the very tiny, small sound Oscillator running when the master knobs are set at ZERO.

One thing interesting is that when I turn the Master knob a little bit, very little like 1~2mm, clockwise, the noise disappers.

Is this a hardware problem?
Will it be possible to be fixed with firmware update?

Not so big major problem, but still makes me concern.

I will be waiting for a helpful solution.


Have a nice week all you guys!!!


Best regards,

circfine from S. Korea.

[fear83]

Has this issue been solved or is there already an explanation? Because I am wondering if I should bring my MB back to the store.
 

[Corporael]

To all discussing the issue.  This may or may not be of any help to anyone, but I hope it at least comforts some folks in some manner.

I own a variety of synthesizers, and some of them are fully discrete analog circuits.  In most of them, like for instance the Mg Rogue, I always hear a tiny bit of the oscillator pitch in the signal path even without depressing a key or routing any modulators.  Obviously, I have heard it occasionally from the MiniBrute.  I assume this is a result of the fact that despite our efforts to ground circuits within mass-produced instruments, there is only so much we can do when you have a combination of circuits packed together with a metal chassis and other conductive parts and made of components that drift over time and during operation slightly (resistors/capacitors/power supply voltage) holding control voltages steady with a bunch of other circuits amplifying everything...etc.etc.etc.

Based upon the fact that I have heard this in practically every analog piece of gear I own, I would assume that it is indicative of normal operation quirkiness...  That or all of my gear has some odd problem.  I never hear this sound during performance/recording etc.  It simply does not make it to the end of the signal chain.  Only directly into an amp when it is cranked or in headphones do you hear some faint wisps of the leaking signal.  Does this help?

[fear83]

Certainly does...
Thanks for the reply. This is my first analog synthesizer so I just wanted to know if something is damaged and I should replace the synth of if it is just normal. The sound is very faint like you said so I dont really mind that much.

[Shy-Guy]

Hey peeps!

I also have this same issue.

I noticed if you pull the jack out of the master output and put it back in to only the first tip you can hear the oscillator louder and clearer. I hope there is some solution to this.

Thanks!

[Bruno@arturia]

I think it comes from a weak grounding between the two boards.
On this machine, grounding is both done by the wires on flat ribbon cable, and by the aluminum enclosure itself.
Maybe during painting process, some painting leaked inside the enclosure and prevent having a good contact between Boards and enclosure.
Can some on you can do a test for me?

- open the machine, following Technote_04
- unscrew the three back screws on rear panel, to release small board.
- on this boards they are 3 metal clamps, used as crew slots. Can you visually check if you can see some painting, or anything the could cause a bad contact, on the enclosure part, where the clamps are supposed to be in contact.

If you take a photo that would be perfect.

Thanks
Bruno

[Shy-Guy]

I think it comes from a weak grounding between the two boards.
On this machine, grounding is both done by the wires on flat ribbon cable, and by the aluminum enclosure itself.
Maybe during painting process, some painting leaked inside the enclosure and prevent having a good contact between Boards and enclosure.
Can some on you can do a test for me?

- open the machine, following Technote_04
- unscrew the three back screws on rear panel, to release small board.
- on this boards they are 3 metal clamps, used as crew slots. Can you visually check if you can see some painting, or anything the could cause a bad contact, on the enclosure part, where the clamps are supposed to be in contact.

If you take a photo that would be perfect.

Thanks
Bruno

Hi Bruno,

I've now included a sound demo of this oscillator issue. In the sound demo you will hear me pulling the master 1/4" jack in and out. The reason being is when you pull the jack out and only plug the first tip of the jack in you can clearly hear the oscillator louder.

I have tried different cables as well so I know that is not the issue.

Also you will need to listen to the attachment loudly as it is quite low in volume.

I will also try out the instructions you put above but just thought I would show you this for the moment! (See attached)

Many Thanks!