My friend has a MK1 that he picked up a few weeks ago.

He is planning on using it for live playback of keyboard sequences. Unfortunately he has notice a persistant background noise that sounds of digital origin.

It seems to have gotten worse with V2.03 Beta using a wave file. It's there with the mp3 version of the same file but quieter.

Is this a bug? I know that this was a problem with the MK1 that was addressed by setting the unit volume to 0db and adjusting the amplified volume but that did not help.

If it's of any interest the unit serial number is 17.

Your help is appreciated.

John

I recently bought a Mk2a after owning a Mk1 for a long time. There is a huge difference in the digital noise between the two of them, on the Mk1 it can be very obvious during quiet moments, on the Mk2a I can't hear it at all. I wasn't expecting there to be this much difference, so I was pleasantly surprised by my Mk2a...

This is a known issue with Mk1 players. It's covered in the FAQ.

Messing with various grounding schemes might help. Maybe a Radio Shack Ground Loop Isolator will work?

From your description, it sounds like he's going to be running it into a mixer of some sort. Doug316 here on the BBS has experienced this exact problem (noise when running the player into a mixer). His solution was to get rid of his Mk1 by selling it to me.

I've always had a low level rumble and twitter which seems to be display noise leak. I've always just put up with it. Is there something faulty with my unit? I could make a recording of it to verify it if you like.

I thought that the noise issue with the MK1 was a problem that only manifested itself in a car installation.

That's too bad. He was planning on using it for live performances but the noise is too distracting for him. I think he is going to dump his MK 1 and go for a MK2a.

Look for it in the "for Sale" forum.

John

I have No. 00015. I did have the same problem ("Mr Squeaky Mouse & Friends), which is exacerbated by various factors:

- using the line outs (Home mode) on the unit with headphones with low impedance
- earth loops, or improper grounding of the unit in the car install
- amp gain set too high on low impedance amps.

I sorted out the squeaky noise in the car by using good quality grounding wire, careful gain setting at the amp, and a good quality amp.

In the end, it is not really possible to completely remove all the noise, since it's a design issue. There is little you can do about this. However, I did improve it a lot as a consequence of having to repair the internal audio harness of the box following a shield wire breakage. In re-soldering the wiring, I also re-arranged the routing of the cables to reduce stress due to bad routing. Once this was done I was surprised to find that the squeaky noises had all but disappeared. Hoowever, this solution would require soldering and the ability to do careful cable re-routing, so this may not be for you. I would be glad to help if you are in the UK or the Netherlands, so please mail me off line.

I am sad that he thinks it's intrusive enough to not use it - I have a friend here who borrows my unit to store keyboard backings for stage performances (he took the photos at the owner's meets) and just plugs it into an input channel to the group's mixer via an isolator transformer.

Maybe it's tie I invested in a better quality amp then.

OK I went over to his recording studio last night and brought my MK2 along with me to compare.

What he showed me was quite astonishing. What I thought was a nice quite component was disturbingly noisy.

The noise was unaffected by the volume setting on the empeg. You could have the empeg turned down all the way and the hum was still there at the same level as before.


While the MK2 did not have the electronic/bionic noises it had a horrible baseline hum.

For reference he was running through a mixer that pre-amp'd out to his PA amps and into his PA stack. He is going to play in clubs and need his stack to run quite loud.

Nothing else in his entire setup, including a home built PC that is running into his system, makes noise.

Here is a link to the two files (I couldn't attach them for some reason?)
MK1 noise
MK2 noise

John

This is incredibly surprising. I've run some very careful tests with headphones, and my headphone amplifier turned to the maximum position and I was not able to find hardly any noise. Obviously at some level there has to be perceptible noise, but I couldn't hear any with music at any volume. My setup has the volume at 0.0dB using an external volume control. I didn't check for noise using the empeg's digital volume control. The empeg has less noise than my Technics CD player, and my Ah! Njoe Tjoeb 4000 (vacuum tube output amped). The 4000 is considered audiophile quality and it's perceptible noise levels are a thousand times more than the empeg.

Calvin

I can here the bass rumble on both my Mk1 and Mk2a, if I pause them and turn the amp right up. However, like you the amount of noise present on the output of my Mk2 is less than on my CD player (cost about $500).

The chirping noise on the Mk1 is very obvious when you pause it and turn amp up, that hasn't stopped me using it as a source through some large PA kit before though.

I was not able to find hardly any noise

[GRAMMAR NAZI]
So you were able to find noise, huh?
[/GRAMMAR NAZI]

The reason you can't attach the files is because they were too large. The BBS very clearly states (in the screen where you do the attaching) that the files can't be bigger than 100k, and those were quite a bit bigger than that.

The Mk1 noise sounded like ordinary par-for-the-course Mk1 noise.

The Mk2 noise should not be there. You've got a ground loop that needs to be solved. Something as simple as using a different power supply, plugging the power supply into a different outlet, or changing your audio routing might solve it.

Try unplugging the audio cables of everything that's going into the mixer. Then plug in the Mk2 and listen for noise. If there is no noise, then start plugging other devices into the mixer one at a time until you locate the unit that's got the ground loop going with the Mk2. Look into solving it at that level.

Also, have you tried grounding the cable shrouds, grounding the player's case, or using these?

Finally, remember that the car player should be turned up to 100-percent volume (0db on the scale) and the mixer input should be used to control the player's volume.

At the maximum volume I couldn't percieve any noise. I tested using a zero bit track (no noise perceivable) and I tested using a very low low low volume track. Let's put it this way, any noise that I might have heard could have come from outside of my headphones and not from the empeg itself. :-D I declare the noise floor of the Mark 2 undetectable at very, very, ear damaging, levels.

Calvin