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Things I learned this weekend


JeffLearman

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1) New Nord pianos are good enough for me to enjoy playing, unlike NE2's. I was very happy to learn this! Despite they way Nord fouled up the UI, there's a good chance of an NE3 in my future.

 

2) I still prefer the sound of NIB4 to NE2, but they sure do sound similar in an A/B comparison. I use "clean" tonewheel setting on NIB4. The NE's tonewheels have more overtones, so it's one can't get as clean a flutey tone.

 

I like NIB4's rotary speaker sim better too, though it does tend to get a bit shrill on fast speed with no scanner unless I back off on the 2nd drawbar, more so than NE2.

 

There's a real nice one-high-note scream I can get from NIB4's overdrive that I just can't seem to get from NE2. NIB4 has more "crackle" at the top, which sometimes I like and sometimes I don't.

 

Of course, NIB4 was the first clonewheel I played regularly (and while I've played a number of real Hammonds I've never owned or played one regularly). So, I'm biased. No doubt if I went back to gigging with it I'd find a few things the Nord does that I can't quite coax out of NIB4.

 

3) Ground loops can have nonintuitive results. At least, I think it's a ground loop.

 

I noticed recently that listening to my laptop's built-in, I can hear noise when I drag something on the screen. Eric mentioned something about ground loops, and I realized I have both my laptop's outs and my MOTU's outs connected to the same mixer. If I disconnect either the MOTU firewire or the analog between MOTU and mixer, the noise goes away.

 

Now, that causing hum I would expect. What I wouldn't expect is for it to be more sensitive to EM noise in the laptop.

 

---

 

Thanks to Eric (erwish) for letting me have some quality time on his Stage EX to try the newer pianos (L versions, not XL), and for mentioning the ground loop thing! Also for showing me his killer montunos. They seemed sensible when I watched him but now that I try I'm missing something. I'll have to listen to some salsa music. :-)

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Now, that causing hum I would expect. What I wouldn't expect is for it to be more sensitive to EM noise in the laptop.

 

Quite a common problem with many actual causes, although they are all ground loops. In my experience the root of the problem is that computer board designers do not understand grounding for audio, so usually the only cure is to use a ground loop isolator and put up with it's shortcomings.

 

The noise heard is because there is a lot of ground current flowing each time the hard drive is accessed, and also sometimes as the video card load changes with various operations. There are others, but those two are the main ones.

 

DigitalFakeBook Free chord/lyric display software for windows.
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I suspect you're referring to what is commonly called "USB Whine".

The kind people at Yamaha service told me how to make some audio cables that act as an isolator - however I just searched my computer for the instructions and can't find it. Maybe someone else knows how to do this?

www.dazzjazz.com

PhD in Jazz Organ Improvisation.

BMus (Hons) Jazz Piano.

1961 A100.Leslie 45 & 122. MAG P-2 Organ. Kawai K300J. Yamaha CP4. Moog Matriarch. KIWI-8P.

 

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I suspect you're referring to what is commonly called "USB Whine".

The kind people at Yamaha service told me how to make some audio cables that act as an isolator - however I just searched my computer for the instructions and can't find it. Maybe someone else knows how to do this?

Dunno about the audio cables trick, but I've got excellent results with this little thing:

http://www.behringer.com/EN/images/products/HD400_P0387_Left_web.jpg

It's a MicroHD400 'Hum Destroyer' ... by Behringer (runs and ducks for cover). Yeah, I know, Behringer, but I'd heard good things about this unit, so I went ahead and purchased it long ago. I've used it with laptops of 3 different makes, and with suprisingly good results. Makes the bad whine go away. No distortion that I could make out.

This is really what MIDI was originally about encouraging cooperation between companies that make the world a more creative place." - Dave Smith
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We encounter some really nasty ground loops from time to time. A few tricks:

 

1) If you don't draw too much current, make sure everything on stage that is connected to one another (via patch/mic cables) is plugged into the same outlet - ext cord with a power strip. Plugging into different circuits, or even the same circuit with resistance in ground wiring from one outlet to the next is the most common cause of ground loops.

2) Make sure you are isolated via transformers from FOH if the mixer is on a separate circuit. Often, the FOH mixer is a good distance from stage, putting the ground at a different potential. As soon as they plug in, you got problems. We use a splitter snake and each channel has a ground lift, which I've used in these instances.

3) I've had horrible problems with laptops - I don't use one live, but just for work/recreation stuff through a PA. In some cases, the only solution was to unplug the power and run it off its battery. This works if you can do it.

4) I have occasionally, recently had MIDI noise issues. Whenever I move my pitch bend or mod wheels, he hears zipper noise in his IEM's. We are connected via a 4 channel snake - his drum module to my rack mount DI. I currently have other keyboard snake issues that I believe could be contributing. MIDI ground should be separate from audio ground. Some keyboards share ground - they should not. I created a ground loop in a previous rig by sharing a common ground for 2 sustain pedals. When I separated, the ground loop went away. So MIDI, Audio, and Pedal grounds should stay separate. If a keyboard ties them together, make a special cable to lift it.

 

BTW - I won't go into details, because most of you are probably already well-educated on the cause of ground loops. But if anybody wants a thorough explanation of what causes them, just reply back and I'll go into detail. It's a fairly simple concept, but can be very difficult to troubleshoot. But once you understand them, a systematic methodology for isolating the culprit can be pretty simple to determine.

Dan

 

Acoustic/Electric stringed instruments ranging from 4 to 230 strings, hammered, picked, fingered, slapped, and plucked. Analog and Digital Electronic instruments, reeds, and throat/mouth.

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