Casio WK 7500 microphone noise problem

[Lawrence Hart]

Hi everyone, I'm new here. Just got a Casio WK 7500 keyboard. One problem I was wondering if anyone else had...the 7500 only accepts dynamic mics, so I tried both Shure SM58, and Samson R31S mics. Both these result in a VERY noticeable amount of noise when used, a kind of high-pitched electronic hiss. The noise happens when you start to sing, stops when you stop singing... or just tapping the mic causes the noise for a second. I ran a mic check on the Shure at the local music shop, tried an inline z-transformer, new cabling, every sound setting I could find on the board, no luck, still got noise. Noise happens also through the instrument input. Both the mic & instrument inputs are supposed to route through a noise gate. Wonder if mine is dead? Thanks for any help!

 

[happyrat1]

Sometimes you just get a lemon. After all, it's a $300 keyboard, mass produced by the millions. Sometimes quality control suffers in the process and a lemon slips thru.

If it's still under warranty I'd say take it back to the store for an exchange or contact Casio for repairs. Technically it's not up to spec and there's no reason you should suffer for it. It's probably just a noisy cap or resistor somewhere in the circuit, but if you're not happy with it and it's under warranty there's no reason you should put up with it.

 

[Grenyes]

Hi Lawrence Hart,

Did you change your keyboard? The new one is presenting the same problem?
I've just get one and have the same problem.

Thank you!

 

[Lawrence Hart]

Hi Lawrence Hart,

Did you change your keyboard? The new one is presenting the same problem?
I've just get one and have the same problem.

Thank you!

Hi. What I did was contact the seller, Kraft Music, they ran tests on their own Casio WK 7500 and said they found the same problem, their explanation was, to get this kind of keyboard for this price, there might be something to give up, and in this case it was the microphone noise. Sorry to hear about yours doing it too. Apparently they all do it.

 

[happyrat1]

I wouldn't accept that as an answer from the vendor.

I'd suggest posting both your complaints at

http://www.casiomusicforums.com/

Where authorized factory reps speak on behalf of the company.

Sounds to me like Kraftmusic is feeding you a line of horse manure and I wouldn't stand for it.

 

[Grenyes]

Thank you all. I have a friend of mine buying this keyboard (I warned him about the mic issue but he don't mind the microphone). I'll try his new one and put here my impressions.

Ah! Except that problem, the keyboard is awesome!

 

[Mozartian]

I'm just about ready to spring for one one these keyboards and the mike feature is one of its selling points for my use. I would like to try out the mike feature in the store before I take it home. What exactly is the setup to determine the noise? What settings are on the keyboard for using the mike? I assume it is produced live through the speakers or is it only through recording on the Casio?

In doing a bit of research, a Trouble Shooting section of a manual of another model Casio (not this one) states that static on the microphone input might result from nearby fluorescent lighting. But the noise you described does sound different than what this trouble shooting guide depicted. Just something to check out.

 

[Lawrence Hart]

I'm just about ready to spring for one one these keyboards and the mike feature is one of its selling points for my use. I would like to try out the mike feature in the store before I take it home. What exactly is the setup to determine the noise? What settings are on the keyboard for using the mike? I assume it is produced live through the speakers or is it only through recording on the Casio?

In doing a bit of research, a Trouble Shooting section of a manual of another model Casio (not this one) states that static on the microphone input might result from nearby fluorescent lighting. But the noise you described does sound different than what this trouble shooting guide depicted. Just something to check out.

Hi, thanks for the post. I think it's basically what the guys at Kraft Music said; that to get this kind of keyboard for this price, there might be something to give up, and in this case it was the microphone noise, and that's really the only problem with this keyboard. It's really not that bad of a problem, but if I were to do a lot of recording I would record my music on the keyboard, and the vocals I would do on the computer using a higher quality system for the mic, or you can pump the keyboard direct to the computer and mix it all there. It's an incredible keyboard for the price, the options and features are practically unbeatable. The setup for mic is pretty simple, you have a 1/4" plug on the back that requires a dynamic mic only, ie., xlr powered type, and it has a "mic volume" knob on the top of the keyboard. Then there's also the main "volume" knob for the speakers... that's it. You can hear it all, your music and vocals, either/or through the onboard speakers, and also record it all, either/or into the SDHC card slot. The onboard mixer is very good, there are a ton of recording tracks and options. But for the mic there appears to be a sound gate problem, so when the threshold of volume is high enough, the mic turns on and you get the noise, which to most people they would barely notice, but to a discriminating someone recording, they would. I tested it this way: plugged in and turned up the mic, I hear no noise at all at first; then I made some very quiet breating sounds, still nothing happens, but as I made louder breathing sounds into the mic, it finds it's threshold and suddenly comes on through the speakers.... with the accompanying noise. Any normal sounds like vocals are loud enough to trigger the sound gate to come on and the noise. I tested your idea on the fluorescent lights, it didn't seem to make any difference, there's still some high pitched noise when using the mic. So.... bottom line, if you are looking for a great, extremely full-featured keyboard, you will probably love this one, & the onboard speakers are top notch, but do your mixdown of vocals on a computer using Garage Band, or Mixcraft. Also one thing to note is, any good powered dynamic mic, like a Shure SM58 etc., will produce some small amount of noise on it's own. I tried 2 different mics, the SM58, plus a Samson R31S, they both produced noise, but the mic noise on this keyoard is probably unnacceptable for recording, and yes, the noise does come through the recording also. Hope that helps, good luck in your search!

 

[Mozartian]

Thanks for your detailed and thoughtful reply. Yes, I must accept the fact that there are "features" and then there are "quality features." A camera I have has autofocus as a feature. But that feature on my camera falls far short of that same feature on cameras costing 3 times as much, sometimes causing that feature to be virtually useless.

In reviews and opinions of keyboards, it would be instructive to see a listing of 10 or 20 common features, for example key-bed quality, quality of specific voices (piano, organ, choir, trumpet, flute, etc.), recording quality, rhythm quality, accompaniment quality, sequencer quality, etc along with ease of use ratings of each feature. Having a "feature" is one thing; having "useful" or flawless features is quite another. Feature evaluation could include categories of performance, such as: useless/flawed/gimmicky; useful but with imperfect implementation; pro quality. The recording quality on the 7500 I assume would fall in the "useful with imperfect implementation" category indicating it falls short of "pro quality" for various reasons: noise, distortion, level, frequency response, etc. (Wouldn't it be a blast to be given a $20,000 budget by Consumer Reports and be the chief reviewer for 50 different keyboards.) Another way to express an evaluation would be the performance of a feature relative to both 1) other devices in its general price range AND 2) devices double the price. I'm guessing the 3500 has features that are mostly equal to performance of other units in its price range. Some of the features may be inferior, some superior. A couple may even rival that feature in top boards.

With all that said in relation to the mike input noise, I understand there are keyboards at HALF the price of the 7500 that have a mike input. They tend to have a Karaoke-type feature. Not many or any in the price range of the 7500 that I am aware of have a mike-in. I wonder how clean or distorted the mike inputs are on these cheaper devices. So, if I'm wanting to record my miked acoustic instrument along with a rhythm track, how obtrusive will this noise be? You indicated that the casual user may not notice or be bothered by the level of noise produced. I know what a bad capacitor sounds like on an audio device - it is a low level background random static which I find distracting and unacceptable. Is this mike input noise that bad? Is it continuous, or is it a microsecond blip when the gate open/closes with changes in input? Could you guess a S/N ratio? Does it consume1% 5% 10% or 50% of the signal capacity?

 

[Ted Nicoson]

Both the mic and inst inputs on my 7500 are perfectly clean. I do not hear any of the aliasing that you describe - until I do an audio recording and play it back. Then I hear it. As a matter of fact, I can even hear it in recorded audio playback of the keyboard itself. This is because when I am just monitoring and not recording, everything at that point is analog, but when I record, the sound goes through analog to digital conversion, and on playback, goes through digital to analog conversion. The aliasing I am hearing is typical of A-D and D-A converters designed with cost savings in mind. I have not had occasion to notice this before now, as I normally do my recording to a Fostex 8 tracker. If you guys are hearing it all the time and not just on audio playback, then I would say you have defective units, as mine is clean as a whistle at that point. As a matter of fact, the inst jack is cleaner than most of my guitar amps on their "clean" setting. Now, before we hang Casio out to dry on this, when Stephen Fortner of Keyboard Magazine reviewed the Roland Jupiter 50 synth ($2000 USD), he expressed surprise that he did not hear any A-D/D-A conversion aliasing. To him, this indicated that Roland had used the same high quality converters in the 50 that they had used in the 80. Apparently it is industry standard to use the pro quality converters only in the top of the line flagships.

If you are hearing this all the time, I am wondering if you are routing your audio through the DSP. If so, then that aliasing could be there all the time, as your signal would be going through the DPS's A-D/D-A converters.

 

[Lawrence Hart]

Both the mic and inst inputs on my 7500 are perfectly clean. I do not hear any of the aliasing that you describe - until I do an audio recording and play it back. Then I hear it. As a matter of fact, I can even hear it in recorded audio playback of the keyboard itself. This is because when I am just monitoring and not recording, everything at that point is analog, but when I record, the sound goes through analog to digital conversion, and on playback, goes through digital to analog conversion. The aliasing I am hearing is typical of A-D and D-A converters designed with cost savings in mind. I have not had occasion to notice this before now, as I normally do my recording to a Fostex 8 tracker. If you guys are hearing it all the time and not just on audio playback, then I would say you have defective units, as mine is clean as a whistle at that point. As a matter of fact, the inst jack is cleaner than most of my guitar amps on their "clean" setting. Now, before we hang Casio out to dry on this, when Stephen Fortner of Keyboard Magazine reviewed the Roland Jupiter 50 synth ($2000 USD), he expressed surprise that he did not hear any A-D/D-A conversion aliasing. To him, this indicated that Roland had used the same high quality converters in the 50 that they had used in the 80. Apparently it is industry standard to use the pro quality converters only in the top of the line flagships.

If you are hearing this all the time, I am wondering if you are routing your audio through the DSP. If so, then that aliasing could be there all the time, as your signal would be going through the DPS's A-D/D-A converters.

Thanks, I'm not doing any routing, it's straight mic to speaker, or mic to SDHC card, you get the noise. Glad yours doesn't do that, maybe there were a few bad items sold and a few good one's. Wish Casio would respond to this thread with their comments and a possible fix. Also, I won't hang them out to dry, if you read my last post I gave a big thumbs up to this keyboard, but there is this one problem that warrants a little concern to anyone wanting to do good recordings.

 

[Lawrence Hart]

Thanks for your detailed and thoughtful reply. Yes, I must accept the fact that there are "features" and then there are "quality features." A camera I have has autofocus as a feature. But that feature on my camera falls far short of that same feature on cameras costing 3 times as much, sometimes causing that feature to be virtually useless.

In reviews and opinions of keyboards, it would be instructive to see a listing of 10 or 20 common features, for example key-bed quality, quality of specific voices (piano, organ, choir, trumpet, flute, etc.), recording quality, rhythm quality, accompaniment quality, sequencer quality, etc along with ease of use ratings of each feature. Having a "feature" is one thing; having "useful" or flawless features is quite another. Feature evaluation could include categories of performance, such as: useless/flawed/gimmicky; useful but with imperfect implementation; pro quality. The recording quality on the 7500 I assume would fall in the "useful with imperfect implementation" category indicating it falls short of "pro quality" for various reasons: noise, distortion, level, frequency response, etc. (Wouldn't it be a blast to be given a $20,000 budget by Consumer Reports and be the chief reviewer for 50 different keyboards.) Another way to express an evaluation would be the performance of a feature relative to both 1) other devices in its general price range AND 2) devices double the price. I'm guessing the 3500 has features that are mostly equal to performance of other units in its price range. Some of the features may be inferior, some superior. A couple may even rival that feature in top boards.

With all that said in relation to the mike input noise, I understand there are keyboards at HALF the price of the 7500 that have a mike input. They tend to have a Karaoke-type feature. Not many or any in the price range of the 7500 that I am aware of have a mike-in. I wonder how clean or distorted the mike inputs are on these cheaper devices. So, if I'm wanting to record my miked acoustic instrument along with a rhythm track, how obtrusive will this noise be? You indicated that the casual user may not notice or be bothered by the level of noise produced. I know what a bad capacitor sounds like on an audio device - it is a low level background random static which I find distracting and unacceptable. Is this mike input noise that bad? Is it continuous, or is it a microsecond blip when the gate open/closes with changes in input? Could you guess a S/N ratio? Does it consume1% 5% 10% or 50% of the signal capacity?

Yes, I've also heard failing capacitors, but this noise is an "unchanging, high-pitch, white noise with a slight ringing." It is continuous as long as there is sound going to the mic. I would guess it uses maybe 10% of the signal capacity. The post just in by Ted Nicoson said he has not had this problem with his 7500.

 

[Mozartian]

A 10% noise level is on the order of that provided by $20 stereo systems sold at Walmart. But maybe since its at a "high pitch" old farts such as myself won't hear much of it. Hey, it may not be an issue at all if the noise is mostly above 8,000 hertz. I suspect my hearing is attenuated 10 or 20 db much above 8K. Trouble is, the hiss will mask out any quality high frequencies in the signal I am able to hear. Fascinating. Growing old does have its advantages. I can buy lower quality audio stuff and not be greatly impacted.

 

[Mozartian]

OK. I got my 7500 and tested the mike. I would not call it a "noise problem." I would call it a specification below the level that would be expected of equipment costing 2 or 3 times as much - and even then not significant for most applications. What I heard was a slight metallic rasp that lasts for less than a quarter second after the input to the mike subsides. I'd guess it occupies less than a percent or two of its S/N ratio. If that was indeed the "problem" in question, it does not bother my purpose in recording and I suggest it would not be an issue for 90% of the users of this sort of instrument. There is also a possibility I did not identify the same problem some people experienced. I will post further if I hear anything more bothersome than this. At my age my highest frequency hearing my be attenuated, but I am still capable of hearing and comparing relative volumes at relative frequencies and this problem was no problem.