Casio GP400 trouble with VST... HELP!

[Eli26]

I'm not here to complain about the built in  tones in th4 GP400.  They are actually quite good.  Nonetheless, I was looking for more levels of control for soft playing, and better sustain (exactly the same things that Casio has improved in the newer models, the 310 and 510).  So I realized this would be  a  good time to buy a VST.  I was looking at pianotech as well as a few others.  There are some issues which prevent me from using a VST, and I suspect that the piano needs repair --- or I need better advice than I can get on pianoworld forums!

Here's the problem: (1) I hooked up the VST in a standard way, namely I plugged the laptop into the piano via a 'printer cable' and ran an audio cable (3.5mm to two 1/4" plugs) from the laptop into the piano.  The VST works, but there is a significant electrical sounding buzzing, obviously the result of interference. As I detailed on pianoworld forums, I tried eliminating every possibility.  I made sure that the cables weren't touching, I tried it with the laptop plugged in vs running on battery, I tried ferrite rollers on BOTH wires to reduce any electrical interference.  I tried different audio cables.  I even tried different USB 'printer' cables. One thing remained constant:  if I plugged in audio cables and the USB cable into my laptop, there was a constant buzzing, making the VST unusable.  The ONLY way I could get it to work was using headphones directly from the computer, which was fine.  But as long as the audio line went into the gp400, there was horrible and unacceptable buzzing (whether I listed via headphones plugged into the GP400 or via speakers).  (2) The advice some gave on pianoworld forums was to use a Roland UM-ONE midi to USB convertor instead of the printer cable.  A friend of mine does gigs and was nice enough to lend me his to try it out tonight.  Hours of fiddling with drivers to get it to work, but again, unacceptable results.  This time, instead of a CONSTANT buzzing, there was a hissing noise which started only after a sound output (usually a key press, but tapping the sustain pedal would create the hissing as well.  The hissing would stop about 6 to 8 seconds after the note/pedal press.  The entire time that music was being produced this hissing was accompanying it.  Two additional points: (a) the hissing phenomenon was softer at lower volumes and louder at higher volumes.  (b) it's the same hissing that I hear (and asked about on these forums) when I record to a USB stick and play it back on the gp400.  Listening to an audio file played back on the gp400 is something I avoid as a result --- it always plays back with hissing, though the file doesn't contain any noise whenplayed backon audacity.  This is the same kind of noise.  I suspect that there is something in the audio processing of this gp400 that is producing this.  

 

I definitely want this taken care of.  The audio files being noisy (on the gp400 playback) isnt a big deal, because once I put them in audacity they sound very clean.  But the inability to use a VST without noise on a digital piano of this caliber isn't really acceptable.  Ironically I'm hoping that this is an issue with my particular piano (as opposed to all of them being like this), because I want to get it fixed.

 

 

 

[Brad Saucier]

Thank you for the detailed post.  I read it several times looking for clues. It sounds like there may be an issue in your particular piano, considering the hissing noise you are reporting with audio recorded and played back on the piano itself.  Audio files played back on the piano should sound clean.  I would say that the line input issue may simply be a gain staging issue (example: laptop level too low for what the piano is expecting), however, there is noise coming from the audio recorder during playback, which should not happen.  The MIDI to USB adapter was the right move to eliminate USB ground loop noise.  The remaining noise seems to be an issue inside the piano, based on what you're describing.  I would try some additional sources of audio into the line inputs and double check gain staging. If nothing helps, I would contact a service center and ask for assistance.  

[Eli26]

10 hours ago, Brad Saucier said:

Thank you for the detailed post.  I read it several times looking for clues. It sounds like there may be an issue in your particular piano, considering the hissing noise you are reporting with audio recorded and played back on the piano itself.  Audio files played back on the piano should sound clean.  I would say that the line input issue may simply be a gain staging issue (example: laptop level too low for what the piano is expecting), however, there is noise coming from the audio recorder during playback, which should not happen.  The MIDI to USB adapter was the right move to eliminate USB ground loop noise.  The remaining noise seems to be an issue inside the piano, based on what you're describing.  I would try some additional sources of audio into the line inputs and double check gain staging. If nothing helps, I would contact a service center and ask for assistance.  

 

OK, so it seems that there are three issues.  I appreciate all your help do far and would like further advice on this.

 

(1) the aforementioned hiss.  The good news is that based on my previous reporting of the hiss on the USB stick playback as well as some keys that were sounding late (and then, when they sounded, the tones sometimes kept going!)  casio has sent parts to the local repair shop for inhome service.  (To be precise, this was an issue last January, and the repair should have been done in early march, but the repair was rescheduled and then.... COVID, so waiting for them to schedule the appointment, which will hopefully be this December.  IN any case, I didn't know what parts they had sent to have it repaired, but the gentleman at the service center whom I just spoke with told me that they sent a new PCB board for audio and the amplifier, as well as for the keybed.....    So I THINK that this hissing noise is likley to be corrected at teh same time, though I can't be certain.....  What do you think???

 

(2) As per the USB ground loop noise --- is there ANYWAY to eliminate it WITHOUT buying the $50 Roland um-one attachment?  There are three reasons (sorry, I'm analytical!) why I want it to work with a standard printer cable.  First, because there was more latency and driver issues than with the printer cable.... by far the fastest and natural response was with the printer cable, which tells me that it's probably NOT the extra few millisecs of midi cable vs regular USB, but the fact that the computer was using different drivers to process the sound, and those drivers which were compatible with the  ONE-UM were just slower..... Second, because why spend $50 when I can use a cable which I already own.  Third, the principle that if CASIO gives me an option of output via a USB cable paired with input via AUDIO IN, they should hav ebeen engineered so as to not produce a loop.  Wondering what your thoughts are..... 

 

(3) as per the gain stuff.  I'm not sure I understand, which I want to.  It's when the volume is too high that I get issues.  If the computer volume is really low, it's hard to get any distortion.  Problem is that if the computer volume is really low, I can't get the sound loud enough even if I put the casio volume on max.  It seems like the distortion occurs if the decibel level hits a certain point (Its not like I measured it, but no matter how I adjust the volume of the computer and the casio GP, if the volume of the piano is anything approaching "normal", when I play forte I get distortion, especially with multiple notes.....

 

 

Overall, not only am I looking for solutions, but I'd like to know if these ARE solvable (because I'm not buying a VST if they are not -- -so far just using Demo VSTs)

[Brad Saucier]

It sounds like the service tech may correct any issues with audio as well.  That's promising. 

 

As far as USB, ground loop is a common problem among devices that combine USB with analog audio cables, not just musical instruments, and not just Casio.  The same USB device can be noise free with one model of computer or mobile device, but noisy with another.  It's not really cut-and-dry on when, or if it will happen.  A quick internet search will show devices (noise isolators) on the market that promise to solve it.  I've seen several forum members have success with them. Unfortunately, the worldwide USB standard was not developed with analog audio in mind.  Fortunately, traditional MIDI ports were designed for it, so they isolate audio noise extremely well.  This is why my first suggestion is always the standard MIDI ports.  

 

As far as gain, I'm not sure I can suggest anything different there.  Based on other Casio models I have experience with, line inputs should be able to match the level of internally generated sounds.  

 

 

 

 

[Eli26]

"As far as gain, I'm not sure I can suggest anything different there.  Based on other Casio models I have experience with, line inputs should be able to match the level of internally generated sounds. "

 

I'm not trying to be obtuse.  I don't understand.  I am not sure what gain staging is. (1) What is gain staging?  (2)  DO you mean that to avoid this issue I should use something else between the audio line in cables and the computer?  (3) DO you think that the issue could be due to an amp issue which could be fixed with the new amp circuit board?  

 

(4) Also are you aware of a better MIDI to USB solution than the Roland UM-ONE unit?  On my laptop, it seems like using that causes a default to a driver which increases latency......

[Brad Saucier]

Gain staging refers to the points in a signal path where you can make level adjustments to volume, which is what you have done.  It sounds like you've done everything you can do.  Perhaps there is an issue with the board that the technician will replace.  

 

MIDI to USB adapter, I have not personally used the Roland, but I have seen numerous forum members use them successfully.  I personally use the E-MU XMIDI 1x1 Tab.  I have never encountered any latency difference between it and USB MIDI ports on my keyboards.  Any latency is usually caused by the audio driver in Windows.  Using the free third party driver "ASIO4ALL" will solve that.  Apple products are usually fine.

[Eli26]

Thanks!  But again, with regards to gain staging ----  what is the most likely way to eliminate it?  Is it by equalizing the volume levels on the computer and the piano?  I was trying to keep the piano volume really low while keeping the computer volume high, as this minimized the hissing when I was using the midi to usb connector.  

[Brad Saucier]

That's all I meant by it, keeping your computer volume as high as it can go without causing distortion in the line input.

[Eli26]

Thanks.  I revisited the Roland Um-ONE, and noticed that it actually does still have a bit of ground noise associated with it (when I use it with the Gacio Gp400 and my laptop), though less than the midi to usb cable.  However, this item: Amazon.com: Mpow Ground Loop Noise Isolator for Car Audio/Home Stereo System with 3.5mm Audio Cable (Black) arrived yesterday (someone at pianoworld suggested it) and it completely eliminated the buzzing even when used with the printer cable.  (As above, there is still background hiss which seems related to the processing of the signal in my GP400).  I think it MAY be affecting the tone a bit, something sounds different, but I'm not certain.  I didn't directly compare the tone through the casio speakers with and without the Mpow isolator, because that annoying buzz is so loud as to make listening to the sound of the piano horrible.  But I will try this.

 

I was wondering about your thoughts on this item ----- is it cutting out a bunch of frequencies, like a graphic equalizer minusing certain frequencies (thereby affecting the tone?)?  Or is it doing something electrical, just removing electrical buzz, thereby leaving the tone untouched?  (I guess a third possibility is that it is actually doing something entirely electrical, but that electrical activity also inadvertently affects the tone).  What do you think?

[Eli26]

an Update: Casio had an in-home service tech at my house yesterday, and he replaced the DSP board and the pre-amp board.  This was partly to deal with the  fact that there were occasional odd tones, and also the hissing.  Unfortunately, the hissing issue is still there, after the repair.  I can define it better now:  Anytime that an external sound source is inputted into the GP400, hissing is added to the tone produced by the GP400. 

 

Having defined the problem in one sentence, I will now explain in more detail.  If Audio is saved by the piano to a USB card card, that audio is crisp and clear in Audacity.  But if I play that same audio, without any manipulation, by using the piano's functions to play from the USB stick, the result is that whenever a tone is playing, there is a bit of background hiss, which disappears about 5 seconds after the sound stops.  Similarly, if I use a VST such as pianoteq, and the pianoteq tones are being playe dthrough teh GP400 I can hear a hissing the entire time that I play, and it disappears about 5 seconds after the last note.  It starts again when I start playing again.  To be clear, the hissing is heard whether using headphones attached to the GP400 or using the piano speakers.  Also, if I instead plug the headphones directly into the computer, that hissing does not happen at all, so it is the fault of the GP400, not pianoteq.  (lastly, I solved the ground noise issue, so it's not that.)

 

Any advice on how I can get this issue to the attention of Casio engineers?  Customer support was unfortunately of little use, they just read portions of the manual.

[Brad Saucier]

Did you mention any of this to the technician before they left?  

 

It sounds like what you are experiencing is normal analog audio noise coming through the line input jacks.  Analog audio connections will always have more noise than purely digital ones.  It is the nature of the beast.  Analog noise can be kept to a minimum by properly setting output level of the device connected to the line inputs.  Set your VST instrument output level at a point which does not cause clipping (distortion), but is not so low as to cause and increase in signal noise. 

 

9 hours ago, Eli26 said:

Similarly, if I use a VST such as pianoteq, and the pianoteq tones are being playe dthrough teh GP400 I can hear a hissing the entire time that I play, and it disappears about 5 seconds after the last note.  It starts again when I start playing again. 

 

It sounds like you are describing a noise gate, which is present on the line input jacks on many Casio digital pianos.  The noise gate will open or close the signal path above or below a preset threshold.  The preset threshold is very low.  Noise that is removed by the gate, evident by the noise disappearing, is considered normal background noise.  

[Eli26]

The technician was there when I was at work.... nyvwife and kids were home.   I did speak to him (by phone) as he was working and he said he would check that after he had replaced some boards and that he'd call me, but he didn't follow through on that.  (I can't blame him, there was a snow storm starting when he was doing the repair,  and in sure he needed to get going while he could still drive safely.)   So when I called after finishing with my patient,  he was already gone.  

 

I'm not sure about the noise being normal.  There is the same kind of background hissing even when playing back audio files on the USB stick (in other words, DIGITAL INPUT, NOT analog line in). Not sure why that would be noisy.  In fact, I made a recording tonight on the usb to try to document the problem, and at various times you can hear all kinds of digital beeps and static when the USB stick is playing through the gp400.  I have to figure out how to transfer that.  I'm wondering if I can record from lineout directly to a computer.   Because it doesn't seem right. 

 

As for noise with the linein, if I take that same signal from pianoteq and run it from the computer to headphones, there is no background hissing.  The hissing is only there when I run the signal into the Gp400. 

 

I suppose the idea that it is a noise gate seems the most likely one (other than something being wrong with the piano).  However, if that is the case, is it odd that it occurs even when the input is a memory stick using USB port in the piano specifically made for recording and playback?  Because that is EXACTLY the same hissing that I get when playing a VST through the line-in.  It seems odd that that digital input would be as noisy  as analog input, or eve that it would be noisy at all.  Also odd is that the exact same video files downloaded on my computer have NO noise.  

 

Lastly, there is the matter of weird digital beeps that re often heard when I playback the USB stick on the GP400.  No idea where they would be from.