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2009-09-22 by karl452055
Hi All, My CZ101 has a low level buzz at the output which can be heard clearly in headphones. If adjusting the DAC might also work for the CZ101, can someone email me a copy of the relevant page of the service manual? Many thanks, Karl May
2009-09-29 by tomulcahy
If the buzz is there when you're not playing sounds, then it's not the DAC. It's some sort of grounding issue. Does it happen with the line output also? I've definitely seen the CZ-1000 service manual around for download, just can't remember where :( But I would say that you could safely refer to the CZ-1 service manual for DAC offset in the 101.
2009-10-06 by karl452055
--- In CZsynth@yahoogroups.com, "tomulcahy" <tomulcahy@...> wrote: > > If the buzz is there when you're not playing sounds, then it's not the DAC. It's some sort of grounding issue. Does it happen with the line output also? > > I've definitely seen the CZ-1000 service manual around for download, just can't remember where :( But I would say that you could safely refer to the CZ-1 service manual for DAC offset in the 101. > Thanks Tom. The hum in my CZ101 appears at both line out and headphone out. It is there when no sound is being played. It is not affected by the volume control. The level of the noise stays the same no matter where the volume control is set. I've tried changing the power supply to no effect. The noise seems to be made up of three separate frequencies. The bottom frequency appears to be AC hum. The next frequency is higher and is a buzzing sound. The highest frequency is an oscillating sound. Something interesting happens when I play a sound. Immediately after I release the keyboard key the middle frequency sound rises in frequency momentarily, then falls back to the original frequency. Any thoughts anyone,and thanks to everyone.
2009-10-06 by Lee Borrell
That sounds like the ADSR signal is getting into the audio signal - could be some sort of a short circuit or maybe a failed or about to fail component? --- On Tue, 6/10/09, karl452055 <kmay@...> wrote:
From: karl452055 <kmay@...>
Subject: [CZsynth] Re: Any Mods to Make CZ101 Quieter
To: CZsynth@yahoogroups.com
Date: Tuesday, 6 October, 2009, 2:06 AM
--- In CZsynth@yahoogroups .com, "tomulcahy" <tomulcahy@. ..> wrote:
>
> If the buzz is there when you're not playing sounds, then it's not the DAC. It's some sort of grounding issue. Does it happen with the line output also?
>
> I've definitely seen the CZ-1000 service manual around for download, just can't remember where :( But I would say that you could safely refer to the CZ-1 service manual for DAC offset in the 101.
>
Thanks Tom.
The hum in my CZ101 appears at both line out and headphone out. It is there when no sound is being played. It is not affected by the volume control. The level of the noise stays the same no matter where the volume control is set.
I've tried changing the power supply to no effect.
The noise seems to be made up of three separate frequencies.
The bottom frequency appears to be AC hum.
The next frequency is higher and is a buzzing sound.
The highest frequency is an oscillating sound.
Something interesting happens when I play a sound. Immediately after I release the keyboard key the middle frequency sound rises in frequency momentarily, then falls back to the original frequency.
Any thoughts anyone,and thanks to everyone.
[Non-text portions of this message have been removed]2009-10-07 by Karl H. May
Thanks Lee. Karl May ________________________________
From: CZsynth@yahoogroups.com [mailto:CZsynth@yahoogroups.com] On Behalf Of Lee Borrell Sent: Tuesday, 6 October 2009 9:29 PM To: CZsynth@yahoogroups.com Subject: Re: [CZsynth] Re: Any Mods to Make CZ101 Quieter That sounds like the ADSR signal is getting into the audio signal - could be some sort of a short circuit or maybe a failed or about to fail component? --- On Tue, 6/10/09, karl452055 <kmay@... <mailto:kmay%40brayecragg.com.au> > wrote: From: karl452055 <kmay@... <mailto:kmay%40brayecragg.com.au> > Subject: [CZsynth] Re: Any Mods to Make CZ101 Quieter To: CZsynth@yahoogroups.com <mailto:CZsynth%40yahoogroups.com> Date: Tuesday, 6 October, 2009, 2:06 AM --- In CZsynth@yahoogroups .com, "tomulcahy" <tomulcahy@. ..> wrote: > > If the buzz is there when you're not playing sounds, then it's not the DAC. It's some sort of grounding issue. Does it happen with the line output also? > > I've definitely seen the CZ-1000 service manual around for download, just can't remember where :( But I would say that you could safely refer to the CZ-1 service manual for DAC offset in the 101. > Thanks Tom. The hum in my CZ101 appears at both line out and headphone out. It is there when no sound is being played. It is not affected by the volume control. The level of the noise stays the same no matter where the volume control is set. I've tried changing the power supply to no effect. The noise seems to be made up of three separate frequencies. The bottom frequency appears to be AC hum. The next frequency is higher and is a buzzing sound. The highest frequency is an oscillating sound. Something interesting happens when I play a sound. Immediately after I release the keyboard key the middle frequency sound rises in frequency momentarily, then falls back to the original frequency. Any thoughts anyone,and thanks to everyone. [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
2009-10-07 by Andrew Salisbury
Why bother? The volume slider is stock standard ;) ________________________________
From: Karl H. May <kmay@...>
To: CZsynth@yahoogroups.com
Sent: Wed, 7 October, 2009 11:23:01 AM
Subject: RE: [CZsynth] Re: Any Mods to Make CZ101 Quieter
Thanks Lee. Karl May
________________________________
From: CZsynth@yahoogroups.com [mailto:CZsynth@yahoogroups.com] On Behalf
Of Lee Borrell
Sent: Tuesday, 6 October 2009 9:29 PM
To: CZsynth@yahoogroups.com
Subject: Re: [CZsynth] Re: Any Mods to Make CZ101 Quieter
That sounds like the ADSR signal is getting into the audio signal -
could be some sort of a short circuit or maybe a failed or about to fail
component?
--- On Tue, 6/10/09, karl452055 <kmay@...
<mailto:kmay%40brayecragg.com.au> > wrote:
From: karl452055 <kmay@...
<mailto:kmay%40brayecragg.com.au> >
Subject: [CZsynth] Re: Any Mods to Make CZ101 Quieter
To: CZsynth@yahoogroups.com <mailto:CZsynth%40yahoogroups.com>
Date: Tuesday, 6 October, 2009, 2:06 AM
--- In CZsynth@yahoogroups .com, "tomulcahy" <tomulcahy@. ..> wrote:
>
> If the buzz is there when you're not playing sounds, then it's not the
DAC. It's some sort of grounding issue. Does it happen with the line
output also?
>
> I've definitely seen the CZ-1000 service manual around for download,
just can't remember where :( But I would say that you could safely refer
to the CZ-1 service manual for DAC offset in the 101.
>
Thanks Tom.
The hum in my CZ101 appears at both line out and headphone out. It is
there when no sound is being played. It is not affected by the volume
control. The level of the noise stays the same no matter where the
volume control is set.
I've tried changing the power supply to no effect.
The noise seems to be made up of three separate frequencies.
The bottom frequency appears to be AC hum.
The next frequency is higher and is a buzzing sound.
The highest frequency is an oscillating sound.
Something interesting happens when I play a sound. Immediately after I
release the keyboard key the middle frequency sound rises in frequency
momentarily, then falls back to the original frequency.
Any thoughts anyone,and thanks to everyone.
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
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[Non-text portions of this message have been removed]2009-10-08 by zoinky420
--- In CZsynth@yahoogroups.com, Lee Borrell <templarser@...> wrote: > > That sounds like the ADSR signal is getting into the audio signal yeah, like that would ever happen.. > could be some sort of a short circuit or maybe a failed or about to fail component? > It's a blown component of the amplifier which has compromised the intergrity of the ground.
2009-10-17 by tomulcahy
I can't remember exactly, but the CZ has some protection on the PSU input. There's a diode at least. I would check the functioning of the diode, and check the grounding in that area first. If that's not it, check grounding and screening in the DAC output area. --- In CZsynth@yahoogroups.com, "karl452055" <kmay@...> wrote:
> > > > --- In CZsynth@yahoogroups.com, "tomulcahy" <tomulcahy@> wrote: > > > > If the buzz is there when you're not playing sounds, then it's not the DAC. It's some sort of grounding issue. Does it happen with the line output also? > > > > I've definitely seen the CZ-1000 service manual around for download, just can't remember where :( But I would say that you could safely refer to the CZ-1 service manual for DAC offset in the 101. > > > Thanks Tom. > > The hum in my CZ101 appears at both line out and headphone out. It is there when no sound is being played. It is not affected by the volume control. The level of the noise stays the same no matter where the volume control is set. > > I've tried changing the power supply to no effect. > > The noise seems to be made up of three separate frequencies. > > The bottom frequency appears to be AC hum. > > The next frequency is higher and is a buzzing sound. > > The highest frequency is an oscillating sound. > > Something interesting happens when I play a sound. Immediately after I release the keyboard key the middle frequency sound rises in frequency momentarily, then falls back to the original frequency. > > Any thoughts anyone,and thanks to everyone. >