Synth-DIY Yahoo! Groups Archives

Thread

Waveshape Chip....Help me Further Diagnose this please....CS80

2009-04-12 by slammah2006

I have just replaced my waveshape converter chips (IC9) on 2 of the M boards in Bank 2...I did this with 2 chips from spare CS60 boards I purchased.
I believed there was something amiss with the board mounted chips when I found that all waveforms at the Chips outputs, were containining floor noise and lacked low end...

I checked White noise through the filters and it is perfectly fine.

The Noise appears in the SIN wave, the Square Wave and the Sawtooth Wave, so it isnt just a problem in the VCF section....

I swapped again some OSC Chips(IC8) and it is the same results with a slightly different tuning....

I dont have access to a scope,

Does anyone have any Ideas of something simple on the M board itself that would cause this type of result?....or could this be something off on some other board that is causing this results and only on these 2 ???

Thanks for any Help in Advance.....

Re: [yamahacs80] Waveshape Chip....Help me Further Diagnose this please....CS80

2009-04-12 by Laurie Curry

Does anyone have an Idea on what could be sucking or phasing away
the low end into to my waveshaper and adding floor noise which then
gets converted to odd waves??

Solder joints seems good all around....It is not the Filter
section....

-----Original message-----
From: "slammah2006" laurie@...
Date: Sat, 11 Apr 2009 21:07:18 -0600
To: yamahacs80@yahoogroups.com
Subject: [yamahacs80] Waveshape Chip....Help me Further Diagnose this
please....CS80

I have just replaced my waveshape converter chips (IC9) on 2 of the M
boards in Bank 2...I did this with 2 chips from spare CS60 boards I
purchased.
I believed there was something amiss with the board mounted chips when
I found that all waveforms at the Chips outputs, were containining
floor noise and lacked low end...

I checked White noise through the filters and it is perfectly fine.

The Noise appears in the SIN wave, the Square Wave and theSawtooth
Wave, so it isnt just a problem in the VCF section....

I swapped again some OSC Chips(IC8) and it is the same results with a
slightly different tuning....

I dont have access to a scope,

Does anyone have any Ideas of something simple on the M board itself
that would cause this type of result?....or could this be something
off on some other board that is causing this results and only on these
2 ???

Thanks for any Help in Advance.....

[Non-text portions of this message have been removed]

Re: [yamahacs80] Waveshape Chip....Help me Further Diagnose this please....CS80

2009-04-13 by Laurie Curry

Success........

I guess I should have suspected the "4.7/16 NP" Caps between the out
of the OSC chip and the in on the Waveshapers all along.... There was
nothing passing through them, and I believe the signal was picked up
Attenna style due to the proximity...lol

All 16 ready for Tuning.....

-----Original message-----
From: "Laurie Curry" laurie@...
Date: Sun, 12 Apr 2009 14:21:25 -0600
To: yamahacs80@yahoogroups.com
Subject: Re: [yamahacs80] Waveshape Chip....Help me Further Diagnose
this please....CS80

Does anyone have an Idea on what could be sucking or phasing away
the low end into to my waveshaper and adding floor noise which then
gets converted to odd waves??

Solder joints seems good all around....It is not the Filter
section....

-----Original message-----
From: "slammah2006"laurie@...
Date: Sat, 11 Apr 2009 21:07:18 -0600
To: yamahacs80@yahoogroups.com
Subject: [yamahacs80] Waveshape Chip....Help me Further Diagnose this
please....CS80

I have just replaced my waveshape converter chips (IC9) on 2 of the M
boards in Bank 2...I did this with 2 chips from spare CS60 boards I
purchased.
I believed there was something amiss with the board mounted chips when
I found that all waveforms at the Chips outputs, were containining
floor noise and lacked low end...

I checked White noise through the filters and it is perfectly fine.

The Noise appears in the SIN wave, the Square Wave and theSawtooth
Wave, so it isnt just a problem in the VCF section....

I swapped again some OSC Chips(IC8) and it is the same results with a
slightly different tuning....

I dont have access to a scope,

Does anyone have any Ideas of something simple on the Mboard itself
that would cause this type of result?....or could this be something
off on some other board that is causing this results and only on these
2 ???

Thanks for any Help in Advance.....

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Re: Waveshape Chip....Help me Further Diagnose this please....CS80

2009-04-13 by zenithaudio2003

So your first gess was right , bravo ! You must be proud !

Me i am begening to understand why my cs-80 was left in a barn for 20yrs . I will need a couple of waveshaper and filter , noooooo ! I was so excited just to ear sounds from it , now that the rush is gone . there is still more work and money envolved !

is there a particular sequence for the calibration , or can i do VCa after vcf . Because since my system was modified by microsine , they have adapted calibration in concequence . Vfc is off , vca also . I dont what to mess with the tuning right now .

and i will change those NP capacitor first thing .. thanks .

Show quoted textHide quoted text

--- In yamahacs80@yahoogroups.com, "Laurie Curry" <laurie@...> wrote:
>
>
> Success........
>
>
> I guess I should have suspected the "4.7/16Â NP" Caps between the out
> of the OSC chip and the in on the Waveshapers all along.... There was
> nothing passing through them, and I believe the signal was picked upÂ
> Attenna styleÂ due to the proximity...lol
>
>
> All 16 ready for Tuning.....
>
>
>
>
>
> -----Original message-----
> From: "Laurie Curry" laurie@...
> Date: Sun, 12 Apr 2009 14:21:25 -0600
> To: yamahacs80@yahoogroups.com
> Subject: Re: [yamahacs80] Waveshape Chip....Help me Further Diagnose
> this please....CS80
>
>
> Does anyone have an Idea on whatÂ could be Â sucking or phasing awayÂ
> the low endÂ into toÂ my waveshaper and adding floor noise which then
> gets converted to odd waves??
>
> Solder joints seems good all around....It is not the Filter
> section....
>
> -----Original message-----
> From: "slammah2006"laurie@...
> Date: Sat, 11 Apr 2009 21:07:18 -0600
> To: yamahacs80@yahoogroups.com
> Subject: [yamahacs80] Waveshape Chip....Help me Further Diagnose this
> please....CS80
>
> I have just replaced my waveshape converter chips (IC9) on 2 of the M
> boards in Bank 2...I did this with 2 chips from spare CS60 boards I
> purchased.
> I believed there was something amiss with the board mounted chips when
> I found that all waveforms at the Chips outputs, were containining
> floor noise and lacked low end...
>
> I checked White noise through the filters and it is perfectly fine.
>
> The Noise appears in the SIN wave, the Square Wave and theSawtooth
> Wave, so it isnt just a problem in the VCF section....
>
> I swapped again some OSC Chips(IC8) and it is the same results with a
> slightly different tuning....
>
> I dont have access to a scope,
>
> Does anyone have any Ideas of something simple on the Mboard itself
> that would cause this type of result?....or could this be something
> off on some other board that is causing this results and only on these
> 2 ???
>
> Thanks for any Help in Advance.....
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
>
> [Non-text portions of this message have been removed]
>