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Emax distortion

Emax distortion

2015-12-03 by Shawn Ward

I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard


I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt

I've also re-seated all the ICs on the output board.


my PSU rails are also showing stable -12.6v +12.6v 5.2v

I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board


any tips to troubleshoot would be great!

Re: [emax] Emax distortion

2015-12-04 by Ted Summers

When you reseated the IC�s did you use DeOxit on the chips and the sockets?  

You can�t get the connector on the ribbon that�s soldered to the board on the one end, just so you know (I went looking for these just recently and can�t find them)�.
You could try and DeOxit on the male side of the connector, also- although I haven�t heard of the ribbon being a common cause of noise.
Usually it�s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem. 


-T



On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@... [emax] <emax@yahoogroups.com> wrote:


I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard


I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt

I've also re-seated all the ICs on the output board.  


my PSU rails are also showing stable    -12.6v  +12.6v   5.2v

I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board


any tips to troubleshoot would be great!





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

RE: [emax] Emax distortion

2015-12-04 by Shawn Ward

hi Ted


so i took your advice and went over the sockets and IC legs on the output board with de-oxit and re-seated them


I'm still getting distortion. its affecting all the outputs and all samples/voices so the problem must be the IC where they are summed

do you know which suspect ICs I should be focusing on in the output board?

I'm still trying to rule out corrupt sample data, but the problem is intermittent and there is no bad data messages on any of the banks i load


I've noticed that sometimes i can load the samples with no distortion then after a while it kicks in






> To: emax@yahoogroups.com
> From: emax@yahoogroups.com
> Date: Thu, 3 Dec 2015 16:43:49 -0800
> Subject: Re: [emax] Emax distortion
>
> When you reseated the IC\u2019s did you use DeOxit on the chips and the sockets?
>
> You can\u2019t get the connector on the ribbon that\u2019s soldered to the board on the one end, just so you know (I went looking for these just recently and can\u2019t find them1;\u2026.
> You could try and DeOxit on the male side of the connector, also- although I haven\u2019t heard of the ribbon being a common cause of noise.
> Usually it\u2019s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem.
>
>
> -T
>
>
>
> On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@hotmail.com [emax] wrote:
>
>
> I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard
>
>
> I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt
>
> I've also re-seated all the ICs on the output board.
>
>
> my PSU rails are also showing stable -12.6v +12.6v 5.2v
>
> I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board
>
>
> any tips to troubleshoot would be great!
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> ------------------------------------
>
> Emax and Emax II User8;#39;s Group
> ------------------------------------
>
> Yahoo Groups Links
>
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>

Re: [emax] Emax distortion

2015-12-04 by krikor kouchian

this may sound silly but try to plug and unplug several times the jacks on the audio outputs, it actually solved it for me
cheers
K

Le vendredi 4 décembre 2015, Shawn Ward shawnjward@... [emax] <emax@yahoogroups.com> a écrit :
>
>
> hi Ted
>
> so i took your advice and went over the sockets and IC legs on the output board with de-oxit and re-seated them
>
> I'm still getting distortion. its affecting all the outputs and all samples/voices so the problem must be the IC where they are summed
> do you know which suspect ICs I should be focusing on in the output board?
> I'm still trying to rule out corrupt sample data, but the problem is intermittent and there is no bad data messages on any of the banks i load
>
> I've noticed that sometimes i can load the samples with no distortion then after a while it kicks in
>
>
>
>
>
>> To: emax@yahoogroups.com
>> From: emax@yahoogroups.com
>> Date: Thu, 3 Dec 2015 16:43:49 -0800
>> Subject: Re: [emax] Emax distortion
>>
>> When you reseated the IC’s did you use DeOxit on the chips and the sockets?
>>
>> You can’t get the connector on the ribbon that’s soldered to the board on the one end, just so you know (I went looking for these just recently and can’t find them)….
>> You could try and DeOxit on the male side of the connector, also- although I haven’t heard of the ribbon being a common cause of noise.
>> Usually it’s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem.
>>
>>
>> -T
>>
>>
>>
>> On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@hotmail.com [emax] <emax@yahoogroups.com> wrote:
>>
>>
>> I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard
>>
>>
>> I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt
>>
>> I've also re-seated all the ICs on the output board.
>>
>>
>> my PSU rails are also showing stable -12.6v +12.6v 5.2v
>>
>> I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board
>>
>>
>> any tips to troubleshoot would be great!
>>
>>
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>>
>> ------------------------------------
>>
>> ------------------------------------
>>
>> Emax and Emax II User's Group
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>> <*> To visit your group on the web, go to:
>> http://groups.yahoo.com/group/emax/
>>
>> <*> Your email settings:
>> Individual Email | Traditional
>>
>> <*> To change settings online go to:
>> http://groups.yahoo.com/group/emax/join
>> (Yahoo! ID required)
>>
>> <*> To change settings via email:
>> emax-digest@yahoogroups.com
>> emax-fullfeatured@yahoogroups.com
>>
>> <*> To unsubscribe from this group, send an email to:
>> emax-unsubscribe@yahoogroups.com
>>
>> <*> Your use of Yahoo Groups is subject to:
>>; https://info.yahoo.com/legal/us/yahoo/utos/terms/
>>
>
>

--
http://www.krikor.fr
+33632199413

For Live&Dj bookings contact: cedric@referenceprods.fr

Re: [emax] Emax distortion

2015-12-04 by Ted Summers

The jacks in these units are old, and often are oxidized.
I don’t recommend just spraying into the jacks, as many times the jack’s covers are missing, then you spread de-oxit throughout the machine.

Remove the audio board, and Deoxit the jacks elsewhere and insert and remove jacks just after spraying several times.
Then see if it’s better.

The fact that you say it comes on after a bit makes me wonder if it’s something else.
It may be helpful to post an audio file of the distortion…

Since you say all channels have distortion, you should focus one Channel.

Let’s say channel 1.
You should get a 6012 DAC and SSM2047 pair or two for testing….and TL084 as well...
If you simply put the new ICs in and distortion went away- that’s pretty telling.

Now on to the troubleshooting checks...
IC 20 and IC 30 and also IC51 on the I/O board belong to channel 1 (IC 2 and IC 3 also contribute- but let’s not go there yet only thing to check there is pin 16 on each have the proper +5V)
It shouldn’t be above 5.1V - too much voltage or undervoltage can also create distortion issues in circuits, generally speaking.


IC20 Pin 20 should be +10V
IC20 Pin 17 should be  -12V
IC 20 Pin 14 is +VREF and 15 is -VREF


IC30 Pin 10 should be -5V
IC30 Pin 18 has indicators on the schematic of  +12V and +10V - so not sure of this value, and don’t have an unit open to check it right now...
IC30 Pin 13 is the outbound audio signal going to IC51

IC51 Pin 4 should be +10V
IC51 Pin 11 should be -12V
IC51 Pin 2 is from IC30 pin 13
IC51 Pin 1 goes through a 1k resistor and connects to the actual center pin of the jack.


hope the detail is helpful.

-T




On Dec 4, 2015, at 11:17 AM, krikor kouchian krikorola@... [emax] <emax@yahoogroups.com> wrote:

this may sound silly but try to plug and unplug several times the jacks on the audio outputs, it actually solved it for me
cheers
K

Le vendredi 4 décembre 2015, Shawn Ward shawnjward@... <mailto:shawnjward@...> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> a écrit :
>  
>
> hi Ted
>
> so i took your advice and went over the sockets and IC legs on the output board with de-oxit and re-seated them
>
> I'm still getting distortion.  its affecting all the outputs and all samples/voices so the problem must be the IC where they are summed
> do you know which suspect ICs I should be focusing on in the output board?
> I'm still trying to rule out corrupt sample data, but the problem is intermittent and there is no bad data messages on any of the banks i load
>
>  I've noticed that sometimes i can load the samples with no distortion then after a while it kicks in
>
>
>
>
>
>> To: emax@yahoogroups.com <mailto:emax@yahoogroups.com>
>> From: emax@yahoogroups.com <mailto:emax@yahoogroups.com>
>> Date: Thu, 3 Dec 2015 16:43:49 -0800
>> Subject: Re: [emax] Emax distortion
>>
>> When you reseated the IC’s did you use DeOxit on the chips and the sockets?
>>
>> You can’t get the connector on the ribbon that’s soldered to the board on the one end, just so you know (I went looking for these just recently and can’t find them)….
>> You could try and DeOxit on the male side of the connector, also- although I haven’t heard of the ribbon being a common cause of noise.
>> Usually it’s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem.
>>
>>
>> -T
>>
>>
>>
>> On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@... <mailto:shawnjward@...> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> wrote:
>>
>>
>> I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard
>>
>>
>> I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt
>>
>> I've also re-seated all the ICs on the output board.
>>
>>
>> my PSU rails are also showing stable -12.6v +12.6v 5.2v
>>
>> I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board
>>
>>
>> any tips to troubleshoot would be great!
>>
>>
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>>
>> ------------------------------------
>>
>> ------------------------------------
>>
>> Emax and Emax II User's Group
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>
> 

-- 
http://www.krikor.fr <http://www.krikor.fr/>
+33632199413

For Live&Dj bookings contact: cedric@... <mailto:cedric@...>





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

Re: [emax] Emax distortion

2015-12-04 by Ted Summers

PS- each TL084 IC does multiple channels of output.

channels 1, 2, 5, and 6 are on IC 51
3,4,7, and 8 are on IC 52

-T



On Dec 4, 2015, at 11:17 AM, krikor kouchian krikorola@... [emax] <emax@yahoogroups.com> wrote:

this may sound silly but try to plug and unplug several times the jacks on the audio outputs, it actually solved it for me
cheers
K

Le vendredi 4 décembre 2015, Shawn Ward shawnjward@... <mailto:shawnjward@hotmail.com> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> a écrit :
>  
>
> hi Ted
>
> so i took your advice and went over the sockets and IC legs on the output board with de-oxit and re-seated them
>
> I'm still getting distortion.  its affecting all the outputs and all samples/voices so the problem must be the IC where they are summed
> do you know which suspect ICs I should be focusing on in the output board?
> I'm still trying to rule out corrupt sample data, but the problem is intermittent and there is no bad data messages on any of the banks i load
>
>  I've noticed that sometimes i can load the samples with no distortion then after a while it kicks in
>
>
>
>
>
>> To: emax@yahoogroups.com <mailto:emax@yahoogroups.com>
>> From: emax@yahoogroups.com <mailto:emax@yahoogroups.com>
>> Date: Thu, 3 Dec 2015 16:43:49 -0800
>> Subject: Re: [emax] Emax distortion
>>
>> When you reseated the IC’s did you use DeOxit on the chips and the sockets?
>>
>> You can’t get the connector on the ribbon that’s soldered to the board on the one end, just so you know (I went looking for these just recently and can’t find them)….
>> You could try and DeOxit on the male side of the connector, also- although I haven’t heard of the ribbon being a common cause of noise.
>> Usually it’s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem.
>>
>>
>> -T
>>
>>
>>
>> On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@... <mailto:shawnjward@...> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> wrote:
>>
>>
>> I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard
>>
>>
>> I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt
>>
>> I've also re-seated all the ICs on the output board.
>>
>>
>> my PSU rails are also showing stable -12.6v +12.6v 5.2v
>>
>> I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board
>>
>>
>> any tips to troubleshoot would be great!
>>
>>
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>>
>> ------------------------------------
>>
>> ------------------------------------
>>
>> Emax and Emax II User's Group
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>
> 

-- 
http://www.krikor.fr <http://www.krikor.fr/>
+33632199413

For Live&Dj bookings contact: cedric@... <mailto:cedric@...>





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

RE: [emax] Emax distortion

2015-12-06 by Shawn Ward

thanks for the tips Ted

I removed the IO board, cleaned all the outputs/sample inputs with deoxit.

Im still getting distortion in the background with the samples playing

I also attempted to sample something from scratch to rule out corrupt data again, now the signal is maxed and cannot be lowered even with no sample source plugged into the sample in jack


i checked voltage on the PSU rails again and they seem to be a bit high +12.5 -12.2, 5.2

also i notice a bit of noise coming and going on the PSU so I'm thinking i might need to recap it before i should troubleshoot the ICs, I'm also suspecting the PSU as the HxC drive is acting strange


i swapped compatible ICs to see if that was the problem but they all give the same voltage readings so I'm thinking this points to the PSU that is feeding them incorrect voltage


IC 20 pin 20 should give +10v but is reading 5.3
pin 17 gives no reading

ICs 2 & 3 read +5.3 on both


i will send a short video clip that shows the distortion


really appreciate the time you took to help me troubleshoot






To: emax@yahoogroups.com
From: emax@yahoogroups.com
Date: Fri, 4 Dec 2015 12:16:28 -0800
Subject: Re: [emax] Emax distortion

The jacks in these units are old, and often are oxidized.
I don’t recommend just spraying into the jacks, as many times the jack’s covers are missing, then you spread de-oxit throughout the machine.

Remove the audio board, and Deoxit the jacks elsewhere and insert and remove jacks just after spraying several times.
Then see if it’s better.

The fact that you say it comes on after a bit makes me wonder if it’s something else.
It may be helpful to post an audio file of the distortion…

Since you say all channels have distortion, you should focus one Channel.

Let’s say channel 1.
You should get a 6012 DAC and SSM2047 pair or two for testing….and TL084 as well...
If you simply put the new ICs in and distortion went away- that’s pretty telling.

Now on to the troubleshooting checks...
IC 20 and IC 30 and also IC51 on the I/O board belong to channel 1 (IC 2 and IC 3 also contribute- but let’s not go there yet only thing to check there is pin 16 on each have the proper +5V)
It shouldn’t be above 5.1V - too much voltage or undervoltage can also create distortion issues in circuits, generally speaking.

IC20 Pin 20 should be +10V
IC20 Pin 17 should be -12V
IC 20 Pin 14 is +VREF and 15 is -VREF

IC30 Pin 10 should be -5V
IC30 Pin 18 has indicators on the schematic of +12V and +10V - so not sure of this value, and don’t have an unit open to check it right now...
IC30 Pin 13 is the outbound audio signal going to IC51

IC51 Pin 4 should be +10V
IC51 Pin 11 should be -12V
IC51 Pin 2 is from IC30 pin 13
IC51 Pin 1 goes through a 1k resistor and connects to the actual center pin of the jack.

hope the detail is helpful.

-T

On Dec 4, 2015, at 11:17 AM, krikor kouchian krikorola@... [emax] wrote:

this may sound silly but try to plug and unplug several times the jacks on the audio outputs, it actually solved it for me
cheers
K

Le vendredi 4 décembre 2015, Shawn Ward shawnjward@... [emax] > a écrit :
>
>
> hi Ted
>
> so i took your advice and went over the sockets and IC legs on the output board with de-oxit and re-seated them
>
> I'm still getting distortion. its affecting all the outputs and all samples/voices so the problem must be the IC where they are summed
> do you know which suspect ICs I should be focusing on in the output board?
> I'm still trying to rule out corrupt sample data, but the problem is intermittent and there is no bad data messages on any of the banks i load
>
> I've noticed that sometimes i can load the samples with no distortion then after a while it kicks in
>
>
>
>
>
>> To: emax@yahoogroups.com
>> From: emax@yahoogroups.com
>> Date: Thu, 3 Dec 2015 16:43:49 -0800
>> Subject: Re: [emax] Emax distortion
>>
>> When you reseated the IC’s did you use DeOxit on the chips and the sockets?
>>
>> You can’t get the connector on the ribbon that’s soldered to the board on the one end, just so you know (I went looking for these just recently and can’t find them)….
>> You could try and DeOxit on the male side of the connector, also- although I haven’t heard of the ribbon being a common cause of noise.
>> Usually it’s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem.
>>
>>
>> -T
>>
>>
>>
>> On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@... [emax] wrote:
>>
>>
>> I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard
>>
>>
>> I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt
>>
>> I've also re-seated all the ICs on the output board.
>>
>>
>> my PSU rails are also showing stable -12.6v +12.6v 5.2v
>>
>> I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board
>>
>;>
>> any tips to troubleshoot would be great!
>>
>>
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>;>
>> ------------------------------------
>>
>> ------------------------------------
>>
>> Emax and Emax II User's Group
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>
>

--
http://www.krikor.fr
+33632199413

For Live&Dj bookings contact: cedric@...

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


RE: [emax] Emax distortion

2015-12-06 by Shawn Ward

here is a clip of the distortion on the Emax


To: emax@yahoogroups.com
Show quoted textHide quoted text
From: emax@yahoogroups.com
Date: Sun, 6 Dec 2015 12:31:56 -0800
Subject: RE: [emax] Emax distortion














 

 



  


    
      
      
      

thanks for the tips Ted
I removed the IO board, cleaned all the outputs/sample inputs with deoxit.
Im still getting distortion in the background with the samples playing
I also attempted to sample something from scratch to rule out corrupt data again, now the signal is maxed and cannot be lowered even with no sample source plugged into the sample in jack

i checked voltage on the PSU rails again and they seem to be a bit high   +12.5  -12.2, 5.2
also i notice a bit of noise coming and going on the PSU so I'm thinking i might need to recap it before i should troubleshoot the ICs, I'm also suspecting the PSU as the HxC drive is acting strange

i swapped compatible ICs to see if that was the problem but they all give the same voltage readings so I'm thinking this points to the PSU that is feeding them incorrect voltage

IC 20 pin 20 should give +10v but is reading 5.3          pin 17 gives no reading
ICs 2 & 3 read  +5.3 on both

i will send a short video clip that shows the distortion 

really appreciate the time you took to help me troubleshoot





To: emax@yahoogroups.com
From: emax@yahoogroups.com
Date: Fri, 4 Dec 2015 12:16:28 -0800
Subject: Re: [emax] Emax distortion














 

 



  


    
      
      
      The jacks in these units are old, and often are oxidized.

I don�t recommend just spraying into the jacks, as many times the jack�s covers are missing, then you spread de-oxit throughout the machine.



Remove the audio board, and Deoxit the jacks elsewhere and insert and remove jacks just after spraying several times.

Then see if it�s better.



The fact that you say it comes on after a bit makes me wonder if it�s something else.

It may be helpful to post an audio file of the distortion�



Since you say all channels have distortion, you should focus one Channel.



Let�s say channel 1.

You should get a 6012 DAC and SSM2047 pair or two for testing�.and TL084 as well...

If you simply put the new ICs in and distortion went away- that�s pretty telling.



Now on to the troubleshooting checks...

IC 20 and IC 30 and also IC51 on the I/O board belong to channel 1 (IC 2 and IC 3 also contribute- but let�s not go there yet only thing to check there is pin 16 on each have the proper +5V)

It shouldn�t be above 5.1V - too much voltage or undervoltage can also create distortion issues in circuits, generally speaking.



IC20 Pin 20 should be +10V

IC20 Pin 17 should be  -12V

IC 20 Pin 14 is +VREF and 15 is -VREF



IC30 Pin 10 should be -5V

IC30 Pin 18 has indicators on the schematic of  +12V and +10V - so not sure of this value, and don�t have an unit open to check it right now...

IC30 Pin 13 is the outbound audio signal going to IC51



IC51 Pin 4 should be +10V

IC51 Pin 11 should be -12V

IC51 Pin 2 is from IC30 pin 13

IC51 Pin 1 goes through a 1k resistor and connects to the actual center pin of the jack.



hope the detail is helpful.



-T



On Dec 4, 2015, at 11:17 AM, krikor kouchian krikorola@gmail.com [emax] <emax@yahoogroups.com> wrote:



this may sound silly but try to plug and unplug several times the jacks on the audio outputs, it actually solved it for me

cheers

K



Le vendredi 4 d�cembre 2015, Shawn Ward shawnjward@... <mailto:shawnjward@...> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> a �crit :

>  

>

> hi Ted

>

> so i took your advice and went over the sockets and IC legs on the output board with de-oxit and re-seated them

>

> I'm still getting distortion.  its affecting all the outputs and all samples/voices so the problem must be the IC where they are summed

> do you know which suspect ICs I should be focusing on in the output board?

> I'm still trying to rule out corrupt sample data, but the problem is intermittent and there is no bad data messages on any of the banks i load

>

>  I've noticed that sometimes i can load the samples with no distortion then after a while it kicks in

>

>

>

>

>

>> To: emax@yahoogroups.com <mailto:emax@yahoogroups.com>

>> From: emax@yahoogroups.com <mailto:emax@yahoogroups.com>

>> Date: Thu, 3 Dec 2015 16:43:49 -0800

>> Subject: Re: [emax] Emax distortion

>>

>> When you reseated the IC�s did you use DeOxit on the chips and the sockets?

>>

>> You can�t get the connector on the ribbon that�s soldered to the board on the one end, just so you know (I went looking for these just recently and can�t find them)�.

>> You could try and DeOxit on the male side of the connector, also- although I haven�t heard of the ribbon being a common cause of noise.

>> Usually it�s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem.

>>

>>

>> -T

>>

>>

>>

>> On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@... <mailto:shawnjward@...> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> wrote:

>>

>>

>> I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard

>>

>>

>> I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt

>>

>> I've also re-seated all the ICs on the output board.

>>

>>

>> my PSU rails are also showing stable -12.6v +12.6v 5.2v

>>

>> I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board

>>

>>

>> any tips to troubleshoot would be great!

>>

>>

>>

>>

>>

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

>>

>>

>>

>> ------------------------------------

>>

>> ------------------------------------

>>

>> Emax and Emax II User's Group

>> ------------------------------------

>>

>> Yahoo Groups Links

>>

>>

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Re: [emax] Emax distortion

2015-12-06 by Ted Summers

You can’t send files directly via email to the group. They are stripped.

5.3V at the 74 series chips is definitely a problem. That’s way too high.  5.1 is actually the highest I would want to see that at….

I can’t disagree with checking the PS or adjusting it (some have a pot)….

-T


On Dec 6, 2015, at 1:26 PM, Shawn Ward shawnjward@... [emax] <emax@yahoogroups.com> wrote:

here is a clip of the distortion on the Emax


To: emax@yahoogroups.com
Show quoted textHide quoted text
From: emax@yahoogroups.com
Date: Sun, 6 Dec 2015 12:31:56 -0800
Subject: RE: [emax] Emax distortion




























thanks for the tips Ted
I removed the IO board, cleaned all the outputs/sample inputs with deoxit.
Im still getting distortion in the background with the samples playing
I also attempted to sample something from scratch to rule out corrupt data again, now the signal is maxed and cannot be lowered even with no sample source plugged into the sample in jack

i checked voltage on the PSU rails again and they seem to be a bit high   +12.5  -12.2, 5.2
also i notice a bit of noise coming and going on the PSU so I'm thinking i might need to recap it before i should troubleshoot the ICs, I'm also suspecting the PSU as the HxC drive is acting strange

i swapped compatible ICs to see if that was the problem but they all give the same voltage readings so I'm thinking this points to the PSU that is feeding them incorrect voltage

IC 20 pin 20 should give +10v but is reading 5.3          pin 17 gives no reading
ICs 2 & 3 read  +5.3 on both

i will send a short video clip that shows the distortion 

really appreciate the time you took to help me troubleshoot





To: emax@yahoogroups.com
From: emax@yahoogroups.com
Date: Fri, 4 Dec 2015 12:16:28 -0800
Subject: Re: [emax] Emax distortion


























     The jacks in these units are old, and often are oxidized.

I don’t recommend just spraying into the jacks, as many times the jack’s covers are missing, then you spread de-oxit throughout the machine.



Remove the audio board, and Deoxit the jacks elsewhere and insert and remove jacks just after spraying several times.

Then see if it’s better.



The fact that you say it comes on after a bit makes me wonder if it’s something else.

It may be helpful to post an audio file of the distortion




Since you say all channels have distortion, you should focus one Channel.



Let’s say channel 1.

You should get a 6012 DAC and SSM2047 pair or two for testing
.and TL084 as well...

If you simply put the new ICs in and distortion went away- that’s pretty telling.



Now on to the troubleshooting checks...

IC 20 and IC 30 and also IC51 on the I/O board belong to channel 1 (IC 2 and IC 3 also contribute- but let’s not go there yet only thing to check there is pin 16 on each have the proper +5V)

It shouldn’t be above 5.1V - too much voltage or undervoltage can also create distortion issues in circuits, generally speaking.



IC20 Pin 20 should be +10V

IC20 Pin 17 should be  -12V

IC 20 Pin 14 is +VREF and 15 is -VREF



IC30 Pin 10 should be -5V

IC30 Pin 18 has indicators on the schematic of  +12V and +10V - so not sure of this value, and don’t have an unit open to check it right now...

IC30 Pin 13 is the outbound audio signal going to IC51



IC51 Pin 4 should be +10V

IC51 Pin 11 should be -12V

IC51 Pin 2 is from IC30 pin 13

IC51 Pin 1 goes through a 1k resistor and connects to the actual center pin of the jack.



hope the detail is helpful.



-T



On Dec 4, 2015, at 11:17 AM, krikor kouchian krikorola@... [emax] <emax@yahoogroups.com> wrote:



this may sound silly but try to plug and unplug several times the jacks on the audio outputs, it actually solved it for me

cheers

K



Le vendredi 4 décembre 2015, Shawn Ward shawnjward@... <mailto:shawnjward@...> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> a écrit :

> 

> 

> hi Ted

> 

> so i took your advice and went over the sockets and IC legs on the output board with de-oxit and re-seated them

> 

> I'm still getting distortion.  its affecting all the outputs and all samples/voices so the problem must be the IC where they are summed

> do you know which suspect ICs I should be focusing on in the output board?

> I'm still trying to rule out corrupt sample data, but the problem is intermittent and there is no bad data messages on any of the banks i load

> 

> I've noticed that sometimes i can load the samples with no distortion then after a while it kicks in

> 

> 

> 

> 

> 

>> To: emax@yahoogroups.com <mailto:emax@yahoogroups.com>

>> From: emax@yahoogroups.com <mailto:emax@yahoogroups.com>

>> Date: Thu, 3 Dec 2015 16:43:49 -0800

>> Subject: Re: [emax] Emax distortion

>> 

>> When you reseated the IC’s did you use DeOxit on the chips and the sockets?

>> 

>> You can’t get the connector on the ribbon that’s soldered to the board on the one end, just so you know (I went looking for these just recently and can’t find them)
.

>> You could try and DeOxit on the male side of the connector, also- although I haven’t heard of the ribbon being a common cause of noise.

>> Usually it’s the ICs (they can go bad), the sockets, or the reference voltage being supplied for the signal being the problem.

>> 

>> 

>> -T

>> 

>> 

>> 

>> On Dec 3, 2015, at 2:08 PM, Shawn Ward shawnjward@hotmail.com <mailto:shawnjward@...> [emax] <emax@yahoogroups.com <mailto:emax@yahoogroups.com>> wrote:

>> 

>> 

>> I'm still having problems with distortion coming through all outputs on my Emax 1000 Keyboard

>> 

>> 

>> I have an HxC drive installed and I've confirmed the samples are loading properly and not corrupt

>> 

>> I've also re-seated all the ICs on the output board.

>> 

>> 

>> my PSU rails are also showing stable -12.6v +12.6v 5.2v

>> 

>> I'm thinking it might be a bad ribbon cable that connects the CPU board to the Output Board

>> 

>> 

>> any tips to troubleshoot would be great!

>> 

>> 

>> 

>> 

>> 

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

>> 

>> 

>> 

>> ------------------------------------

>> 

>> ------------------------------------

>> 

>> Emax and Emax II User's Group

>> ------------------------------------

>> 

>> Yahoo Groups Links

>> 

>> 

>> 

> 

> 



-- 

http://www.krikor.fr <http://www.krikor.fr/>

+33632199413



For Live&Dj bookings contact: cedric@referenceprods.fr <mailto:cedric@...>



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