Emu XL-7 & MP-7 User's Group

(1) Is this on the digital outs?
(2) Are the clicks there when you route audio to the sub outs and monitor the sound from the sub outs?

If (1) = No and (2) = No, I faced that problem (and may have written about it.  If the clicks are non-existent on the sub-out, its the FX chip(s). My solution was to use the sub outs.

--- In xl7@yahoogroups.com, <loren_steele@...> wrote:
>
> I have done some searching on google and this list and haven't found a solution for the clicks I hear on my mp7. I read on tarekeiths FAQ that it could pertain to channel volumes and filter types, but I hear these clicks even when no pattern is playing, the panning of the clicks are all over the place. My question is if anyone else on the list has had this problem and how it could be solved? Thanks in advance! Loren
>

If the clicks are not on the sub outs (i.e., they are only on the main outs), try this thread:  http://launch.groups.yahoo.com/group/xl7/message/20422.

Steve

--- In xl7@yahoogroups.com, "steve_the_composer" <smw-mail@...> wrote:
>
> (1) Is this on the digital outs?
> (2) Are the clicks there when you route audio to the sub outs and monitor the sound from the sub outs?
> 
> If (1) = No and (2) = No, I faced that problem (and may have written about it.  If the clicks are non-existent on the sub-out, its the FX chip(s). My solution was to use the sub outs.
> 
> --- In xl7@yahoogroups.com, <loren_steele@> wrote:
> >
> > I have done some searching on google and this list and haven't found a solution for the clicks I hear on my mp7. I read on tarekeiths FAQ that it could pertain to channel volumes and filter types, but I hear these clicks even when no pattern is playing, the panning of the clicks are all over the place. My question is if anyone else on the list has had this problem and how it could be solved? Thanks in advance! Loren
> >
>

From what I could make out, heating the Xlilnx FPGA chip near the MIDI connectors made things worse, so I figured I'd try to get a replacement and see if that made a difference. Unfortunately I have not been able to source the chip (Xilinx SPARTAN FPGA XCS05XL in a PLCC-84 package). There is a seller on eBay who apparently sells these chips; I purchased one but after having removed the original chip and replacing it with a socket, it turns out the replacement chip was either faulty or fake; I'm leaning towards the later, as the print on the replace chip is white whereas on the original one it is golden. There's a variant of the chip in a different packaging which seems possible to get hold of, but building an adaptor would be a nightmare so I'm not going down that route.

 

My XL-7 exhibited a problem like this. The clicks were present on both the analog and S/PDIF outputs, and were apparently processed by the effects processor as reverb settings would affect the sound.

Example here: http://www.butoba.net/downloads/xl7click.wav

I never tried the sub outputs to see if the problem was only on the main outs.

All diagnostics (in the XL-7 diagnostics meny) passed without problems.

At the time I was in contact with EPR Electronics, who claimed they'd never heard of a problem like this.  Their best option was to purchase a new replacement motherboard from them, but including postage, customs and tax it would have cost me about the same amount as another Command Station, so by chance I got hold of a PX-7 whose mainboard now populates my XL-7 without problems. Only gripe is that it says 'PX-7' in the display when it starts up.

Back to the problem: In my case it got more frequent when the machine was warm, i.e. after having been switched on for a while in a warm room (I noticed the problem in the summer, no air conditioning). I tried narrowing the problem down by running it with the case open and heating various parts of the board with a hot air gun (hair dryer would do too). From what I could make out, heating the Xlilnx FPGA chip near the MIDI connectors made things worse, so I figured I'd try to get a replacement and see if that made a difference. Unfortunately I have not been able to source the chip (Xilinx SPARTAN FPGA XCS05XL in a PLCC-84 package). There is a seller on eBay who apparently sells these chips; I purchased one but after having removed the original chip and replacing it with a socket, it turns out the replacement chip was either faulty or fake; I'm leaning towards the later, as the print on the replace chip is white whereas on the original one it is golden. There's a variant of the chip in a different packaging which seems possible to get hold of, but building an adaptor would be a nightmare so I'm not going down that route.

The fact that heating the FPGA caused the problem to get worse doesn't really mean the problem is actually in the FPGA, it could be another chip that's actually the culprit, but at least it's a place to start. I was considering the FX RAM chip, but heating that area didn't affect the frequency of the problem so I decided not to try replacing it even. I did get hold of a spare from some plug-in-RAM board though just in case.

My recommendation if it is in fact the same problem as I had is to replace the mainboard, either with a spare one, or get a whole unit. I would be happy to test a replacement FPGA on my original XL-7 board but it doesn't seem possible to get hold of one.

/Ricard

> UMMMM...... You do know that an FPGA needs to be programmed right?

> It won't do a darn thing if it's factory fresh, or has the wrong

> programming. You'd likely be unable to get the original program from 

> anywhere, unless the left the chip unprotected and you

> could read it off a good chip. Not likely.

Traditionally, FPGA:s were designed as you say, with some form of fusable link technology akin to a PROM which had to be programmed once and for all. However, these days, FPGA:s tend to be RAM based, and that also goes for the Xilinx Spartan series that the FPGA in the XL-7 belongs to. Thus, the configuration of the device is loaded every time the unit starts up and no prior programming is needed.

Were that not the case it would indeed be as you say, that a correctly programmed FPGA would have to be obtained and it would be highly unlikely to get access to the required program outside of the E-MU development department or factory.

/Ricard

 

> UMMMM...... You do know that an FPGA needs to be programmed right?

> It won't do a darn thing if it's factory fresh, or has the wrong

> programming. You'd likely be unable to get the original program from 

> anywhere, unless the left the chip unprotected and you

> could read it off a good chip. Not likely.

Traditionally, FPGA:s were designed as you say, with some form of fusable link technology akin to a PROM which had to be programmed once and for all. However, these days, FPGA:s tend to be RAM based, and that also goes for the Xilinx Spartan series that the FPGA in the XL-7 belongs to. Thus, the configuration of the device is loaded every time the unit starts up and no prior programming is needed.

Were that not the case it would indeed be as you say, that a correctly programmed FPGA would have to be obtained and it would be highly unlikely to get access to the required program outside of the E-MU development department or factory.

/Ricard

 

My XL-7 exhibited a problem like this. The clicks were present on both the analog and S/PDIF outputs, and were apparently processed by the effects processor as reverb settings would affect the sound.

Example here: http://www.butoba.net/downloads/xl7click.wav

I never tried the sub outputs to see if the problem was only on the main outs.

All diagnostics (in the XL-7 diagnostics meny) passed without problems.

At the time I was in contact with EPR Electronics, who claimed they'd never heard of a problem like this.  Their best option was to purchase a new replacement motherboard from them, but including postage, customs and tax it would have cost me about the same amount as another Command Station, so by chance I got hold of a PX-7 whose mainboard now populates my XL-7 without problems. Only gripe is that it says 'PX-7' in the display when it starts up.

Back to the problem: In my case it got more frequent when the machine was warm, i.e. after having been switched on for a while in a warm room (I noticed the problem in the summer, no air conditioning). I tried narrowing the problem down by running it with the case open and heating various parts of the board with a hot air gun (hair dryer would do too). From what I could make out, heating the Xlilnx FPGA chip near the MIDI connectors made things worse, so I figured I'd try to get a replacement and see if that made a difference. Unfortunately I have not been able to source the chip (Xilinx SPARTAN FPGA XCS05XL in a PLCC-84 package). There is a seller on eBay who apparently sells these chips; I purchased one but after having removed the original chip and replacing it with a socket, it turns out the replacement chip was either faulty or fake; I'm leaning towards the later, as the print on the replace chip is white whereas on the original one it is golden. There's a variant of the chip in a different packaging which seems possible to get hold of, but building an adaptor would be a nightmare so I'm not going down that route.

The fact that heating the FPGA caused the problem to get worse doesn't really mean the problem is actually in the FPGA, it could be another chip that's actually the culprit, but at least it's a place to start. I was considering the FX RAM chip, but heating that area didn't affect the frequency of the problem so I decided not to try replacing it even. I did get hold of a spare from some plug-in-RAM board though just in case.

My recommendation if it is in fact the same problem as I had is to replace the mainboard, either with a spare one, or get a whole unit. I would be happy to test a replacement FPGA on my original XL-7 board but it doesn't seem possible to get hold of one.

/Ricard

Do you have service manual for emu command station? I would like to source more reliable switches.

Did you try attaching a heat sink to the problematic chip? 

Mine is not grounded. If I ground the ring on the digital out it will work fine, if not digital won't lock.

Take the cover and see the side of the box where the two panel (top and the bottom) is get contacted, scracth the surface with smooth sandpaper and take back the Cover, take back the screews and mybe all gone like in my XL7. 

this is fix my click and pops for years now,

i get this problem in different ways when i use spdif output, my soundcard has one broken diode and create clicks and pops.. im fixed and now that click ar gone...

hope your gone too