Hello!
Does anyone know where I can obtain a schematic for a Telex EV SonicXS computer speaker system? I know it's not exactly new. I have an issue with a loud buzzing sound when the unit is turned on. The Power is not directly applied through a switch, but through a low voltage setup where a switch on the volume pot powers a relay through a seperate circuit with it's own transformer, drive circuit and relay. If I bypass this power up circuit and connect the main transformer directly to power, the buzz is gone, and the amps work fine. The relay seems to work okay, and is only switching the hot side of the AC power. Don't know if the amp circuits are picking up this loud hum through a bad cap or other device in the power switch circuitry, or what is going on. Anyone with similar issues? If so, help would be greatly appreciated. Thanks.
Does anyone know where I can obtain a schematic for a Telex EV SonicXS computer speaker system? I know it's not exactly new. I have an issue with a loud buzzing sound when the unit is turned on. The Power is not directly applied through a switch, but through a low voltage setup where a switch on the volume pot powers a relay through a seperate circuit with it's own transformer, drive circuit and relay. If I bypass this power up circuit and connect the main transformer directly to power, the buzz is gone, and the amps work fine. The relay seems to work okay, and is only switching the hot side of the AC power. Don't know if the amp circuits are picking up this loud hum through a bad cap or other device in the power switch circuitry, or what is going on. Anyone with similar issues? If so, help would be greatly appreciated. Thanks.
Richard, my EV Sonic XS are doing the same. I don't guess you figured out your problem?
Richard, you didn't by chance get schematics or any repair docs did you? Or even just a few pics of the inside of the control unit? My 4.1 system is having a popping/rumbling problem, but I believe it to be related to the 9-pin jack on the control satellite. I think it was stressed in its former location and might have a loose connection issue. I would prefer to have some sort of documentation before I just tear into the thing. Any help you can provide would be welcome!
This has been sitting on my workbench for a while and I already got some smaller/cheaper replacement speakers. But I decided to get back on it. The big capacitors are epoxied down, and I can't easily take them out without destroying it. Two of the smaller caps, one was fine and the other wasn't showing anywhere near what it should. I ordered a replacement on aliexpress, after I receive it, I'll report back if it solved my issue.
So, interesting thing. Anyone who owns the 2.1 versions or the 4.1 version should know this information.
I did some digging based on previous posts and found the cause of my problem. Turns out the low-power line to activate the main relay passes not only through the volume pot/switch, but also routes directly through the power LED on the main/control speaker unit.
On my system I found that the LED was making only occasional contact because a trace on the connector for the feed wire had lifted. This was hard to see, but once I physically applied pressure to the connector I could see it move ever so slightly. Since this system runs the low-power line which controls the on/off function through the LED, it caused intermittent contact, thereby interrupting power to the entire system for split seconds at a time when the control speaker was bumped.
This explains why any jostling of the speaker or even the desk they were on would cause cracking/rumbling from the speakers. Most would first think this was related to a bad 9-pin jack or cord, but turns out it was completely unrelated. One bodge-wire later, and a wire extension on the way too short wires for the LED on the faceplate, I have a system operating like new.
While you have it disassembled, check all the solder joints to make sure nothing has lifted. I prefer to follow the traces using a DMM to verify continuity. A visual inspection doesn't always tell the tale, as explained above.
Also, all three pots are not very well mounted, and are easily broken as I found while fitting the knobs on reassembly. Fitting the knobs can apply enough pressure to break them, and/or free of their mounting on the board. Ask me how I know. Be very gentle.
Some things to keep in mind during disassembly of the control speaker-
I hope this helps someone!
I did some digging based on previous posts and found the cause of my problem. Turns out the low-power line to activate the main relay passes not only through the volume pot/switch, but also routes directly through the power LED on the main/control speaker unit.
On my system I found that the LED was making only occasional contact because a trace on the connector for the feed wire had lifted. This was hard to see, but once I physically applied pressure to the connector I could see it move ever so slightly. Since this system runs the low-power line which controls the on/off function through the LED, it caused intermittent contact, thereby interrupting power to the entire system for split seconds at a time when the control speaker was bumped.
This explains why any jostling of the speaker or even the desk they were on would cause cracking/rumbling from the speakers. Most would first think this was related to a bad 9-pin jack or cord, but turns out it was completely unrelated. One bodge-wire later, and a wire extension on the way too short wires for the LED on the faceplate, I have a system operating like new.
While you have it disassembled, check all the solder joints to make sure nothing has lifted. I prefer to follow the traces using a DMM to verify continuity. A visual inspection doesn't always tell the tale, as explained above.
Also, all three pots are not very well mounted, and are easily broken as I found while fitting the knobs on reassembly. Fitting the knobs can apply enough pressure to break them, and/or free of their mounting on the board. Ask me how I know. Be very gentle.
Some things to keep in mind during disassembly of the control speaker-
- The wire to the LED is so short as to be almost impossible to remove from the connector on the board. I ended up cutting mine and extending the wires for easier (dis)assembly in the future should it be needed.
- Also, removal of the control board is difficult due to being epoxied to the back of the case. In addition, there are two screws holding it in which look like they are in heatsinks, but they are not. They are simply metal mounting points soldered to the control board.
- You do not need to remove the audio wire, nor the screw on the back of the speaker.
- Again, when reassembling, I can't stress enough to be careful when fitting the knobs, as the pots are not very solidly mounted and are of questionable manufacture.
I hope this helps someone!
Just as an update, I replace the cap (found out it was indeed leaking from the bottom). It solved my problem. For reference, it was the cap in the red box in the photo below.
The replacement caps I got from Aliexpress were 10 for $1.45, so I have 9 more if I ever need to replace it again. 😅
Unfortunately I found out the speaker surround on the L and R had completely deteriorated. After much consternation, I looked for replacement drivers and I didn't have much luck, at least not at an affordable price. Then I found some some replacement surround foam on Amazon for $7, glued them in with E6000 glue, and it's all back up and working again. Photos below.
The replacement caps I got from Aliexpress were 10 for $1.45, so I have 9 more if I ever need to replace it again. 😅
Unfortunately I found out the speaker surround on the L and R had completely deteriorated. After much consternation, I looked for replacement drivers and I didn't have much luck, at least not at an affordable price. Then I found some some replacement surround foam on Amazon for $7, glued them in with E6000 glue, and it's all back up and working again. Photos below.