Hello, I just recieved a Topping TP20 from Amazon. It worked fine for a few minutes but then the right channel went out. Long story short, if I bypass the capacitor marked C20 on the board and connect the right channel negative directly to the capacitor behind it, it works at full volume. Could anybody tell me what the capacitor does? Should I just replace it? If so, should I replace all of them or just that one?
Yikes! Send it back! If it was a ~$15 YJ or Lepai then you could dick with it, fruitlessly, to your whim.
But at $80 ? Likely the Cheap Clone Ta chip died.. they do that
sooner or later.
Personally I'd try for a $ refund rather than a replacement unit.
But then I've had several Clone Ta chips die exactly the same way.
Consequently there's a Bit of a bias, I'm willing to admit.
But at $80 ? Likely the Cheap Clone Ta chip died.. they do that
sooner or later. Personally I'd try for a $ refund rather than a replacement unit.
But then I've had several Clone Ta chips die exactly the same way.
Consequently there's a Bit of a bias, I'm willing to admit.
Sorry for the sparse information. I was trying to finish the post on my lunch hour.
The reason I think it is the capacitor and not the chip is because if I touch the negative speaker wire to the output of the capacitor labeled C20 on the board, the volume is extremely low. If I touch it to the capacitor labeled C6 It goes to full volume.
The reason I think it is the capacitor and not the chip is because if I touch the negative speaker wire to the output of the capacitor labeled C20 on the board, the volume is extremely low. If I touch it to the capacitor labeled C6 It goes to full volume.
Still need to see a circuit diagram to give a definitive answer... best guess so far is that one side of the bridged Class D output stage is zapped and you are putting the speaker across output and ground.
Send it back.
(and if you're convinced its the cap then change it. Takes less time to do that than read these replies Having done that, then then you can send it back)
Send it back.
(and if you're convinced its the cap then change it. Takes less time to do that than read these replies
Having done that, then then you can send it back)So... I replaced the capacitor and it didn't do anything. You guys were absolutely right, Having said that, There was a slight incident while trying to remove the volume knob and returning it isn't an option. Does anybody have any ideas on what I should do next? Something I could check with my multimeter to figure out what's wrong?
Okay, I'm still a noob at all this. (which is why I was probably stupid to even open it up in the first place). Aren't I trying to put the speaker from output to ground? Or is negative speaker output different from ground?
On a bridged amp (which I think this is) the speaker is connected between the output of two identical amplifiers. As the output of one goes up, the other goes down so that you end up with twice the voltage available to drive the speaker. So no, the speakers are not ground referenced in any way.
They're all part of the output reconstruction filter. Does the error is somewhat touch/bend sensitive? Maybe its just about bad soldering the IC side. This can be tested by putting some force here and there (slighty).
Another test would be to cool down the whole setup. I'd guess you haven't any cooling spray around? You might try isobutane/propane to freeze the filter section (when power is plugged off) and check afterwards. (In cold state)
Edit: As noted from the datasheet, you may check for the following as well:
Voltage on Pin 6 (OVERLOADB) should measure >3.5V in reference to GND (if not, theres a problem on the input stage/side)
Voltage on Pin 18 (FAULT) should measure <1.0V in reference to GND (if not, theres a problem with the IC [thermal overload])
In any case, you'll need to put an amperemeter in the +-line of your supply to see any shorts or fried output-stage(s). With no input signal supplied, the quiescent current of the IC is at ~75mA. Having a fried output-stage often results in massive current-draw - heating up the ICs and the coils in the output filter section.
Another test would be to cool down the whole setup. I'd guess you haven't any cooling spray around? You might try isobutane/propane to freeze the filter section (when power is plugged off) and check afterwards. (In cold state)
Edit: As noted from the datasheet, you may check for the following as well:
Voltage on Pin 6 (OVERLOADB) should measure >3.5V in reference to GND (if not, theres a problem on the input stage/side)
Voltage on Pin 18 (FAULT) should measure <1.0V in reference to GND (if not, theres a problem with the IC [thermal overload])
In any case, you'll need to put an amperemeter in the +-line of your supply to see any shorts or fried output-stage(s). With no input signal supplied, the quiescent current of the IC is at ~75mA. Having a fried output-stage often results in massive current-draw - heating up the ICs and the coils in the output filter section.
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Quieter, and with DC present because the output of each amp sits at mid supply voltage... so not good for the speakers.
Okay, I'm not so sure its not that capacitor that I replaced. When I touch the speaker wire to one side of the capacitor, it outputs at the same very quiet volume as when I connect it to the back of the amp. I'm also pretty sure this pad has a trace to the that output. When I touch the wire to the other lead of the cap, it outputs at full or near full volume. Can anybody explain this?
Yep, you guys were right. It wasn't the caps. It appears that the amp will output the same volume with or without the caps. Unfortunately when I was trying to check out the TA2020 with my multimeter I think I accidentally bridged couple of pins that I should not have. It immediately shut off and now it will not play any sound. So I think I may be in need of a new amp.
On that note, anybody have any suggestions on a good amp under about $150?
On that note, anybody have any suggestions on a good amp under about $150?
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