jjptkd Posted March 8, 2022 Author Share Posted March 8, 2022 5 minutes ago, babadono said: I'm curious of all the solder connections on the TRS jack board and the ribbon cable that goes to the other board. I looked everything over as closely as I could, lightly pressed and wiggled on the ribbon cable connections both sides to ensure proper seat but they didn't move pretty tight already. I may plug the thing back in and try to retest now that it's been apart and I wiggled on things a bit see what happens. Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted March 8, 2022 Share Posted March 8, 2022 19 minutes ago, babadono said: it is probably a BTL (Bridge tied load) type of output as are most class D amps. Grounding of the negative output is a no-no. But you knew that Yes most people are familiar with linear amps and not Class D amps, the isolated jacks aren't just for signal/earth noise separation. Typically with the higher end Class D amps they don't tell you that in the manual because there is protection and a quick power off/on will clear the fault. Not with the PA5, it will just damage it beyond repair apparently. The TPA32XX chips have short circuit protection with error reporting but as I said Topping must have not used the error reporting to keep cost down and a short circuit protection is not self clearing, it needs to toggle the reset pin to clear. I just found it odd that with a short at the output they said major damage will occur when the chips offer short protection. Quote Link to comment Share on other sites More sharing options...
jjptkd Posted March 8, 2022 Author Share Posted March 8, 2022 7 minutes ago, babadono said: The 2 inputs for each channel are in parallel? Can you put a signal into one and take it out the other? that would test that the jacks are OK. I'm not sure how they're wired exactly but I've tested both inputs 1 and 2 numerous times the right channel works on both inputs the left does not on either one. Quote Link to comment Share on other sites More sharing options...
babadono Posted March 8, 2022 Share Posted March 8, 2022 1 minute ago, jjptkd said: I'm not sure how they're wired exactly but I've tested both inputs 1 and 2 numerous times the right channel works on both inputs the left does not on either one. But when you choose which input to use for each channel do you have to throw a switch or are both inputs always active? Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted March 8, 2022 Share Posted March 8, 2022 2 minutes ago, jjptkd said: I'm not sure how they're wired exactly but I've tested both inputs 1 and 2 numerous times the right channel works on both inputs the left does not on either one. Do you have a multimeter where you can input a cable (not plugged in to anything else besides the PA5) and do a beep test to make sure the connections are good? Quote Link to comment Share on other sites More sharing options...
jjptkd Posted March 8, 2022 Author Share Posted March 8, 2022 4 minutes ago, captainbeefheart said: Not with the PA5, it will just damage it beyond repair apparently. I really don't know how I could have damaged the amplifier It's not like I'm new to this the amp was not hooked up to power until all connections were made and secure and right out of the gate no sound from one channel. Upon inspection of the wiring everything was found in proper place and secure 1 minute ago, babadono said: But when you choose which input to use for each channel do you have to throw a switch or are both inputs always active? There's a switch on the front only one input works at a time. Quote Link to comment Share on other sites More sharing options...
babadono Posted March 8, 2022 Share Posted March 8, 2022 2 minutes ago, jjptkd said: There's a switch on the front only one input works at a time. Roger. So nix my idea of putting signal in one and taking it out the other to see if the jacks are good. Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted March 8, 2022 Share Posted March 8, 2022 3 minutes ago, jjptkd said: I really don't know how I could have damaged the amplifier It's not like I'm new to this the amp was not hooked up to power until all connections were made and secure and right out of the gate no sound from one channel. Upon inspection of the wiring everything was found in proper place and secure It does sound strange and I'm not trying to imply you broke it, it's just most faults will clear and the only one that needs a reset toggle to clear is short circuit or over current. The manual states if you short the output damage can occur which it shouldn't if the protection is working, but if the protection does work it won't reset itself. It's a sophisticated board and chip and it's possible static or magnetic interference caused damage during transport. It's a great chip but the amp itself is budget so they aren't taking full advantage of all the options the chip offers like error reporting and toggle hard reset. Quote Link to comment Share on other sites More sharing options...
babadono Posted March 8, 2022 Share Posted March 8, 2022 7 minutes ago, jjptkd said: There's a switch on the front only one input works at a time. When you throw that switch can you hear the relays switching. I am assuming those 2 little white rectangular components next to the flex cable do the input switching. 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted March 8, 2022 Share Posted March 8, 2022 Just saying unplug for a few and power up. Basic reset.. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 8, 2022 Share Posted March 8, 2022 1 hour ago, captainbeefheart said: It's a great chip but the amp itself is budget so they aren't taking full advantage of all the options the chip offers like error reporting and toggle hard reset. The evaluation board for TI 3255 has a reset toggle switch if I recall... 2 Quote Link to comment Share on other sites More sharing options...
Shiva Posted March 8, 2022 Share Posted March 8, 2022 I assume you made sure those golden nuts are tight. 😀 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted March 8, 2022 Share Posted March 8, 2022 Would also use magnify glass to look @t chips for hairline crack. Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted March 9, 2022 Share Posted March 9, 2022 7 hours ago, mike stehr said: The evaluation board for TI 3255 has a reset toggle switch if I recall... I am almost certain they do. I have the layout including the netlist file for the evaluation board I can have a look at. Even if I don't plan on making something I still take as much literature I can from the manufacturers, it's great to learn from the layouts. Eventually I plan to make some nicer subs and I plan to power them with Class D. Tough part for me is programming the controller so I'll most likely purchase an amp because it's just very time consuming for diy to only make a couple amps. Quote Link to comment Share on other sites More sharing options...
OO1 Posted March 9, 2022 Share Posted March 9, 2022 On 3/7/2022 at 2:42 PM, jjptkd said: Welp I took a trip to my Montana house this weekend / week and was excited to try out my PA5 in my living room system but looks like I'm dead in the water. Current system includes my modified / refurbished KP-301-II's powered by a refurbished Sunfire Ultimate Receiver source is my Samsung TV running Youtube and music downloaded to a hard drive. System as is sounds great I'm always impressed with how good it sounds every time I come here but sitting on an extra Sunfire TGP-III figured I'd give the little PA5 a run. Got everything swapped out and no sound from the left channel-- double checked all connections and still a no-go. Swapped inputs on the amp, speaker cables, inputs on the pre-amp, even swapped pre-amps since I have my brother's TGP-III sitting here and nothing. Thought it might be the XLR to TRS input cables swapped them out and nope, problem has been isolated to the left channels on the amplifier, both inputs. This thing was working when I disconnected it at my house in WA right before I left not sure what happened? This is probably my last trip out here until Fall so a bit frustrating I didn't get to do a comparison but oh well I guess, hopefully the amp is still under warranty I'll have to check that out I just bought this new not that long ago. the issue is either a defective processor on the main board , or corrupt firmware , that needs to be reloaded Quote Link to comment Share on other sites More sharing options...
jevchance Posted July 28, 2022 Share Posted July 28, 2022 Just wanted to chime in that I have a PA5 that also has a bad left channel. Wondering if this is a known issue. Just emailed Topping for replacement. It was purchased in March. Quote Link to comment Share on other sites More sharing options...
Onlinehead Posted February 25, 2023 Share Posted February 25, 2023 Also just wanted to say my PA5 left channel dead after ~7 month of use. No overload, nothing, using in the dry room with dx3 pro+ in pair. Left channel started to cracking sometimes and then once after a laud "khhzz" it not just stopped to work normally, but output with a half of the power. Like it has a bridge inside and one of 2 amplifiers for a channel is dead. Quote Link to comment Share on other sites More sharing options...
jjptkd Posted February 25, 2023 Author Share Posted February 25, 2023 3 hours ago, Onlinehead said: Also just wanted to say my PA5 left channel dead after ~7 month of use. Sorry to hear that I got lucky and was able return mine for a refund ended up selling the one I had with it. Quote Link to comment Share on other sites More sharing options...
.thumb.jpg.b17aa177a6f4e1497ac4340ed5725674.jpg)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.