I got mine on ebay. I'm sure you can also find opamps of all kinds on amazon, mouser, whatever. These chips are ubiquitous in all kinds of electronics, are you seriously having trouble finding some? Getting the case open is not an issue, it uses hex screws, however the front and back are 2 different sizes. I have one of those iFixit toolkits so getting pretty much anything open is no problem. Going to the linear PS was not as much of an improvement as with the Wiener or similar TPA3116 but enough that its still worth while. In any case I already had it. Just needed to chop off the cable off the power brick, strip it, and put some banana plugs on. The cable was actually pretty decent looking, decent thickness real copper conductors, separately shielded, stripping it went quicker than expected. Just noticed these FX502s are all out of stock now! I wonder if they will make more? The price is pretty good that I may buy an extra one in a year or something just to have a later rev and have a spare to play with modding.
Just so you know I am not an engineer or anything, taking the amp apart was pretty easy, just be careful taking the cover off not to bang any of the components inside. Also why would they put socketed opamps inside and then rivet the case shut so you cant get to them?
swank42 u need to isolate why youre getting the error. Try to rule out some stuff. It could be the heatsink is not mounted well and the chip overheats. This is fixable. For power issues you will have to try an alternative power supply, but that may be difficult without cutting up the one it comes with. If you really did get a dud it does suck, shipping from CN can take forever. I'm hoping some of these ebay vendors get some US stock of this amp in.
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That's similar to my experience - been building all kinds of chip amps - TPA3116, IRS2092, etc. Bought TPA3250 from 3-e (as well as TPA3255). 3250 sounds way better - has better dynamics (probably due to better PS section used), significantly lower noise floor. 3-e board has provisions for SE and balanced connection, and balanced is the way to go...
My only reservation is the output filter design that limits the choice of speakers pretty much to 4 ohm.
My FX502 turned up from China yesterday. It took about 2 weeks to get to the UK.
Has anyone else noticed the case is a bit 'buzzy'?! If I run the back of my finger across the metal case I can feel there's some power there buzzing away. I don't have a clue what this is, or if it's a problem. I checked it with the multimeter and saw a max of about 7v AC to earth.
Has anyone else noticed the case is a bit 'buzzy'?! If I run the back of my finger across the metal case I can feel there's some power there buzzing away. I don't have a clue what this is, or if it's a problem. I checked it with the multimeter and saw a max of about 7v AC to earth.
nope absolutely not. sounds like grounding issue or something inside shorted where it shouldnt be, maybe binding posts not insulated properly. im crap at electronics tho maybe someone else has better idea make sure your source and amp are common ground. I would open it have a look inside, could just be something loose swank42 my experience same as yours... went from ta2020, 2024, tk2050 to tpa3116, to better tpa3116. learning experience... at least they are cheap ones
anyone wanna buy a ta2020 lol? BTW PS I use is Tekpower TP3005T, was about 80$usd on amazon. They also have new programmable TP3005P version for a little more. Great chinese alternative to expensive lab powersupplies. I got tired of the noisy fan inside and just opened it up and cut the fan leads. With the power levels I am at, ~0.2A I don't think its necessary, and anyway I have another fan blowing toward the PS lightly. I always get a laugh out of the fact that my PS cost more than the actual amplifier.
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According to the BOM on the EVM Users Guide, it is this switch:
GT11MCBE C&K Components | Mouser Europe
Thanks for checking the buzzing guys. I'll try it in some different plug sockets around the house and take a look inside if needs be.
Sound impressions... It's impressive! I haven't tried it on high end hifi speakers yet, but it does sound very good compared to my 2024. It goes loud too, while keeping firmly in control.
Sound impressions... It's impressive! I haven't tried it on high end hifi speakers yet, but it does sound very good compared to my 2024. It goes loud too, while keeping firmly in control.
Might be some capacitive coupled voltage, does the power supply offers "real" earth connection? May you try a different power supply?
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The PSU isn't connected to earth as it only has a 2 pin power lead. I don't think I have a spare 24v supply. I guess I could try a 12v and see if it comes on. It doesn't seem to affect the sound output.
When tested with the multimeter, whatever power I felt on the case seemed to discharge quickly through the multimeter to earth, with the reading going from about 5-7VAC down to zero quickly.
I have the FX502SPRO, replaced the NE5532 with LME49720 like I said before...it sounds very good, I may even consider getting the metal can version but its a bit more expensive. Are there any other mods that are worth doing on this amp that are cheap and worthwhile? Those inductors, maybe replace with some denon or coilcraft if they fit? maybe the caps? Will there be any improvement there?
Thanks, good to hear
For anyone who does have this and wants to get the most out of it: -Better opamps (LME49720) - Worth it IMO -Good power supply esp. Linear - Worth it IMO -Open lid off enclosure for better cooling - Probably a good idea -Cryo-treatment - what? Other than that, this looks like as good as it gets. I'm guessing there will be more stock once chinese new year is over.
I've just started modding a TPA3255 board (from Taobao) - the chip looks very similar to the 3250 except for the maximum voltage rating.
The mods I've found making a difference so far as PSU-related. Looks like the FX502 has a buck regulator (the 5pin device) which will generate plenty of noise. Hence filtering out its noise pays dividends in SQ. I also just found out that more decoupling on the TPA's analog regulator output (pin14) improves dynamics and transparency. I started off with 470uF (put in parallel with the 1uF the application shows) and I've since moved up to 1800uF.
I've yet to try upgrading the opamps (TL072 on mine) but I may try that at some stage, along with biassing the outputs into classA with a current source.
I'm documenting the mods here : TPA3255 - all about DIY, Discussion, Design etc.
Got my FX502SPRO amp today and immediately unpacked it and connected it to a small system in my study. Hardware wise it looks and works really well, but the power cord was quickly replaced. It uses some kind of horrible adapter from US to EU pins, not at all safe for children (or even adults).
I use a Chromecast audio as input and a pair of XTZ 95.21 speakers with 89 dB efficiency. This is my third class-D amp and a smaller sibling to my TPA3255EVM.
After connecting everything and power on it was dead quiet from the speakers. Even when turning the volume way up I had to put my ear very close to the speaker to hear any noise, and it could very well come from the Chromecast.
The output level of the Chromecast is very high, I had to dampen the output from it and only turn up the volume on the amp two clicks from zero to play at a level suitable for background music.
Playing some music I can quickly relate the sound to the 3255, same type of dynamic and easy flowing sound that don't stand out in any way - a bit boring in fact.
Quality wise, the amp needs a few days playing before it can give its best, but I don't suspect it will stand up to the EVM board.
Later I will probably see what can be gained by changing out the op-amp.
I use a Chromecast audio as input and a pair of XTZ 95.21 speakers with 89 dB efficiency. This is my third class-D amp and a smaller sibling to my TPA3255EVM.
After connecting everything and power on it was dead quiet from the speakers. Even when turning the volume way up I had to put my ear very close to the speaker to hear any noise, and it could very well come from the Chromecast.
The output level of the Chromecast is very high, I had to dampen the output from it and only turn up the volume on the amp two clicks from zero to play at a level suitable for background music.
Playing some music I can quickly relate the sound to the 3255, same type of dynamic and easy flowing sound that don't stand out in any way - a bit boring in fact.
Quality wise, the amp needs a few days playing before it can give its best, but I don't suspect it will stand up to the EVM board.
Later I will probably see what can be gained by changing out the op-amp.
maybe some ideas for mod ....... there...?
Drop in replacement for NE5532?
DIY Audio Projects Forum • NE5532 vs. OPA2134
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