This inductor is selfmade
RM8, ferrite 3C96 Al400 5 turns wire.Thantalum very bad?
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Does anyone know how good the channel separation is of these chips in SE and BTL mode? I can't seem to find it in the datasheet but might have missed it?
Nice boards btw doctormord. PCB only and then Mouser for parts? Have hand soldered 0805, how small are the smallest parts in your designs?
Nice boards btw doctormord. PCB only and then Mouser for parts? Have hand soldered 0805, how small are the smallest parts in your designs?
Thanks doctormord. I ask as the T-amps, especially 41hz have a nice channel separation and very low distortion when not pushed more than 70%. I love the sound they make and have not liked the PAM chips nor the 3116 on red boards from China. I tried a cheap TDA chip too but didn't like it.
As many speak fondly of the 325x series it could be interesting to compare. I assume the same benefits apply to the TPA series as the T amps? U-low ESR caps, specific output filter coils (saw your comparison) and film capacitors.
As many speak fondly of the 325x series it could be interesting to compare. I assume the same benefits apply to the TPA series as the T amps? U-low ESR caps, specific output filter coils (saw your comparison) and film capacitors.
I wonder why you emphasize that much on channel separation.
For my knowledge analog sound sources like a turntable or a magnetic tape recorder are limited to 30~40dB channel separation. Which is fair enough.
Improving channel separation beyond these limits is easy done with amplifiers, but will not produce audible benefits.
From that point of view I would not expect channel separation being an issue even with chinese el-cheapo pcbs.
For my knowledge analog sound sources like a turntable or a magnetic tape recorder are limited to 30~40dB channel separation. Which is fair enough.
Improving channel separation beyond these limits is easy done with amplifiers, but will not produce audible benefits.
From that point of view I would not expect channel separation being an issue even with chinese el-cheapo pcbs.
After a few months of pulling together all the parts, I finally setup the TPA3255EVM over the weekend. Firstly, this was the easiest build yet. I am still very much a novice and this was my third successful build. I originally ordered the case for a 4 channel setup (2x TPA3255EVMs), however when I added the amps and power supplies it was too tight for my liking. So, this is the first stereo amp and I am thinking of creating a mono for the center speaker as the next build.
I connected the amp up to my test speakers and laptop, and hit the power switch. What struck me first was how quite it was, both the amp/power supply and the speakers. I played a few songs through the laptop and was very impressed. When I switched the amp off I heard a thump through the speakers. Many others have reported a thump on start up, but mine was quite. Has anyone have a solution for reducing/stopping the thump on power off?
I connected the amp up to my test speakers and laptop, and hit the power switch. What struck me first was how quite it was, both the amp/power supply and the speakers. I played a few songs through the laptop and was very impressed. When I switched the amp off I heard a thump through the speakers. Many others have reported a thump on start up, but mine was quite. Has anyone have a solution for reducing/stopping the thump on power off?
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I left out that I plan to use this amp in a home theatre setup. I control my other DIY amp via a wifi power switch and I am planning on doing the same with this amp.
Could I put a wifi relay switch between the power supply and TPA3255 to turn off the power to the amp before the power supply turns off?
Something like this: WiFi Relay Delay Switch Module Self-Lock Mode Low Power Smart Home Remote Control DC 12V Compatible with iOS Andriod 2G/3G/4G Network
Could I put a wifi relay switch between the power supply and TPA3255 to turn off the power to the amp before the power supply turns off?
Something like this: WiFi Relay Delay Switch Module Self-Lock Mode Low Power Smart Home Remote Control DC 12V Compatible with iOS Andriod 2G/3G/4G Network
I spoke to soon about the easy build. I switched on the amp this afternoon and the red fault light came on. The manual refers to this as an over temperature indicator. I have double checked every input and output and I cannot find any issue. The power supply lights up, as does the green indicators on the amp.
Any ideas?
Any ideas?
You could try this... bing the Reset switch to a switch on the front panel. Label it On/off.
Use the Wall switch to power on the Amp.
So when you will switch on the Wall socket, the reset will be engaged. Disengage Reset to listen to music. Reverse, when you switch off.
Hello all. I've just received the 3255EVM from TI as well as the Mean Well LRS-350-48 PSU. I have it all wired up in a temporary home (fastened to a piece of MDF). The sound is incredible out of the gate. However, I do notice some audible hiss when I place my ear right next to the speaker as opposed to my Marantz integrated which is dead silent. The hiss is there no matter which source I use and does not seem to increase in volume as I increase the volume on my source. I have not tried shielded RCA cables yet to see if that helps. Just wondering if this is normal behavior or something I should spend time on trying to fix.
Thanks!
Thanks!
One other thing I noticed, the heat sink was not securely fastened to the board. It was missing one of the screws and just sorta moving freely. I temporarily secured it with a screw thats probably way too small. If I understand correctly the heat sink actually provides a ground connection that should help with EMI. Any chance that could be the source of the hiss I'm hearing? I've contacted TI support asking for a replacement, but we'll see what happens. Thanks again for your help.
^ Looks like this board is a bit suspect on assembly that I'd remain "unconfident" in its overall performance.
Unless your Marantz integrated out has terrible output impedance (input impedance on the EVM is 9.1k, i.e. 10k||100k), it shouldn't be making much in the way of hiss.
That said, the 3255 isn't the quietest thing on the planet either (85 uV A-weighted; having a gain of 28.5 is what's doing the damage here), so if you're running some sensitive speakers, it might just barely hiss when your ear is next to the speaker. Good signal to noise ratio, but that's also relative to 1% distortion output, which is pretty big.
Unless your Marantz integrated out has terrible output impedance (input impedance on the EVM is 9.1k, i.e. 10k||100k), it shouldn't be making much in the way of hiss.
That said, the 3255 isn't the quietest thing on the planet either (85 uV A-weighted; having a gain of 28.5 is what's doing the damage here), so if you're running some sensitive speakers, it might just barely hiss when your ear is next to the speaker. Good signal to noise ratio, but that's also relative to 1% distortion output, which is pretty big.
That makes sense. Speakers are KEF LS50 which are 85db so not very sensitive. Luckily it is not at all noticeable from my listening position, and it really does sound good. I think mayyyyybe if I was using them nearfield it might be audible, but since I'm not I will probably just enjoy it as is. Thanks for the suggestions and help. It is much appreciated.