You could saw/cut and remove the small pcb and design a new one with filter. The hard way but a nice way. Also nice for other PA3S owners.
Or just find another one with now the criterium that it needs an output filter 🙂
Or just find another one with now the criterium that it needs an output filter 🙂
Planned to do this by ferrites + caps. This is best type of filter according to manufacturer
You do run balanced input?
I don't have that problem as desktop with any EMI but my other with longer speaker cable have some.
But not enough to build filters.
I don't have that problem as desktop with any EMI but my other with longer speaker cable have some.
But not enough to build filters.
Just bought 50pcs MA12070XUMA1 from Newark for $1.09 each on an impulse buy. They didn't have any MA12070PXUMA1, unfortunately. Doubt I'll ever do anything with them, but seeing how they've been discontinued, I couldn't pass them up. Almost bought all 72 they had left in stock. I didn't want to be greedy though. 🤣
Also got a couple cheapish MA12070 amps from Ali to use the PCBs for an active 2-way TWS BT speaker project. The boards have comically tiny 10uH output inductors.
Also got a couple cheapish MA12070 amps from Ali to use the PCBs for an active 2-way TWS BT speaker project. The boards have comically tiny 10uH output inductors.
Attachments
I use it with both inputs with different DACs, it's sounds good for it's money with both variants. But as always with surprises from manufacturers. I also don't feel any problems with EMI but it take place without output filter.
Search Infineon-ApplicationNote_Integrated_Audio_ICs_Merus_EMC_Output_Filter_Recommendations-ApplicationNotes
The sabaj a20 a, was good with its small ferrites....
But the XLRs ...... transformed into asymmetrical ......
YES...But it's better than NOTHING.
do you have a link to this card?
They are so cute.😀
@mamocel https://www.aliexpress.us/item/3256804562557241.html?
It's actually a little pricey for what it is, considering you can get a BRZHiFi in a metal enclosure for a few dollars more. It's also not a good candidate for modding. The plastic housing is glued together and I had to destroy it to get it apart. I just wanted the board out of it anyway.
I will replace the inductors with ferrite beads. It will be housed inside some 44 year old diecast Victor S-M3 speakers, so radiated EMI is no problem. I will drive the board with 2x PCM5102A DACs. Each DAC will have a mono signal with one channel inverted to drive the MA12070 with balanced signals. DACs will be fed from an ADAU1466 in each speaker. Way overkill for what it is, but it's a project for fun.
It's actually a little pricey for what it is, considering you can get a BRZHiFi in a metal enclosure for a few dollars more. It's also not a good candidate for modding. The plastic housing is glued together and I had to destroy it to get it apart. I just wanted the board out of it anyway.
I will replace the inductors with ferrite beads. It will be housed inside some 44 year old diecast Victor S-M3 speakers, so radiated EMI is no problem. I will drive the board with 2x PCM5102A DACs. Each DAC will have a mono signal with one channel inverted to drive the MA12070 with balanced signals. DACs will be fed from an ADAU1466 in each speaker. Way overkill for what it is, but it's a project for fun.
I measured mine both unbalanced and balanced. It measured just the same regarding noise and harmonics. So my impression is that the built in ballanser circuit is pretty good
Did not meassure EMI. But no problem to reach voltage clipping with single ended input. Same THD just before clipping.
I also generally prefer balanced.
I also generally prefer balanced.
@Solve: Not a problem directly noticed by ear may still be heavy EMI. Effect of EMI is not a loud full volume overdriven robot voice shouting “EMI, EMI, EMI!!!!!” through the music 🙂 It can have effect on the signal deteriorating total results. A while ago I noticed somewhere that EMI is sometimes understood to be something else than it is. And if it is not the amplifier itself having EMI trouble then it might be a source having less optimal results.
In short: it is wise to prevent possibility of EMI.
In short: it is wise to prevent possibility of EMI.
Last edited:
Apparently not enough with PA3S be it via inputs or via supply lines, it comes highly likely from its own outputs and the speaker cables being antennas. That is why Anatolii_A added the filter. The manufacturer also clearly described when the filter can be omitted and that is AFAIK with speaker wires shorter than 60 cm so in boomboxes.
Last edited: