Larudakote
Member
Hi!
I build loudspeakers cabinet for more than 40 years, I play with electronic crossover for 30 and I try to assemble amplifier board for more than 20.
From the moment more than 2 channels have been made, I have never reached "zero noise" amplifier because of "hum" and "buzz"...
The famous ground loop syndrome
And then, I decided to build a last 2.1 chanel for my son. The parts:
Now, I can't hear any buzz, my ear sticked to the speakers; just a normal slight high-pitched noise. Finally !
I achieved this goal thanks to 3 factors:
Two features:
- volume knob via miniDSP (digital control) particularly useful when RCA input is used;
- automatic switch between BT and RCA input via the excellent LQCS module (really helpful!).
Right to the amplifier, my last DIY cabinet made for my niece.
OK, it is not a perfect back plate, but I don't own a drill press...
Now I'm confident I plan to build another 2.1 system for my daughter, around an excellent 3E Audio EAUMT-0100-3-A I bought used (because discontinued TPA3251).
I will use exactly the same setup (only one SMPS300RS) in a smaller Galaxy case.
PS: my similar main HTPC system is, also, groundloopless because I removed an auxiliary (unused) PSU... noisy!
I build loudspeakers cabinet for more than 40 years, I play with electronic crossover for 30 and I try to assemble amplifier board for more than 20.
From the moment more than 2 channels have been made, I have never reached "zero noise" amplifier because of "hum" and "buzz"...
The famous ground loop syndrome
And then, I decided to build a last 2.1 chanel for my son. The parts:
- subwoofer: Hypex UCD180ST + SMPS240QR PSU
- satellite: aliexpress TPA3255 board + SMPS300RS PSU
- miniDSP 2x4, powered with TPA3255 12V output
- LQSC BT board (with aux input), powered with SMPS240QR 12V output
- Galaxy GX248 case
Now, I can't hear any buzz, my ear sticked to the speakers; just a normal slight high-pitched noise. Finally !
I achieved this goal thanks to 3 factors:
- only class D amplifiers (I tried AB gainclone or similar for a long time)
- qualitative SMPS from Connex Electronic: it is not cheap but essential (note I first tried a very noisy aliexpress 36V SMPS)
- independent power supply for each PCB, which is particularly important for the BT module
Two features:
- volume knob via miniDSP (digital control) particularly useful when RCA input is used;
- automatic switch between BT and RCA input via the excellent LQCS module (really helpful!).
Right to the amplifier, my last DIY cabinet made for my niece.
OK, it is not a perfect back plate, but I don't own a drill press...
Now I'm confident
I plan to build another 2.1 system for my daughter, around an excellent 3E Audio EAUMT-0100-3-A I bought used (because discontinued TPA3251). I will use exactly the same setup (only one SMPS300RS) in a smaller Galaxy case.
PS: my similar main HTPC system is, also, groundloopless because I removed an auxiliary (unused) PSU... noisy!
