Class D amplifier with TPA 3250 board
Hello,
I'm new to this forum. I recently purchased my endgame setup comprised of Closer Acoustics Ogy speakers (91 SPL), REL T5X subwoofer and a custom hand built tube amplifier with EL34 tubes. The tube amplifier is giving me trouble with hissing noises, so it's constantly at the artisan's workshop. Since my speakers are extremely efficient, I was wondering about smaller amplifiers as an escape route (if the artisan can't fix the amp, he surely can). The Octavio Amp looks nice on paper. So does the Atoll IN80. Is one obviously better than the other for my revealing speakers?
Folks on another forum I shall not name seem to heavily imply that all amplifiers should sound the same (or very similar). They rave about these cheap tiny Topping/Aiyima amplifiers with class D TPA 3250 amplifier boards. These same boards are used in Genelec active monitors, so they must be good? I'm flustered because there no direct comparisons between these TPA 32xx amplifiers and more conventional/expensive branded amplifiers. The same folks on the forum I shall not name imply that I'm a dunce for spending so much money on a tube amplifier (quote: it's a distortion factory and it can't play grindcore metal music so it sucks). If it weren't for the hiss I wouldn't post here.
Can I cheap class D amp replace a custom hand-wired EL34 tube amplifier for extremely revealing Closer Acoustics Ogy speakers?
I have built several Class D amplifiers. I used a TPA3255 by 3e audio. I switched out a few key caps on the board. I used a 12 amp switching supply and added 120,000 mfd for the supply. I engaged the PFFB circuit which makes the frequency response stable at all impedance loads, I wired it for balanced operation. It was very good. I had several amps selling on marketplace and sold a few. That amp was snatched up first. |
If you drive the sub from the preamp, yes.
That's not high efficiency! That's a moderate efficiency; you enter high efficiency territory when the speaker is about 97dB or higher. If you are listening nearfield I can understand using such low power. In a typical American room you'd want about 50-60 Watts to make a speaker of that efficiency play properly. The only conversion from AC to DC I can think of for the amp (to which you referred above) would be creating a DC power supply for the filaments of the tubes in the amp. FWIW this is sending up a bit of a warning flag for me. We use AC filaments in almost all of our amps and they are plenty quiet enough to use on horn speakers. In addition, if you are getting a hum from the filaments of the tubes, the hum would be 50Hz and not 100Hz (because its induced at the line frequency)! So while I am keeping all this in abeyance, I must admit to having lost some faith in your 'artisan'. Of course this is all hearsay... |
@atmasphere 50W is a lot! My terrible tube amp doesn’t even go to 20W and I have the volume set to minimum. My room is about 24m^2, maybe less. My speakers are rated at 15W max. I am also listening from a distance of 1~3m. Yeah the artisan sucks. Tell me something new. I’m gonna be using my Sure amplifier for the time being (when it arrives home). You know the cheap T amp. At this point my expectations have been lowered so far down that any amplifier which doesn’t exhibit a loud noise floor will sound like angels singing from the sky. |
@kokakolia Seriously, getting an amp to be quiet on a speaker that's only 91 dB should be a walk in the park! 15W seems surprisingly low for a speaker rated with that low sensitivity FWIW! |
