Guys! I think I found a D-Class gem. here is the link:
https://www.alibaba.com/product-det...offerlist.normal_offer.d_image.3af81d2bXJLDpT
https://www.ti.com/lit/ds/symlink/tpa3255.pdf?ts=1723525425731&ref_url=https%3A%2F%2Fwww.google.com%2F
running it at around 100w a channel and 200w on subwoofer channel, or less, would give the optimal distortion performance of around 0.01 THD.
regarding the psu situation, i have a great transformer core, with no usable windings. i will rewind it to make a suitable transformer, with a Shotki-diod based rectifier, and a Nichicon KS Series 10000uF, 63V cap.
Thoughts?
https://www.alibaba.com/product-det...offerlist.normal_offer.d_image.3af81d2bXJLDpT
However, judging by the datasheet figures given here of the chip itself:https://www.ti.com/lit/ds/symlink/tpa3255.pdf?ts=1723525425731&ref_url=https%3A%2F%2Fwww.google.com%2F
running it at around 100w a channel and 200w on subwoofer channel, or less, would give the optimal distortion performance of around 0.01 THD.
regarding the psu situation, i have a great transformer core, with no usable windings. i will rewind it to make a suitable transformer, with a Shotki-diod based rectifier, and a Nichicon KS Series 10000uF, 63V cap.
Thoughts?
i defently will. tomorrow i will go to the old garage where that thing is. Hopefully its not rusted or anything. sorefor being a dummie and not rembering what it actually is. thoughts on the amp?
The goal is to find a cheap amp that anyone can enjoy. you are right. am at a loss. with all the money is spend i really just should have bought that thing or another board from the very beginning. what do i do now?
Your music taste is probably too hot 😀
No, seriously, don't plug or unplug the amps while they are on. Aside from the 'pop' and static that could go into the amp, you probably put ground on the input pins, which has a potential difference. That is technically not the fault of the amp. Try a galvanic separation on the amp.
For starters use a "normal" PSU. Can be an SMPS but make sure to to use the right voltage. Avoid computer garbage and extra DC-DC conversion. The shortest way from A to B is a straight line so keep stuff overseable and simple. Never plug/unplug anything while devices are energized.
You have had enough flak for now. Please show us the next device you have constructed and show it before switching it on. That is a way more positive experience. We seem unkind here but that is only perception 🙂
Or buy a ready made rock solid class D amplifier that is able to skin cats alive.
You have had enough flak for now. Please show us the next device you have constructed and show it before switching it on. That is a way more positive experience. We seem unkind here but that is only perception 🙂
Or buy a ready made rock solid class D amplifier that is able to skin cats alive.
You have been a lot of help Jean! thanks! as soon as i cobble somthing togather, am posting it here. wish me luck!
No thanks, yes I do wish you luck. It is a nice hobby but one needs a little experience and some technical Fingerspitzengefühl (google that one). Comes automatically by making many errors, we all did.
got some news. to keep stuff cheap for now, i will revive one of my old amps, and mod it. the TDA7298E one. i will order the chip and solder it in. curiously after referring to the chips data sheet the main capacitors are supposed to be 2200uf a line. on this board there was 470*6 a line, 2820uf a line. the caps are a bust anyways, so i will replace em. should i go with this 2820 route or datasheet mandated 2200?
its one of thees boards: https://aliexpress.ru/item/10050053...w.productlist.search_results.2.5f2d39cf9zP4CK
its way cheaper than what i bought it for but meh. the main caps are totally getting changed, i think something like nichicon FG will be really good. anything else i should change to get more quality sound out of it? thanks in advance for every recommendation!
(goal Voltage: 24-30v power: 80w*2. will likely use some cheap but deaccent bt pcb to feed it. or something you see fit)
its one of thees boards: https://aliexpress.ru/item/10050053...w.productlist.search_results.2.5f2d39cf9zP4CK
its way cheaper than what i bought it for but meh. the main caps are totally getting changed, i think something like nichicon FG will be really good. anything else i should change to get more quality sound out of it? thanks in advance for every recommendation!
(goal Voltage: 24-30v power: 80w*2. will likely use some cheap but deaccent bt pcb to feed it. or something you see fit)
That capacitor rating isn’t critical, just needs to be adequate. The series resistance is more important after the baseline capacitance. I have no experience with that 7298 board, bit your voltage level is more realistic for sure.
The $20, dual tpa3116 Bluetooth boards have worked well for me. These run on $40, used 18V 10A laptop switching supplies. Usually add a Panasonic FC capacitor at the amp power terminals also, class D amps seem to really work well with those.
Several years under teenager use with 4 ohm loads, what else can I say?
I wouldn’t expect great results by running the amps at high levels while using voltages near their limits and marginal amp ratings. When you take apart consumer equipment, you’ll likely find lower supply voltages that sag with load, a self preservation measure that saves money in several ways.
The $20, dual tpa3116 Bluetooth boards have worked well for me. These run on $40, used 18V 10A laptop switching supplies. Usually add a Panasonic FC capacitor at the amp power terminals also, class D amps seem to really work well with those.
Several years under teenager use with 4 ohm loads, what else can I say?
I wouldn’t expect great results by running the amps at high levels while using voltages near their limits and marginal amp ratings. When you take apart consumer equipment, you’ll likely find lower supply voltages that sag with load, a self preservation measure that saves money in several ways.
very very true! another question. is it worth to replace the low quality smd caps with equivalent foil ones? i can do the job decently.
Likely not worth it, the surface mount parts offer so much lower inductance and that can often be more of a desirable feature with devices like this.
Also have seen the whuzi amp boards not survive a simple power supply capacitor swap, using nice equipment and care, so I would not advise changing much on these.
I would just use a decent power supply of a conservative voltage and then focus on the speakers or something else.
Also have seen the whuzi amp boards not survive a simple power supply capacitor swap, using nice equipment and care, so I would not advise changing much on these.
I would just use a decent power supply of a conservative voltage and then focus on the speakers or something else.
Those chip amps generally don't have much clean power, at least what I've seen tested at https://www.audiosciencereview.com/forum/index.php
Metal and hard rock are definitely categories where there is a tendency to "turn it up to 11" and you need lots of real power. If IF IF your speakers can actually handle it-most all non-horn speakers I've heard can't, excepting the Monitor Audio Silver 300, just turn into distorted hash.
I think A/B is passé by now. Class D should run cooler "at 11" though it's not magic/miracle, you still need good heatsinking. I'd be wanting some like >300W@4Ω IcePower or Hyper or PuriFi etc module-based design. Be sure to use capacitors the size of those aftermarket Japanese car exhaust tips ha ha! Concentrate on the 4Ω or better yet 2Ω specification because that is into resistors and real loudspeakers are a more difficult load.* Many "8 ohm" speakers today are lying and really more like "4Ω" per Stereophile tests.
*You were posting " 4.8 ohms, sub is 5.5" which I assume are the DC resistances you measure with a voltmeter? Speaker impedance is way way more complicated than that. The "4Ω" and "8Ω" nomenclatures are just very rough estimates; it varies a lot with frequency.
yes, i measured with a multimeter. specifically without leads for further accuracy. guess am super wrong?