just got
YJ TPA3255 CSR64215 PCM5100 Bass Treble +Bluetooth 120W+120W+240W Class D AMP on Aliexpress.com | Alibaba Group
how ever, with my nice, good quality consumer speakers that seam to be fairly sensitive. There is a poor noise floor with no audio playing 🙁.
My seams to have cheaper caps in it :/.
anyone else got the YJ 2.1 tpa3255 amp from other sellers? any better qualirty of components, noise floor?
This seller shipped amp with very little packaging. No padding for pots/VR/volume nobs 🙁.
The bluetooth anterior is also missing 🙁. I thought this seller was cheapest cus they where new and trying to get feedback. there feedback had been very positive, seamed more helpful than other sellers of this amp but other sellers do have positive feedback for that batch of amps they where selling... hmm maybe i should have got it from them...
YJ TPA3255 CSR64215 PCM5100 Bass Treble +Bluetooth 120W+120W+240W Class D AMP on Aliexpress.com | Alibaba Group
how ever, with my nice, good quality consumer speakers that seam to be fairly sensitive. There is a poor noise floor with no audio playing 🙁.
My seams to have cheaper caps in it :/.
anyone else got the YJ 2.1 tpa3255 amp from other sellers? any better qualirty of components, noise floor?
This seller shipped amp with very little packaging. No padding for pots/VR/volume nobs 🙁.
The bluetooth anterior is also missing 🙁. I thought this seller was cheapest cus they where new and trying to get feedback. there feedback had been very positive, seamed more helpful than other sellers of this amp but other sellers do have positive feedback for that batch of amps they where selling... hmm maybe i should have got it from them...
bad noise from bluetooth mode. high pitch mix of noise.
lossless recording. normalized using "sox --norm". so quite recording is near 0db but without dynamic range compression or clipping. converted to acc in mp4 format so forum accept upload. used 800k bitrate.
do wish forum accepted flac, ogg, opus uploads. there html5 compatible formats. apple and m$ users can use vlc, firefox, chrome to play them.
lossless recording. normalized using "sox --norm". so quite recording is near 0db but without dynamic range compression or clipping. converted to acc in mp4 format so forum accept upload. used 800k bitrate.
do wish forum accepted flac, ogg, opus uploads. there html5 compatible formats. apple and m$ users can use vlc, firefox, chrome to play them.
To fix the issues all at once, you'll need to connect the bluetooth module differentially to the TPA32XX input stage bypassing all that stuff in between. (Volume/Tone Control, Line driver, AUX relais etc.)
You may also try using shielded wire from the output of the line-driver (DRV602/3) to the front of the board (most likely the relais) grounding the shield only on side, presumely somewhere at the relais. (To hopefully get around the dcdc converter) Cut the traces at the output of the line-driver and relais (So both sides to not form another antenna).
You may also try using shielded wire from the output of the line-driver (DRV602/3) to the front of the board (most likely the relais) grounding the shield only on side, presumely somewhere at the relais. (To hopefully get around the dcdc converter) Cut the traces at the output of the line-driver and relais (So both sides to not form another antenna).
Also if the unit actually used the analogue audio outs of the bluetooth module it could simply be noisy. I know the ones I use are.
What module do you use?
The CSR DAC at the 8645 and up aren't that bad. I used them in the past for my bike-pa and don't find then noisy at all. It is possible to use these, even in single-ended configuration and a connected to a DRV602/3 all connected to the same supply with the power-amp, without noise/buzz when done somewhat right.
The CSR DAC at the 8645 and up aren't that bad. I used them in the past for my bike-pa and don't find then noisy at all. It is possible to use these, even in single-ended configuration and a connected to a DRV602/3 all connected to the same supply with the power-amp, without noise/buzz when done somewhat right.
I mainly want analogue input. so i don't mind about bt being crap so much but its a shame. They used a fancy DAC PCM5100 IC for better (low noise i guess, ha) audio from bluetooth! well something is wrong, cus it not working 😛
I guess relais=relays?
hmm I’m not seeing a DRV602/3 on the board?
I guess relais=relays?
hmm I’m not seeing a DRV602/3 on the board?
My fault, the DRV602 i'd "seen" is the PCM5100 you mentioned. 🙄
Relais == Relays - correct.
Getting better analog sound most likely mean to cut the traces coming from the PCM into the relay at the relay - or - desolder the relay as well and bridge the RCA directly.
arr thanks for the suggestion. I’d like to try that fix. will be nice to have cleaner analogue input 🙂. I will wait and see how my dispute goes first. was thinking of giving the unit away to a cheap skate after i got refunded my money 🙂. I guess the bluetooth module controls the relays?
arr just found a differently branded, over priced product that has matching product pictures. I guess mine is a clone!?
K.GUSS AD21 Class D HIFI audio TPA3255 2.1 Bluetooth (IIS) DAC PCM5100 power amplifier 150W+150W+300W-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
maybe i should order one directly from YJ? more ££ postage but at least it will be real deal. just no dispute option... but compared to fuss of a dispute and potently loss of some money... maybe its less of a risk 🙂. ordered from yj ages ago but one of my tpa3116 boards died from them but i was not sure if i had made a mistake with it....
K.GUSS AD21 Class D HIFI audio TPA3255 2.1 Bluetooth (IIS) DAC PCM5100 power amplifier 150W+150W+300W-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
maybe i should order one directly from YJ? more ££ postage but at least it will be real deal. just no dispute option... but compared to fuss of a dispute and potently loss of some money... maybe its less of a risk 🙂. ordered from yj ages ago but one of my tpa3116 boards died from them but i was not sure if i had made a mistake with it....
ok, so aliexpress accpected my dispute. i have partial refund of ￡ 41.04 or return for full refund. looks like tracked postage to china is £11~ . It cost me ￡ 68.39 to buy. so im losing £11 anyway if i was to return. so keeping it comes at a cost of £57.85~. opted to keep it but feeling now maybe i should have returned it... arrgh well if i sell it on for £17 then i will have lost the same if i returned it... and someone else can hack it up on the cheap...
anyway so i was looking at "fixing" by disabling bluetooth. snag i realised is gnd audio connection is not switched. the rca tracks go directly to the relay. so in rca input mode. any noise is noisefloor or interference from the bluetooth stuff.
So i need to cut power to bluetooth stuff so the gnd loop or other bt ,pcm noise interface is not a problem anymore. right?
so i was looking at pcb tracking to where to cut power tracks for bluetooth stuff. snag is in the power circuits section of pcb is the regulator for the preamps and i guess power for the replys. So i need to keep power to those.
those green caps i have a bad feeling about, where i wonder if i should have just returned the dam thing and only lost £11 on this thing and saved my time trying to fix it... arrgh
Well it would be good to see if i can fix it...
anyway so i was looking at "fixing" by disabling bluetooth. snag i realised is gnd audio connection is not switched. the rca tracks go directly to the relay. so in rca input mode. any noise is noisefloor or interference from the bluetooth stuff.
So i need to cut power to bluetooth stuff so the gnd loop or other bt ,pcm noise interface is not a problem anymore. right?
so i was looking at pcb tracking to where to cut power tracks for bluetooth stuff. snag is in the power circuits section of pcb is the regulator for the preamps and i guess power for the replys. So i need to keep power to those.
those green caps i have a bad feeling about, where i wonder if i should have just returned the dam thing and only lost £11 on this thing and saved my time trying to fix it... arrgh
Well it would be good to see if i can fix it...
i guess theres are the tracks. next is to measure voltage with test meter. i guess 5v for bt... pcm ill check datasheet.
Attachments
Last edited:
I cut the 3.3v power traces from the 2 liner regulators. cus the pcm dac has a digital 3.3v power in and another pin for analogue 3.3v power from the middle liner regulator. the digital power pin gets it power from the bt module power liner regulator.
I thought with the bt module is not getting +3.3v getting power, then no need to cut its gnd trace?
no more low level bt noise at beginning of analogue input mode. just hiss noise floor. not good for sensitive or half decent speakers. i guess with cheap speakers, the noise floor might be less noticeable.
I also didnt cut the audio traces from the pcm dac. as i didn't see the point when the relay is not connecting them to the amp.
upgrade pre-amps to get better noise floor? I am not intending too, as i guess the other components or design may be part of the noise floor problem? if it helps i could try... or i can send my time on a new better made in the first place amp 🙂. got some e3audio tpa325* amps to finish boxing up 🙂
I thought with the bt module is not getting +3.3v getting power, then no need to cut its gnd trace?
no more low level bt noise at beginning of analogue input mode. just hiss noise floor. not good for sensitive or half decent speakers. i guess with cheap speakers, the noise floor might be less noticeable.
I also didnt cut the audio traces from the pcm dac. as i didn't see the point when the relay is not connecting them to the amp.
upgrade pre-amps to get better noise floor? I am not intending too, as i guess the other components or design may be part of the noise floor problem? if it helps i could try... or i can send my time on a new better made in the first place amp 🙂. got some e3audio tpa325* amps to finish boxing up 🙂
Correct, LEDs go there.
The hiss comes from the AFE (analog frontend) pcb layout and gain structure. Does it corresponds to the volume pot setting? (So lowest noise on middle?)
The hiss comes from the AFE (analog frontend) pcb layout and gain structure. Does it corresponds to the volume pot setting? (So lowest noise on middle?)
hmm, no hiss stays the same what ever the vol pot is set too. as the vol is turned up to near max the hiss just gets mixed into loud music but for music at lower vol or that has quite bits in it, the hiss i expect will be noticeable. so not good for hifi desk listening if avoidable.
Last edited:
- Status
- Not open for further replies.