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Fosi Audio BT30D Pro review

Pixelwarfare

Member
Joined
Oct 3, 2022
Messages
16
Likes
40
BSWeutj7jcKZZJJ6ufT1ojTNFOJb4tEp_lJNPQTlUdIkQeF6-9TB9pJRpvO4fYNgww-wx8JOfjyNXPGdFI12LFRAxEaCK6Cjb_uI1uDB49A1QLbgDnYVTQqanlgnPOnt0IEFwzQZ3UUCHBMIsabJZVaLuE5vtKyF9wKt8W098jZ-ckYn7yay6-uygNRM
k9i8MePDPHzLEcJHTevKp-jiQ57LTtWKIZN5GYhpHsqt6oaHc0it7UFyVmN9j_FaLOzR7hUrBfKae68iaVPvQqWKxMsE2hyfQFqM1aKHnPYdMozhqu0vN0yrrdj3zsHkJ2E49ZweaJFdICiyn1ZrpgvDujxhPqijNVl8GYEPcgKgYPDxK7H6E2Vwgz6p


gkKGcHTByAinxGUe6ZgfGcFD_OULvrqp6hDKMz1qJdiZ8xo0jVNB5C0P8Z_B9sY3XiDqSqMA9pHRibmqbmKBD6jcSefmNS4BnQWaz3XHNBScelVj-CnSRTL7bS8U2IPLdkfNm8Y49xQx17ZLwDVBcT3Klz7h_ZZ3zoQBj3a29lU-SXOEXvsf3GI3i_lm

Compared to the BT30D non-Pro (left), the Pro version is quite a bit longer and heavier (430g vs 620g).


RAt4S8qHWMW8G5iS4jfB2-tMoIwG95KLlJ0J9jTPknRt8WtEQNorh5Ewef3vpWL-BmbePNn710fTVSPqldyLggW7WVcWyFKSvixb5rkJrRTBOD1mUthd5WztSwtMP5m6YQnBOdSyLLACG4EgSDRzTO3jf4_2ru3MhbJKyVrbP1J_LslGR7r34YFu6ZVN
iifki-0_9Xcc9jp7LkLa_9WAdCY2EumlIUhBTXwxTgdESoQ3jdOw95LRGR_vQL-iO2Pw_FKkwKjxLKoztGAiH3Wlh5RwhRj4X-p2JHE1R8Jj6UKENueiYl0vdMBnST8ioWdz3e4jJadL-o9pmC5chLm5sFupntS34dzHUCPX9UT75JKHMDCDz4d3NBH1


The knobs are made of aluminium, different texture compared to the no-pro, a bit more resistance to turn. Same throw switch used to power on.

The 3.5mm PRE OUT is full range.

Bluetooth will be always-ON so your neighbour can hijack your device just like the non-pro version. Remove the antenna to prevent this from happening if you don’t use BT. Come on Fosi Audio, please fix this.

The amp has a 4” tall BT antenna, again it's better than the 7” incher of the DA2120C that looks like a CB radio... Please give us the 1 incher for future products, for once the smaller the better.

The spec in the manual is different from the official website, give us the true data!!!
trkCcaNfCi-QStobo7aPdVZvFvdXDblLki--fcyjLN8SyxqkWD1D3Vtoq_EIDUcenTtdxjo4Me_xEFsqUXNSqyWIdfCRZmJyDUTuSCJ2-DVuc2CpaM8YvaY_qKdVDARHRNu5NtFcY4o4GtzvuQ0mQl6z8pV4Px6K2azWWjYKEvjwxOQbp4go83yv3c4


BT uses an ATS2853 chip that is also found on the BL20A.
2vDiDVTetsJRhUoZRO1JLuKh6W6FBktlJQ-_VSXz6_pxsxR_5DVatjB3bohE0iCO_uIPoQ00dHHqcWCKw3XZwxmb-Vr6w14J-TZFUmiVXzCoTcoMtwtLuusLOnSovPP1AUNOidrJpxkuIVNRLF5L0Cy_LHn_Ic6j3jgkowSZ47djyJeHo6-ZufY3qTVV



How does it sound?

I did a comparison with Onkyo RZ50 pure output mode (airplay), Aiyima T9 (BT), and the BT30D non-Pro (BT). All using RP5000F towers, with an amp selector switch.

GLUEZOAkBYGGHqFyQvOh7kjA5BbrPNcKfNsTMy4O3cZNmvNLKmA-P68ITgUwGOh21kgljt3SpF3xEkOy4aODxY1FaRcjzEBMoj2LD7vZWcdW-8rqC3xHnHWJNXEgZnaZxKOsZX3rdQiEe89BvcyyQzV6_Dr_7nBqJ94pHUYE73cefI9JazHv4L9ZmrI


Right away there’s a BIG difference between the non-Pro and the rest.

The Pro version is much more dynamic, the voices are clearer, bass is more present and punch harder.

I honestly cannot tell any audible difference between the RZ50 and the BT30D Pro. The T9 sounds only a tad warmer (thx lamp); Even that it was really hard to tell and it depends on the song being played.
The Pro version sounds definitely better than the non-Pro.

To test the passive sub output, I hooked up my gutted Z2300 logitech subwoofer, it works wonderfully and has a very capable output. However, I didn't like the sub crossover control, the adjustment doesn't feel linear. There are no frequency indications on the knob, it can only be tuned by ears.

Now the technical stuff:

The PCB: The board is very well built
AXQchWS2XoDy-Ea52QNWQhMxri4MoPLTejeX5TG63lc9ZKq25336BudprJxqJZyCgJ0ZGKnnr0atNyFVMLRFy6abi9urHRqTakbJRJlJ4j0128QEDs20kQmUU0N_IW_hljeem2q-e-Zwiru50x9myqtIGPINxrr9vjEt9_hFWyl6QQd7UtXbAl_xuSw
KO0UUM4ScJ2UfhLh0Pwt5WyN3jV8bss3a9QWODLHV_EYGWqWQ6GtiDuNM6ELe0PgKoWkL-ZBDbzr23rnoXT94kwxutHo7e5WdcgmYxD0mkckR0FqFgiUMpno8v9YCYFgXA0iNTyvhGj5ZUS8ibv8bsqeA0dzQe_lg5Bno3HGekABE4nnRKt8kdTFcQ8


Caps:
lfAL1MLd8olvZ2MIwif2JO9-H8kr5xhJa9xHGRLpfjCF46dWluIzVT_kq381H2EN-2yTCAxXXsgI4y93nfJPw_X2uaoQFPt427WdgVBwF_YiHogfghTSJ73LG1AK8BaY3VrEFxAuWY1hDIhSn9L5HJ02K9ZOvjvKXntAIdb1_2i_-BZGnTOsu5waur0


Relay: It does the click (barely audible) only during power on. Maybe that's why no more sparks.
QGIwA7aK9OkRBSd5Szi86OmnyFNVgxQKgY6HUirXjPVliyBkfu04aNc_K8BcnNiq5S0fVw1efh0PGrwQAiSoXS_G5jZonSxOv1-_kQidbfDexxacOfgekKqfqU_h9Maj9B3wAhTlZRFU5HYOQtxNhjwgw_KcfNh7qRXofugXiyhcFUdP6g-4f-Mqdik

The muscle: TPA3255 x 2:
2jS3OCwQHnwK3iu5148YNhSByIsFOVD9H0f2nVJPulGLt2cugaTWnSZAQ0TYGJEnWQ8N1hw0DDme9B9JuigAKNFqV_huPeSYMKmU6EpfhYkc9AtfUF2PU2V6zDkXUd0QVEBbs_qepBWkElxz9FeVPrrY6Xm46pMJOBNvcO5Ga80rLS5ffstEBiEW1w0


rpv7Hbum--7WdOgP98OXLpH3LAwOxD7Tp4Y5gGIBzDAid1P3GdsrkTd3euBKYgxmqFHATRVk1Q2zfhR3qRJBvIkRSLVeTZusHzVVEtsc6S8z37rr6FK4SEl33cUQYMVkZsqIIy_YI2CkNj93EEDuYOGANQB865v96LiE28UeU_LB_x02-2-r0a3Y6bQ


vCp0x4beQ9jRxnTZ1ir6EGa4KFsmregb3YwwUUcPSGTXvT0bN1s9uSBFLk9DdI_d9uyree-rMUWvStjF9y9Vrs3TvtcQQ7HcRXglKU6igJwW8ifA7tMifFa1Yc2hoMj4pQXK7Q_bQBYhbUKw0KMThYi1k9I2dHy06z_kpXj_CKnyuCQXtQ3lGZ66yPc




PSU idle voltage: 32.3V
i8B62JvlzQRE5tx6r6HzpFT6ekO0ndZK26h2CzPpUGUxksMr6X9oZURFRbySUPpTflgqYsyda37TjRX0UtpxKYqPI0pxo2LzcFES4XEMAiGX_JVJZiYVF0X7y7l-HHhN_X9I4-3NAbFM5TfG7IfJ0vkE3a8BZS4wpsTT7vfn75dXv4fLAKMxKeVawF4

touhiwRgvD2-O41fGo8saPz5WQtA8GIDkjvAt2uurgbfHrbLP_jhkevOGcbVY-6rT3ZBa9T5IDzS7paAeTDEY-1kBpy7i7cYo1L_PHPnMnFK405xH6ltYBpPFoYWLsmWdYqaxbDG6c-RR-4_4NDJRnADp8Jp_mX7F56aUc6hH2p4siBWv-XR37-jE5o

Power adapter output @ 8ohm load current and voltage, 125W:
z2j2skABUomLRKUwk_V2jFbT2NE801YgmKTFAum-e82SehaI5g-OKCd1Lw617sfCLxsMNC3CB0Ty2yCn9fLiLe7v0oWOWWEQC89iYmbA3FYsOECMufasos1zlm0zg2cZ5KXQBfnlvtPTCuYFoscQenKdO30sf5gNjRjf4ktI0GPm4loY6DTHNUIEcC8

Same 32V5A adapter used for multiple models. No sparks occurred while plugging in the DC plug compared to the DA2120C I've tested, I made multiple attempts to make sure this is repeatable.
gp2O88Qf_HNzMAFvQbnCKfGvNAT8Z2NirEiPBnYyXAdRX9X77qq9g8_J4oWrh6Z1PMUlwU5rDl9zUxx9hFkiynhDyklwHyunqXfiRBIJL_s70kLHMpEmkUyxdIP_g3VY9Hbehb4RkysmOGNYw5LrUeCJVu9WqLlfl_yCzsVBpTGNnyQCap6z7Dlm_NI5



Here I am trying to figure out the max usable volume before getting a bad shaped sine wave, The volume knob is at 3 o'clock, BT reference volume maxed out on my mobile device, no EQ, no tone.

L & R Channel, 8 Ohm load, 1000hz tone, 26Wrms per channel
r9ukKHmjLXEQ5BI2LHdbYkRL2Ax5N_a-cMMpydCRVz841J9nUHg_tN0j6-BvVp29zl139PaRKBbUAwuDm9PKY5e-0EVmdX-F_CU4K3jj26nlGHeJRcib8MOn4Ps-rlN3KDFYRWHxAS1IWO_bu1iCIt0YVezYLhBgZW5MomF-oZ9dLnlF6YhPlqcP1IU


L & R Channel, 8 Ohm load, 1000hz tone, clipping at 60Wrms
oyTbv91ci_CsCcCdXfv5XfwcrPwNltyZWZ6TLoyxr98HHyZVMF7qV_AK_slp2MSTY4adD4-IWLy8PHgMxFyBQnlrNosLpkruV6DFgOjJz-PJ_U-eMbVtKKxWP3JXCUZXiII4mSIY0Kl4yJcUBEflZ0u4IHMRgmFnmpTvdI9I9lb5824DARpK-xODvUY


L & R Channel, 4 Ohm load, 1000hz tone, 40Wrms per channel
Iz3S8Mgcd2h0SFfuvCl5MQl6av4ZFfjFSlwZowZFpVC_hdOi8sjJQ6iFGvBL5G4-9FshES5tVGMxCu2hsDQNeH7qSGQQ3zoEsXgB30EnsJZaIiA_TMwkHk7kvTI8Xxf6cTMIyonJ9V2DTqVsfWEcOLoX8RMWyJEoZVy4AIn7KVjoWFc1wxfwrNPjKMI


L & R Channel, 4 Ohm load, 1000hz tone, clipping at 100Wrms
-QEqDwZ5w7HiXd5CFQb3J1BZwjgx2Fo9KKKJWO9I8NmHzWChqgf5cEwuXP9oEyRGyT7VJo7PdUXxW2UbPazU6LduzJCOLsu5JEPgrXl7brj7VNN_lvwPbplcRSvyvP6giJLOWgv08nkkqa3iKVt89YINMGne8yXs5p_lS19w3X95aQY8M500u3ygnTM




Sub channel @ 4 Ohm load, 75Wrms:
niJMOFhS5Kzhcy_34HRhyv0yPaBiundZZgBsabcO__hthkEkPs46rwxOex_Rn7coylgWZv4ZzJa9Z2yKOKF_6YY9vgH2eMkEusHyIY8trW4uqbaD_QAMhp4wosNu9hfHM4NpISUOFLRwNq2L7jJjTYYapfRJg5UiCXLv4pwQy40PQpgIx8LKVeeSDco


Sub channel @ 4 Ohm load into clipping, 121Wrms:
0W1By14JsKwSD71f5iU46KJ9tkz6SkyWrQckZEhMd9xQqtET6Jzkop9EmRo2W5c67Bgnrj3SuEPMMOcDv8EX_ypgvxWBdyQqrcHIwfEPKWu5sxaikgLFF2Hp4FNgB2EUjDL7A0g49JSXfqjWl2m9v1SCVv05kudn-dIpACguo1dyv_STyFxPV6hccY8



Noise, tested with max volume:
BT30D non-Pro, audible hiss from speakers during powerup, circuit shuts off when no input signal for 5 secs to prevent constant hissing.
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BT30D Pro, barely audible hiss from speakers, you have to stick your ear on the tweeter to hear it. no circuit to shut off the signal, it's not needed because it is not audible sitting away from speakers.
xYv9lOP9td_kUrfMuskFLCFnWsBvGsIejAVGi1B2jAoEoIK7gk8VXBc6y_A9HefGlc1B3gja66L_u3H3hGx2sgOO1rd1GdlQcNMBv_B5vVO7cwZVV6flA8uh7x1TK1AvxUx1VcMec3b4HrqzwtaQr03B2j7I0wWnBeqqFMU3yv0SbHDHmkpZHjwu0cU




The TPA3255 chips are hungry AND efficient. If you can feed them, they will put out a respectable amount of power for its size. You can upgrade to a 36V power adapter if you are looking to squeeze more juice out of it. It seems most of the manufacturers using this chip have set the bottleneck to the power supply. If you are looking for a 2.1 amplifier with passive sub output, look no further.

The BT30D Pro is way better than the non-Pro version.


Pros:

  • Great build quality
  • Excellent sound quality, to my ear it’s on par with the Aiyima T9 and RZ50
  • Low noise floor
  • Runs cool and efficient


Cons:
  • Cannot turn BT off
  • Sub frequency needs indication and more linear tuning
  • Power limited by the power supply
  • 1" BT antenna plz
 
Last edited:

Graham849

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This would be a great amp if, and I 100% agree with you , Bluetooth could be turned off.

Also what is row of components between capacitors?

Thanks for your review, regards G
 

Graham849

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OP
Pixelwarfare

Pixelwarfare

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This would be a great amp if, and I 100% agree with you , Bluetooth could be turned off.

Also what is row of components between capacitors?

Thanks for your review, regards G
The row components are inductors (chokes) Typically used for output filtering
 
Last edited:

nikolai

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What is the difference between "SUB OUT" and "PRE OUT" of the two amps? Is it just about having / not having the low-pass filter? I mean, would it be a good idea to connect an active subwoofer to the PRE OUT port?
 
Last edited:
OP
Pixelwarfare

Pixelwarfare

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What is the difference between "SUB OUT" and "PRE OUT" of the two amps? Is it just about having / not having the low-pass filter? I mean, would it be a good idea to connect an active subwoofer to the PRE OUT port?
That’s correct, yes the full range preout can be used to connect an active sub, then adjust the low pass on the sub itself.
 

Fosi Audio

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gkKGcHTByAinxGUe6ZgfGcFD_OULvrqp6hDKMz1qJdiZ8xo0jVNB5C0P8Z_B9sY3XiDqSqMA9pHRibmqbmKBD6jcSefmNS4BnQWaz3XHNBScelVj-CnSRTL7bS8U2IPLdkfNm8Y49xQx17ZLwDVBcT3Klz7h_ZZ3zoQBj3a29lU-SXOEXvsf3GI3i_lm

Compared to the BT30D non-Pro (left), the Pro version is quite a bit longer and heavier (430g vs 620g).


RAt4S8qHWMW8G5iS4jfB2-tMoIwG95KLlJ0J9jTPknRt8WtEQNorh5Ewef3vpWL-BmbePNn710fTVSPqldyLggW7WVcWyFKSvixb5rkJrRTBOD1mUthd5WztSwtMP5m6YQnBOdSyLLACG4EgSDRzTO3jf4_2ru3MhbJKyVrbP1J_LslGR7r34YFu6ZVN
iifki-0_9Xcc9jp7LkLa_9WAdCY2EumlIUhBTXwxTgdESoQ3jdOw95LRGR_vQL-iO2Pw_FKkwKjxLKoztGAiH3Wlh5RwhRj4X-p2JHE1R8Jj6UKENueiYl0vdMBnST8ioWdz3e4jJadL-o9pmC5chLm5sFupntS34dzHUCPX9UT75JKHMDCDz4d3NBH1


The knobs are made of aluminium, different texture compared to the no-pro, a bit more resistance to turn. Same throw switch used to power on.

The 3.5mm PRE OUT is full range.

Bluetooth will be always-ON so your neighbour can hijack your device just like the non-pro version. Remove the antenna to prevent this from happening if you don’t use BT. Come on Fosi Audio, please fix this.

The amp has a 4” tall BT antenna, again it's better than the 7” incher of the DA2120C that looks like a CB radio... Please give us the 1 incher for future products, for once the smaller the better.

The spec in the manual is different from the official website, give us the true data!!!
trkCcaNfCi-QStobo7aPdVZvFvdXDblLki--fcyjLN8SyxqkWD1D3Vtoq_EIDUcenTtdxjo4Me_xEFsqUXNSqyWIdfCRZmJyDUTuSCJ2-DVuc2CpaM8YvaY_qKdVDARHRNu5NtFcY4o4GtzvuQ0mQl6z8pV4Px6K2azWWjYKEvjwxOQbp4go83yv3c4


BT uses an ATS2853 chip that is also found on the BL20A.
2vDiDVTetsJRhUoZRO1JLuKh6W6FBktlJQ-_VSXz6_pxsxR_5DVatjB3bohE0iCO_uIPoQ00dHHqcWCKw3XZwxmb-Vr6w14J-TZFUmiVXzCoTcoMtwtLuusLOnSovPP1AUNOidrJpxkuIVNRLF5L0Cy_LHn_Ic6j3jgkowSZ47djyJeHo6-ZufY3qTVV



How does it sound?

I did a comparison with Onkyo RZ50 pure output mode (airplay), Aiyima T9 (BT), and the BT30D non-Pro (BT). All using RP5000F towers, with an amp selector switch.

GLUEZOAkBYGGHqFyQvOh7kjA5BbrPNcKfNsTMy4O3cZNmvNLKmA-P68ITgUwGOh21kgljt3SpF3xEkOy4aODxY1FaRcjzEBMoj2LD7vZWcdW-8rqC3xHnHWJNXEgZnaZxKOsZX3rdQiEe89BvcyyQzV6_Dr_7nBqJ94pHUYE73cefI9JazHv4L9ZmrI


Right away there’s a BIG difference between the non-Pro and the rest.

The Pro version is much more dynamic, the voices are clearer, bass is more present and punch harder.

I honestly cannot tell any audible difference between the RZ50 and the BT30D Pro. The T9 sounds only a tad warmer (thx lamp); Even that it was really hard to tell and it depends on the song being played.
The Pro version sounds definitely better than the non-Pro.

To test the passive sub output, I hooked up my gutted Z2300 logitech subwoofer, it works wonderfully and has a very capable output. However, I didn't like the sub crossover control, the adjustment doesn't feel linear. There are no frequency indications on the knob, it can only be tuned by ears.

Now the technical stuff:

The PCB: The board is very well built
AXQchWS2XoDy-Ea52QNWQhMxri4MoPLTejeX5TG63lc9ZKq25336BudprJxqJZyCgJ0ZGKnnr0atNyFVMLRFy6abi9urHRqTakbJRJlJ4j0128QEDs20kQmUU0N_IW_hljeem2q-e-Zwiru50x9myqtIGPINxrr9vjEt9_hFWyl6QQd7UtXbAl_xuSw
KO0UUM4ScJ2UfhLh0Pwt5WyN3jV8bss3a9QWODLHV_EYGWqWQ6GtiDuNM6ELe0PgKoWkL-ZBDbzr23rnoXT94kwxutHo7e5WdcgmYxD0mkckR0FqFgiUMpno8v9YCYFgXA0iNTyvhGj5ZUS8ibv8bsqeA0dzQe_lg5Bno3HGekABE4nnRKt8kdTFcQ8


Caps:
lfAL1MLd8olvZ2MIwif2JO9-H8kr5xhJa9xHGRLpfjCF46dWluIzVT_kq381H2EN-2yTCAxXXsgI4y93nfJPw_X2uaoQFPt427WdgVBwF_YiHogfghTSJ73LG1AK8BaY3VrEFxAuWY1hDIhSn9L5HJ02K9ZOvjvKXntAIdb1_2i_-BZGnTOsu5waur0


Relay: It does the click (barely audible) only during power on. Maybe that's why no more sparks.
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The muscle: TPA3255 x 2:
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rpv7Hbum--7WdOgP98OXLpH3LAwOxD7Tp4Y5gGIBzDAid1P3GdsrkTd3euBKYgxmqFHATRVk1Q2zfhR3qRJBvIkRSLVeTZusHzVVEtsc6S8z37rr6FK4SEl33cUQYMVkZsqIIy_YI2CkNj93EEDuYOGANQB865v96LiE28UeU_LB_x02-2-r0a3Y6bQ


vCp0x4beQ9jRxnTZ1ir6EGa4KFsmregb3YwwUUcPSGTXvT0bN1s9uSBFLk9DdI_d9uyree-rMUWvStjF9y9Vrs3TvtcQQ7HcRXglKU6igJwW8ifA7tMifFa1Yc2hoMj4pQXK7Q_bQBYhbUKw0KMThYi1k9I2dHy06z_kpXj_CKnyuCQXtQ3lGZ66yPc




PSU idle voltage: 32.3V
i8B62JvlzQRE5tx6r6HzpFT6ekO0ndZK26h2CzPpUGUxksMr6X9oZURFRbySUPpTflgqYsyda37TjRX0UtpxKYqPI0pxo2LzcFES4XEMAiGX_JVJZiYVF0X7y7l-HHhN_X9I4-3NAbFM5TfG7IfJ0vkE3a8BZS4wpsTT7vfn75dXv4fLAKMxKeVawF4

touhiwRgvD2-O41fGo8saPz5WQtA8GIDkjvAt2uurgbfHrbLP_jhkevOGcbVY-6rT3ZBa9T5IDzS7paAeTDEY-1kBpy7i7cYo1L_PHPnMnFK405xH6ltYBpPFoYWLsmWdYqaxbDG6c-RR-4_4NDJRnADp8Jp_mX7F56aUc6hH2p4siBWv-XR37-jE5o

Power adapter output @ 8ohm load current and voltage, 125W:
z2j2skABUomLRKUwk_V2jFbT2NE801YgmKTFAum-e82SehaI5g-OKCd1Lw617sfCLxsMNC3CB0Ty2yCn9fLiLe7v0oWOWWEQC89iYmbA3FYsOECMufasos1zlm0zg2cZ5KXQBfnlvtPTCuYFoscQenKdO30sf5gNjRjf4ktI0GPm4loY6DTHNUIEcC8

Same 32V5A adapter used for multiple models. No sparks occurred while plugging in the DC plug compared to the DA2120C I've tested, I made multiple attempts to make sure this is repeatable.
gp2O88Qf_HNzMAFvQbnCKfGvNAT8Z2NirEiPBnYyXAdRX9X77qq9g8_J4oWrh6Z1PMUlwU5rDl9zUxx9hFkiynhDyklwHyunqXfiRBIJL_s70kLHMpEmkUyxdIP_g3VY9Hbehb4RkysmOGNYw5LrUeCJVu9WqLlfl_yCzsVBpTGNnyQCap6z7Dlm_NI5



Here I am trying to figure out the max usable volume before getting a bad shaped sine wave, The volume knob is at 3 o'clock, BT reference volume maxed out on my mobile device, no EQ, no tone.

L & R Channel, 8 Ohm load, 1000hz tone, 26Wrms per channel
r9ukKHmjLXEQ5BI2LHdbYkRL2Ax5N_a-cMMpydCRVz841J9nUHg_tN0j6-BvVp29zl139PaRKBbUAwuDm9PKY5e-0EVmdX-F_CU4K3jj26nlGHeJRcib8MOn4Ps-rlN3KDFYRWHxAS1IWO_bu1iCIt0YVezYLhBgZW5MomF-oZ9dLnlF6YhPlqcP1IU


L & R Channel, 8 Ohm load, 1000hz tone, clipping at 60Wrms
oyTbv91ci_CsCcCdXfv5XfwcrPwNltyZWZ6TLoyxr98HHyZVMF7qV_AK_slp2MSTY4adD4-IWLy8PHgMxFyBQnlrNosLpkruV6DFgOjJz-PJ_U-eMbVtKKxWP3JXCUZXiII4mSIY0Kl4yJcUBEflZ0u4IHMRgmFnmpTvdI9I9lb5824DARpK-xODvUY


L & R Channel, 4 Ohm load, 1000hz tone, 40Wrms per channel
Iz3S8Mgcd2h0SFfuvCl5MQl6av4ZFfjFSlwZowZFpVC_hdOi8sjJQ6iFGvBL5G4-9FshES5tVGMxCu2hsDQNeH7qSGQQ3zoEsXgB30EnsJZaIiA_TMwkHk7kvTI8Xxf6cTMIyonJ9V2DTqVsfWEcOLoX8RMWyJEoZVy4AIn7KVjoWFc1wxfwrNPjKMI


L & R Channel, 4 Ohm load, 1000hz tone, clipping at 100Wrms
-QEqDwZ5w7HiXd5CFQb3J1BZwjgx2Fo9KKKJWO9I8NmHzWChqgf5cEwuXP9oEyRGyT7VJo7PdUXxW2UbPazU6LduzJCOLsu5JEPgrXl7brj7VNN_lvwPbplcRSvyvP6giJLOWgv08nkkqa3iKVt89YINMGne8yXs5p_lS19w3X95aQY8M500u3ygnTM




Sub channel @ 4 Ohm load, 75Wrms:
niJMOFhS5Kzhcy_34HRhyv0yPaBiundZZgBsabcO__hthkEkPs46rwxOex_Rn7coylgWZv4ZzJa9Z2yKOKF_6YY9vgH2eMkEusHyIY8trW4uqbaD_QAMhp4wosNu9hfHM4NpISUOFLRwNq2L7jJjTYYapfRJg5UiCXLv4pwQy40PQpgIx8LKVeeSDco


Sub channel @ 4 Ohm load into clipping, 121Wrms:
0W1By14JsKwSD71f5iU46KJ9tkz6SkyWrQckZEhMd9xQqtET6Jzkop9EmRo2W5c67Bgnrj3SuEPMMOcDv8EX_ypgvxWBdyQqrcHIwfEPKWu5sxaikgLFF2Hp4FNgB2EUjDL7A0g49JSXfqjWl2m9v1SCVv05kudn-dIpACguo1dyv_STyFxPV6hccY8



Noise, tested with max volume:
BT30D non-Pro, audible hiss from speakers during powerup, circuit shuts off when no input signal for 5 secs to prevent constant hissing.
jzd7aBIvEtLBElpIlZqv2uoBbProBNtBZciOHWzwY0w48TU78wa-GjTpzweYfwgeURfoQHzxLIoXiSz9v306j_ZzL-wxpkwKG6zP3ExS9xxCU_1Qy_2OKPjoMZe1736XGJLPMJOo6RpOf7d2p-SwWaX821HwMx4O9AgwcYffECOsWgiXpmhCOlAhe4w


BT30D Pro, barely audible hiss from speakers, you have to stick your ear on the tweeter to hear it. no circuit to shut off the signal, it's not needed because it is not audible sitting away from speakers.
xYv9lOP9td_kUrfMuskFLCFnWsBvGsIejAVGi1B2jAoEoIK7gk8VXBc6y_A9HefGlc1B3gja66L_u3H3hGx2sgOO1rd1GdlQcNMBv_B5vVO7cwZVV6flA8uh7x1TK1AvxUx1VcMec3b4HrqzwtaQr03B2j7I0wWnBeqqFMU3yv0SbHDHmkpZHjwu0cU




The TPA3255 chips are hungry AND efficient. If you can feed them, they will put out a respectable amount of power for its size. You can upgrade to a 36V power adapter if you are looking to squeeze more juice out of it. It seems most of the manufacturers using this chip have set the bottleneck to the power supply. If you are looking for a 2.1 amplifier with passive sub output, look no further.

The BT30D Pro is way better than the non-Pro version.


Pros:

  • Great build quality
  • Excellent sound quality, to my ear it’s on par with the Aiyima T9 and RZ50
  • Low noise floor
  • Runs cool and efficient


Cons:
  • Cannot turn BT off
  • Sub frequency needs indication and more linear tuning
  • Power limited by the power supply
  • 1" BT antenna plz
Thank you for testing and your great suggestions.

As per "Cannot turn BT off", we have try to add a switch to select BT or AUX like our Fosi Audio T20 does, but many people reported that the product was useless when it was received, but the fact is they didn't select the true input mode, do you have any ideas to solve this problem?

Sub frequency needs indication and more linear tuning
==> This is a great idea, we will consider it carefully.

Power limited by the power supply
==> We are developing such power supply and also consider to develop amplifiers with built in power supply to solve this issue. I will let you know once it is completed.

1" BT antenna plz
==> Also many people want a longer antenna, maybe I can provide different antennas to select.
 

Fosi Audio

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This would be a great amp if, and I 100% agree with you , Bluetooth could be turned off.

Also what is row of components between capacitors?

Thanks for your review, regards G
Thank you, any ideas about how to solve this problem?
Because we want to keep the front panel as neat as possible. But if I add on the back panel, then many people will ignore it.
 

Graham849

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Thank you, any ideas about how to solve this problem?
Because we want to keep the front panel as neat as possible. But if I add on the back panel, then many people will ignore it.
As above, switch to select OFF, RCA, BT or OFF, BT, RCA.

If buyers cannot select correct user mode, maybe a card on top of amp with picture of instructions. We are certainly entering the digital remote/ touchscreen age when physical switch use is unfamiliar.

However, if user is capable of connecting speakers/ subwoofer I wonder why they cannot understand input selection.

Thanks again for product development and user interaction.
 

Fosi Audio

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As above, switch to select OFF, RCA, BT or OFF, BT, RCA.

If buyers cannot select correct user mode, maybe a card on top of amp with picture of instructions. We are certainly entering the digital remote/ touchscreen age when physical switch use is unfamiliar.

However, if user is capable of connecting speakers/ subwoofer I wonder why they cannot understand input selection.

Thanks again for product development and user interaction.
Thank you, it's really helpful, we will consider your suggestion carefully.
 

Toku

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It is very disappointing to see that the volume pot for volume control still uses a taper B 50kΩ.
It is common sense in audio technology to use a taper A for the volume pot for volume control.
Manufacturers such as AIYIMA have gradually been modified to use Taper A.
 

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It is very disappointing to see that the volume pot for volume control still uses a taper B 50kΩ.
It is common sense in audio technology to use a taper A for the volume pot for volume control.
Manufacturers such as AIYIMA have gradually been modified to use Taper A.
This might also be the reason of crossover that is not linear and hard to tune.
 

Fosi Audio

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It is very disappointing to see that the volume pot for volume control still uses a taper B 50kΩ.
It is common sense in audio technology to use a taper A for the volume pot for volume control.
Manufacturers such as AIYIMA have gradually been modified to use Taper A.
Thank you so much for pointing it out, I have forwarded to our R&D department.
 

Fosi Audio

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It is very disappointing to see that the volume pot for volume control still uses a taper B 50kΩ.
It is common sense in audio technology to use a taper A for the volume pot for volume control.
Manufacturers such as AIYIMA have gradually been modified to use Taper A.

Our R&D responsed Taper A will go up exponentially, and taper B will go up slowly at first and faster in the middle and will go slowly again in the end.

So do you think it is better to go up exponentially?
 
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