In addition to this thread:
http://www.diyaudio.com/forums/clas...bluetooth-speaker-protection-eq-any-good.html
I just bought one of these boards to measure how they'll do and got a v2.2.
Sticking down a heatsink like this is rather useless. Anyway, cleaning the snot off:
Listening to this amp reveals a slight "hiss" of HF/RF interference when having a stream connected and muted or having quiet passages in the music/sound.
From the other thread:
Point 2 is fixed now.
As the noise is independent from the CSR's digital volume level, the hiss is suspected to come from the link between the CSR8635 module and the TPA3116 itself and/or most likely from the power supply design.
Sanwu decided to do a Differential 2 Single-Ended Conversion to feed the TPA3116, why ever, as shown here
Having a direct differential link is all it needs to be dead quiet, so more hiss/noise.
The populated coupling caps are 4.7uF in 0603, most likely X5R 6.3V, so with 32dB gain and 15k input impedance, the f3 frequency will be at 2.3Hz. Changing them for 1uF X7R would give 10.6Hz, still low enough for normal listening.
Another benefit is the now lowered quiescent current.
Before the mod:
Idle without Link (aka TPA3116 shut down): 20mA
Connected to a device and lowest volume level: 50mA
After the mod:
Idle without Link (aka TPA3116 shut down): 15mA
Connected to a device and lowest volume level: 45mA
http://www.diyaudio.com/forums/clas...bluetooth-speaker-protection-eq-any-good.html
I just bought one of these boards to measure how they'll do and got a v2.2.
Sticking down a heatsink like this is rather useless. Anyway, cleaning the snot off:
Listening to this amp reveals a slight "hiss" of HF/RF interference when having a stream connected and muted or having quiet passages in the music/sound.
From the other thread:
I have the same board since december and it is a disappointment in several aspects:
1) poor connectivity
2) hiss
3) unresponsive buttons
4) loud beeps when pairing and pushing buttons
5) no sound until a button is pressed
maybe you were lucky to receive a "first run" board
Point 2 is fixed now.
As the noise is independent from the CSR's digital volume level, the hiss is suspected to come from the link between the CSR8635 module and the TPA3116 itself and/or most likely from the power supply design.
Sanwu decided to do a Differential 2 Single-Ended Conversion to feed the TPA3116, why ever, as shown here
Having a direct differential link is all it needs to be dead quiet, so more hiss/noise.
The populated coupling caps are 4.7uF in 0603, most likely X5R 6.3V, so with 32dB gain and 15k input impedance, the f3 frequency will be at 2.3Hz. Changing them for 1uF X7R would give 10.6Hz, still low enough for normal listening.
Another benefit is the now lowered quiescent current.
Before the mod:
Idle without Link (aka TPA3116 shut down): 20mA
Connected to a device and lowest volume level: 50mA
After the mod:
Idle without Link (aka TPA3116 shut down): 15mA
Connected to a device and lowest volume level: 45mA
Attachments
-
SANWU_TPA3116_CSR8635_V2.2_1_1024.jpg151.6 KB · Views: 4,924
-
SANWU_TPA3116_CSR8635_V2.2_2_1600.jpg403.4 KB · Views: 4,799
-
SANWU_TPA3116_CSR8635_V2.2_4_1600.jpg431.6 KB · Views: 4,567
-
SANWU_TPA3116_CSR8635_V2.2_4_Orig_1600.jpg432.9 KB · Views: 4,501
-
SANWU_TPA3116_CSR8635_V2.2_4_NoiseFix.jpg477.8 KB · Views: 4,517
Last edited: