Hi,
does anyone knows tested low noise tested circuit? I want updgrade Bmw HIFI Logic 7 amp. Problem is engine noise if I connect direct RCA on TDA8566Q balanced input. So I decide build low noise pream wich will convert balanced to unbalanced signal.
I dont want to use audio processor is too expensive, Hi-Low converters I dont like too (poor audio quality), so I think the best solution make converter.
There is one big problem, preamps using dual PSU in Logic 7 single... Maybe I`am not right cause I get balanced output from digital section to TDA8566Q?
I did some drawings LOGIC7 - Image on Pasteboard
TDA8566Q input impedance 120Kohm by datasheet.
THANK YOU!!
does anyone knows tested low noise tested circuit? I want updgrade Bmw HIFI Logic 7 amp. Problem is engine noise if I connect direct RCA on TDA8566Q balanced input. So I decide build low noise pream wich will convert balanced to unbalanced signal.
I dont want to use audio processor is too expensive, Hi-Low converters I dont like too (poor audio quality), so I think the best solution make converter.
There is one big problem, preamps using dual PSU in Logic 7 single... Maybe I`am not right cause I get balanced output from digital section to TDA8566Q?
I did some drawings LOGIC7 - Image on Pasteboard
TDA8566Q input impedance 120Kohm by datasheet.
THANK YOU!!
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I forgot to mention signal output to TDA8566 is from balanced DAC AD1833ACST (Full-Scale Output Voltage at Each Pin (Single-Ended)1 (2.8)V rms (V p-p))
So my question how to connect rca from dac output with minimal noise?
So my question how to connect rca from dac output with minimal noise?
I think I found a solution pls look my drawing. I will add balanced to unbalanced converter ( GHXAMP NE5532 Balanced XLR to Single ended RCA Output Dual op amp circuit board small size low distortion low noise|Amplifier| - AliExpress ) inside aftermarket amp. Maybe I will tune aftermarket amp and do not buy converter, depends what preamp circuit inside. Than power up converter from dual PSU. But now main problem L7 SGND and GND is the same signal. In aftermarket amp SGND and GND are separate signal lines, I`am confuse what I should to do...??? It will get huge interference...
My drawing: L7 - Image on Pasteboard
My drawing: L7 - Image on Pasteboard
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The schematic looks reasonable (but no decoupling?), but those Signetics marked 5532's don't look like mine (1980's originals), and will be junk I fear.
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Thank you. NE5532 will be fake 100% but I am not worry I have OEM. I am worry what will be with interference.. SGND/ GND not he same signal lines.
Very good information about balanced-to-unbalanced circuits from DIY audio guru extraordinaire Rod Elliott:
Balanced I/O
Balanced Transmitter and Receiver II
Balanced I/O
Balanced Transmitter and Receiver II