Is LM4562 good for DAC output?

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#22
galouche said:
I'm waiting for your feeling about the opa2134 ... 🙂 I'm building a pcm1794 multi dac but don't know exactly wich opa choose ...

un compatriote ... 😉
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2134 is a great op-amp with again a long life for it. ;-)

New updated version of the Tag AV32R circuit. General clean-up.

Advice welcome to adapt the circuit for a LM4562 at DAC output. Currently, high frequency are too present. Guitar, cymbal, clavecin are bad. Vocals, piano, organ wonderful.

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#23
Try replacing the 10uF tantalums with ordinary electros. Tantalums seem to have a similar effect to ceramic bypass capacitors. They often make HF sound "metallic".
IMHO, you shouldn't need tantalum or ceramic in that area UNLESS there are fairly long supply tracks from the VREGS.
Even the AD8066, which the makers tell you to use 100n ceramic (or equivalent) bypass caps for stability, sound much better with ordinary 100n polyester close to the supply pins PROVIDED that the VREGS are close by.
If you have LM317/337 VREGS, try replacing the usual 10uF "adjust" electro with a 10uF tantalum, and listen to the result. Definitely NOT an improvement in SQ normally. Same with low esr electros too.
SandyK
 
#24
stef1777 said:
The end for today. Complete version from DAC to output with all the stages.

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Perhaps controversial, but if it were me, I'd isolate the bypass caps from the 12.5V PSU by a resistor. The more the better.

My thought is the PSSR starts to deteriorate at high frequencies, so I filter it. Say with a 100ohm resistor into your 10uF bypass that at least filters out stuff above 160Hz at 6dB per octave.
Keeps right and left from talking to each other....
You do get a bit more potential ripple but only do to what that op amp is doing.

I do see that your using the dual for both Right and left, so maybe the benifit is marginal. It can alway be a zero ohm though.

Good Luck

Mike
 
#27
Portlandmike said:

Perhaps controversial, but if it were me, I'd isolate the bypass caps from the 12.5V PSU by a resistor. The more the better.
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If I don't say a mistake, you built a snubber. One question, do we need one resistor for each opamp close to the pins, or one for all the +-15v PSU somewhere in the circuit (where we find the right space).

Do we need to use a non inductive resistor or what we found?

Stef...
 
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