OK, i made a firmware modification for my relais volume control in BZLS, for individual volume settings of each of both sources. One source is the balanced TDA1543 test DAC with passice I/V. Other source is the build in DAC of CD PRO 2. I have a cable - remote (switch) to tell the PIC to change sources and set right volume. Volume is adjusted for same level. Now for listening.
The balanced AD1865N-K DAC with D1 stage will be something special - i hope. But before that one comes the balanced TDA1541A DAC in rev a) passive I/V and rev b) D1 stage....
The balanced AD1865N-K DAC with D1 stage will be something special - i hope. But before that one comes the balanced TDA1541A DAC in rev a) passive I/V and rev b) D1 stage....
In the circuit diagramm simply 2 lines are shortet accidently. They shoud not.
The TDA1543 DAC seems to be noisier than the TDA1305. Thus it pretends to sound a little brighter.
I did expect more sonic difference.
The TDA1543 DAC seems to be noisier than the TDA1305. Thus it pretends to sound a little brighter.
I did expect more sonic difference.
OK, i can´t get out of this TDA1543 thing real voltage. I put pots as Rref and Ri/v in one noninvertet DAC. Voltage is fixed 5V, with more i got more THD. I played with those pots while measuring. Signal Sine 1kHz 0dB. I got 40mV RMS, with more more THD.I got Ri/v 1,2k, Rref must be lower than 400R, this picture is Rref at 320R. could be lower, at > 400R Vout climbs drastically but Also THD...
The inverted DAC with 74HCT04 has much more noise floor than the noniverted. Suggestions?
The inverted DAC with 74HCT04 has much more noise floor than the noniverted. Suggestions?
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till said:
Put non-inverting buffers in the SCK and WS lines.
The inverter in the data line makes delay and maybe the chip don't like it.
The poor THD in general is because it's a
economy
el cheapo
low quality
bad THD performance
DAC chip.
See the datasheet for details
i read it, i know - you know all those people claiming TDA1543 is the best sounding DAC and LM3875 the best sounding amplifier? I suspect the best sounding is the easiest tom use.
I want to get it wotking with this 75Cent chip before testing more expensive TDA1541. Its a bit expensive to burn 1541 in experiments.
I don´t understand those resistors all the 1543DAC builders use and the voltage output they claim. For more voltage i need larger reaistor also on Rref and THD goes up. With 5V i can not get better results and more than those few ten mV as in the screenshot.
till said:
Maybe:
The dac's are not equal: swap them and measure again. Or
The neg dac gets a little dc offset on it's output (the lsb issue).
Maybe it does not like the dc component (it is there before the cap). Or do you measure the dc as noise (where are your probes connected?).
Greetings,
Till,
try 1kHz sine with -30dB or -40dB...
The 1543 gets even worse then, according to datasheet.
try 1kHz sine with -30dB or -40dB...
The 1543 gets even worse then, according to datasheet.
I have some problem going too low because of the limitet v of soundcard. Also, these speacs can´t be taken absolute - 5m cable and i don´t know about the quality of a cheap soundcard in a diy noisy computer.
off topic
For the 1541, can I connect digital and analog ground to the groundplane, or is it better to have separate grounds if the analog and digital PSUs are already separate ?
For the 1541, can I connect digital and analog ground to the groundplane, or is it better to have separate grounds if the analog and digital PSUs are already separate ?
there was a digital IC grounding thread last days, experts seem to have different opinions on this.
What setup do you build with TDA1541? circuit?
What setup do you build with TDA1541? circuit?
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