Hi,
I made a zero oversampling dac with CS8412 and TDA1541A S1 chips and transformer output stage. The problem I have is, that when started cold there is no sound at all in the beginning, then it is very distorted for about 3 minutes and then it is OK. If I turn it on for a few minutes and then start playing music it is also OK. I have preregulated the positive and negative rails with 7805 and 7918 regulators and each power supply is then regulated with TL431. Has anybody else experienced such problems and what did you do to correct this?
Best Regards, Saso
I made a zero oversampling dac with CS8412 and TDA1541A S1 chips and transformer output stage. The problem I have is, that when started cold there is no sound at all in the beginning, then it is very distorted for about 3 minutes and then it is OK. If I turn it on for a few minutes and then start playing music it is also OK. I have preregulated the positive and negative rails with 7805 and 7918 regulators and each power supply is then regulated with TL431. Has anybody else experienced such problems and what did you do to correct this?
Best Regards, Saso
Saso said:
Mmm
First a 7805 and then TL431 also set to regulate to 5 Volts??
Think the 7805 then needs to be a bit higher, use a 7806 or put a diode or led between ground pen and ground. This lifts the output also with 0.6 to 1.2 volts.
GuidoB
I've seen this before.
Make sure the CS8412 is set to the correct mode. It needs to be in Output I2S mode like this:
M0(pin 23) = gnd
M1(pin 24) = +5V
M2(pin 18) = gnd
M3(pin 17) = gnd
Make sure the CS8412 is set to the correct mode. It needs to be in Output I2S mode like this:
M0(pin 23) = gnd
M1(pin 24) = +5V
M2(pin 18) = gnd
M3(pin 17) = gnd
Did you check the voltages with a scope?
BTW Where did you get the S1s from? (and at which price?)
Cheers
Andrea
BTW Where did you get the S1s from? (and at which price?)
Cheers
Andrea
to guido:
Sorry, the positive preregulator is 7809 and not 7805 as I wrote before.
to headshot:
Would I hear anything at all if the mode wasn't set correctly?
Because now when I turn it on I can hear the music in the noise and then after a few minutes the converter plays well, with no noise. In this period of a few minutes I can hear the noise changing and music getting louder and louder until all gets well and the noise is gone.
to andypairo:
Unfortunately I don't have a scope🙁 , but I guess I'll have to find someone who has one.
I bought the S1 at a small electronic components store here in Ljubljana and if I remember correctly the price was around 5 or 6 Euros.
to all:
Do you think the problem could be due to a ground scheme. The dac as it is now is three boards, one with the rectifiers and preregulators then connected to another board with TL431s and this then connected to the dac board. Ground connections between the boards are just a piece of wire. Earth connection on the power input plug isn't connected yet, just line and neutral to the power transformer.
Thanks for your answers.
Best Regards, Saso
Sorry, the positive preregulator is 7809 and not 7805 as I wrote before.
to headshot:
Would I hear anything at all if the mode wasn't set correctly?
Because now when I turn it on I can hear the music in the noise and then after a few minutes the converter plays well, with no noise. In this period of a few minutes I can hear the noise changing and music getting louder and louder until all gets well and the noise is gone.
to andypairo:
Unfortunately I don't have a scope🙁 , but I guess I'll have to find someone who has one.
I bought the S1 at a small electronic components store here in Ljubljana and if I remember correctly the price was around 5 or 6 Euros.
to all:
Do you think the problem could be due to a ground scheme. The dac as it is now is three boards, one with the rectifiers and preregulators then connected to another board with TL431s and this then connected to the dac board. Ground connections between the boards are just a piece of wire. Earth connection on the power input plug isn't connected yet, just line and neutral to the power transformer.
Thanks for your answers.
Best Regards, Saso
Hi saso
I had a friend who built a CS8414 TDA1543 DAC and his mode was set incorrectly. When he turned it on, there was a lot of noise, then after a moment, the noise gradually went away and the music came through completely. This is exactly what you're describing. So check the mode.
I had a friend who built a CS8414 TDA1543 DAC and his mode was set incorrectly. When he turned it on, there was a lot of noise, then after a moment, the noise gradually went away and the music came through completely. This is exactly what you're describing. So check the mode.
I checked the mode and it is set correctly.
The weird thing is if I turn the dac on and wait for a few minutes and then start playing it sounds good immediately.
BR, Saso
The weird thing is if I turn the dac on and wait for a few minutes and then start playing it sounds good immediately.
BR, Saso
It seems like a oscillation in the power supply.
Doede Douma also had it (he uses a LT1085 in his TDA1543 DAC), and managed to eliminate it adding more capacitance to the output of the regulator (100 uF) making it stable.
I'd suggest changing the pre regulator to LM317 and see if things change.
PS Can you buy other TDA1541A-S1 in your local shop (at that price?)
Cheers
Andrea
Doede Douma also had it (he uses a LT1085 in his TDA1543 DAC), and managed to eliminate it adding more capacitance to the output of the regulator (100 uF) making it stable.
I'd suggest changing the pre regulator to LM317 and see if things change.
PS Can you buy other TDA1541A-S1 in your local shop (at that price?)
Cheers
Andrea
Thanks for the info. I will check this.
I got two more TDA1541A, no crown versions, but that will probably be it. The price was 5 euros, let me know if you are interested.
I got two more TDA1541A, no crown versions, but that will probably be it. The price was 5 euros, let me know if you are interested.
I wold be also interested in the crown version...
i am a student and i live in a little city in italy where is even impossible to get the regular one....
i am a student and i live in a little city in italy where is even impossible to get the regular one....
Saso said:
Hi Saso,
Seems a locking problem to me. Are both supply voltages present on the CS8412 and is ground connection OK?😎
Yes, the voltages are present. If I leave it on for some time without connecting the transport and then connect the transport it locks immediately and starts playing. If I turn it on without connecting the transport and turn the volume on amplifier up I can hear strange very loud noises which then suddenly stop (after about a minute or two) and everything is OK.
The DAC is constructed on 3 separate prototype boards. I am using copper foil as ground on each of them and every board is then connected with a piece of wire to earth tag on IEC connector.
To others:
I will check if they'll get any more crown version dacs, however I don't think it is very likely. I will let you know if that happens.
Best Regards, Saso
The DAC is constructed on 3 separate prototype boards. I am using copper foil as ground on each of them and every board is then connected with a piece of wire to earth tag on IEC connector.
To others:
I will check if they'll get any more crown version dacs, however I don't think it is very likely. I will let you know if that happens.
Best Regards, Saso
Problem
Hi Saso,
Maybe a reset after power on will help.
http://java.audioasylum.com/cgi/m.pl?forum=tweaks&n=64677&highlight=elso+reset&r=&session=
Hey, that's funny is this the same Saso on AA?
Did you implement the reset circuit?😉
Hi Saso,
Maybe a reset after power on will help.
http://java.audioasylum.com/cgi/m.pl?forum=tweaks&n=64677&highlight=elso+reset&r=&session=
Hey, that's funny is this the same Saso on AA?
Did you implement the reset circuit?😉
Yes, I am the same Saso🙂
and no, I didn't implement the reset circuit. It
seems to work without it.
I think I have made some progress now. I put two
switches in, one for the positive and one for the negative
power supply. When I switch the positive off and on, it all
works perfectly from the get go. But if I switch off the negative
supply and then turn it on again, I get distortion. The negative
supply is used for -15 and -5V on TDA1541A. I think I will be redesigning it for the LM337 regulator. I do not trust that 7918 part, I already had one faulty and maybe this one is bad too.
Best Regards, Saso
and no, I didn't implement the reset circuit. It
seems to work without it.
I think I have made some progress now. I put two
switches in, one for the positive and one for the negative
power supply. When I switch the positive off and on, it all
works perfectly from the get go. But if I switch off the negative
supply and then turn it on again, I get distortion. The negative
supply is used for -15 and -5V on TDA1541A. I think I will be redesigning it for the LM337 regulator. I do not trust that 7918 part, I already had one faulty and maybe this one is bad too.
Best Regards, Saso
Since you're using TL431's, I would check you're not starving the TL431 for current, that is, supplying enough current by either your current source or series resistor.
Check the -15V is really measuring -15V and not something like -8V or so. This will result in the internal DEM circuit not working correctly, lot of hiss and distortion.
Try increasing the current a bit.
Check the -15V is really measuring -15V and not something like -8V or so. This will result in the internal DEM circuit not working correctly, lot of hiss and distortion.
Try increasing the current a bit.
Thanks, I will check this. When I measure the voltage, I get -14.7 V.
Do you think this means that I am not supplying enough current?
Best Regards, Saso
Do you think this means that I am not supplying enough current?
Best Regards, Saso
Newbie question 
does too much amperes kill composants ?
For example, 300mA up to 700mA are required for a composant according to its datasheet.
The regulated PSU provides 2A.
Will the composant explose ? Do I need a resistor to level down the ampers after the regulated PSU ? In that case, do I use the 300mA or 700mA to compute the resistor value ?
does too much amperes kill composants ?
For example, 300mA up to 700mA are required for a composant according to its datasheet.
The regulated PSU provides 2A.
Will the composant explose ? Do I need a resistor to level down the ampers after the regulated PSU ? In that case, do I use the 300mA or 700mA to compute the resistor value ?
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