PCM board and tda1541 up and running
I finally got around to working on my tda1541a board yesterday to incorporate the PCM board. My dac board is a diy veroboard tda1541a with 74HC175 for reclocking and 74HC4040 for BCK division for dem clock, based on Thorsten's many recommendations and suggestions. A WaveIO provides the I2S, using the u.fl output.
I removed both ICs and reconfigured the dem clock with a 2.2nF capacitor and redid the I2S attenuation for 3.3v signals, and changed pin 27 to -5v.
The PCM board is powered by the supply that previously powered the 74HC175.
After two days of work, including hot air rework soldering for the first time (u.fl connectors to the PCM board), and a few hours of trouble shooting bad solder connections of the micro sized coax cables to the dac board (an old analog oscilloscope sure helped), music is finally playing.
Even with a tda1541 (non-a chip) for testing, music feels more alive. I tried some 192 kHz music but the sound was not clear. After some research, I found that the non-a chip only does 4x oversampling so 176 kHz is the maximum frequency.
I will be reinstalling my tda1541a single crown tomorrow and I will try 192 kHz again.
Next, install the fifo and dual clock board and isolator.
Thank you, Ian, for making this possible.
Ben
I finally got around to working on my tda1541a board yesterday to incorporate the PCM board. My dac board is a diy veroboard tda1541a with 74HC175 for reclocking and 74HC4040 for BCK division for dem clock, based on Thorsten's many recommendations and suggestions. A WaveIO provides the I2S, using the u.fl output.
I removed both ICs and reconfigured the dem clock with a 2.2nF capacitor and redid the I2S attenuation for 3.3v signals, and changed pin 27 to -5v.
The PCM board is powered by the supply that previously powered the 74HC175.
After two days of work, including hot air rework soldering for the first time (u.fl connectors to the PCM board), and a few hours of trouble shooting bad solder connections of the micro sized coax cables to the dac board (an old analog oscilloscope sure helped), music is finally playing.
Even with a tda1541 (non-a chip) for testing, music feels more alive. I tried some 192 kHz music but the sound was not clear. After some research, I found that the non-a chip only does 4x oversampling so 176 kHz is the maximum frequency.
I will be reinstalling my tda1541a single crown tomorrow and I will try 192 kHz again.
Next, install the fifo and dual clock board and isolator.
Thank you, Ian, for making this possible.
Ben
Hey Ben,
Good to know, looking forward to a TDA1541 implementation myself. Reading the datasheet, the chip will only go to 176 regardless of a/non a from what I see. I need to read the manual again but havent as I misunderstood a need to update the fifo, Ian has kindly assisted with this and with much patience!
I want to play with this muchly, but I would recommend getting it operating on the non a with the fifo etc so you dont smoke the a chip accidentally. Have a mate who smoked an S2......he wasnt happy about that. ....
Good to know, looking forward to a TDA1541 implementation myself. Reading the datasheet, the chip will only go to 176 regardless of a/non a from what I see. I need to read the manual again but havent as I misunderstood a need to update the fifo, Ian has kindly assisted with this and with much patience!
I want to play with this muchly, but I would recommend getting it operating on the non a with the fifo etc so you dont smoke the a chip accidentally. Have a mate who smoked an S2......he wasnt happy about that. ....
further tda1541a 192kHz
I tried 192kHz material with the tda1541a single crown installed today and the same result as with the tda1541 non-a -- noise with music at low volume in the background. Looking back, the non-a probably should also be able to play 192kHz material as 4x48kHz=192kHz.
I checked the PCM board output on the 'scope and the CLK was approximately 5v and the rest at 3.3v. I did not attenuate the CLK at the dac, and the rest of the output is attenuated to approximately 1v at the dac. 44.1kHz and 96kHz music plays fine, but 192kHz does not. At 192kHz, the CLK waveform did not look as good as at the lower frequencies. I don't know if this is due to my old 20 mHz analog scope and cheap probe or due to other issues, or whether this is the cause of the 192kHz playback problem. Or is the signal level at the dac too low at approximately 1v? It does work at the lower frequencies at 1v though.
Just an observation - when I had the WaveIO feeding I2S directly to the dac, I tried 192kHz material and the audio output sounded exactly like it does now with the PCM board in place.
I did not have any 176kHz material to check to see if that works.
At this point, I'm inclined to just leave it as is since I don't have much 192kHz material. I'm wondering though whether the 5v CLK is normal.
Ben
I tried 192kHz material with the tda1541a single crown installed today and the same result as with the tda1541 non-a -- noise with music at low volume in the background. Looking back, the non-a probably should also be able to play 192kHz material as 4x48kHz=192kHz.
I checked the PCM board output on the 'scope and the CLK was approximately 5v and the rest at 3.3v. I did not attenuate the CLK at the dac, and the rest of the output is attenuated to approximately 1v at the dac. 44.1kHz and 96kHz music plays fine, but 192kHz does not. At 192kHz, the CLK waveform did not look as good as at the lower frequencies. I don't know if this is due to my old 20 mHz analog scope and cheap probe or due to other issues, or whether this is the cause of the 192kHz playback problem. Or is the signal level at the dac too low at approximately 1v? It does work at the lower frequencies at 1v though.
Just an observation - when I had the WaveIO feeding I2S directly to the dac, I tried 192kHz material and the audio output sounded exactly like it does now with the PCM board in place.
I did not have any 176kHz material to check to see if that works.
At this point, I'm inclined to just leave it as is since I don't have much 192kHz material. I'm wondering though whether the 5v CLK is normal.
Ben
Hey Ben,
To try 176, try using Audiogate by Korg to downsample, if you have dbpoweramp you could use that too. The only thing im thinking is the clock is 22Mhz for a 44.1 sample rate family, rather than the 24Mhz for the 48 Khz family.
No idea if that helps, praps a photo of your setup wwithIans board?
Cheers,
Drew.
To try 176, try using Audiogate by Korg to downsample, if you have dbpoweramp you could use that too. The only thing im thinking is the clock is 22Mhz for a 44.1 sample rate family, rather than the 24Mhz for the 48 Khz family.
No idea if that helps, praps a photo of your setup wwithIans board?
Cheers,
Drew.
PCM waveforms
Continuing with my 192kHz tda1541a non-performance, I have attached some shots of the PCM signals at the dac chip input pins for 44, 96, and 192 kHz. Approximate calculated CLK frequencies from the scope are 2.8 mHz for 44 kHz, 6.0 mHz for 96 kHz, and 12.5 mHz for 192 kHz. The vertical scale is 1v/division and the horizontal scale is 2uS/division, except for the large CLK images the scale is .1uS/division. The scope is 35 MHz, not 20 MHz as previously mentioned. The picture titles give descriptions of the waveforms.
The CLK waveforms appears to ok to me, but I don't know much about digital so if anyone has a comment, please let me know. The frequencies also appear in the ballpark to me.
As noted before, the CLK is not attenuated at all and it appears to be approximately 5 v peak to peak. The unattenuated LLLR and DL and DR (no pictures) are approximately 3.3 v and their attenuated value at the dac chip is approximately 1v as shown in the pictures.
I also upgraded the WaveIO firmware to the latest and tried playing the 192kHz material again, but no success. The WaveIO also has its own power supply capable of supply more than .5A so power should not be an issue.
Ben
Continuing with my 192kHz tda1541a non-performance, I have attached some shots of the PCM signals at the dac chip input pins for 44, 96, and 192 kHz. Approximate calculated CLK frequencies from the scope are 2.8 mHz for 44 kHz, 6.0 mHz for 96 kHz, and 12.5 mHz for 192 kHz. The vertical scale is 1v/division and the horizontal scale is 2uS/division, except for the large CLK images the scale is .1uS/division. The scope is 35 MHz, not 20 MHz as previously mentioned. The picture titles give descriptions of the waveforms.
The CLK waveforms appears to ok to me, but I don't know much about digital so if anyone has a comment, please let me know. The frequencies also appear in the ballpark to me.
As noted before, the CLK is not attenuated at all and it appears to be approximately 5 v peak to peak. The unattenuated LLLR and DL and DR (no pictures) are approximately 3.3 v and their attenuated value at the dac chip is approximately 1v as shown in the pictures.
I also upgraded the WaveIO firmware to the latest and tried playing the 192kHz material again, but no success. The WaveIO also has its own power supply capable of supply more than .5A so power should not be an issue.
Ben
Attachments
If it helps, i could add some waveforms of my running Red Baron DAC this weekend.
Just tell me what waveforms you would like to have.
Cheers,
Oliver
Thanks, Oliver. The reason I posted the waveforms was to see if anyone sees anything wrong with them since I cannot get my WaveIO-PCM board- tda1541a dac to play 192kHz material. 44 and 96 kHz work and sound great but 192kHz is noise with very low level distorted sounding music in the background.
Right now I am wondering about the 5v CLK. The CLK seems high since the PCM board is supposed to output 3.3v as I understand it.
I am attenuating the LLLR, DL, and DR with 1k ohm in series to the dac input and 680 ohm pull down to ground and 1k ohm up to +3.3v supply. The level at the PCM board is 3.3v and the level at the dac chip input is approximately 1v. Right now I am wondering if that is too low.
Ben
I may try decreasing the attenuation tomorrow. I'm not worried about toasting the chip though as the attenuation is for performance, not safety. The measured 1v may too close to the threshold at the higher frequency although it works at the lower frequencies.
Ben
Ian,
Sorry to jump in with a couple of questions:
1 - Did you connect the TDA1541 board to your system?
2 - Were you running it in NOS?
3 - What if any were the audible improvements at higher speed(s)?
Thanks,
Gary
Hi Ian,
Thanks for your help.
Yes, I did try half speed, which worked at 96kHz and lower but did not work for 192kHz.
I have read all of the forum posts and did read your post re:tda1541a and 384kHz. My understanding of that is you could not get it to work with the WaveIO but could get it to work with the Amanero. Did you get it to work with the WaveIO later on?
I also read Merlin el Mago's posts about his problems with his WaveIO-PCM board-1704 dac not able to work above 96kHz also. I couldn't find anything about whether he finally got it to work or not.
But a common thread appears to be the WaveIO, as I am also using the WaveIO.
Ben
Hi Gary,
I only have TDA1541A, so not sure what is the maximal Fs TDA1541 can achieve.
2. I ran TDA1541A at NOS mode with simultaneous input (driven by PCM board).
3. I didn't notice any audible difference between full/half speed mode. But theoretically full speed mode comes with lower noise from digital signals. However, half speed can make DAC running at higher Fs
.Hope your are receiving your board soon.
Regards,
Ian
Hi Ben,
Yes, you may already get the point. But I still have no time to address this issue. I suspect it's a source timing related problem at higher Fs .
But even with WaveIO, I didn't have any problem at 192KHz.
Another thing I need to mention is that half-speed mode makes DAC running at higher Fs. Because half-speed make the timing of DAC not that 'tighten'. Please reference to the link below for my PCM board jumper setting running at 384KHZ. I think you could have no problem at 192KHz with the same jumper setting.
http://www.diyaudio.com/forums/digi...rsal-i2s-pcm-driver-board-53.html#post3621653
Regards,
Ian
From you waveforms, CLK signal looks good, but LLLR and DL, DR are definitely too low(compare with CLK), did you measure them with same probe?
Try to measure those PCM signals again with/without load (TDA1541A) to see it that is a load related problem. Probe set at X10.
Good luck
Ian
Hi Gary,
I only have TDA1541A, so not sure what is the maximal Fs TDA1541 can achieve.
2. I ran TDA1541A at NOS mode with simultaneous input (driven by PCM board).
3. I didn't notice any audible difference between full/half speed mode. But theoretically full speed mode comes with lower noise from digital signals. However, half speed can make DAC running at higher Fs
Hope your are receiving your board soon.
Regards,
Ian
Ok - interesting to hear about your observations on impact to sound. Looks like package is on the way, thanks again Ian.
Hi Ian,
The PCM signals appear low at the dac chip pins because of a signal attenuation circuit that I described in post #608, which had been used in the past by ecdesigns. I measured the signal at the PCM board output with the 1541a attached and they were between 3 and 4 volts, so I don't think it is a load problem. The signals are reduced by the attenuation circuit, and appear about right for the component values of the circuit.
I will take out the attenuation circuit in the next few days when I take the setup apart to install the fifo and see if 192kHz works. I will turn my one box dac into a two box dac in order to fit all of the fifo/ isolator/dual clock/PCM boards and power supplies. Then it will be easier for me to remove and replace the tda1541a board in order to make changes.
Ben
Ben,
We are on the same sort of path.. I have had the WaveIO working well with TDA1541A and also then with FIFO, ISO and Dual XO in-between - which was a nice improvement. I have the I2S > PCM board at hand and just finalising to install (need to build a new discrete 5V supply, parts on hand but little free time). IIRC Ian had WaveIO and 1541A running PCM at 35x.xx with WaveIO source with no problem.
Shane
We are on the same sort of path.. I have had the WaveIO working well with TDA1541A and also then with FIFO, ISO and Dual XO in-between - which was a nice improvement. I have the I2S > PCM board at hand and just finalising to install (need to build a new discrete 5V supply, parts on hand but little free time). IIRC Ian had WaveIO and 1541A running PCM at 35x.xx with WaveIO source with no problem.
Shane
Total 134
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JustBuildLspkAS.x3 &1 fifo kit finished for pcm1704 (ihave AD1862 ,pcm63,pcm1704)
54: PET-240 2 * TDA1541
TonyB
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brettlb x 2
Gogi x1
TV Man x 2
merlin el mago
rtd
jameshillj
erin x1 (or 2)
Nikola Krivorov x1
Rupor54
vitalica
analog_sa x 1
andrea_mori x 5
dsavitsk
tagheuer
hirez69 x 2
ccliu x 2
BDL
cddumat
regal x 2
zoran
Jogi
Zen(zenelectro) x 2
Buzzforb
SPWON
crobbins5421 X 2
marcus1 x1 (or 2)
casshan x 2
Dweeb99 X 2
jackw X 2
kazap X 2
danzup x 3
Giordano x2
Tony_T
Tubo x1
clivem x2
noizas x4
JoeyDD x2
skullaudio
dinos8746 x2
dvb-projekt
bisesik x2
guglielmope x1
Valeriano x1
mhgawel x1
av-trouvaille x 1 (or 2)
iloveswan x1
dtses
Flyboi X1
Lil' Knight x1 (or 2)
skippyboy x1
acccruz x1 (or 2)
WhiteBull x1
hksidney x 1
vts2006 x 3
JustBuildLspkAS.x3 &1 fifo kit finished for pcm1704 (ihave AD1862 ,pcm63,pcm1704)
54: PET-240 2 * TDA1541
TonyB
damohpi x1
iloveswan x 1
Joseph K x 2
mefistofelez x2 (pcm63P)
JLOP x1 (WaveIO, AD1865 NOS SRPP)
sceglar x1
4me2ctv x 1
tubesguy x 1
ctrange x 1
spm x 1
Joonas x1
Loboone x 1
flowerpot x 1
pavelal x 1
Steve Ha x 1
new2hifi x 1
Superdad x 1 (WaveIO, PCM1704K, discrete I/V)
Greg Stewart x 1
panther5429 x 1
supra x 3
Clsidxxl x 1
Uchi Deshi x 1
kvl x 1
palmito x 1
davej x 1
crowlie x 1
WhiteBull x2 (and one Dual XO Board, in case ones left)
nedi x 1
gonmar x 1
LuisMCP x 1
chansiukwing x 2
tassosk x 1
NATDBERG x 2 (NOS dual differential 2x D20400 project, NOS 384KHz TDA1541A project later)
Jcastellano x1
Marek x1
SVStube x 3
mksung x 1
JimS x 2
brettlb x 2
Gogi x1