We can, the power supply is just as important for SQ of the Ultimate-nos-dac-... as anything else.
I'm sorry guys, I didn't realize that John (EC Design) is also using batteries. I want to apologize...
50Hz DEM adapter
On my diy dac board, there was no room to install some and/or no access for connections of the 100uf capacitors. After some thought, I came up with an adapter which incorporated the 14 100uf capacitors and the one 1uf capacitor. The board already had 6k8 ohm resistors to pins 16 and 17 and also had a 2.2nf capacitor between pins 16 and 17. I left them in place along with the exisiting 14 smd capacitors on the underside of the board.
After listening for a while, I think I hear a higher level of resolution during quieter passages.
Prior to this work, I had replaced Ian's I2S to PCM board with Ryan's ECDesigns I2S to Simultaneous board, and I heard changes similar to what Ryan heard. My iv is passive with 63 ohm diy handwound resistors along with +2mA bias. This is then fed into my preamp.
So if you have a TDA1541A dac board that has no room to install the large capacitors but you want to try the 50Hz DEM, perhaps a diy adapter such as the one that I built may work for you.
On my diy dac board, there was no room to install some and/or no access for connections of the 100uf capacitors. After some thought, I came up with an adapter which incorporated the 14 100uf capacitors and the one 1uf capacitor. The board already had 6k8 ohm resistors to pins 16 and 17 and also had a 2.2nf capacitor between pins 16 and 17. I left them in place along with the exisiting 14 smd capacitors on the underside of the board.
After listening for a while, I think I hear a higher level of resolution during quieter passages.
Prior to this work, I had replaced Ian's I2S to PCM board with Ryan's ECDesigns I2S to Simultaneous board, and I heard changes similar to what Ryan heard. My iv is passive with 63 ohm diy handwound resistors along with +2mA bias. This is then fed into my preamp.
So if you have a TDA1541A dac board that has no room to install the large capacitors but you want to try the 50Hz DEM, perhaps a diy adapter such as the one that I built may work for you.
Attachments
So I got around to pulling my DAC apart and joined the 50hz DEM club.
Obviously because I had to pull my old caps etc. I can’t do a A-B but I like what I hear.
Still running I2S (as I am still to get BOM for making up convertor boards I got from Ryan)
Previous version was
pin 13 & 18: 2.2 uF PPS
pin 12 & 19: 470 nF oscon
other decoupling caps: 220nF mkp
And some other DEM reclocking that I can’t remember - but was probably 6.8k x 2 and small value cap?
Now 14 X 100uf/25v Nippon Chemi-con KY, with the 12k pin 15/17 and 2.2uf PPS on pin 16/17
As you can see from the pics I alternated the caps top/bottom to fit them to the board.
(In the process I found some errors elsewhere from my dodgy work and I was surprised that my DAC was working at all!!)
Obviously because I had to pull my old caps etc. I can’t do a A-B but I like what I hear.
Still running I2S (as I am still to get BOM for making up convertor boards I got from Ryan)
Previous version was
pin 13 & 18: 2.2 uF PPS
pin 12 & 19: 470 nF oscon
other decoupling caps: 220nF mkp
And some other DEM reclocking that I can’t remember - but was probably 6.8k x 2 and small value cap?
Now 14 X 100uf/25v Nippon Chemi-con KY, with the 12k pin 15/17 and 2.2uf PPS on pin 16/17
As you can see from the pics I alternated the caps top/bottom to fit them to the board.
(In the process I found some errors elsewhere from my dodgy work and I was surprised that my DAC was working at all!!)
Attachments
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Have you check the new dem clock frequency? I use 1uf on pins 16/17, with 10k to -15 from both pins and dem is about 50Hz. (not sure whether any difference would be audible).
Simultaneous operation + stopped clock you will find, makes a big difference to sq.
And do you also hear some noise in one or both channels for a few minutes after initial turn-on?
Writing as one of those fools that observes datasheets, I wonder, does the performance loss of the TDA1541A scale with amount by which one violates compliance.
I use Nichicon UKL very low leakage 100uf caps and there is noise for less than 10seconds when first powered up.
What violation are you referring to? Dem clock frequency.
If you stick to the datasheets you'll hear what Philips want you to which is a compromise to keep 99% of consumers happy and get good magazine reviews.
It makes sense to me that high frequency dem clocking is at the least going to pollute the power supplies in addition to what the digital signals do, and having tried 50Hz dem clocking, I like the result.
I also like 100R passive I/V + transformer output. 100R may contravene the output compliance but only at DC because the transformer primary impedance is reduced by the load resistance on the secondary (by the square of the step-up ratio), so reduces the AC impedance.
That speaks more to limited knowledge of the variety of designs based around the TDA1541A.
I am indifferent to dem reclocking.
Does not change anything. The violation remains.
Not that I've noticed. But because of the tube output in my DAC I always turn it on first and it will be on for quite a few seconds before everything else is power up and I'm pressing play.
The KY is at least a factor of ten higher leakage. Seems to be fine as far as this noise issue goes. This is my working rig and I plan to use better spec caps in my final 2x tda1541a DAC.
I don't have the capacity to check DEM frequency. I'm just playing follow the leader 😉
Next time I get the urge I will try your configuration.
Yes, I'm looking forward to getting simultaneous operation etc. but that will be another couple of months yet.
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I tried the 50hz thingy on my AyA Ds dac with 100uf Pana FC caps.
It sounded pretty natural but upon further listening, I notice the pace of the music
that Im very familiar with have slowed down a little & slam has weaken, sound of instruments have become larger as well. No sure if it is the FC caps. Im running direct I2S coonection from my SD Trans 384.
Cheers
It sounded pretty natural but upon further listening, I notice the pace of the music
that Im very familiar with have slowed down a little & slam has weaken, sound of instruments have become larger as well. No sure if it is the FC caps. Im running direct I2S coonection from my SD Trans 384.
Cheers
DC voltage output compliance for lowest distortion.
As to the resultant performance 'loss', an increase in 2H which may or may not be complimentary in an overall system context. More violation, greater imbalance in 2H to 3H ratio, and also higher overall THD.
It's a compromise, so variation in subjective opinion based on experiences comes without surprise.
Overall lower THD vs a more complimentary even to odd harmonic spectra within that now overall increased level of THD - marketing dept wins, datasheet recommends for lowest overall THD.
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