Those in the pic are P14s gapped at AL=160. Seeing as you mention your current DAC is PCM1704, you do realize this is only a 16bit DAC? The limitation on number of bits in the TDA1545s is the main reason for wanting to incorporate an analog volume control, with more bits to play with digital volume may be a more attractive solution.
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I am still on the Phidac quad. My previous setup was usb isolator -> usb es9018 -> spidif -> AKM4418 ->I2s -> Phidac. Very nice, musical and better than anything else I have ever heard. So after years of humming and hawing over getting the Singxer F-1 to replace the es9018 I pulled the trigger.
This setup was usb Singxer F-1 -> AKM4418 -> I2s -> Phidac. Immediate improvement. Dynamics galore. Bass !! Full and thick and glorious. It moves air in my headphones now. Presentation is slightly muddled on complex songs. Some music is too intense because the top end feels sharp and muddled at the same time. It is too hard to follow and so becomes fatiguing.
So today I had time to pull out the soldering iron. Now it is just usb Singxer F-1 -> I2s -> Phidac. It didn't make sense to have the F-1 decode usb just to encode to spdif and then have the AKM4418 decode spdif to I2s.
Now there is a solid presentation. Things don't get muddled anymore. But this is not the thing I wanted to mention. The Singxer F-1 is an enormous improvement in dynamics, bass, pratt, full thick and detailed sound. It is just so much more and the interesting part is that the little Phidac stepped up. I hadn't even known what it was capable of before. It also prefers 24bit to 16bit input. 16bit sounds flat compared to 24bits.
So now I will be moving on to Celibidache because I have to know how could it possibly get better than this.
Let me put it this way, if I was told the Phidac quad I have right now would be the last dac I could ever have, I would be ok with it.
So a question to you all who have moved through the various iterations. In what ways is the Celibidache better than the Phidac?
This setup was usb Singxer F-1 -> AKM4418 -> I2s -> Phidac. Immediate improvement. Dynamics galore. Bass !! Full and thick and glorious. It moves air in my headphones now. Presentation is slightly muddled on complex songs. Some music is too intense because the top end feels sharp and muddled at the same time. It is too hard to follow and so becomes fatiguing.
So today I had time to pull out the soldering iron. Now it is just usb Singxer F-1 -> I2s -> Phidac. It didn't make sense to have the F-1 decode usb just to encode to spdif and then have the AKM4418 decode spdif to I2s.
Now there is a solid presentation. Things don't get muddled anymore. But this is not the thing I wanted to mention. The Singxer F-1 is an enormous improvement in dynamics, bass, pratt, full thick and detailed sound. It is just so much more and the interesting part is that the little Phidac stepped up. I hadn't even known what it was capable of before. It also prefers 24bit to 16bit input. 16bit sounds flat compared to 24bits.
So now I will be moving on to Celibidache because I have to know how could it possibly get better than this.
Let me put it this way, if I was told the Phidac quad I have right now would be the last dac I could ever have, I would be ok with it.
So a question to you all who have moved through the various iterations. In what ways is the Celibidache better than the Phidac?
I want to consult you about biasing the TDA1387.
The TDA1545 is very similar, the DS says if you bias 2ma instead of1ma they Ifs, the -60db THD+N falls to 1.4% from 1.7%.
The TDA1387 has also the same 11k in Iref input with Vref of 1/6Vcc. If I sink the current to devide 1ma Ifs, I get 13.2 which is exactly the Afs of TDA1545. I conclude that if I ground the Vref pin with another 11k, I will get 2ma Ifs= I bias on TDA1387 and maybe 1.4%.
The question is, with Ifs doubled, did I also doubled the gain to 2ma p-p output?
The TDA1545 is very similar, the DS says if you bias 2ma instead of1ma they Ifs, the -60db THD+N falls to 1.4% from 1.7%.
The TDA1387 has also the same 11k in Iref input with Vref of 1/6Vcc. If I sink the current to devide 1ma Ifs, I get 13.2 which is exactly the Afs of TDA1545. I conclude that if I ground the Vref pin with another 11k, I will get 2ma Ifs= I bias on TDA1387 and maybe 1.4%.
The question is, with Ifs doubled, did I also doubled the gain to 2ma p-p output?
Hi Hayk - the TDA1387 pin7 is a voltage input, not current. The way to get more current out is to bias pin7 with a resistor to pin5 (VDD). I don't think 2mA is possible but I get ~1.5mA with 110k to VDD when VDD=5.5V. You might find my blog useful : https://www.diyaudio.com/community/threads/tda1387-and-tda1545a.384224/post-7030615
I don't think Philips troubled themselves to make the Iref generator much different. From the figure 1 of TDA1545, the voltage across the Rref is already 1/6Vdd. As they could bring the compliance to 0, the Vref was needless so as the outside resistors.
If the 1545 can out 2ma Ifs with 22k from Vdd, I don't see why the 1387 can't. In your case that would be too much heat because multiple// but I am investigating to use only one pair loading each positive and negative of each channel in the same chip for differential output.
The minimum possible THD+N at -60db is -42db, with 0.14% only 4db is away from best.
If the 1545 can out 2ma Ifs with 22k from Vdd, I don't see why the 1387 can't. In your case that would be too much heat because multiple// but I am investigating to use only one pair loading each positive and negative of each channel in the same chip for differential output.
The minimum possible THD+N at -60db is -42db, with 0.14% only 4db is away from best.
George, a customer of you, has posted very interesting measurements.
https://www.diyaudio.com/community/threads/16-bit-dac-at-60db.406935/page-2#post-7547967.
https://www.diyaudio.com/community/threads/16-bit-dac-at-60db.406935/page-2#post-7547967.
I haven't noticed any differences between those labels in my experience. I don't think I have any NXP labelled chips, all mine are older, recycled ones from 'Soundblaster' cards and the like.
What I have noticed in testing a few hundred chips is the ones with 'THAILAND' printed vertically like this :
TL
HA
AN
ID
have on average a lower output current level than those with 'THAILAND' printed horizontally. The difference is small and unlikely to be audible.
What I have noticed in testing a few hundred chips is the ones with 'THAILAND' printed vertically like this :
TL
HA
AN
ID
have on average a lower output current level than those with 'THAILAND' printed horizontally. The difference is small and unlikely to be audible.