"Reference" TDA1541A DAC with I2S-BUS architecture

[ernesternest]

I see that clarifies. Should have better paid attention what I was looking at (DCB1, not DAC).

By the way, EC-designs has identified that his ultra-simple output stage is not optimal either. He is now using a bit more complex topology.

Yes, as Oliver already stated, the sound was not as expected. Flat and somehow grainy! John mentioned two issues, one was a missing small cap to prevent stage from oscillating. After that it was much better than before but still not good enough. The other issue cannot be solved with this design So still far away from my other DAC. Johns new design is not much more complex from the builders point, so I stay on his track. Beside that, meanwhile a few nice 6n2p tubes are on the way to me

Regarding the X2: A friend led a cable from the input of pulsetransformer directly to the RCA output, removed the 5V regulator and powered the thingie by external 5V and after that he was very very happy with the result compared to his first impression. Finally he will feed it with its own 5V shunt. If one wants to have the ultimate solution, one needs a 3.3V shunt to feed the chips within this litte box. Only the clock is running on 5V, he told me.

Cheers Ernst

 

[dvb projekt]

Regarding the X2: A friend led a cable from the input of pulsetransformer directly to the RCA output, removed the 5V regulator and powered the thingie by external 5V and after that he was very very happy with the result compared to his first impression. Finally he will feed it with its own 5V shunt. If one wants to have the ultimate solution, one needs a 3.3V shunt to feed the chips within this litte box. Only the clock is running on 5V, he told me.

Cheers Ernst

Hi Ernst,

that´s a cool idea to run also the 3,3V on a separate shunt.

As you could see in my post #194, my X2 runs with one of my +5V shunt modules
and it´s no problem to cancel the 3,3V regulator behind the USB plug.

The small modification that´s needed to run my shunt module on 3,3V (post #124) is also no problem.

I think i will solder a bit more when the ordered USB Isolator module is delivered...

 

[ernesternest]

Hi Ernst,

that´s a cool idea to run also the 3,3V on a separate shunt.

As you could see in my post #194, my X2 runs with one of my +5V shunt modules
and it´s no problem to cancel the 3,3V regulator behind the USB plug.

The small modification that´s needed to run my shunt module on 3,3V (post #124) is also no problem.

I think i will solder a bit more when the ordered USB Isolator module is delivered...

Thanks and UUps, missed that.

The separation chip gave a good improvment at my Monica. Hope to get my second X2 quickly, since I gave my first to my friend.

Cheers Ernst

 

[studiostevus]

Yes, as Oliver already stated, the sound was not as expected. Flat and somehow grainy! John mentioned two issues, one was a missing small cap to prevent stage from oscillating. After that it was much better than before but still not good enough. The other issue cannot be solved with this design So still far away from my other DAC. Johns new design is not much more complex from the builders point, so I stay on his track. Beside that, meanwhile a few nice 6n2p tubes are on the way to me


Cheers Ernst

Yep... I am also looking for an alternative solution besides John's. It unfortunately is still not ultimate... I found this tube solution on the forum. Looks intriguing. http://www.diyaudio.com/forums/digital-line-level/157940-tubed-ccda-i-v-amp-tda1541.html

And still I read that sound-quality wise, a discrete solution is regarded to be better than tube solutions. Not sure what to make of it

 

[ernesternest]

Yep... I am also looking for an alternative solution besides John's. It unfortunately is still not ultimate... I found this tube solution on the forum. Looks intriguing. http://www.diyaudio.com/forums/digital-line-level/157940-tubed-ccda-i-v-amp-tda1541.html

And still I read that sound-quality wise, a discrete solution is regarded to be better than tube solutions. Not sure what to make of it

Hi Studiostevus,

I'm running the AD1865 with a tubed outputstage (E182CC Anode Follower With HV shunt and CCS - currently changing to 6n6p) and can say the sound is really amazing! Never before before heard a DAC like this one.
Good, better, worse, ... is always a matter of personal taste.... I have no preferrence, I'd like to have a veeeryveeeeeeeery good but simple soundsystem in the end. I'm still comparing an ECs seems to be simple and will be very good in the end. I'm pretty sure.

Radioman's approach is also good in my eyes, nevertheless not very progressive. Low I/V resistor value and a classic preamp approach with voltage amplification in the first and current amplification in the second stage. Have heard such preamp stage, actually I own one. Hm, sound is good, could try it. Could also be built with 6n2p tubes, since they are close to ECC83 and could be good for people they don't like SRPP. Heard they exist

Cheers Ernst

 

[dvb projekt]

USB-Isolator

Thanks again to Ryelands for his post #262!

The small USB-Isolator pcb from Circuits@Home arrived yesterday. The soldering of the few parts was no problem.
The design is based on Analog Devices ADuM4160 USB Isolator IC.

An externally hosted image should be here but it was not working when we last tested it.

Because i want to use the best power solution, i ordered the "Isolator only"-Kit and connected it to the
+5V Salas Shunt module, witch also powered my X2 USB to I2S converter.

An externally hosted image should be here but it was not working when we last tested it.

Now the DAC is completely isolated from the computer input side, including the GND line.

An externally hosted image should be here but it was not working when we last tested it.

Only the pure USB signal goes into the DAC. And the result....

Chapeau!!!

Better dynamics, enhancement of the low end, better 3D soundstage and a deeeep black background.

From my side:

Highly recommended ​

 

[studiostevus]

Hi Studiostevus,

I'm running the AD1865 with a tubed outputstage (E182CC Anode Follower With HV shunt and CCS - currently changing to 6n6p) and can say the sound is really amazing! Never before before heard a DAC like this one.
Good, better, worse, ... is always a matter of personal taste.... I have no preferrence, I'd like to have a veeeryveeeeeeeery good but simple soundsystem in the end. I'm still comparing an ECs seems to be simple and will be very good in the end. I'm pretty sure.

Radioman's approach is also good in my eyes, nevertheless not very progressive. Low I/V resistor value and a classic preamp approach with voltage amplification in the first and current amplification in the second stage. Have heard such preamp stage, actually I own one. Hm, sound is good, could try it. Could also be built with 6n2p tubes, since they are close to ECC83 and could be good for people they don't like SRPP. Heard they exist

Cheers Ernst

Hi Ernst,
So essentially what you are saying is that there are a lot of options out there and you should build many to find out what your preference is... cha... that must be true, but doesnt help me further on where to start

What's your best output stage for this dac so far? Have you tried any solid state ones?

Also interested in your anode follower CCS Shunt solution for the TDA1541

 

[LucasAdamson]

I think that starting with SRPP 6N2P as I have done, is a vary wise move. The circuit is very popular on the whole. Extremely detailed and lush. Powerful, dynamic, intriguing and all round pleasant. I can't find fault in this DAC to be honest, other than poorly recorded stuff seems to disappoint, even when the music was previously admired - now good music, badly recorded is no longer fun.

What I can tell you is that I am listening to 2xTDA1541A with 6N2P SRPP right now and it is quite sublime. Best I've heard. First DAC I've had to equal the record player with the best discs.

 

[LucasAdamson]

TERALINK X2 USB linking problem

I am having a bit of a pain though -

The Teradak X2 takes several (maybe 1x or 5x) on/off/on switches before it registers on the Macbook Pro, even with a 2m cable.

With a 5m USB cable, it simply doesn't connect at all (at least 20x on/off attempts). I've tried two 5m cables now. I'm really a bit fed up with it. I can't listen to music and sit on my sofa with the computer like I usually do.

I want for the DAC to be easily usable without having to know the knack of getting it to work (like Fonzy hitting the juke box in just the right place) so the wife and kids feel they can use it.

Any suggestions? Any similar experiences to report?

 

[dvb projekt]

Hi Lucas,

i had connected the X2 with a 5m cable to my iMac and had similar experiences
as you with a 2m cable.

I try to get an answer to this behavior from TeraDak. It would be interesting to know,
if the Windows user have also this problem.

 

[LucasAdamson]

Was anybody able to connect the Twisted Pear SPDIF adapter to this dac yet?

I may go down that route and use my airport express to wirelessly zap the bits to the dac.

Despite being a small wifi file transfer, Airport Express has been proven to pass bit-perfect music file information to the optical out port, so I am happy with the quality. I have used it for several years with previous DACs and never questioned it. Re-clocking is all that is required, I believe.

For laptop users, the convenience is futuristic and revolutionary - no wires and perfect hi-fi!

 

[ernesternest]

Hi Lucas,

i had connected the X2 with a 5m cable to my iMac and had similar experiences
as you with a 2m cable.

I try to get an answer to this behavior from TeraDak. It would be interesting to know,
if the Windows user have also this problem.

Oliver,

we tested the X2 last week an Thursday using OS Linux with a normal cheap 5m computer (not Highend) USB cable. No Issue! Worked flawless. I'll try it with windows as soon as possible.

Cheers Ernst

 

[ernesternest]

Hi Ernst,
So essentially what you are saying is that there are a lot of options out there and you should build many to find out what your preference is... cha... that must be true, but doesnt help me further on where to start

What's your best output stage for this dac so far? Have you tried any solid state ones?

Also interested in your anode follower CCS Shunt solution for the TDA1541

Hi, tried only ECDesign MK4 which meanwhile turned out to be lets say suboptimal. John has a MK5 design and I'm going to test it, since it is simple and does not nead any extra PSU. In the end I want to build Johns power amp as well, since as I understand, his designs are working best within his chain.

I have not tried any other I/V stage so far. My 6n2 tubes have not arrived so far. After arrival I'll try SRPP, radiomans approach and anode follower (with and without CCS). Since I'm gonna make p2p wiring, changes can be done easily.

The tnt outpustage should be very good as well and cheap to make....

Yes, not easy to decide. If you look at Lukasz site, you can see, that his stuff is easy to build even without a board. So give it a try.

Cheers Ernst

 

[LucasAdamson]

Yes, if I were doing it again, now that I know Lukasz feelings about 6N2P are so right, I would not hesitate to make a smaller p2p wired Lampizator, but with lower i/v resistors than he uses (half - ie 56R not 100R he uses, or 28R for 2x DAC etc.)

Oliver's boards do have many conveniences, however, for improving the sound, over Lukasz's p2p methods, but are very large in my opinion, which has caused some problems finding a suitable case.

Ideally I would make a new dedicated 6n2p SRPP pcb or p2p matrix board with HV shunt built in, without relays and with a more convenient signal connection, and a lot smaller.

 

[dvb projekt]

I am having a bit of a pain though -

The Teradak X2 takes several (maybe 1x or 5x) on/off/on switches before it registers on the Macbook Pro, even with a 2m cable.

With a 5m USB cable, it simply doesn't connect at all (at least 20x on/off attempts). I've tried two 5m cables now. I'm really a bit fed up with it. I can't listen to music and sit on my sofa with the computer like I usually do.

I want for the DAC to be easily usable without having to know the knack of getting it to work (like Fonzy hitting the juke box in just the right place) so the wife and kids feel they can use it.

Any suggestions? Any similar experiences to report?

Lucas,

did you power the X2 over the USB port or as i do over an external psu?
I am in contact with Teralink and they ask the question, if the sync. problems are also with USB-Power.

 

[LucasAdamson]

Hi Oliver,

I can switch between USB and externally powered with a shunt module, using the switch.

The USB powers the device no problem with all cables. Power is instant and plentiful.

The problem is more to do with the computer not recognising the DAC is present, in my opinion.

Thanks for researching this, by the way.

 

[dvb projekt]

Lucas,

sure we have a syncronisation/recognising problem, but do you have it in USB an external powerd modus?

 

[studiostevus]

Hi, tried only ECDesign MK4 which meanwhile turned out to be lets say suboptimal. John has a MK5 design and I'm going to test it, since it is simple and does not nead any extra PSU. In the end I want to build Johns power amp as well, since as I understand, his designs are working best within his chain.

I have not tried any other I/V stage so far. My 6n2 tubes have not arrived so far. After arrival I'll try SRPP, radiomans approach and anode follower (with and without CCS). Since I'm gonna make p2p wiring, changes can be done easily.

The tnt outpustage should be very good as well and cheap to make....

Yes, not easy to decide. If you look at Lukasz site, you can see, that his stuff is easy to build even without a board. So give it a try.

Cheers Ernst

Yeah....

Probably I'll order some resistors and caps, some tubes (6n6p or others), a transformer (240V ??) and a Salas HV reg.

And then just play around

 

[LucasAdamson]

Lucas,

sure we have a syncronisation/recognising problem, but do you have it in USB an external powerd modus?

Yes the problem is the same whatever power source is used - USB or Salas shunt.

 

[ernesternest]

Yeah....

Probably I'll order some resistors and caps, some tubes (6n6p or others), a transformer (240V ??) and a Salas HV reg.

And then just play around

I don't think that 6n6p give enough gain for 1541 without a socalled i/v transformer. You need higher gain! So try 6n2p or similar. 6n6p is suitable for AD1865. In my eyes Lucas Adams plan should work.

Maybe you could try the circuit without HV shunt first. Keep it simple until you know where you want to go. Transformer, some resistors, some caps, some tubes and finally some effort.

Cheer Ernst