My first DIY DAC, advice needed

[mr_push_pull]

I forgot to thank Doede for his answer, excuse my rudeness. I'll look into it as soon as possible!

Originally posted by maxlorenz
Good memory

Would you believe me if I tould you that I read every single reply on that thread? Speaking about no-life freaks...

Originally posted by maxlorenz
My 36Ah battery will last 36hrs if I didn't recharge it
And is humm free
Appart for the fact that it reduces/eliminates digital artifacts.

Don't get me wrong, but somewhere in my head lurks the idea that one should not depend on battery power. Makes me feel insecure I know, I'm insane.

Originally posted by maxlorenz
Why don't you go active?

Budget? One more thing is that it's probably not worth the effort, at least not now. I'll use 2-way DIY speakers w Morel drivers (somethink like Dynaudio Audience 42), I think that active is justified only for speakers with more that 2 ways. Btw, if I manage to finish the DAC I'll have a 100% DIY system. If the amp counts as 100% DIY

Originally posted by maxlorenz
The dynamics of this configuration are overwelming (did I wrote this wright? )

Use this simple rule: when in doubt, there probably is an 'h' after the 'w' I use it with good results

Originally posted by maxlorenz
How would I know?
Ask the wise. Ask Doede.
The philosophy is "simpler is better" everytime you add an active stage you introduce distortion. The best opamp is no opamp
The second best is OPA627, maybe.

I'm asking everyone The only objective opinions that I can collect are the ones based on experiment and comparison... but wait a minute, that's subjective. I guess it's as objective as subjective can get

Originally posted by maxlorenz
Hey, I'm only beginning with it! So far I would say:
Output coupling capacitor make a huge difference. Non polar BG 22uF parallel Wima 0.47 uF made the sound very warm and relaxing, with good dynamics but lack of HF extension.
BG non polar 4.7uF in super-E-cap configuration (antiparallel) is very, very transparent and extended but takes eons to burn-in!!! This DAC is up to down detailed.

After all, does a decoupling transformer have to be expensive? What about DIY decoupling transformer?

Originally posted by maxlorenz
Add independent regulated supply for Tent clock (even with 7805, said to be very bad, but is the only one that I know how to use) made a better soundstaging (depth) and "presence"
Even wiring makes a change

Rod Elliott says on his page that the adjustable regulators are better. On the other hand, I'm sure there are plenty of better discrete schematics available

Originally posted by maxlorenz
Good luck, Calin.

Mauricio

Thanks, keep in touch.

Originally posted by wa2ise


I/V circuits ain't that scary Anyway you could feed to an external preamp circuit the I/V signal. The preamp would be similar to a phono preamp except no RIAA equalization circuit. Your favorite circuit that would amplify a 100mV signal up to line levels, 1 to 2V is all you'd need. Could be tube, transistor or op-amp.

Anyway, take a look at my web page on modifying the analog section of CD players . The preamp circuit need not be in the same box as the rest of the CD player. For someone starting with tubes, it would be easier to have the tube circuits inside a separate box.

I guess I'll just jave to see and experiment. So many possibilities, so little money Thanks for the link.

Later I will post some links I've come accross, maybe some could comment.


Best regards,
Calin Dorohoi

[maxlorenz]

Rod Elliott says on his page that the adjustable regulators are better. On the other hand, I'm sure there are plenty of better discrete schematics available

Excellent. More stuff to learn about

I'll use 2-way DIY speakers w Morel drivers (somethink like Dynaudio Audience 42), I think that active is justified only for speakers with more that 2 ways.

I think active speakers will allways sound better than passive: more controled/relaxed and better bottom extension. You can look at specs of comercial ones that come in this two options to verifie. Appart that my active crossover costs +/- US$120 and is tweakable.
Other option: conserve your 2 ways as they are and build two big woofers two complete a fullrange system. I made mine with Eminence delta15 and 5-7 cm real wood panels, trapezoid shape , all for US$180.

I/V circuits ain't that scary Anyway you could feed to an external preamp circuit the I/V signal. The preamp would be similar to a phono preamp except no RIAA equalization circuit. Your favorite circuit that would amplify a 100mV signal up to line levels, 1 to 2V is all you'd need

About I/V, I forgot to mention that DDDAC1543's 8*DAC tower drives enough current to kill a mouse That's why you only need a resistor load to choose your desired Vout (and taste, through different R types).
The kit's stock max Vout is 1.6V
Did I explained it well, Mr Douma?

Would you believe me if I tould you that I read every single reply on that thread? Speaking about no-life freaks...

Me too! I live in DIY/audiophile isolation down here
Thanks God, this is the best Hobby in the world and the forum is great.

Arrivederci
Mauricio

[dddac]

About I/V, I forgot to mention that DDDAC1543's 8*DAC tower drives enough current to kill a mouse That's why you only need a resistor load to choose your desired Vout (and taste, through different R types).

well said Mauricio, although my DAC is not meant to kill any living creatures

I have used several output stages, including opamps and transformers, but with a simple resistor always convinced me ...

doede
www.dddac.de

[maxlorenz]

although my DAC is not meant to kill any living creatures

Well, maybe my new 16DAC's tower will...

BTW, TDA1543 does support direct I2S, wright? I'm too lazy to search the specs file
It's just that my DIYer fever had a relapse when I saw the CDPRO-2M transport

Regards
Mauricio

[Alien8]

Hi Calin

Concerning voltage regulators, have a look at this...

Voltage regs....

I'm certainly not a pro, but learned a lot from this site's pages.

As the aspect of why one regulator would by better than any other ?
Consider this : every power pin on a dac, opamp, even discrete transistor circuit can be regarded as an additional input. Most opamps do very well in amplifying PS noise above a few kHz...

HTH
A8

[maxlorenz]

This info is superb...and wright on time for me!

I am indebted...

Best wishes.
Mauricio

[maxlorenz]

Well, I built my 16*1543 DAC tower yesterday, for my DDDAC1543
I had to set again R load and bias R to obtain the 3.85VDC desired. For R load I choose 120R to match better with my active CX wich I use as preamp. The bias R is a multiturn variable resistor and it was difficult to settle this time. Maybe I'm on the limit of it. I also swapped a few wires to solid silver wich usually takes long to burn-in.

Well, it worked at the first attempt I think my beginner's luck doesn't want to live me

It's too late to tell but I noticed even more relaxed and natural midrange, with better soundstaging and instrument definition.

What's next? I have to change the stock R to Riken-Ohm and must explore super-regulators for independent supplies.

As I said, Doede's DDDAC1543 starter kit is a great project: there's no relation between the price paid and the high sonic quality obtained.

Now, I'm expecting to build a CDPRO-2M transport wich probably will include a direct I2S connection to a TDA1543 tower.

Good luck to everybody and enjoy!
Mauricio

[Black Heart]

Originally posted by maxlorenz
Well, I built my 16*1543 DAC tower yesterday, for my DDDAC1543
I had to set again R load and bias R to obtain the 3.85VDC desired. For R load I choose 120R to match better with my active CX wich I use as preamp.

I'm just curious, don't you resistor I/V afficianados find sonic degradation due to the high output voltage on the DAC? The 1543 is spec'd at only 25mV max voltage compliance, right? I haven't done any tests on it, but on the Burr Brown PCM series with 1.2 mA output I found that the sound got better and better the lower the voltage got, until I was down to 10 ohms, which would require way too much gain, so decided at that point it was better to go with a current mirror since I could easily get below 10 ohms impedance with no feedback and it sounded quite a bit better than my previous 100 ohm resistor and more complex discrete gain stage. And much better than any of the opamp circuits, like the AD811. But I guess it's all about tradeoffs and what works best in your system. Looks like a fun project.

Probably be a good topic for a separate thread, but maybe you've all hashed it out ad nauseum in the past.

[maxlorenz]

I hope your nickname does not reflect your mood tonight

The 1543 is spec'd at only 25mV max voltage compliance, right?

Where did you find that number? Never mind, because I'm unable to answer you in a technical way

I can asure you that it sounds very good, whatever may this mean to you.

Maybe having 8 or 16 DAC's in parallel limits the drawback you mention. My max Vout must be around 1.4V now.

Help needed, Doede

[Black Heart]

Originally posted by maxlorenz
I hope your nickname does not reflect your mood tonight

Not really, but I am listening to a CD that a friend recommended by Matt Elliott called The Mess We Made and is is a little on the melancholy side, but that's usually the way I like it. One of my favorite bands is The Black Heart Procession, so I just decided to appropriate part of their name for my nickname here. Might have to play one of their albums next, most likely the one simply titled '2'. Great stuff

Where did you find that number? Never mind, because I'm unable to answer you in a technical way

I remembered it from working some with the TDA1541 a long time ago, but just checked and it is in the datasheet for the 1543, page 7 in the one I just downloaded. I'll attach that part of the pdf below but if it doesn't come out for some reason just go to page 7 at http://www.vlsi.informatik.tu-darmst...ep/tda1543.pdf ...