4xtda1541a Nos Dac Project

[Moynet]

Hi Dvb Projekt.

Your DAC project is superb. I have doing a lot of research over internet viewing several DAC projects, yours is one of the best homemade DAC to me.

Here´s a link to Lukasz Fikus comments about this DAC board (without mods):
fourTDA_dac

At first he saids its too many power and no quality, but its exactly the way you go... you upgrade each part to high quality components. Making it better and better, step by step.

I would like to go this way but there are not more DAC units like this in ebay.

I have one question to you...

Originally Posted by dvb-projekt

Right out of the box it sounds very promising to beat my PS Audio DLIII with Cullen upgrade Mod. IV.

So... what can you tell us now?

For the one of sexiest analogue section I ever seen, You took the "lampizator" and upgrade it, isn´t it?

In digital domain: The only thing I wonder its USB at the source. In the motherboard there are several clocks running at diferent frecuencies, and they are feeding from the same PSU and the computers PSU aren´t too electrical quiet exactly.

I think that If one wants to approach to the best USB implementation one may need a dedicated PCI express card to USB like this:


At PCI express you have still perfect signal (like in RAM, like in Hard disk) because its burst, no streaming data. Here with PCIx to USB card, you have dedicated conversions chips to make the USB streaming. Once you are in USB scope, the clock signal is a relevant issue, and it takes the computer as a master clock. But with this PCIx card, synchrony, its taked from his own clock. In the card, I would install a special filter to the card like "Invisus 2 Voltage Regulators" between generic PC-PSU +3.3V and the PCIx USB card. And of course, I will change -the stock clock- to a dedicated PSU + Clock kit, in order to achieve more stable clocking to the USB streaming.

I think this is the best way to maintain as low as possible the jitter issue. After that, the USB cable quality become to play an important role I think. When we´ll feed directly from USB to the I2S (Inter IC Sound) it will doesn´t need reclocking, and we feed the I2S with quality and dedicated signal right from the start. I don´t know. It maybe an interesting experiment. Isn´t it?

Congratulations again dbv-projekt, thumbs up for you.

[serph1nia]

I think the output stage can easily be upgraded.

Take any 40-60 mu triode and make it ccs or choke loaded.

d3a, c3g and E180F come to mind because they sound great and are very affordable. Please don't use the overhyped 6c45. You can play around with output caps, ways to bias (try LED) etc.
Ofcourse you can always get a high quality interstage transformer, but it's expensive and you can't fool around as easily

c3g, CCS and LED bias is a good starting point.

[dvb-projekt]

Thank you for the flowers Moynet.

To your question with my "old" PS Audio DLIII with Cullen upgrade Mod. IV.:

The "Blue-Monster" with Lukasz Lampizator (all standard parts incl. 6N2P) beats the DLIII !!!

One word to the DAC Units on ebay.
In the beginning of my tweaks i mailed raindrop_hui making a redisign of his board, to get
the decoupling caps as short as possible to the TDA´s as Lukasz recommended.
I hope he will do that. The best thing is to mail him with regards from me and ask for the upgraded board.
Perhaps you are the lucky one who could buy this new board first.

Beacuse i have an iMac, i must had a perfect solution to come from the USB to the I2S input on the board.
The USB/I2S receiver from Doede Douma is this solution. A very well designed Kit.
Perhaps you would like to share your thoughts with him.

At this time i am ready with the case for the DAC and will integrate the parts this weekend.

So stay tuned. It will look absolutely fantastic

[dvb-projekt]

It take a long time, but my DAC is ready!
I will invite you to have a closer look.


Tatttaaaaaaa here it is:













And now..... time to listen

[Markuzz]

Hi DVB,

First of all, congrats on this great DAC!

I've ordered one myself and it's in transit somewhere between China and Holland at the moment. Considering your experiences with this DAC, what is the top 5 of most important tweaks you would recommend?

Cheers,

Mark.

[Moynet]

Wow! Dvb-projekt

There are very good gadgets you added for the final make up.

1. The input AC switch (Very nice).
2. I see down the tube rectifier a little circuit. That is new. ¿What is it?
3. There is a switch in frontal panel, to choose between USB (doede douma´s I2S direct) and SPDIF standart receiver in the blue dac I imagine. (This is really nice).
4. What brand is that ultra nice USB conector at the input? I have never seen one of them. SPDIF input is WBT as well as analog RCA outputs isn´t it?
5. What are indicating the 3 blue led (blue like the main dac card)? I can see some letters that said “heater”. But means voltaje to heater O.K. or, that bulb´s heater are ready to the performance?
6. There are 2 power switch? (behind and front)
7. The E813CC tubes doesn´t heat too much?

Your work really likes me. How much do you invest on this project without the chassis? And with chassis?
I ´m craving for the sound review. Highs, mids, bass, macro and micro dynamics, soundstage space, tonal balance, resolution, warmth, of course all that is subjetive up to you. Whereas you have referenced PS audio with Cullen mods level IV, that is something we can take as a point to compare.

Congratulations. Superb DAC you have.

Check your personal messages.

[dvb-projekt]

Originally Posted by Markuzz

Hi DVB,

First of all, congrats on this great DAC!

I've ordered one myself and it's in transit somewhere between China and Holland at the moment. Considering your experiences with this DAC, what is the top 5 of most important tweaks you would recommend?

Cheers,

Mark.

Hi Mark,

i would say:

- BG Decoupling caps with position mod.
- BG caps on each power input of the TDA´s (+5V, -5V, -15V)
- Rectifier in the PSU
- OS-CON´s in the regulater circuits
- Quality of the output C´s (i use ClarityCap MR) !!!

Originally Posted by Moynet

Wow! Dvb-projekt

There are very good gadgets you added for the final make up.

1. The input AC switch (Very nice).
2. I see down the tube rectifier a little circuit. That is new. ¿What is it?
3. There is a switch in frontal panel, to choose between USB (doede douma´s I2S direct) and SPDIF standart receiver in the blue dac I imagine. (This is really nice).
4. What brand is that ultra nice USB conector at the input? I have never seen one of them. SPDIF input is WBT as well as analog RCA outputs isn´t it?
5. What are indicating the 3 blue led (blue like the main dac card)? I can see some letters that said “heater”. But means voltaje to heater O.K. or, that bulb´s heater are ready to the performance?
6. There are 2 power switch? (behind and front)
7. The E813CC tubes doesn´t heat too much?

Your work really likes me. How much do you invest on this project without the chassis? And with chassis?
I ´m craving for the sound review. Highs, mids, bass, macro and micro dynamics, soundstage space, tonal balance, resolution, warmth, of course all that is subjetive up to you. Whereas you have referenced PS audio with Cullen mods level IV, that is something we can take as a point to compare.

Congratulations. Superb DAC you have.

Check your personal messages.

Hi Moynet,

to your questions:

2- This is a small new board that switch the main AC for the transformer over a solid-state-relais. So i have only 12V on the small switch at the front.

4- The USB connector is from Neutrik and the SPDIF also from WBT.

5- The LED´s indicate that the heater voltage of the output tubes and rectifier is ok. The third one is for the B+ of the OT-Tubes.

6- Yes. The switch on the back is the main switch. The front one switch to stand by.

7- The TechTube E813CC is the "coldest" Tube i ever have. Absolute no problem.

To the costs... Puhh, i think about 1.000,- EURO without chassis. The chassis with selfmade front and back design is about 350,- EURO.

Best regards,
Oliver

[fff0]

Well done !!!

Can you do up a step by step mod for newbie like me?

Whats the transport used?

[dvb-projekt]

Well i documented the single steps in the thread!

I use my iMac (USB) and my Yamaha GT-CD1 (SPDIF) as input devices.


Regards,
Oliver

[Markuzz]

Guys,

Unfortunately I have to abandon my DAC project

So I have a brand new 4 x TDA1541 DAC (with transformer) as described in this thread for sale. In case anyone is interested, send me a PM.

Cheers,

Mark.