No,
First you talk if you were John, are you?
. Second I never talked about DIY but if you think than buying a cell to a website or a supermarkett is diy... what can I answer ???
Third I didn't ask for it, see it more as a technical question about batteries & sound which was not adressed to you btw. I just illustrated you it is possible but if a cell has no sense in relation to a sound improvment : please re read my questions to John.
Forth it's simple to have a switch toggle or push button position between AC for grid -wall and DC from an internal cell zone on a device : think about a remote for illustration : where is the diy option when putting two cells inside?
At a conclusion I believe you readed my question to John as a critic of him, his great job and great inputs according your post above
Buy the UPL96ETL; do the mod to connect a battery power supply (spoiling your warranty) and find out yourself if it is an upgrade.
You can find the answer why there is no battery supply above; it was first hand information from John.
Try to stick to the subject of this thread, which is TDA1541A dac...
you are right, I wanted to say : finish you yourself ... there are things that are universal and that you show extremly well whatever the language ...attitude behind, between the words ! It's extremly... crystal clear in your "english" sir ! Just forget me, you are not John. And what I readed too fastly beteen two thread Matt's question and thought he asked about the two streaming devices of EcDesigns and not the Mac set up... so what ? What give you any things & right to call that a non sense... c'mon !
... there are things that are universal and that you show extremly well whatever the language ...attitude behind, between the words ! It's extremly... crystal clear in your "english" sir ! Just forget me, you are not John. And what I readed too fastly beteen two thread Matt's question and thought he asked about the two streaming devices of EcDesigns and not the Mac set up... so what ? What give you any things & right to call that a non sense... c'mon !
Last edited:
Indeed I believe this is the right way if well implemented.
Assuming the DAC's switches operate on the rising edge or the falling of the LRCK, like most R2R DAC, this signal is the most crucial of the digital to analog conversion process.
So the above signal has to be as clean as possible and jitter free.
We have to not be worried about the jitter of the BCK, it does not affect the conversion, the only purpose of the BCK is to clock the shift registers of the DAC, and also we can stop the clock after data are loaded in the registers avoiding interference with the LRCK.
Since the LRCK has to be free of jitter as possible is mandatory to send it to the DAC via copper, optical isolation introduces a lot of jitter.
We need a very low phase noise master clock, that means a state of the art oscillator, to be divided down to get the right LRCK frequency depending on the sample rate family.
To do the division we need a low phase noise divider circuit, otherwise we add jitter in the division process.
To do the best, we should start from a 5/6 MHz XO, since at these frequencies we get the crystals with the higher Q as possible, that means, if well implemented, the lower phase noise as possible.
Now we have a very clean LRCK virtually free of jitter, so the DAC's switches will operate the best.
Obviously, the source (or the FIFO buffer) has to be slaved to the LRCK.
To do this in the cleanest way we have to isolate BCK and DATA signals from the DAC and from the LRCK.
So we have to send back the LRCK to the source (or the FIFO) and also we have to feed the DAC with the above BCK and DATA.
The cleanest way is to use optic fiber cable, that is really a "wall" against EMI/RFI, nothing can affect this data transmission.
It's true that we are introducing a lot of jitter using the optic fiber, but as already said we can ignore this jitter because it affects only the signals that are not crucial for the conversion.
The LRCK, the only crucial signal, remains clean, it's not affected by the jitter of the other signals, so the DAC operates at its best.
This way the DAC is no longer source dependent.
Just invert LRCK with BCK, for the other DACs switching on the BCK signal, and this way works too.
I forgot, only a little expensive way.
Last edited:
Hi matthiasw,
The Fractal PowerDAC has NO conventional analogue signal path with RCA interlinks and (pre) amps. There is no built-in digital nor analogue amplifier or analogue buffer of any kind.
PowerDAC signal path:
Balanced stabilised power supply -> 32 digital power switches (18V / 4.5A / 0.02R Rdson) -> 40 power resistors (10W 0.01% thin film resistor clusters mounted on a big heat sink) -> speaker.
My aim was not attempting to improve the analogue signal path (interlinks, (pre) amps) but simply throwing it out completely. This will also eliminate all related problems, distortion and degrading.
To answer your question, the PowerDAC provides most realistic music reproduction as it no longer suffers from analogue circuit degrading.
The Fractal PowerDAC is basically a high power version of the existing DA96ETF:
DA96 ETF: 3V6pp output, 375 Ohm output impedance, 2 milli watts rms in 250 Ohms.
Fractal PowerDAC: 3V6pp ... 18 Vpp, 1.7 Ohm output impedance (golden ratio matching with my open baffle speakers) and up to 6W rms output.
The speaker is connected to the Fractal power resistor array. There are no active buffers or amplifiers, nothing, just digital on/off switches and power resistors to generate a pure analogue output signal for the speaker.
This is no class D or DSD!
Efficiency is low (15% max.) so it is primarily intended for driving efficient speakers (90dB and up) and it is ideal for driving headphones
The PowerDAC consumes up to 120 watts continuous (at max. volume setting), so it has a huge heat sink and it doesn't even look remotely like the DA96ETF.
The prototype has a built in (insulated) U192ETL (the improved modified version). So it's basically a complete audio set in one box, Mains power in, USB in, speakers out.
Because I use the original DA96ETF logic board it is still possible to connect the PowerDAC to an external UPL96ETL.
Lossless volume control is obtained by programming the supply voltage and with stepped power shunts (parallel with the speaker). Volume can be controlled with an IR remote control.
The list of factors that can still degrade music reproduction quality is roughly narrowed down to:
- Recording quality.
- Source (has to offer verified bit-perfect playback and reasonably low interference).
- Speakers.
The Fractal PowerDAC has NO conventional analogue signal path with RCA interlinks and (pre) amps. There is no built-in digital nor analogue amplifier or analogue buffer of any kind.
PowerDAC signal path:
Balanced stabilised power supply -> 32 digital power switches (18V / 4.5A / 0.02R Rdson) -> 40 power resistors (10W 0.01% thin film resistor clusters mounted on a big heat sink) -> speaker.
My aim was not attempting to improve the analogue signal path (interlinks, (pre) amps) but simply throwing it out completely. This will also eliminate all related problems, distortion and degrading.
To answer your question, the PowerDAC provides most realistic music reproduction as it no longer suffers from analogue circuit degrading.
The Fractal PowerDAC is basically a high power version of the existing DA96ETF:
DA96 ETF: 3V6pp output, 375 Ohm output impedance, 2 milli watts rms in 250 Ohms.
Fractal PowerDAC: 3V6pp ... 18 Vpp, 1.7 Ohm output impedance (golden ratio matching with my open baffle speakers) and up to 6W rms output.
The speaker is connected to the Fractal power resistor array. There are no active buffers or amplifiers, nothing, just digital on/off switches and power resistors to generate a pure analogue output signal for the speaker.
This is no class D or DSD!
Efficiency is low (15% max.) so it is primarily intended for driving efficient speakers (90dB and up) and it is ideal for driving headphones
The PowerDAC consumes up to 120 watts continuous (at max. volume setting), so it has a huge heat sink and it doesn't even look remotely like the DA96ETF.
The prototype has a built in (insulated) U192ETL (the improved modified version). So it's basically a complete audio set in one box, Mains power in, USB in, speakers out.
Because I use the original DA96ETF logic board it is still possible to connect the PowerDAC to an external UPL96ETL.
Lossless volume control is obtained by programming the supply voltage and with stepped power shunts (parallel with the speaker). Volume can be controlled with an IR remote control.
The list of factors that can still degrade music reproduction quality is roughly narrowed down to:
- Recording quality.
- Source (has to offer verified bit-perfect playback and reasonably low interference).
- Speakers.
a power DAC something I have dreamed about for a long time, even in theory it is obvious this concept is the only way to achieving ultimate transparency.
Also truly ideal conditions for NOS, with only ears/transducers performing reconstruction naturally.
very excited to hear more.
Also truly ideal conditions for NOS, with only ears/transducers performing reconstruction naturally.
very excited to hear more.
Last edited:
Congrats,
this is a great achievement!
I am very curious to listen to this PowerDAC,
Do you think you can launch a higher powered version with say 25W per channel?
Thanks
Matt
The big dream .... it was my dream from the beginning of digital audio in the early 80's, but finally I gave up for a lot of reasons.
Have you solved the big issues related to the MOSFET limits?
Usually power MOSFETs have high input and output capacitance, that affects the switching speed.
Moreover power MOSFETs usually have different turn-on and turn-off delay, that causes temporary short circuit and shoot through during the transiction.
May we get some info about your open baffle speakers if they are not proprietary design? Are there any description of them anywhere?
Last edited:
May we get some info about your open baffle speakers if they are not proprietary design? Are there any description of them anywhere?
- ECdesigns
Matt
- ECdesigns
Matt
Hi andrea,
Yes, gate drivers (4.5A peak drive current, cross conduction protection, level translation) + suitable MOSFET H-bridges.
The Fractal D/A converter is entirely different from (segmented) R2R ladder DACs, this made the PowerDAC concept possible. I tried the PowerDAC concept in the past (using R2R) and had to give up on this too.
Yes, gate drivers (4.5A peak drive current, cross conduction protection, level translation) + suitable MOSFET H-bridges.
The Fractal D/A converter is entirely different from (segmented) R2R ladder DACs, this made the PowerDAC concept possible. I tried the PowerDAC concept in the past (using R2R) and had to give up on this too.