I've been trying to find exactly the same thing: differential 1704 with balanced analog out. With no luck, unfortunately...
My Denon 1650SR has dual differential topology with single ended analog out, and it certainly has potential, but still far away from NOS 1541A. Mainly because of sheer complexity and very poor single sided PCB - ground topology. I believe strongly in differential 1704 and simple analog, balanced filter/buffer.
I recon, whoever comes first with this KIT design, will make some serious money... like sonic frontiers did with their DAC’s with 1702…
Extreme_Boky
My Denon 1650SR has dual differential topology with single ended analog out, and it certainly has potential, but still far away from NOS 1541A. Mainly because of sheer complexity and very poor single sided PCB - ground topology. I believe strongly in differential 1704 and simple analog, balanced filter/buffer.
I recon, whoever comes first with this KIT design, will make some serious money... like sonic frontiers did with their DAC’s with 1702…
Extreme_Boky
I'm currently working on a pcm1704 based dac that I’ve thought of modding to be balanced output
The first prototype I guess you could call is just about done, I’m just waiting on some new pcm1704 chips to arrive as the ones I got are suspected dead (and if replacing them doesn’t fix it I’m screwed
)
Schematic, Board, Assembled pic 1, and 2
I’ve got plans to extend it to balanced by just an add-on board (main board, and add-on) that sits on top of the current analog section and tap into the data lines to feed another 2 pcm1704's and just by tying the INVERT pin of them low their outputs are then inverted to have your balanced output
Also a redesign of the analog psu from the quick and nasty lm78/9** I tacked onto the current one to lm317 for the opamps +/-15v and AD826 and LT1027 setup for the dac's psu that has been reported to work very well (I think I seen it done like that on a levison dac with pcm1704's)
This is all still just work in progress so far,
The first prototype I guess you could call is just about done, I’m just waiting on some new pcm1704 chips to arrive as the ones I got are suspected dead (and if replacing them doesn’t fix it I’m screwed
)Schematic, Board, Assembled pic 1, and 2
I’ve got plans to extend it to balanced by just an add-on board (main board, and add-on) that sits on top of the current analog section and tap into the data lines to feed another 2 pcm1704's and just by tying the INVERT pin of them low their outputs are then inverted to have your balanced output
Also a redesign of the analog psu from the quick and nasty lm78/9** I tacked onto the current one to lm317 for the opamps +/-15v and AD826 and LT1027 setup for the dac's psu that has been reported to work very well (I think I seen it done like that on a levison dac with pcm1704's)
This is all still just work in progress so far,
Guido Tent said:
Really, are u sure! What a surpricing contribution to this thread.
This board may be all about nonos, redbook and and TDA 15 whatever but I have news for you.....there are a few of us who could not care less and as indicated in the subject its not what this thread is about.
Please stay on topic if you want to participate in the thread.
Most definately!
I have yet to hear anyone theorize why the dual converter solution is better. My guess is that high-end companies are doing it solely for the marketing aspects. It's not a real benefit, only a perceived one.
jh
(Yes I am biased, having chosen to sell a single 1704 per channel)
As someone who's been following Daki][er's work very closely I'm wondering what the best way is really to do fully balanced work. There's only 3 ways I see this along with their potential problems
1. Missmatched DACs when using 2 per channel.
2. Active crap with a variety of phase and sounds in the signal path if you use a dedicated chip to convert the signal to differential.
3. Possible phase distortions when a transformer is used and once again coloured sound.
So far every PCM1704 cdplayer I've liked but none have been balanced, but the other 2 options would alter the sound. So ignoring the cost is using an extra 2 chips a bad thing?
1. Missmatched DACs when using 2 per channel.
2. Active crap with a variety of phase and sounds in the signal path if you use a dedicated chip to convert the signal to differential.
3. Possible phase distortions when a transformer is used and once again coloured sound.
So far every PCM1704 cdplayer I've liked but none have been balanced, but the other 2 options would alter the sound. So ignoring the cost is using an extra 2 chips a bad thing?
A 8 said:
This thread is about balanced operation of 1704.
My contribution is my exprerience about that, and I came to the conclusion that single 1704 operation with care on jitter and some other things sounds better.
Please explain me (and others) what the off toppic part of my contribution is.
Guido,
My question was simple ie "I am looking for pcb's that are well designed using 2x BB PCM1704 per channel in balanced mode"
I was hoping that would give me a few alternatives to explore (thanks to those who provided a few).
The way you approach my question does not help at all, if anything it shuts the door on my original question.
With all due respect to your experiance I am not interested.
I am not looking for a debate on why or why not PCM1704, balanced or not.
If I had don't you think I would have framed the question differently?
/Michael
My question was simple ie "I am looking for pcb's that are well designed using 2x BB PCM1704 per channel in balanced mode"
I was hoping that would give me a few alternatives to explore (thanks to those who provided a few).
The way you approach my question does not help at all, if anything it shuts the door on my original question.
With all due respect to your experiance I am not interested.
I am not looking for a debate on why or why not PCM1704, balanced or not.
If I had don't you think I would have framed the question differently?
/Michael
I tend to agree with Jim and Guido, but.........
If there really is interest in a DIY PCB, then I am willing to make some. Mind you, that does not mean one. It could be done. The cost of a single PCB is not that much.
The time to create it is. Seriously, someone said that the first guy to make a really good one will clean up. I have not seen any suggestion of that yet. Correct me if I am wrong.
Jocko
If there really is interest in a DIY PCB, then I am willing to make some. Mind you, that does not mean one. It could be done. The cost of a single PCB is not that much.
The time to create it is. Seriously, someone said that the first guy to make a really good one will clean up. I have not seen any suggestion of that yet. Correct me if I am wrong.
Jocko
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