This one is particularly funny. Why do you need higher than 44.1kHz? I don't recall (although I didn't fully scrutinise it) any mention of easing the job of the analogue filtering after the DAC.
Perhaps they don't really 'get' capacitors at all?
Its all starting to make sense to me.
Enjoy....
http://www.hydrogenaudio.org/forums/index.php?showtopic=40134
Perhaps they don't really 'get' capacitors at all?
Its all starting to make sense to me.
Enjoy....
http://www.hydrogenaudio.org/forums/index.php?showtopic=40134
What have I started?
Hydrogen Audio does have its uses - developing LAME MP3 encoder for a start. I don't mind MP3 when I'm walking down a busy London street, but it gets switched off when my front door closes.
Anyway, look at this - CD6000 with TDA1541...
As you said before Martin, there are players with more room inside to play that already have TDA1541 in them.
But, I wonder if it's feasible to add an I2S port. Or would one lose too much rise time in cable capacitance.
A nice off-board 1541 DAC fed by non-OS I2S anyone... (or a ready-built or kit one with the S/PDIF receiver bypassed.)
Hydrogen Audio does have its uses - developing LAME MP3 encoder for a start. I don't mind MP3 when I'm walking down a busy London street, but it gets switched off when my front door closes.Anyway, look at this - CD6000 with TDA1541...
As you said before Martin, there are players with more room inside to play that already have TDA1541 in them.
But, I wonder if it's feasible to add an I2S port. Or would one lose too much rise time in cable capacitance.
A nice off-board 1541 DAC fed by non-OS I2S anyone... (or a ready-built or kit one with the S/PDIF receiver bypassed.)
Glenn,
This is exactly what I do. After my CD63 died, I moved on to a Philips CD940, reclocked with all the oversampling and bitstream gubbins stripped out, and converted the I2S output from the decoder to a differential output (on CAT5 TP) to an external TDA1541A DAC (No S/PDIF, wahey!).
without the diffferential conversion, I2S does seem to work for a few inches or so of cable (I didn't try much further), but the diff version works over a good few metres if needs be.
It sounds nice
, but its still in prototype form.I might post some pictures on a new thread if I ever get round to it.
But after looking on hydrogenaudio, I might just bin it all and get into MP3
I wonder why I've wasted so much time, and so many nice capacitors LOL.
That would be good - let us know if you do.
How did you do the differential conversion?
I think with a lot of players, like the more recent cheapo Philips and Marantz units the oversampling is done in the decoder and there is no separate digital filter. Short of re-programming the CPU to not ask for O/S you're stuffed.
I think the CD63 and CD67 are a good basis for this as the DAC does the 8xO/S so the raw I2S is available as it enters the DAC, and you can still buy fresh lasers... and they are pleasant and responsive units to use. Some of those older CDMs are difficult to find.
How did you do the differential conversion?
I think with a lot of players, like the more recent cheapo Philips and Marantz units the oversampling is done in the decoder and there is no separate digital filter. Short of re-programming the CPU to not ask for O/S you're stuffed.
I think the CD63 and CD67 are a good basis for this as the DAC does the 8xO/S so the raw I2S is available as it enters the DAC, and you can still buy fresh lasers... and they are pleasant and responsive units to use. Some of those older CDMs are difficult to find.
Hi Glenn,
I was under the impression that the decoder nearly always output NOS I2S - but I could be wrong (all the CDPs I've worked with are about 10 years old or so).
I will have trouble if my CDM9 croaks it.
To do the differential conversion, I use DS9638 chips to convert to, and DS9637 to convert back to TTL. They're 8 pin DILs, and you'll need two of each (each chip will convert two signals).
They're about £3 a pop from Farnell, and they're dead simple to use (power, one input two outputs, and vice versa on the receiver chip, you'll need 100ohm termination resistor across the inputs of the receiver, and that's about it). You can google for the circuits.
A CD63 would be ideal for something like this.
I'll get some pictures together and start a new thread on this after Easter. I wouldn't want to take this thread off subject (that never happens )
Cheers,
Phil
I was under the impression that the decoder nearly always output NOS I2S - but I could be wrong (all the CDPs I've worked with are about 10 years old or so).
I will have trouble if my CDM9 croaks it.
To do the differential conversion, I use DS9638 chips to convert to, and DS9637 to convert back to TTL. They're 8 pin DILs, and you'll need two of each (each chip will convert two signals).
They're about £3 a pop from Farnell, and they're dead simple to use (power, one input two outputs, and vice versa on the receiver chip, you'll need 100ohm termination resistor across the inputs of the receiver, and that's about it). You can google for the circuits.
A CD63 would be ideal for something like this.
I'll get some pictures together and start a new thread on this after Easter. I wouldn't want to take this thread off subject (that never happens
)Cheers,
Phil
Actually it is going to happen (sort of) This might interest you all.
As you know I have one of Brent's mid-level modded '67's with the LM4562's. I just got a loan of my "old" Sony cdp-X3000ES for a while. As some will remember, this player is about 10 years old and was the last gasp of Sony's "real" Esprit series before they went mid-fi. Beautifull player, gorgeous construction, makes the Marantz look like junk. Sound-wise it nips at the heels of the Marantz. Well not quite. The M. is more extended, more transparent, more dynamic etc. But the Sony has a very sweet mid-band, good pace and the potential to be a great player. Brent you're gonna love this. I'm sure with the right mods this is going to kill the Marantz. I don't mind. I should never have sold it!
This might interest you all.As you know I have one of Brent's mid-level modded '67's with the LM4562's. I just got a loan of my "old" Sony cdp-X3000ES for a while. As some will remember, this player is about 10 years old and was the last gasp of Sony's "real" Esprit series before they went mid-fi. Beautifull player, gorgeous construction, makes the Marantz look like junk. Sound-wise it nips at the heels of the Marantz. Well not quite. The M. is more extended, more transparent, more dynamic etc. But the Sony has a very sweet mid-band, good pace and the potential to be a great player. Brent you're gonna love this. I'm sure with the right mods this is going to kill the Marantz. I don't mind. I should never have sold it!
Hi Glenn,
I didn't realise that. Well, in life, I think you can be certain of death, taxes, and cost cutting. Ho hum.
Mind you, having said all this, I am also interested in finding a DIL digital filter that will oversample maybe 2x or 4x - just to see how the 1541A compares in different modes. NOS, especially unfiltered, does suffer from high frequency attenuation, which I think is why so many regard it as a bit more laid back and less bright than OS.
But, NOS is less sensitive to jitter and interference as it is so low frequency (which makes circuit building easier).
Cheers,
Phil
I didn't realise that. Well, in life, I think you can be certain of death, taxes, and cost cutting. Ho hum.
Mind you, having said all this, I am also interested in finding a DIL digital filter that will oversample maybe 2x or 4x - just to see how the 1541A compares in different modes. NOS, especially unfiltered, does suffer from high frequency attenuation, which I think is why so many regard it as a bit more laid back and less bright than OS.
But, NOS is less sensitive to jitter and interference as it is so low frequency (which makes circuit building easier).
Cheers,
Phil
I dont actually have a problem with the treble roll-off, even if it is non-linear. It's one of those constant things you can get used to - and, I suspect, a major element in the popularity of the NOS approach amongst thos ewho compare it to vinyl. It' sa forgiving characteristic. However - apart from the awful HF noise - the thing I really dislike about NOS is the quite audible intermodulation products which results ina kind of aural 'fuzz' ...like vinyl discs in sore need of a wash.
Actually I don't thnk this is by any means as clear-cut as some proponents would have you believe.