Upgrade to Assemblage DAC 3.0

[aarsoe]

I am the happy owner of an Assemblage DAC 3.0 (the daugther company of Sonic Frontiers, that unfortunatly are now closed).

The DAC is based on 1704 DA's and originally with either a PMD-100 or 1704 filter chip - the last one giving you 24/96, but you loose HDCD.

Now my question is if there is another chip that is pin compatible with the PMD100 giving my 24/96 and HDCD as I dont really like the sound of the 1704 filter chips.

I, was by mistake, under the impression that I could just swap the PMD 100 for a 200 - but no, requires completely different circuit and is a 100+ pin chip.

Any help would be appriciated, as I really love my DAC..

[rfbrw]

Originally posted by aarsoe
I am the happy owner of an Assemblage DAC 3.0 (the daugther company of Sonic Frontiers, that unfortunatly are now closed).

The DAC is based on 1704 DA's and originally with either a PMD-100 or 1704 filter chip - the last one giving you 24/96, but you loose HDCD.

Now my question is if there is another chip that is pin compatible with the PMD100 giving my 24/96 and HDCD as I dont really like the sound of the 1704 filter chips.

I, was by mistake, under the impression that I could just swap the PMD 100 for a 200 - but no, requires completely different circuit and is a 100+ pin chip.

Any help would be appriciated, as I really love my DAC..

Are there any 24/96 HDCD encoded DVD/DAD discs available?

[aarsoe]

To be honest - I dont know, but that is not the point.

I would like to have both HDCD and 24/96 - now I can only have one of them.

I was thinking more in terms of the possibility of replacing the filter chip DF1704 with DF1706 (24/192) and the dacs PCM1704 to PCM1796 (also 24/192) - but even if theese chips seems to be pin compatible, I dont know if it can be done.
Also, will I need to change the CS8414 input reciever - and if so, to what? Have not been able to see if a newer model giving 24/192 exist. The CS8414 is only 24/96 for sure..

[rfbrw]

Originally posted by aarsoe
To be honest - I dont know, but that is not the point.

I would like to have both HDCD and 24/96 - now I can only have one of them.

I was thinking more in terms of the possibility of replacing the filter chip DF1704 with DF1706 (24/192) and the dacs PCM1704 to PCM1796 (also 24/192) - but even if theese chips seems to be pin compatible, I dont know if it can be done.
Also, will I need to change the CS8414 input reciever - and if so, to what? Have not been able to see if a newer model giving 24/192 exist. The CS8414 is only 24/96 for sure..

Ahh but it is the point. If all you need the PMD100 for are the 44K1 discs, then you have more options. The PMD100 demoboard had two digital filters to allow easy comparison between the PMD100 and a standard filter. Using the same principle it is possible to run the PMD100 alongside filters like the NPC5842/3/7 series or the DF1704/6 series with the PMD100 decoding HDCD material and the standard filter dealing with everything else.
The datasheets will tell you what you need to know about the PCM1704 and the PCM 1794 and the main manufacturers of digital input receivers are AKM,Cirrus Logic and Texas Instruments.

[aarsoe]

Hmm - see what you mean, but still un-able to give a full answer, as I dont know if you maintain the HDCD if you upsample.
Also I must admit I prefered the PMD 100 sound compared to the DF1704, and was hoping that the 1706 would sound better.

I guess I should also mentioned that another reason I want to do this is that I have an eye out for a new cd drive that will allow me to output 24/192 digitally.

So back to my question - even if I can compare the white papers on the individual chips, I dont know if the layout, support circuit etc will support the newer chips - can you help me here?

[transducer]

Originally posted by aarsoe
.

Now my question is if there is another chip that is pin compatible with the PMD100 giving my 24/96 and HDCD as I dont really like the sound of the 1704 filter chips.

What is it that you don't like about the 1704 filter chip? I ask because I have a pair of blank boards for the Assemblage DAC 2.6 which I was planning on building soon. This unit also can use either the PMD100 or the DF1704. I was planning on using it with the DF1704 (I don't like the sound of my DAC2.0, which uses the PMD100). I'm curious what it is that you don't like about the 1704.

By the way, is your 1704 mounted to a small daugherboard?

Thanks,
Ron

[aarsoe]

First of all, let me stress thateven if I find the PCM100 to be better than the 1704, - then this could be very depending on my speakers, amp etc.. In other words, you may like the 1704 better - but thats up to you to judge.

Difference - well the PCM100 is more soft, warm and maybe not as detailed as the 1704 - but it has a wonderfull way of letting you experience the music as a whole, and not just the details.
Its not that anything is missing from the 1704, but it is a little to clinical for my taste.
However the differences are not huge, but suddle and as I said, could very much tip the scale one way or another depending on the entire chain.

I should also say that comparing the Dac 2.0 with the pcm100 to the dac 3.0 with pcm 100 is not that easy as the dacs are different, the 3.0 have two dacs pr. channel and as I recall the 2.0 only has one. Could be a major difference there.
However it would be fairly easy to test as you already have the pcm100 chip and the DF1704 option is not that expensive..

Yes - my DF704 is on a small daugther board.

PS. What I really would like is a 3.1 input board, but according to Chris at the new parts connection they are completely gone..

[transducer]

aarsoe, thanks for your reply. You describe the PMD100 exactly, and in my system, I find it too soft in the details. As you said, this could be all system balancing. Currently I'm using a D/A converter from Analog Devices, with their upsampler. I can't remember the chip numbers right now. It sounds wonderfully open, but I'm not thrilled with the upsampler, it seems to add some form of distortion.

I would contact Paradigm, who bought out Sonic Frontiers, which as you know, owned Parts Connection, and Assemblage. The "new" Parts Connexion (notice the spelling!) is owned by the former owner of SF (Chris), who would have no access to the boards. I'm not saying that there are boards available, but Paradigm does have stock of some things for repairs etc. I recently needed a new servo board for my Sonic Frontier SFT1 transport, and they had it. Contact their service department.

Ron

[aarsoe]

Ron

Thanks - Will try that.

[rfbrw]

Originally posted by aarsoe
Hmm - see what you mean, but still un-able to give a full answer, as I dont know if you maintain the HDCD if you upsample.
Also I must admit I prefered the PMD 100 sound compared to the DF1704, and was hoping that the 1706 would sound better.

I guess I should also mentioned that another reason I want to do this is that I have an eye out for a new cd drive that will allow me to output 24/192 digitally.

So back to my question - even if I can compare the white papers on the individual chips, I dont know if the layout, support circuit etc will support the newer chips - can you help me here?

You would need an input receiver that supports single-wire 192khz e.g. the CS8416. This would probably need some changes made to the PLL section.
Then you would need to decide how you want to set up the relationship between the two filters.
The above two modification could be done with minimal alterations to the DAC 3.0 pcbs and the addition of a daughter board or two. Any thing beyond that, e.g. replacing the PCM1704 with the very different PCM1794, and you might as well design a new DAC from the ground up.
BTW, what CD drive are you looking at?