this thread is an extension of a previous one on this player:
http://www.diyaudio.com/forums/showthread.php?threadid=3971
there are a few of us here who own the NS500V and feel it has good potential as a CD/SACD player, so we're beginning a collaborative project to modify it. our upgrade priorities:
- analog stage
- clock circuit
- complete power supply rebuild
by collaborating we're hoping both to get good results with the player and save money by pooling resources, e.g. getting batches of PCB's fabricated.
more info to come soon...
http://www.diyaudio.com/forums/showthread.php?threadid=3971
there are a few of us here who own the NS500V and feel it has good potential as a CD/SACD player, so we're beginning a collaborative project to modify it. our upgrade priorities:
- analog stage
- clock circuit
- complete power supply rebuild
by collaborating we're hoping both to get good results with the player and save money by pooling resources, e.g. getting batches of PCB's fabricated.
more info to come soon...
service manual etc.
LeoV has kindly posted service manual, schematics, and pictures for the NS500V on his site:
http://www.leov.net/~leo/sacd/
the service manual is for the NC650V, which is the changer version of the NS500V... functionally equivalent. it's 27MB, but if you want just the schematic for the NS500V you can find that here:
http://dorkus.org/diy/ns500v
cheers,
dorkus
LeoV has kindly posted service manual, schematics, and pictures for the NS500V on his site:
http://www.leov.net/~leo/sacd/
the service manual is for the NC650V, which is the changer version of the NS500V... functionally equivalent. it's 27MB, but if you want just the schematic for the NS500V you can find that here:
http://dorkus.org/diy/ns500v
cheers,
dorkus
service manuals
also check out my previous thread:
http://www.diyaudio.com/forums/showthread.php?threadid=8452
nifty site that will sell you manuals in Adobe PDF format for cheap.
also check out my previous thread:
http://www.diyaudio.com/forums/showthread.php?threadid=8452
nifty site that will sell you manuals in Adobe PDF format for cheap.
Dorkus:
Sounds like a good plan. My primary concern would be getting my hands on some spare loader mechanisms. They are the ony mechanical peice, and the most likely to wear out and fail over time (especially given how much I use mine!). They're also pretty nice quiet mechanisms! But, the trick will be to get them at a reasonable price... the replacement service parts seem to cost an arm and a leg, so buying a new player is probably cheaper. I'll have to somehow find out if there's a cheaper / more available model with the same loader type.
As far as mods go, I still want to keep mine in the original chassis, so PSU should fit where the existing one goes. It should also duplicate the power-down switching circuitry so that the rest of the unit has no idea anything's changed. Standard regulators are fine by me (317/1085 type), as I don't believe anymore that it's worth it to do anything fancier in the way of active regulation. I tend to focus on improving the passive circuitry to maximize performance - passive power supply conditioning seems to have a much higher return on investment. Shunt regulation is the only active scheme I really like, but it's only practical for low powered circuits.
At some point I'm going to design an interface board so that I can extract the raw DSD and PCM data at the internal DACs, and pipe it directly out to an external DSP/DAC setup. But first I have some Aleph-X stuff to attend to...
Sounds like a good plan. My primary concern would be getting my hands on some spare loader mechanisms. They are the ony mechanical peice, and the most likely to wear out and fail over time (especially given how much I use mine!). They're also pretty nice quiet mechanisms! But, the trick will be to get them at a reasonable price... the replacement service parts seem to cost an arm and a leg, so buying a new player is probably cheaper. I'll have to somehow find out if there's a cheaper / more available model with the same loader type.
As far as mods go, I still want to keep mine in the original chassis, so PSU should fit where the existing one goes. It should also duplicate the power-down switching circuitry so that the rest of the unit has no idea anything's changed. Standard regulators are fine by me (317/1085 type), as I don't believe anymore that it's worth it to do anything fancier in the way of active regulation. I tend to focus on improving the passive circuitry to maximize performance - passive power supply conditioning seems to have a much higher return on investment. Shunt regulation is the only active scheme I really like, but it's only practical for low powered circuits.
At some point I'm going to design an interface board so that I can extract the raw DSD and PCM data at the internal DACs, and pipe it directly out to an external DSP/DAC setup. But first I have some Aleph-X stuff to attend to...
the mods will fit in the existing chassis. the regulation board will replace the current power supply board exactly, but there will be an external power supply with transformers and rectifiers. there is not really enough room inside to cleanly mount new transformers. a simple DIN connector could be used ot attach to the external supply, would not be a huge hassle.
if you use the newer micro-power regulators for digital you can still have the digital circuitry power down as in the original supply. looking at the block diagrams in the service manual, i don't think trying to "trick" the control circuitry is really an issue. i do believe we should select the regulators carefully, as they will have a great influence on the final sound of the player. LT1085 is an OK choice, for digital the aforementioned newer-generation regulators may be better and are even easier to implement. for analog i prefer a simple pass-MOSFET supply which is also extremely easy to implement, and sounds very natural. shunt regs are probably even better, but i don't know how practical it will be for this project - it would take some experimentation and i'm too lazy to try something new at this point.
good luck trasmitting the DSD stream off the main board - it will take a lot of careful engineering to keep such a high speed signal cleanly to an external device! i don't believe external DACs are the way to go, if properly implemented an all-in-one player will outperform an equivalent transport/DAC any day. i think it would be better to take a player like the CE775/C222ES, which is more modular, and build an all new DAC/analog/clock board for it. i bet you could get some great results, i'm toying with doing it myself with AKM DACs but i think it may not be worth the trouble. but hey, if you can pull it off, more power to you. again, the CE775 would be a much easier player to hack for that, since you can grab the signals right off the connector to the DAC board.
if you use the newer micro-power regulators for digital you can still have the digital circuitry power down as in the original supply. looking at the block diagrams in the service manual, i don't think trying to "trick" the control circuitry is really an issue. i do believe we should select the regulators carefully, as they will have a great influence on the final sound of the player. LT1085 is an OK choice, for digital the aforementioned newer-generation regulators may be better and are even easier to implement. for analog i prefer a simple pass-MOSFET supply which is also extremely easy to implement, and sounds very natural. shunt regs are probably even better, but i don't know how practical it will be for this project - it would take some experimentation and i'm too lazy to try something new at this point.
good luck trasmitting the DSD stream off the main board - it will take a lot of careful engineering to keep such a high speed signal cleanly to an external device! i don't believe external DACs are the way to go, if properly implemented an all-in-one player will outperform an equivalent transport/DAC any day. i think it would be better to take a player like the CE775/C222ES, which is more modular, and build an all new DAC/analog/clock board for it. i bet you could get some great results, i'm toying with doing it myself with AKM DACs but i think it may not be worth the trouble. but hey, if you can pull it off, more power to you.
again, the CE775 would be a much easier player to hack for that, since you can grab the signals right off the connector to the DAC board.
Hrm.. power requirements for this player are quite modest. I really don't think there's a need for external transformer, and personally, I'd very much prefer to avoid the additional chassis work, connectors and clutter on the equipment rack. A small toroidal should fit in there quite easily I think... unless you plan on using more than one trannie (?). Some people seem to go waaaay overboard with separating power supplies *cough* <i>Peter Daniel</i> *cough*... With a little design effort, it's not too difficult to provide excellent isolation between the digital and analogue rails. I don't even want to think about the separation provided by the stock supply though! But, ultimately I'll be using the unit primarily as a transport only, so I may even just stick with the stock PSU. My motivation for changing to a linear supply would mostly be to reduce the noise thrown back at the mains and hence my other audio gear.
You're probably right about integrating the DAC right into the player, though I still have these gradiose plans for an external DSP for speaker crossovers etc. And now with the Aleph-X arriving on the scene, I'll be looking to do balanced output DACs too.
Using LVDS, getting the 2.8MHz DSD data to an external box should be a cakewalk. Doing it well will take a bit more effort, but shouldn't pose any insurmountable problems. If it comes down to it, I may build a PLL circuit to generate the NS500V clocks from a master clock located in the DAC box.
You're probably right about integrating the DAC right into the player, though I still have these gradiose plans for an external DSP for speaker crossovers etc. And now with the Aleph-X arriving on the scene, I'll be looking to do balanced output DACs too.
Using LVDS, getting the 2.8MHz DSD data to an external box should be a cakewalk. Doing it well will take a bit more effort, but shouldn't pose any insurmountable problems. If it comes down to it, I may build a PLL circuit to generate the NS500V clocks from a master clock located in the DAC box.
i would try to squeeze in a single transformer but i would want multiple windings, and getting a custom transformer is expensive. would also be crammed with all the regulators (i will need at least 5). the external supply would be quite small (a plastic Radio Shack project box would do just fine), would connect conveniently to the unit with a DIN plug (so not much different in convenience than using an IEC power cord) and would require very minimal drilling (just enlarge the existing hole). CAT5 cable could be used to carry the multiple DC signals to the DIN plug. also i do not want to use toroids, i'm going to try split bobbin as it has better isolation than toroid. R-core would be even better but they are hard to find. i think trying to squeeze everything in the chassis would end up being more difficult if anything, i've thought it out and it is too tight inside.
First off - Thanks on the comments about where to get the service manuals!
So, does anybody have some more info on mods to a NC650V? I haven't taken mine apart yet... (guess I'll have something to do tonight then).
My main concern is that darn changer drawer and transport... I don't really think it's going to be very easy to get at all the boards in there to modify them... much less replace them.
I think upgrading this thing could have some really strong potential... I definetly want to replace the output opamps - I have a couple OPA2134s laying around at home yet. And, I'll definetly bypass those stupid lytic caps at the output. I will also be try to alter the supply power for the DACs and opamps as HifiZen noted on his NS500V. The supply decoupling caps also sound like a good idea.
Dorkus: Here, you mention that the NS500V has AKM DACs... Do you know if the NC650V does also? Also - do you have plans/schematics done for the new power supply?
So, does anybody have some more info on mods to a NC650V? I haven't taken mine apart yet... (guess I'll have something to do tonight then).
My main concern is that darn changer drawer and transport... I don't really think it's going to be very easy to get at all the boards in there to modify them... much less replace them.
I think upgrading this thing could have some really strong potential... I definetly want to replace the output opamps - I have a couple OPA2134s laying around at home yet. And, I'll definetly bypass those stupid lytic caps at the output. I will also be try to alter the supply power for the DACs and opamps as HifiZen noted on his NS500V. The supply decoupling caps also sound like a good idea.
Dorkus: Here, you mention that the NS500V has AKM DACs... Do you know if the NC650V does also? Also - do you have plans/schematics done for the new power supply?
dorkus said:
Custom transformers aren't too expensive. Victoria Magnetics is near my place here in Atlanta, and the owner will wind custom transformers for reasonable prices. He doesn't charge large setup charges. I have talked to him a lot, so if we decide to go with a seperate transformer, I can work out one with him, and we can get a reasonable deal. I got a small toroid for my BOSOZ from him.
--
Brian
disassembling a change takes some patience, but it's easy once you get the hang of it. i took apart my C222ES with no problems but there is also a step-by-step disassembly procedure in the service manual to guide you through it.
modifying the NC650 should be no different from modding the NS500V, apart from space considerations inside the chassis. i would go for it if you're feeling confident.
i used a OPA2134 i had lying around with good results as well. better yet, try a AD8620.
650V uses same mainboard as 500V, so yes, it has AKM DACs as well.
no schematics for the power supply yet, but i'll try to work something up soon.
cheers,
dorkus
modifying the NC650 should be no different from modding the NS500V, apart from space considerations inside the chassis. i would go for it if you're feeling confident.
i used a OPA2134 i had lying around with good results as well. better yet, try a AD8620.
650V uses same mainboard as 500V, so yes, it has AKM DACs as well.
no schematics for the power supply yet, but i'll try to work something up soon.
cheers,
dorkus
brian, lemme work out a rough draft of the supply schematic, and i'll try to estimate the size of the physical layout. the digital regulators i want to use are SMT so we may very well be able to squeeze things in. there is also a little bit of extra space behind the drawer mechanism if we need to use it.
dorkus said:
Here is a picture of my small BOSOZ transformer, on top of my two 1kVA Aleph 2 transformers:
http://www.prism.gatech.edu/~gte619j/transformers.jpg
Would that size work? An external chassis might be best.
--
Brian
http://www.diyaudio.com/forums/showthread.php?threadid=3971&perpage=15&pagenumber=3
you need to learn to look a little harder.
you need to learn to look a little harder.
Tieftoener said:
from that thread:
dorkus said:the 6-channel DAC is an AKM AK4357.
you can see the (albeit skimpy) datasheets here:
http://www.asahi-kasei.co.jp/akm/usa/product/audio.html
It was right there on the first page (40 per page)
--
Brian
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