0 oversampling, Filterless DAC NOT $$$ Audio Note/47labs!

[rtsyrtsy]

http://home.student.utwente.nl/f.s.bouw ... nonoz.html
http://home.triad.rr.com/scottnixon/dac.htm

Check it out, folks.

The 1st one is DIY. Any idea on cost? Are parts available here? It has a passive output stage so signal that comes out is only at 1V (vs. 2V typical of CD players).

More Questions:

1--can a tube output stage be built into this?

2--(this may be stupid) since output is only 1V, can I use the phono stage on my pre amp?

The second one is available US$350 assembled and I think <US$300 in kit form. Any feedback from your worldwide network of audio nuts on this?

One complaint on the 2nd model is the wall-wart that comes w/ it. Did I understand it right that it uses 12VAC, same as the output of my X-PSU?

It might be too early but any interest for a group buy?

[yeo]

do check out http://www.diyparadise.com/rm20dac.html

this thing only cost me rm20 to build. yes! that cheap! well, i avoided using cs8412 which is quite expensive (~usd15).

man, if you own a marantz cd63, you have lots of goodies to play with. ditto with cd57, cd67...

i'm still optimizing it but it's a good start!

yeo

[rtsyrtsy]

Thanks, Yeo!

Questions:

1--How different would a NAD 502 be?

2--How did your Marantz sound after conversion to zero oversampling?

[yeo]

1--How different would a NAD 502 be?

2--How did your Marantz sound after conversion to zero oversampling?

hmm... i wouldn't know how different would a nad 502 be. i have the marantz cd63 service manual and i practically worked my way from there. of course, all other resources from the net helped a lot! do you have the service manaul of the 502? if you have, please forward it to me, and i'll try see what i could come up with.

at present, i coudln't really tell the sound yet. the voltage output is still too low. one option is to use opamps or tube for gain stage but i'm trying to avoid that route for now. don't want to get too complicated.

just tried raising supply to 8v, piggy-backed 4 pieces and it's still too low. dang!

don't worry, i'll try my best and once this is sorted out, it'll be on my website.

yeo

[rtsyrtsy]

at present, i coudln't really tell the sound yet. the voltage output is still too low. one option is to use opamps or tube for gain stage but i'm trying to avoid that route for now. don't want to get too complicated.

Very stupid question so if you folks would throw tomatoes at me, make sure they are still crisp so I can turn them into salad, OK?

If you take that low voltage output from your CD63's DAC and feed it into a phono stage on a pre-amp, will it work?

Next question, how may I procure service manuals for my NAD 502?

[vintage_dog]

If you take that low voltage output from your CD63's DAC and feed it into a phono stage on a pre-amp, will it work?

russel, all phonstages have a special RIAA circuitry that equalizes the signal coming from the records into something that is "listenable". even if you feed a very low signal from a CDP into a phonstage, you will get an amplified sound that's very unbalanced, not listenable at all.

[rtsyrtsy]

Oh yes, RIAA. Actually, oh no, RIAA!

Any way to kill the RIAA circuitry?

[yeo]

thanks to vintage_dog for clarifying the RIAA issue.

rtsyrtsy, try to contact NAD and see whether they are willing to give you the service manual.

it's very useful to have the service manual. a lot of mods can be performed on it!

yeo

[vintage_dog]

Next question, how may I procure service manuals for my NAD 502?

i have the operating manual but not the service manual. my NAD 502 needs some repair - clicking digital sound when selecting tracks. if anyone knows anyone fix CDPs, let me know. thanks

[toobs]

Hi rtsyrtsy,

Will check out the sites you mentioned above.

When I was looking for an upgrade to my Marantz CD-67SE, I was looking at the Heart 6000SE and the Audio Note Dac 1.2. At the end of the day I ended up getting a rotel 1070 due to;

a. Heart 6000SE - the US distributor was so strict that he does not accept any credit card outside the US.

b. The Audio Note Dac 1.2 - freight cost wil cost me a fortune when shipped from Canada. Then I also need to purchase a new CD player with good transport since my Marantz 67SE is already retiring its lenses.

I would have bought the Audio Note for its upgradability and the big chassis is a big advantage for DIYs like myself. You can then use your NAD as transport. Why not check out the Audio Note? Their assembly manual is very user friendly based on my previous experience with their preamps. It even comes with a fully assembled digital board which is a big plus for DIYs since ICs are more delicate to solder on the boards. The analog boards are relatively easy to build over the weekend and I can help you in the building part.

toobs

[yeo]

hi toobs,

don't discount the marantz cd67. or 63 for the matter. with a little modifications, they are really excellent! great value for money!

the optical lens part does wear out quick but can be quite easily replaced. i have replaced mine and it's not that difficult.

i'm also done with optimizing my dac in my cd63. hey, you coudl try this too!

yeo

[rtsyrtsy]

Will check out the sites you mentioned above.

Thanks! I really would appreciate your inputs since as you all know, I'm an electronics dummy.

a. Heart 6000SE - the US distributor was so strict that he does not accept any credit card outside the US.

Our fellow Pinoydiophile, Ferdi Ludo of Sounds & Images Cebu distributes the Hearts here now. CD6000 OSE LE at <PhP65k, CD5000 at <PhP40k, CD4000 at <PhP30k. Call him for exact prices. Stocks run oput pretty quickly.

To the Cebu-based Pinoydiophiles or to whoever has heard these models, please share your comments. I know I've gotten your views verbally but it'd be nice to share them with other Pinoydiophiles here.

The stock Marantz CD6000 OSE is being sold by Rene Rivo for <PhP20k. Hmm, over PhP30k difference from the Heart. I'm sure the board's DIYers are already imagining the possibilities.

b. The Audio Note Dac 1.2 - freight cost wil cost me a fortune when shipped from Canada. Then I also need to purchase a new CD player with good transport since my Marantz 67SE is already retiring its lenses.

I would have bought the Audio Note for its upgradability and the big chassis is a big advantage for DIYs like myself. You can then use your NAD as transport. Why not check out the Audio Note? Their assembly manual is very user friendly based on my previous experience with their preamps. It even comes with a fully assembled digital board which is a big plus for DIYs since ICs are more delicate to solder on the boards. The analog boards are relatively easy to build over the weekend and I can help you in the building part.

Ah, in my still endless digital source search, I have heard quite a bit. Those I like in order of preference are:

1--Audio Note 2003's Audio Note CDT-1 & DAC 2.1x (heavily modded by now to all tantalum, etc.) in an all Audio Note system
2--Audio Note CDT-Zero & DAC One.1x using my headphone system
3--Ah! Njoe Tjoeb 4000 w/ upsampler in my reference system (Hyperion's, he-he)
4--QDS15, a.k.a. nOrh CD1 in Hyperion's system w/ Svet's, right, Epoy?

The Rotel 1070, MF A324, and Arcam CD72 are also in the list but unranked due to absence of tubes. This is all your fault, guys, I now look for glowing tubes in all my gear!

Audio Note stopped selling their kits already or I think they're just finishing off stocks. Peter Qvortrup is fixing up his operations daw so till that's done, he'll stop kits.

As Ferdi knows very well, I'm sold on the Audio Notes. Just not yet on their price. I've actually stashed the funds away already (and already duly converted to the correct currency) for a CDT-Zero/DAC One.1x but still can't get myself to part with the hard-earned dough.

My father is Ilokano.

While the Nixon DAC is "just" $350, I haven't gotten around to getting it since I can't convince myself that I'd stop dreaming about them Audio Notes even after the Nixons.

As for transport if I go w/ the Nixon, probably my Pioneer DV525 (this handily kicked my NAD's butt as a transport). The 502 goes w/ the 34.1 to the office waiting for my future AKG K1000. The HT gets an entry level prog scan player.

Sorry to the Pinoydiophiles who by now must be very tired of my digital source saga.

[rtsyrtsy]

i'm also done with optimizing my dac in my cd63. hey, you coudl try this too!

How's it sounding?

Am I understanding it correctly that if you take go non-oversampling, you automatically go filterless?

[yeo]

How's it sounding?

well, compared to stock, i find it more high end now. the cd63 actually has quite some bass. stock player doesn't have but after some simple mods here and there, and you'll be smiling like an idiot. you can find lots of info on the net on how to modify the cd63. here's a good one.
http://www.tnt-audio.com/clinica/cd67.html

Am I understanding it correctly that if you take go non-oversampling, you automatically go filterless?

output wise yes. no need for digital filter, no need for complex analog filter. in fact, don't have to worry much about jitter as there's no oversampling here.

yeo
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[rtsyrtsy]

Are you taking the analog output signal straight from the DAC now or did you put in a line stage to bring level back up to 2V?

If yes, what did you do? A pair of 6922s?

[yeo]

Are you taking the analog output signal straight from the DAC now or did you put in a line stage to bring level back up to 2V?

If yes, what did you do? A pair of 6922s?

the beauty of the 1543 is that, you don't need another gain stage. you can parallel or piggy back a few pieces. most folks parallel 4 pcs to get up to 2v output. if using 1 pc, then will get something like 0.7v or less. i don't know, i can't measure it. i have a test cd track that puts out 0db but my cheap multimeter doesn't tell me anything useful.

if you wish, you could definitely put in a tube gain stage!

yeo

[rtsyrtsy]

Another electronics dummy question: does the piggy backing solution invert phase?

[yeo]

Another electronics dummy question: does the piggy backing solution invert phase?

piggy back means, i place another chip on top of the existing chip. it's like paralleling them but without taking up much space. as such, it doesn't invert phase at all.

this dac by design inverts phase though.

yeo