Have you tried the zero oversampling mod? It's fantastic.

[lorcoll]

Hi.

I have modified my Philips CD-960 with this mod and the sound is now natural, dinamic and warm and fabulous with the horns.

Have anyone tried this mod in a CD-Player based on the TDA-1541?

It's extremely simple.

Here is the description:

The old 16x4 Philips CD-players can be easily converted to no-oversampling-digital-filter-less CD-players. Just open your CD-player and look for digital receiver SAA7210 (or SAA7310), for digital filter SAA7220 and for converter TDA1541. If you find them you can start to work. Please, remember you can find the 16x4 Philips chipset in many CD-player: Philips, Marantz, Quad, Cambridge, Rotel, Mission and more. Best CD-players ever made are in my opinion: Revox-Studer B226, Philips CD960, Marantz CD94 (but they sound 'dark and old style' without any modifications). They all use the hard solid Aluminium mechanism Philips CDM-1; IMHO nowadays the most CD transport mechanisms are very poor comparing to the old Philips Aluminium CDM-1. Modifications are very easy: just cut 3 traces on MB and by-pass the digital filter SAA7220 using 3 cables to get a real non-oversampling sound.

- The TDA1541 DAC has three connections to the SAA7220 (word, clock and data):

from pin 18 of the SAA7220 to pin 1 of the TDA1541

from pin 16 of the SAA7220 to pin 2 of the TDA1541

from pin 15 of the SAA7220 to pin 3 of the TDA1541

Look for these traces and cut them carefully using a cutter or a small drill. Now, using miniature coax (RG196), connect:

pin 39 of the SAA7210 (or pin 1 of the SAA7220) to pin 1 of the TDA1541

pin 38 of the SAA7210 (or pin 2 of the SAA7220) to pin 2 of the TDA1541

pin 37 of the SAA7210 (or pin 3 of the SAA7220) to pin 3 of the TDA1541.

Done! You can close your CD-player and start your no-oversampling listening lession.

But... the muting function (in the SAA7220) has been bypassed and the CD-player will produce

pops and crackles when skipping tracks and when the music starts. To restore muting function

connect pin 23 of the SAA7220 to pin 11 of the SAA7210. Easy! I want to thank Ryan that first made

the no-oversampling modification, Carlo that first made the muting restore trick and Recce for technical help.

And this is the link:

http://xoomer.virgilio.it/hi_fi/com.htm

Lorenzo

[sfogg]

You realize doing this is going to add ultrasonic aliases (noise/distortion) to your output.. right?

The analog filtering in your CD player hasn't changed. It is still placed for a system using oversampling... IOW the filtering is still further away from audible analog region.

Now you aren't implementing the oversampling (and the digital anti-alias filtering) so to prevent aliasing from getting into the output the analog filtering needs to be lowered to be below 22kHz and be made very steep.

Yet it hasn't been.

End resulting is you are adding ultrasonic noise and distortion to the output of your CD player.

Shawn

[sunnysal]

yup shawn is right...

[lorcoll]

Shawn,

I know that, but many think that the human ear is a better filter and in this way the signal have a good phase.

The sound is truly fantastic and more more better than the standard configuration.

Technically it isn't correct but to my ears it sounds more analog type.

Other links:

http://web.tiscali.it/rogers/misure.htm

http://www.sakurasystems.com/articles/Kusunoki.html

http://www.tnt-audio.com/intervis/kusunoki_e.html

http://www.wdehaan.demon.nl/mono/dactda1543.html

[sfogg]

"I know that, but many think that the human ear is a better filter and in this way the signal have a good phase."

Phase likely hasn't changed in any meaningfull way all. The analog filter is still in the signal path and the digital filtering can be made to not effect phase. You just filled the space from 22kHz to the analog filters will probably loads of noise and distortion.

"but to my ears it sounds more analog type."

Why? The ultrasonic noise/distortion could be causing ringing/distortion in the tweeters, modulation distortion in the tweeters, could make some marginally designed amps go unstable, might cause power compression in the tweeters...etc..etc..

"Other links:"

Look hard enough and you can probably find a link supporting any idea. Go back 15 years or so and read all the reviews of oversampling when it was getting integrated into CD players and the benefits it brought.

Shawn

[DrWho]

well of course it sounds more analog...there's more distortion

(that was meant in jest btw so no hard feelings)

[PrestonTom]

In fact, is the analog filter in the path?

My understanding was that by oversampling, the aliased frequencies are now shifted upwards and a anti-aliasing filter is now uneccessary or a very gentle one can be used (since the limited bandwidth of the speaker and our ears will in effect filter the aliased image).

Regarding the phase shift, this is a non-issue. The phase shift introduced by a filter (esp if it is a gentle or single pole filter) is small. Given that the phase shifts are near the corner frequency of the filter, a phase shift at a such a high frequency is certainly inaudible (trust me on this one).

-Tom

[lorcoll]

Ok.

I think: if the actual sound is in another league respect to the non modified CD-960, what can I hear if I modify the analog filter (or can I eliminate it)?

Can you tell me other simple mods in the analog section?

Anyway, one thing is true: never I return back to the harsh and metal sound of the original CD-960.

Lorenzo.

[Number 9]

My McIntosh MCD-7005 CDP is based on the Philips TDA1541A, also uses the heavy-duty Philips drive mechanism with glass optics which has become scarce.

I installed this little chip that not only replaces the 7220, but also adds a clock buffer, a more accurate clock, and converts to non-oversampling. Swapping one chip is a lot easier than rewiring the pins IMO. Also easily reversible.

http://www.net-audio.co.uk/tda1541nos.html

Maybe there is ultra-sonic noise going on, who knows ... sounds better to my ears. Maybe I like distortion. I certainly don't "hear" any of the potential negative effects described. My amp is not oscillating, and my Forte tweeters are not frying. Hey, I was skeptical too ... I didn't want to hurt my McIntosh amp or Klipsch speakers.

I installed a socket to be able to take the chip in or take it out during my A/B testing, and it always sound somewhat smoother with NOS. Adding a 1541A double-crown chip version also helped, but the biggest improvement overall came by swapping the op-amps in the audio stage. To be honest, my Mc CDP prior to mods never sounded harsh. But these changes overall added a lot more clarity and depth to what I hear. The op-amp swap was probably the most bang for the buck overall.

Too bad my McIntosh 7005 did not make into the best all time CDP list ... its built like a tank, and now sounds great (to my ears).

[Duke Spinner]

Mac ....

didn't make that player...

[sfogg]

"In fact, is the analog filter in the path?

My understanding was that by oversampling, the aliased frequencies are now shifted upwards and a anti-aliasing filter is now uneccessary or a very gentle one can be used (since the limited bandwidth of the speaker and our ears will in effect filter the aliased image). "

The analog filter is still very much neccessary,(it is what reconstructs the analog waveform) but like you said because of the oversampling it can be placed at a higher frequency (and slower slope) then if the DAC was running at native rate.

Shawn

[Parrot]

----------------

On 5/26/2005 5:36:50 PM sfogg wrote:

Look hard enough and you can probably find a link supporting any idea.

----------------

This is so true, I think it should be highlighted.

Look hard enough and you can probably find a link supporting any idea.

[Erinp]

Thanks Lorenzo,

I tried your suggestion on my Philips CD460, and..........WOW!!!!!.................... what a huge improvement.

Thanks for the clear instructions. I did the mod in about 15 minutes.

Its people like you who share their knowledge which makes Hi-Fi Audio (on a budget) a reality for many people.

This simple mod turned a dark, average, and congested sounding CD player into a lovely open detailed sounding player.

The HF is now alive and very realistic.

I suggest and recomend this mod to anyone who has an old CD player with the TDA1541 DAC - its easy and will yeild an immediate and noticeable improvement.

Cheers mate!!!!

[PrestonTom]

Although this is a very old thread, the problem remains. This is a bad idea!

My guess is that if you are hearing a difference, this added "detail" is simply distortion being added to the signal.

[DrWho]

I was just thinking that there is actually less phase shift when oversampling...in fact, less of everything bad. I mean seriously, why would the engineers put in the extra cost for something that makes it worse. Seems to me people are trying to "fix" imaginary problems they don't understand. In fact, I would go as far as suggesting that systems that sound better with this tweak must have some serious issues in other aspects of performance. When I get a spare moment, I'll have to go take a look at the datasheet for this component to see what all else is going on. D/A's usually have more ripple and higher distortion in their passbands when run at slower clock rates. And that's even ignoring the quality of the lowpass filter, which in this case isn't even being addressed.

[Erinp]

Hi Dr. Who,

Well, i wouldn't have believed the improvement either unless i had heard it myself.

I'm a qualified electronics technican, so ive learnt about nyquists theorum etc. All the theory says that you should filter the HF "hash". Oversamping moves the "hash" above the hearing frequency etc. etc.blah blah.........

Well after years of trying to find a digital player that reproduces "music" instead of reproducing a vague interperetation of music.. i have finally found a way of doing it that works for me.... Ive been listening to the modded cd player for the past two days and i just cant believe how realistic the music is. I mean jaw dropping to the ground.... big smiles.... OMG its that good. HF up to the sky and Bass to the ground, I mean im so happy because i was never happy with the sound of music off CD. I used to mostly like listening to Vinyl because the sound is generally more realistic but its a bit of a hastle and has problems of its own that we will all be aware of..........and so i was depressed that my only option was CD so I just descided to buy various DACs and try this and that and change op-amps capacitors etc... to try to find some digital source that makes music.

WELL THIS IS IT!!

As for the datasheet... who cares man... let the music flow... oversampling was developed by philips to compensate for their first 14bit audio dac before they developed their 16 bit dac... and i guess they just lost the plot. Remember the 80's,everything had to be "better and better" 4x oversampling 8x oversampling16x oversampling but i guess they justgot confused somewhere along the line and then all the companies started doing it cause its all marketing... if its 8x oversampling then it MUST be better than 4 its the 80's here man could you imagine a company trying to sell a Non overampling CD player for $800-$1200 in the 80's when the other guy is selling an 8x OS.... well thats probably something like how it went. Maybe the engineers did know but couldnt do anything about it because of marketing???? I dont know????

If you are skeptical just try it for yourself.... it will take anywhere from 15min onwards to do this mod. And then you can let me know what you think about the sound. I mean when you look at Viny how on earth could it possiblysound good.. a tiny groove,dust,a diamond stylus.tiny electrical signal,pre amp,tracking error,pre/post echo - but it sounds good!!!!! and thats what matters.

Therory says that lots of things shouldnt work but people try them and it ends up working, and thats what matters.

Anyway this is my personal opinion

which i wanted to share with others for the sake of making the world a better place and music a better experience for all to listen to.

Best of luck, peace man :-)

[PrestonTom]

No one is denying that this modification will make things sound "different". If you like the result, then great and enjoy it. However, the rest of us will remain skeptical about whether this difference is an actual improvement.

[Don Richard]

I was just thinking that there is actually less phase shift when oversampling...in fact, less of everything bad

Doc, are the digital filters in a CD player Infinite Impulse Response? If so, why not use Finite Impulse Response filters? Is anyone, in fact, doing FIRs in a CD player? It seems like phase shift would be greatly reduced with thier use.

[jacksonbart]

I hear magic rocks work well too, as long as they are not over sampled and over polished.

[Erinp]

Well, bearing in mind that the title of this thread was "Have you tried the zero oversampling mod?"- I was just replying to the person who started it and was thanking him for his suggestions,and also agreeing that it is fantastic.

I think that being skeptical is a good thing, we certainly should not go around believing everything that we are told. We should go and try things for ourselves.

We should have our own thoughts and opinions and experiences.

I bothered to try this mod because there are so many people giving positive feedback and reviews of NOS Dacs/CD players on the internet - Google it and see what im talking about.

I certainly in no way was suggesting that enjoyable results cant be achieved using oversampling or modern Delta Sigma DAC processing. - I have tried these methods and i personally think that Non Oversampling has the edge (to put it mildly)

I was just intending to add to the vast body of feedback. Considering that this mod is easy and that there are so many NOS DACs and kits available why not just try it for yourself? None of them are particularly expensive. Hey you may end up liking it.

Anyone else tried it yet?

P.S.

FYI, im totally agianst all that magic rocks "HIFI" nonsense, mostly because the magic rocks always seem to cost $$$$$$$$$.

What i am into, however, is good sound - preferably costing me as little as possible, and that is something that i would never lie about.

Thanks