Compact disc player sonic differences by various signal procesing devices before DAC

[tiefbassuebertr]

There are many informations and discuss about the sound of various digital to analogue converter units and jitter reduction methods. But I don’t find informations about the sound influence of the various decoder technologies. At bottom I listed examples of good known chipsets (except that one of first generation), where as the first three I would prefer. What are your experiences regarded different sonic quality only concerning the part before DAC?

Philips (used in a wide range of high end cd player models)
1) M4804A/SAA7210 (PCM Dec) SAA7220P/B (PCM-Decoder)/ uPD41416C (dynamic RAM/FiFo) TDA 5708, TDA5709 (RF/Servo)
2) SAA7310 (PCM Dec) SAA7323 (Servo) TDA 8708, TDA8709 (RF/Servo)
3) SAA7324 (newest PCM Decoder from NXP, inside by VAM1254/CDpro2LF)

Sanyo (found in cheap but very good sounded NAD 5325)
LA9200NM (RF/Servo) LC7863A (PCM-Dec.), LC3517-B5-15 (S-RAM)

Hitachi:/Sony (found in Linn Karik)
CXD2500Q (CXD2500AQ, CXD2500BQ, PCM Decoder + DF) HA12158NT (HA12158, RF/Servo, Hitachi/Renesas)

Mitsubishi/Philips
M27256FI (PCM Dec) SAA7220P/B (PCM-Decoder)/ uPD41416C (dynamic RAM/FiFo)
TDA 5708, TDA5709 (RF/Servo)

Mitsubishi/Sony
M51564P (Optical Pickup Servo Control, SSOP-36) M50422P (PCM-decoder, QFP-80, 80P6-B, Mitsubishi), M5M4416P-15 (dynamic RAM/FiFo) CX20109, SO-24, RF, SONY),

Matsushita/Panasonic/Technics
8802SC56.4 (MN8802(?) RF-amp MN66271RA (Servo), Technics 8389S (= AN8389S, Servo-Driver+Output Stage) RJB 1123A /CU3C (PCM Dec)

SONY
1)CX20109 (20109, SO-24, RF), CX20108 (20108, SO-30, Servo), CX23035 (QFP) MP8416-20L (dynamic RAM/FiFo)
2) CXA1081S (RF) CXA1082BS (Servo) IC103: CXD1135Q/CXD1165Q/CXD1167Q (Dec, QFP 80-pol, formerly Version: CXD1125Q (PCM Decoder, QFP) with UM6116M-2L (dynamic RAM/FiFo)
3) CXD2500Q (Dec, QFP), SM5840DP (DF, NPC), CXA1471S (HF), CXA1372Q (Servo, QFP)
4) CXD2500AQ (PCM Dec), CXD2552Q (Servo), CXD1244 (DF) KSS240 include RF-Amp

[flavio81]

You have completely ignored and forgotten the first generation philips TDA1540/TDA1541 players. Consequently, you will never reach audio nirvana...

[just joking ]

[tiefbassuebertr]

both TDA 1540 and TDA 1541 are digital to analouge converter (DAC) !!! That should be not the topic.

[Eric Juaneda]

Hi tiefbassuebertr,
Few years ago I wrote an article about listening digital filter. I have a player where you can choose different digital filter.
You can find on my web site: Listening digital filter

It's a very interesting discussion. Each digital filter has its own sonority.
I have at home during one year many DAC with various digital filters like SAA7220, Wadia or DAX with various algorithms. It's very interesting to listen to each of one.

Some "digital sound family" is often introduced by digital filter and not digital process.

[tiefbassuebertr]

Thank you for your advice to this website.

[AndrewGM]

I agree with Flavio81

[tiefbassuebertr]

Originally Posted by AndrewGM

I agree with Flavio81

DAC IC's are not the subject of this discussion (is my english so bad ? Please read the headline carefully).

[SoNic_real_one]

Agree that the filter chip makes a difference. But don't forget the controller for the RAM buffer needed to eliminate the optical mechanism low-frequency jitter (there because of tracking imperfections).

Right now I am convinced of the utility of a DSP post processing. The cheap chips that do OS/digital filter don't seem to have enough processing power to do a proper interpolation, noise shaping dithering, upsampling, etc. FIR taps and bit depth are limited by the silicon proformance in the year that the filter was designed. Poor on SAA7220, better in SM5847, even better in DF1706... but always limited.
I have the Denon AL24 Processing Plus and beats clearly the other old timer SAA7220 or the other PCM DAC's without DSP processing (that I have too).
I did hear also the Anagram's ATF in a CA Azur 840C and CA DACMagic... they are better than any dedicated cip filter ever made.
Even the Harman Kardon HD990 sounds better than a "normal" player - but I didn't have enough time to listen it properly (just in demo store).
Some companies, recognizing the limits of integrated fiters, sell custom-made DSP filters as upgrades for their equipment.

DSP-based filters have also the advantage to separate the jitter domains using a bigger buffer memory. None of the integrated chips have that ability. This is maybe more important than the quality of filtering and upsampling.

PS: Of course this apply only to CD sources. On higher resolution DVD-A, the differences are diminishing to none.
PPS: Independent opinions, not identical with my findings, but conclusion is the same - dedicated DSP is the best solution.

[adason]

do not forget the JVC JCE4501
JVC legendary DD converter

[studiostevus]

I am curious what you guys think and know of the "S.T.A.R.S." system developed by Anagram Technologies (swiss) and used as preprocessing in Audio Aero players?