Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!uwm.edu!csd4.csd.uwm.edu!info-high-audio-request From: tomp@vicom.com (Tom Pohorsky) Newsgroups: rec.audio.high-end Subject: Re: Phillips DACS Message-ID: <6809@uwm.edu> Date: 8 Oct 90 13:00:17 GMT Sender: news@uwm.edu Lines: 58 Approved: tjk@csd4.csd.uwm.edu > Can you submit another article about this mod? It's the first I've heard of > it. Moderator: feel free to post any or all of this. I was leafing thru the Philips data book on audio IC's and noticed later revisions of chips for both the DAC (TDA1541) and digital filter (SAA7220), compared to what was in my early CAL Tercet player. So I thought, hmm simple chip swapping even I can do. I posted a call for info on these and received the following: ****************************************************************** From: Message-Id: <9004011818.AA14770@a.inf.ethz.ch> Subject: Re: upgrading Philips DAC's >Organization: Informatik ETH Zurich There is even a better version, which is pin-compatible. They are called TDA 1541 A 'Silver Crown', also pin compatible. For getting the full 3 dB enhancement, you need to exchange the SAA7220A versus the SAA7220B. These are the digital filters. Both, they make really a big difference in sound quality, i can tell you ! Greetings - Urs Schaltegger, Zurich, Switzerland ****************************************************************** I talked to a rep at Philips/Signetics and he said the "Silver Crown" (aka TDA1541A-S1) was the standard chip, but represents individual chips selected by Automated Test Equipment as having very good linearity. While the filters are pretty easy to get (SAA7220B is the latet rev and only version they ship now), the warehouse had a policy of shipping S1's only 15 or more at a time. A fair bit of begging and luck got them to ship only 3 (I was modding 2 other similar players). If you don't have the wholesale connections thru work, you can get these from Euphonic Technology, note their ad in Speaker Builder, but their cost is ~$130 a set, vs $60 wholesale. Pretty much every player is going to have the chips soldered to the board. Fortunately the (very good) rework person in our lab volunteered to take out the old chips and solder in sockets for the new. This is a pretty touchy operation, probly best done with one of those solder vaccuums for sucking up the old solder. Results are subtle, but noticeable. A definite improvement in low- level detail, and easier to listen to all around. You'd want to be a real hobbyist to do this yourself, unless your as lucky as I was. good luck. -- ames!vsi1!tomp tomp@vicom.com