Best way to hook up SDDS to CP500 Thru Analog Acc Rack Connection

[Frank Raia]

According to Sony bulletin TN99061402, SDDS DFP-D3000 should be hooked into the CP500 Analog Acc Rack connection. That works for me because all the other inputs are already being used. The bulletin instructs to use pins 2 thru 7 for input into the Analog Acc rack connection. Dolby Ref diagram says that those pins are direct input to the 682 card. I believe this bypasses all of the CP500 and is a direct out.

What would happen if I connected the SDDS to pins 15 thru 19 of the Analog Acc rack connection. They say Input To Noise Reduction Resources.

[Tj Hopland]

If you scroll through the possible pre built formats is there one that seems like it could be for that 2-7 input or does that doc say what format to use? My guess is Sony said this because they want you to use their EQ and level set and such and that direct connection was probably some sort of input used for studio sorts of things.

The 15-19 would have been used for magnetic like 70mm and studio stuff which usually required NR. For more than 2 channels of NR (35mm optical) I think you needed a daughter board that let you plug in more NR cards. My guess is to get any of the formats that would use those inputs to activate you need that daughter board and possibly the NR cards installed. I'm guessing that if there are no NR formats available they would still require the cards to be there and just go into a bypass mode. Format 40 I think it was doesn't use NR but used the academy filter so even if that worked without the NR cards that would still not be ideal. I'm not sure where the academy filters are in this later family, they could also be on the NR cards since this used the sort of next gen 2 channel cards.

Note that part of the 70mm kit other than the NR cards and daughter card was I think the 685 6 channel A to D card. You said your other inputs are being used which I assume means the 6 channel input so you probably already have that card.

You can assign unsupported formats to the front panel and a little circle with the slash symbol will appear meaning you don't have the hardware installed to support that format. The 500 would let you do some custom stuff with the formats but I seem to recall still had limits so a custom format may not help you either.

I think there was going to be an actual accessory rack chassis for the CP500. Seems like I saw a prototype at a class but I don't think it ever went into production because the digital sound formats pretty much took over so there was very little to no demand for a bunch of analog stuff especially since at the time they were still supporting the CP200 so if you wanted a bunch of legacy stuff and the new stuff you could just update your CP200.

[Marcel Birgelen]

Ah... SDDS... Just out of curiosity... Since you're going to use the CP500 as master, you're not going to run SDDS-8. Is there any specific reason to keep SDDS running, other than nostalgia?

For optimal results when running SDDS-6 with the CP500 as master, you should do the room EQ and setup on the DFP-D3000 and use the CP500 solely as "pass-through". That's why you want to use Pin 2 to 7 on the ACC connector. The other pins, like Tj Hopland indicated, will do NR on your signal and that's most definitely not what you want.

You need to create a User format on the CP500, where you open up the ACC channels and map them to the correct output. Also, you need to assign the format to SK6 if you want automatic fallback to the CP-500 if SDDS fails.

If I remember correctly. the DFP-D3000 came with a pre-made D25 to D-37 cable or our supplier back then supplied it for us. Anyway, if you don't have this anymore or cannot use it, because you're already using other pins for other stuff, the DFP-D3000 manual should have the right pinout of this cable.

[Frank Raia]

[QUOTE=Marcel Birgelen;n57317]Ah... SDDS... Just out of curiosity... Since you're going to use the CP500 as master, you're not going to run SDDS-8. Is there any specific reason to keep SDDS running, other than nostalgia?

Marcel, this is not a theater set up, it is in my basement as a hobby and for nostalgia reasons. I added SDDS just because I could. I wanted to have all 4 sound options ( SR, DSR, DTS, SDDS). There really is no need for SDDS 8 channel for the small space that I have. I did make a user format and mapped the channels as outlined in the Sony tech doc. Also made my own cable and everything works.

Reading past posts that said it was preferred to use the cp500 for eq rather than sony, I was confused by this setup.

[Marcel Birgelen]

If you want to use the EQ from your CP500, I guess you're going to need the Cat. 685 for that and connect it via J7/J8 instead, then you can use Format 11.

[Frank Raia]

I have the 685 card but it is being used for DTS and DVD video surround

[Marcel Birgelen]

I'm afraid you're out-of-inputs then.
You need something external to switch between sources then... or have to put in the work to calibrate the DFP-D3000.

There just was a recent discussion about an A/B switch for AES in another topic.

[Tj Hopland]

I would start with scrolling through the possible pre built formats and see what's there that may look promising. If there are any you may have to load one to one of the 8 buttons to see if its got the little no symbol. Otherwise go in to edit a user format and see what options it gives you for inputs to start. With user formats I don't recall how they handle unsupported options. I don't recall if it just won't let you select say the 6 channel input if you don't have the 685 card or if its like the prebuilts where you have to load it to a button to see if its supported.

[Marco Giustini]

Reading past posts that said it was preferred to use the cp500 for eq rather than sony, I was confused by this setup.

Interesting. The CP500's SR capabilities are superior than the SDDS' but in terms of EQ I thought the DFP3000 was the superior choice.

Just bear in mind the Sony - as any "pro" gear - is a ZERO HEADROOM device. That is, if you turn up one gain of 1dB, full amplitude signal WILL CLIP by 1dB. If you use positive EQ or gain, you'll have to counter that somewhere else to avoid clipping.

This is something that never existed with Dolby (or Cinema) processors which were build with about 27dB of extra headroom in them to basically avoid any sort of EQ/levels to be applied and still avoid clipping. Dolby's approach is safer but compromises in S/N ratio.

[Steve Guttag]

Sony cheats to make their systems sound brighter. Their Pink Noise is a little HF deficient. So, if you tune your systems identically, the Sony will have a little more high end. I once did a triple shootout (Dolby Digital vs DTS vs SDDS).

[Frank Raia]

Sony cheats to make their systems sound brighter. Their Pink Noise is a little HF deficient. So, if you tune your systems identically, the Sony will have a little more high end. I once did a triple shootout (Dolby Digital vs DTS vs SDDS).

So in my tiny space the highs will be even more high I guess. Do you have any suggestions on which freq's that should be cut? Ones that sony boosted?

[Marcel Birgelen]

Sony cheats to make their systems sound brighter. Their Pink Noise is a little HF deficient. So, if you tune your systems identically, the Sony will have a little more high end. I once did a triple shootout (Dolby Digital vs DTS vs SDDS).

Back in early 1999 we ran such a "shootout' with "Enemy of the State" in the same room. We did a blind test, those who knew what format was being played weren't allowed to vote. I remember that DTS won with a small margin, but none of the formats had a really clear advantage.

In my biased opinion, I was always under the impression that Sony's SDDS handled the high-end frequencies better, while SRD had a better low-end. Being a former avid MiniDisc user, I always found that ATRAC handled high-end better than most MP3 alternatives at low bitrates.

Both DTS and SDDS had significantly higher bitrates than SRD and I always thought that you could hear this in the more complex parts of the sound track, all other things being equal. The differences were pretty small though. But MPEG Layer 3 has the tendency to sort-of "whisper" at lower bandwidths and during complex soundscapes. These kind of artifacts were pretty common in the 1990s and early 2000s, when many radio stations used MP3 over ISDN for live audio transmissions. Maybe I'm hearing ghosts, but I sometimes think I can hear those same artifacts in some SRD soundtracks.

[Marco Giustini]

Ah yes, the cheating Sony pink noise!
Can you use the CP500's pink noise if it goes through the DFP?

I know it's a debated subject but my experience with mainly SRD and DTS was that they were both great sounding systems. To catch some minor difference you'd need a VERY good auditorium, very well tuned and also hope that whatever difference you were hearing was not due to bad mastering. My experience also suggests that a well aligned SRD on a decent and clean projector would be more reliable than the average DTS machine. Too many things could go wrong with DTS: mechanical drive failure, readers not working well for whatever reasons etc. When working, DTS was bullet proof. When working.

[Steve Guttag]

Whenever I did the shootout. Either there was no clear winner or Dolby Digital won by a slight margin. At the Uptown, for those that thought that they preferred one or the other...I'd switch systems on the changeover and then ask them to tell me which reels sounded better. Again, either no noticeable difference or Dolby won.

To my ears, DTS never sounded as good as the other two, particularly on the high-end. DTS also didn't have bass on the surrounds since they were using those tracks for the subwoofers. A particularly bad combination was DTS and EV speakers (with a DH1 compression driver). That is so painful I can't sit through the movie.