CP650 Issue

[Steve Guttag]

If it is film that the person wants...there are STACKS of 35mm film processors available, not just the CP650. You could put a CP65 in, if you wanted, with a DA20 (for which there are stacks to be had, as well).

I have a site where film is due to go in on the next phase of renovation/construction. The booth was laid out for 3-projectors. The film processor will be a Panastereo CSP1200 with a DA20. Worried about those failing too? There are three of each that customer owns on their own shelf (from their film days) and they have one other site already with film using the same equipment.

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As for recapping a CP650 to keep it going. Go for it. I have no objections to the effort. The CP650 does, in a neat package offer most of the film needs/wants. I've done it myself, in the not too distant past (NMAAHC museum in DC) and treat film as a source on their Digital Cinema processor (DCP 200, I think it was my last film system before I started putting in Q-SYS and the site needed most everything the DCP 200 had, right out of the box, including a booth monitor!).

[Marcel Birgelen]

I've never tried the Heisenberg compensator on the CP-200, but I guess you can confirm it just works beautifully?

[Leo Enticknap]

If it is film that the person wants...there are STACKS of 35mm film processors available, not just the CP650. You could put a CP65 in, if you wanted, with a DA20 (for which there are stacks to be had, as well).

If refurbishing two decade-old equipment and then keeping it on life support is a viable option for a given venue/project, then by all means. Doing that will mean having a tech available who is comfortable doing circuit bard-level diagnosis and repair, and coming up with creative solutions for situations in which replacement parts are no longer available from the OEM. It also means accepting that reliability will likely not be what it would with currently supported equipment, and down time may be longer if a problem happens.

However, if it is desired to install equipment that is fully supported, and for which any fault can be fixed by swapping out a component that the OEM has ready to ship overnight, and by a tech who is competent, but not to the extent of doing surgery with a soldering iron, then if you need 35mm film audio capability, your options are now very limited. AFAIK, the AP25 with the H338 card is the only one.

[Steve Guttag]

Tell me Leo...what is the failure rate on a CP65? You are talking about rather robust circuitry. It was, seemingly designed around high-availability, high reliability components (TL07x Op amps, CD4000 CMOS switches)...so the best fix is the one that you don't need. There is less to fail with the CP65 and its ilk. And, again, there are stacks to be had so sell two of them and calibrate both cards for full redundancy without the need beyond being able to pull a board and put in another. The last Panastereos I sold new, for a client running film, I did just that...the spare cards are on site, in a box and labeled as such. My goal was to ensure that for, at least 20-years that the system would make it. Heck, the AFI/Silver has a spare CP200, all tricked out, on the shelf plus dual power supplies. Want to know how many times it has needed service? Zero.

As for NEW equipment, yes, the AP25 is the choice, I believe...unless you want to roll your own with something like QSYS and then deal with NR and film based digital audio externally (which the AP25 has to do for Dolby or SDDS).

I hope the AP25 remains available as people that have them seem to love them. It is not a processor we ever went to. We used Dolby, Panastereo, Rane, QSC's Basis/DCPs and now QSYS. You have to admit, there have been times when DTS/Datasat was on questionable grounds with an uncertain future.

[Marcel Birgelen]

Dolby NR in the different incarnations could be done entirely in software, but licensing may be a challenge. Film-based digital audio remains a challenge, difficult to solve without extra hardware.

[Steve Guttag]

I suspect that licensing SR or A isn't a challenge as their patents are long gone and as for software...Dolby did it with the CP650, USL and DTS have done it with their respective processors. Of course, one could also obtain some 363 frames with CAT300s and be set for life too. The problem with someone else, say QSC doing a software emulation is that they would have to expend resources to develop that for what could, even optimistically be, a "niche" market. How many people, even in pro-A/V are looking for a software emulation of Dolby A or SR?

[Scott Norwood]

It would be an interesting move for Dolby to license the CP650 software A/SR decoder to QSC (and/or others) for use in their products. It would basically be free money for Dolby, plus cinemas could use a modern processor and correctly (and legally) advertise "Dolby Stereo."

[Marcel Birgelen]

I suspect that licensing SR or A isn't a challenge as their patents are long gone and as for software...Dolby did it with the CP650, USL and DTS have done it with their respective processors. Of course, one could also obtain some 363 frames with CAT300s and be set for life too. The problem with someone else, say QSC doing a software emulation is that they would have to expend resources to develop that for what could, even optimistically be, a "niche" market. How many people, even in pro-A/V are looking for a software emulation of Dolby A or SR?

While certainly a niche, Dolby's analog NR technologies have been used for other purposes too, like tape recordings. A "software DSP implementation" of Dolby NR products could've a broader appeal and maybe even something Dolby could come up themselves and license to other parties, a bit like Scott indicated.

[Mark Gulbrandsen]

Tell me Leo...what is the failure rate on a CP65? You are talking about rather robust circuitry. It was, seemingly designed around high-availability, high reliability components (TL07x Op amps, CD4000 CMOS switches)...so the best fix is the one that you don't need. There is less to fail with the CP65 and its ilk. And, again, there are stacks to be had so sell two of them and calibrate both cards for full redundancy without the need beyond being able to pull a board and put in another. The last Panastereos I sold new, for a client running film, I did just that...the spare cards are on site, in a box and labeled as such. My goal was to ensure that for, at least 20-years that the system would make it. Heck, the AFI/Silver has a spare CP200, all tricked out, on the shelf plus dual power supplies. Want to know how many times it has needed service? Zero.

As for NEW equipment, yes, the AP25 is the choice, I believe...unless you want to roll your own with something like QSYS and then deal with NR and film based digital audio externally (which the AP25 has to do for Dolby or SDDS).

I hope the AP25 remains available as people that have them seem to love them. It is not a processor we ever went to. We used Dolby, Panastereo, Rane, QSC's Basis/DCPs and now QSYS. You have to admit, there have been times when DTS/Datasat was on questionable grounds with an uncertain future.

Its not failure rate Steve, so much as it is slow deterioation of sound. Not so much a problem with the tantalums as it is with the electrolytics. And there are much higher grade electrolytics that can be installed today vs. what could be bought back when those were manufactured.

[Steve Guttag]

Yeah, okay. You are talking about either optical sound, which, itself, has a very limited dynamic range and frequency response and digital on film, which uses a rather small portion of B-Chain and when used in a combo film/DCinema system, often is barely using anything (no need for separate EQs and such). Go ahead, recap and trick out a CP65 and put it up head-to-head with an existing one (that works) and have an audience A-B them and see if their is a notable preference for one. This isn't esoteric hi-fi stuff. This is sound played through a sheet of vinyl.

[Mark Gulbrandsen]

Yeah, okay. You are talking about either optical sound, which, itself, has a very limited dynamic range and frequency response and digital on film, which uses a rather small portion of B-Chain and when used in a combo film/DCinema system, often is barely using anything (no need for separate EQs and such). Go ahead, recap and trick out a CP65 and put it up head-to-head with an existing one (that works) and have an audience A-B them and see if their is a notable preference for one. This isn't esoteric hi-fi stuff. This is sound played through a sheet of vinyl.

Steve, Analog SR is not exactly what I would call a limited bandwidth system. It's full range on any properly set up A chain and quite often sounds better then the DD counterpart. Also, you overlook the fact that not only do capacitors today sound better... it's because typically exhibit way less phase shift and distortion then older ones did... so they actually sound far superior to the old crap that was being used. Why do you think Norm used all WIMA capacitors in the Panastereo's. It's all about sound quality bub. Also, those pesky full range digital systems fed many of the processors out there and still do. And all those aux and digital inputs are all analog too. CP-65, CP-200, CP-500. Today the Rubicon and Nichion audio grade electrolytic's are miles ahead of what was being used. Since Dolby often used pretty decent analog IC's... there is no reason for the rest of the signal path to not be as good.

[Mark Gulbrandsen]

Dolby NR in the different incarnations could be done entirely in software, but licensing may be a challenge. Film-based digital audio remains a challenge, difficult to solve without extra hardware.

The ORC digital system was actually the best sounding and had a lot of advantages as far as sound quality. It was just not robust enough on the film to be reliable.

[Steve Guttag]

Mark, optical SR is STILL pretty limited dynamic range. First off, Dolby NR applies NOTHING above reference level or 50% modulation. So, without altering the level, if one tunes to 85dBc you only have 6dB more level to attain on optical films, if you went to 100% modulation...for which you are on the cusp of clipping the signal. Yes, Dolby SR for optical did apply a 3dB boost to the level so the max output is a whopping 94dBc if you are on the edge of clipping. With Dolby-SR you take optical sound which is on the order of 45-50dB S/N and bump it out to about 65-70dB S/N (or about that of a cassette deck). SR gets you another 10-15dB but still not really in the league of either magnetic or digital audio.

As to you super-duper capacitors...again, trick out a processor with them...get it really at its maximum quality and put it up against the same make/model (and it has to be working, of course, nothing outright failed) and see if you can A-B them in a theatre. See how many people can identify the "better" one.

I'm not saying that one cannot improve the sound via better capacitors (or resistors...seriously...one would be amazed at the sonic difference between carbon versus metal film) or the elimination of ceramic capacitors from audio signal paths (they are microphonic). But, know your audience. These are movie theatres, not home hifi. There are tons of other areas where one can improve the sound that most anyone would pick off that are far above the choice of capacitors used (like room acoustics, speaker choices...and so forth).

[Mark Gulbrandsen]

Steve, It's not as you think it is. It's about doing the best possible job you can when you do it, and yes, the units also sound a little cleaner. I always believed in that and the few extra bucks for the better caps was money well spent. Some of those CP-65's and all the 200's are still in service.

[Steve Guttag]

So we've gone from, should one recap a processor to achieve modern capacitors, even if nobody will find the sound to have changed to when your recapping a processor to use better capacitors with superior sonic benefits. They are two different discussions. As to the latter, if one is talking about $20 difference over the cost of the job, sure, put in the better sonic piece as the cost of the labor far exceeds the marginal difference in parts cost. If the superior capacitors (and possible other components) doubles the cost of the job, for something nobody is going to notice, probably not.