Can you run a CE ASR-30R or similar on +/- 15v (Dolby CP650) versus +/- 12v?

[Ethan OToole]

CE = Component Engineering

Making progress on my restoration of Simplex projector. I terminated a DB-25 on the short bit of cable for the Dolby CAT700 but so far it's not picking up digital soundtrack. Lamp is working, lightpipe seems good -- but I haven't gotten around to hooking o-scope up to test points on the CP650 to see if it sees video signal. Had mode set to 10, Dolby Digital optical showed on the LCD. I have been super careful to not plug/unplug the DB-25 to the sound head unless the CP-650 is powered down and power cable removed.

In the meantime, I discovered that there is a Component Engineering analog reader! A nice reward after hours of dremelling off rust and coating things in silicone lubricant.

One question.... can I power the CE reader pre-amp from the +/- 15v from the CP 650 analog DB-9 connector? I see the real PSU for the CE is +/- 12v, but since it's analog maybe it's tolerant? I pinged CE and they sent me here ;-) I would love to be able to handle the power with the CP 650 as that keeps it all on a DB-9

I will be careful to current limit on the LED. 5V PSU and 330 ohm resistor is what I will start with.

Thanks in advance!

[Sam Chavez]

Preamp power from 650 should work fine. As to the LED power supply, current limit is one issue but filtering is even more important. Any more than 1mVolt of AC ripple will easily be heard in your sound system. CE did make a nifty LS 40 power supply that takes care of everything in one little box. Might be one on E-Bay. Your Cat. 700 likely has a blown CCD. If that turns out to be the case, give a shout as I have new ones very reasonably priced.

[Mark Gulbrandsen]

Preamp power from 650 should work fine. As to the LED power supply, current limit is one issue but filtering is even more important. Any more than 1mVolt of AC ripple will easily be heard in your sound system. CE did make a nifty LS 40 power supply that takes care of everything in one little box. Might be one on E-Bay. Your Cat. 700 likely has a blown CCD. If that turns out to be the case, give a shout as I have new ones very reasonably priced.

Yep, at least two of them...

[Ethan OToole]

Thanks for the info!!! Yea, I saw the LS-40 boxes on eBay but at this point I'm trying to roll a bit cheap on things since I am still feeling my way around and there other issues I may have to tackle as well. Also, with the Dolby CP-650 putting out +/- 15v it seems like it would be easy to just terminate a DB-9 on the cables hanging off my machine that were cut and connect it to the Dolby box.

Rackmount power supplies are sexy though!

Depending on what friends are up to tonight I might get more time to poke at it and scope out some of the stuff.

Here is about 28 random photos of my progress so far:
https://imgur.com/a/E6gR0mB

Thanks!

[Mark Gulbrandsen]

Don't blow out the LED... expensive little part!

[Ethan OToole]

Okay, spent a little time last night on sound.

First I terminated the CE reader cables to a DB-9, all cabled up to the CP650 for +/- 15v and the cells +/- and ground. I used a 330 ohm resistor + bench supply and ran the LED max @ 5v. Saw it light. It DOES look pretty special and I can see where it would be expensive. Thanks for the heads up on it! Tried running my film loop and nothing. Turns out I didn't clean up one of the mechanisms in the simplex audio basement good enough, so I tore that down and did some work. The part where you can squeeze the "clip" type thing together and lock the one mechanism against the flywheel was rusted in place. It's all cleaned up now and lubricated.

I tried backing down the LED voltage and stuff, no go there. And in order to clean the one part I had to unbolt the optical reader but I marked off pretty well where it was at plus azimuth.

I tested the CP650 using a nosync input (line in) and audio is good on it.

Hooked up the Dolby CAT700 again and loaded up the Windows software on an XP laptop. It shows the light input to the camera is coming in at around 1.1V peak no film. I played around and it is changing, so the camera is reading. Didn't get around to hooking up an oscope or anything. I looked inside to see if the lightpipe was dirty at all but the optics look clean so I didn't touch any of it. But I think in the manual it says it should be around 4V.

Next troubleshooting steps will be to the check the +/- 15v from the CP650 and look at the signals.

Had an incident where I accidentally trashed my test loop, need to splice up another one. 3d printing some rollers and also 3d printed someone's splice tool.

Good stuff!

[Sam Chavez]

I'm assuming since you said Cat. 700, its a Quartz Halogen bulb? Just so you know, theres no magic video Voltage below which it stops working. 1 Volt should be fine. More is better for lower error rate. It's an ETP bulb but not all brands focus at the same point. GE's work best. I have stock of the good ones.

[Ethan OToole]

I was showing friends this evening after pinball and when looking at the halogen bulb I did find that the output light wasn't centered on the lightpipe input (through some kind of dichroic filter?) Once I centered it -- then I was getting ~3-3.4v.

I didn't get a chance to hook up oscope to the processor yet. Will do that tomorrow night hopefully.

Still a bit puzzled about the CE ASR analog reader, I don't want to push the LED assembly too hard -- but I do notice at 6v / 330 ohm resistor I do see on the spectrum analyzer the bottom most bars trigger just a tad.
I forgot to look behind the door at the status LEDs. Never heard anything from the output. Will scope the output from it as well.

[Tim Androes]

you will need to do a complete A-chain alignment of the Simplex soundhead

[Sam Chavez]

Regarding te ASR; the LED has a very small sweet spot so if its out of position even a couple of degrees you'll get practically no audio output. It's best to run Cat. 69 loop and rotate the led bracket slightly to see if audio increases or decreases. You'll get the hang of it pretty quickly.

[Ethan OToole]

One big question I have ... what should the voltage be to the LED? I'm running @ 5vdc, 330 ohm resistor and the bench supply is saying it's drawing 0.01 amps (No idea how accurate it is that low, BK Precision PSU.)

I don't have any alignment films -- just trailers out the wazoo. I've been running them in a loop, the film is getting destroyed fairly quickly I wouldn't want to put any kind of valuable alignment films through it until I can make dead sure that it does as little damage as possible to the film.

It was in alignment I would assume on both the penthouse Dolby 700 and the basement CE ASR reader when I got it, I've knocked the read side out of alignment on the analog reader when I had to move it to clean the mechanism behind it but haven't touched the LED emitter side -- so hopefully that is still proper. It should be easy to find the proper position of the reader side (focus and azimuth)? Just not sure if I'm running the LED hard enough, and don't want to harm it.

Going to hook up an oscope tonight to the CP650 and see what the digital output looks like (following manual.)


Thanks for all the info! Slow progress but progress!

[Ethan OToole]

Got the info from the LS-40 spec sheet (thanks CE!)
4.5v max up to 750ma max. Will try tonight at 4.5v in the 200-400ma range see what it does.

[Sean McKinnon]

It going to be hard to get something with a trailer loop. Make sure you're in mono so the NR is fighting you if you are trying to achieve signal level by ear. The problem is the optics are all interdependent on each other. As Sam suggested start with the led swivel up and down. If you don't have buzz track try to center the lateral position of the film so that its centered on the pickup lens then rotate the LED and try also moving it side to side once you get some sort of signal then you can try work from there but without at least a tone loop this isn't going to be super easy.

[Mark Gulbrandsen]

Next up.... He'll be out buying a dual trace scope, spectrum analyzer, and looking for test films... Happens to everyone!

[Ethan OToole]

I already have a dual trace OScope ;-) (Well, Rigol DSO with 4 channels and an analog 20MHz thing with 2.)

So I did manage to get audio out of the analog side, I had to remove the resistor and push the LED harder. It definitely worked and I could hear audio, but there was something of a buzz sound over top of it. It wasn't a 60hz hum, and it changed in speed with the film. I will probably revisit this -- but probably with a real LS-40 supply. The bench supply I was using (BK Precision) was doing my current limiting and it might have something to do with that. I never took it over 300ma and it was reading like 2v not 4.5v.. Dunno.

I also have started poking at the Dolby Digital head more. I plan to follow the stuff in the manual about focusing it and checking how it sits on the oscope screen as read from the test points on the front of the cp650.

I still have other battles. Stand, light source, motor starter/run capacitors and the lenses are wrong throw distance for scope and missing part of it for flat. Couldn't get it in focus in a garage, which is understandable as it's probably a long throw.

Good stuff though, and slow progress! Thanks for all the pointers!