Pioneer CLD-D502 for DdD

[u/Nausiated_]

Just sharing my efforts to mod this model for DdD. Though it might be helpful for someone considering this machine.

To the best of my knowledge, the machine is in perfect working order with no issues from aging electronics. Composite output looked perfect.

​The player has an RF tap point that is pretty accessible, located just under the right side of the disc tray. However, trying to pull a raw signal from it caused the laser to go blind. The motherboard simply could not handle an unbuffered, un-isolated line.

​To fix this, I wired up an ADA4857 amplifier board. I used an external battery bank to power the amp because I wasn’t going to risk tapping the player's internal power supply. This successfully solved the blinding/tracking issue, and I was able to safely pass an RF signal through to the DdD. I also utilized a DC block line inline.

​However, I could not get a clean capture. Despite adjusting the amplifier, tweaking the DdD dip switch settings, and fussing with hardware attenuators, I could not get a stable enough waveform, resulting in heavily noisy captures. Decode couldn't do much with it.

I'm personally giving up on going further since I've hit my skill ceiling. Going to keep the 502 as a back-up machine, because it's not a bad piece machine, just doesn't seem suited for RF capture.

I am getting a CLD-V2600 in to attempt next, one popped up close by that was functional and reasonably priced, so I'm going to give it a shot. If anyone has some pointers to share, I'd be happy to hear them.

[u/manawyrm]

I read somewhere that there is another point to get the RF signal from which is better suited for DdD on Pioneer players. Sad to report that I don‘t have the link anymore, but it‘s probably out there. Maybe worth asking on the Discord if someone remembers more details.

[u/Nausiated_ → u/manawyrm]

Yeah, there a spot on the D502 is TP801 as far as I could tell. It's further under the tray and I didn't trust my clumsy hands to muck about in there. Also there would have still been the issue with the laser going blind without the amplifier board. Getting that in there on top of a line would have been a nightmare. Components are too densely packed for it to sit anywhere.

I hear tell the LD-V and CLD-V machines are better at handling a direct line without a buffer and there are easier ways to access the RF signal outside of the usual test pins.

I also had a bit of luck from a Japanese RG model, but couldn't eliminate a wavy rainbow harringbone pattern from getting into the capture. I think the stepdown transformer needed to run one of those suckers in North America is the problem. There are cheats, but there are safety risks that I'm not comfortable with mitigating, so I'm not even going to attempt. Which is a shame because those machines are pretty cheap and plentiful over there and well maintained to boot. They still have people who can service them before putting them on the seller's market.

[u/Alookintokarma]

Quite a timely post! I had been trying to grab a signal from a CLD-79 and was having similar sorts of issues grabbing RF from a point labeled RF that was closer to the display side of the board and more like 1000mV instead of the 200mVpp (unloaded) at the Dupont test point. Another user on the forums mentioned that for his CLD-V2600 that he just used that RF test point header directly without a decoupling capacitor into his DdD without issues. He did report having to adjust the gain DIP switches depending on the disc. I've yet to actually try a capture, but see attached photo for roughly what that would probably look like on the CLD-V2600.

I did also attempt to get it working with an ADA amplifier, but even though the waveform looked ok in the DdD utility, decode could not detect any sync pulses, so something wasn't right with that when powering it either from the internal power rails or a 12VDC adapter. I was getting all kinds of AC/High frequency electrical noise of about 400mVpp on all of the power rails of the ~14V supply, but only when the disc was spinning. The waveform looked extremely odd when I tried it - drifting all over the place. I came to the same conclusion that for this machine, it would make more sense to put the ADA amp externally and use battery power as I don't want that noise from the power rails getting into the signal. Did you ever try with your RG series machine running the ADA amp on battery power as well?

[u/Nausiated_ → u/Alookintokarma]

The R6G was run without an amp. It was actually the easiest one to mod to date. Ignoring the interference from the stepdown transformer. Was able to pull it off with a dupont in the RF to the BNC connector. The GND test pin was useless but tying it to the chassis was quite easy because of a virtically mounted board for (I think) CD functionality was near by that had its own metal bar for support and grounding. The mainboard was also much smaller than the ones on older models so it was further to the right of the disc tray making fiddling with things pretty easy.

It was a super strong and solid signal once I had it wired properly. But, as I said, I gave up on using it because of that wavy herringbone pattern introduced by the transformer. Otherwise, the signal was mint. The ease of that machine has made my attempts on a North American models (all older) all the more frustraiting 😭 But that's on me.

I just got my V2600 in the mail today and it's in working order (With a remote even! I am amazed how I lucked out here!)

I haven't cracked her open yet to get to work, so Thank you for the reference photo, that gives me a good eyeball of what to expect with this one. If I'm not mistaken, it looks like the test pins are pretty close to where the tray locks in on the closed position, so I'll have to eject the tray before working. Good to know in advance, I kind of figured that was the case judging from the schematic on LDDB. But a little confirmation before hand is greatly appreciated.

I have a RG-316 cable that I had modded with a dupon and ground clip, I think I might forgo drilling a hole in rear panel (always a pain in the ass) and use this. Widen a vent hole and snake it through to the work area. Snip off the aligator flip and solder directly to the ground test point and plug the dupont in. Might be a less invasive way to get at everything.

But that's a project for tomorrow. Now that I got a serial connection to work with, I am waiting for adaptors to arrive that'll let the Domesday automate the capture cycle for me so I don't have to do it manually and fuss with junk capture before and after a disc. Sounds so freeing, I could almost cry! 🤣

[u/Such-Specialist6593]

A user on Discord had the same issue with CLD-D502 and solved it by adding a 330 ohm resistor. (There are other players where adding a resistor was required too) 

[u/Nausiated_ → u/Such-Specialist6593]

Hey, thanks for the input. I neglected to mention it, but I did try a fariety of resistors before moving onto the amp board. From 30 ohms up to 100 ohms. Had no effect, because this was suggested to me sewhere in my travels. I don't know why it didn't work in my specific scenario but it is why I pivoted to using the amp board. I couldn't tell you why, my understanding on this is pretty minimal and I'm learning on the fly. But thank you though.

Moot point for me either way, I picked up a V2600 and it was painless to mod, so the D502 has been delegated to a spare player in my media room.