Anyone knows NEC CDROM?

[omar]

I've got one NEC multispin 6Xi and want to modify it to be my transport.
Anyone familiar with this CDROM?
I found that there is one 7805 regulator IC inside and not sure what does this do.
Or anyone have it's circuit diagram?


THANKS!!

[jonclancy]

I found a load of stuff over at Audio Asylum (or was it tweakers' Asylum??).

Unfortunately, it is on my other machine, so if you'd like it posted here, I can do that next week.

Jon

[jonclancy]

Hi,

here are the extracts I gathered from the Asylum. I think all the names of those who posted are still in the text - all credit to them for their efforts.

QUOTE:

Hi,

I got a NEC multispin cdr-602. I'm starting to mod it. I already found the crystals and added a small chunck of blue tack on them. I have a new IEC connector that is also a EMI/RFI filter. I have a question about the digital output running from the cd-drive itself to the back of the plastic box. There is a circuit board that is doing a conversion. I saw several posts on the topic but I still don't understand what could be done. Some has kept the circuit as is. I saw a post where someone said he ran a 75 ohms coax from the cd-drive to the RCA output. Is that correct, can I do this? It is a lot simplier than trying to upgrade the conversion circuit.

what is the best option?

Posted by Tubes n' Hornz ( A ) on September 26, 2003 at 14:23:12

In Reply to: Re: CD-ROM caddy tweak- Questions! posted by Dan on September 26, 2003 at 12:19:42:

Dan - Have not tried the paint tweak - or the blue LED. Do either of these give a noticible difference ?
What I have done is -

1. gutted external case of all wire, switch and plugs. Used regulated power supply with 2 separate transformers etc. for 12/5 volts and ran wire and connector into back of drive

2. stripped plastic off electrolytics in NEC and supply

3. tack on 3 crystals (2 cans, 1 chip)

4. cut away plastic on rear of drive and soldered my IC's directly to the pins on the board - analog on one drive and digital on another drive (i use same power supply for both)

5. put small gobs of tack on the drive case(top/bottom)before putting it back in the external case

You can do this to any ROM drive, internal or external. I find the NEC fun to work with. "Too much is a too much, and not enough is a not enough" Chico Marx - I think.
Also found some old posts on cutting the angle on the edge of the CD. At present I'm trying to destroy some discs in the garage. Hooya tooya! Steve

UNQUOTE

I had my 602 in bits last night . A really nice bit of engineering!! Anyway, suffice to say I but the BluTack (R) on the crystals and chip. Also stripped the caps.

Anyway, I'm listening to it with my Scott Nixon DacKit at the moment and it sounds vey nice indeed. Almost as good as my 600UKP Arcam when I use it as a transport!!

I have listed all the ICs, and will post seperately. The IC123 SONY CXD1808AQ 536H10E (CDROM DECODER) is the one I would like to find the datasheet for, as I want to get at the digital signal before it becomes TTL 5v output.

Cheers

Jon