A (slightly) modified 1541 Philips Cd160!

[josha]

Hi all,

After an enormous amount of help from everyone here I have reached a bit of a milestone where the modification of my Philips CD160 is concerned. This is really just a ramble about how this sot of thing can be done really cheaply!

Done so far.....

- Swapped 1541 for 1541A
- NOS (I'm waiting for a replacement saa7220)
- Clock with dedicated transformer
- DEM re-clock
- Dedicated Analogue & Digital PSU's
- Dedicated PSU for SAA7210
- Converted to 'open top'

Big gains were from the dedicated PSU's (especially the 7220 before it went pop) and the clock.

The DEM reclock (based on a NOR gate) - I've read several differing reports about this, some like it, some don't, to some it makes no difference. Well, having had some success with the cap mod (120pf) I persevered with it and I'm glad that I did! This isn't a 'hit you in the face' mod but it really grows on you - it seems to balance the whole player bringing out detail and tone that I wasn't aware was even missing. This is applied to an R1 chip so your millage may vary.

I know some people will think why bother with the 1541? Well, a working player is cheap, it's easy to work with and there's stacks of information out there, plus it seems there is an almost limitless number of tweaks to make in every area.

As far as cost is concerned I haven't done an accurate count but I think I could do it all again for under £100. I haven't used any expensive tools (just basic student types, eg no temp control soldering iron) and (so far!) no exotic components. The biggest single cost was the clock at £25.00 and I think you'd be hard pushed to build one for that.

The conversion to open top is a bit tricky. You basically have to 'fool' the player into thinking that the drawer is always closed (I just tied the wires together that previously went to the micro switch and disconnected the other switch and the motor). Now you can still press the 'eject' button, the cd stops, swap the disc, press the eject button and it re-reads the disc! Not the best solution but it works

Still to do!

- A decent chassis (this ones an MDF prototype for layout)
- The transport (yes - that is laminate floor underlay poking out under the transport
- Better(?) Psu's everywhere
- Decoupling caps for the TDA 1541
- Back to OS if I can find a reasonably priced 7220
- Better output caps (I'm using Maplin's own at the moment, I think the postman is currently enjoying my Mundorfs, grrrr)
- A much better 'puck' - That really is a volume knob stuck to the original spinner
- Output stage - I'd like to try them all but I'm still dying to try valves here.

I think it sounds fantastic, especially if you shut your eyes (and you should, it's not the best looking CDP is it?). Ripping it all out and mounting it on a board makes it a lot easier to work on though.

I can't really 'do' audiophile speak but it's very detailed without being harsh, it's musical and it makes you want to listen to all your cd's again, the bass is very tight and has tone. I can't comment on the soundstage or depth really yet as my listening area is far from ideal at the moment.

All in all, for under £100 it's incredible value and I would highly recommend a project like this to anyone, take this as proof that with very little starting knowledge or skill, and even without sophisticated tools you can create an amazing player by following basic principles and tapping into the wealth of knowledge and information available here.

Apologies for the quality of the pics and comments welcome! I already know the looks need some work

Cheers, Josh.