"playing" with an old dvd player!

[DoomPixie]

Hey there,
I have an Acoustic solutions dvd player i "rescued" from the trash a few months back, When i got it home it wouldnt play anything but i quikly stripped it and found a hair in the laser asembly.. well.. works fine now! But i thought.. why not have a little fun with it..
So far i have replaced the output capacitors for the front channels (im only useing it for Cd audio anyway)..
It has a pretty simple set up for audio.. CS4338K DAC that goes through an op-amp which i believe is set up a s a buffer, then it went through a horrible cheap electrolytic and out to the output board.. Not all that bad a sounding cd player and there is a deffinate improvement after just changeing the output capacitors (more bass and softer highs) (i know.. i know.. this will never be a killer player, this is just a bit of fun so bear with me!)

Anyway.. some photo's of what ive done!

After i opened it up:


The main pcb still connected to the output board:


The Underside of the main pcb showing the DAC's and soem other "stuff" i havent identified yet:

[DoomPixie]

Identify the output capacitors for the front chanels (circled):


Turned out to be cheap nasty 4.7uF 25V Polarised electrolytics, Picked out some replacements which are what i use in pretty much everything at the moment, some nice cheap blue 1uF 250V capacitors i got of ebay in bulk, think they are polyproplene or metalized something ot other or something, not really sure but they do ok in the signal path for things like this..lol

Replace!:



edit: not sure what happened to that last pic :S must have a gremlin in my camera or something :S
Owen

[oshifis]

Don't forget: laser optics don't like cigarette smoke...

[DoomPixie]

i know.. the room is VERY well ventilated and its my misses that smokes.. she has been at work since 9am.. i just stole the front room to do the work seing as she is out.. she'd kill me if i did it when she was here..lol
Owen

[DoomPixie]

The chassis is actually pretty sturdy, made of decent thikness steel (makes a change) But still, i'll add some damping material next after i have finished listening to it.. Anyone have any other ideas for nice simple mods? this is just a bit of fun, i am bored, I am pretty sure there are still more electrolytics in the signal path aswell between the dac and op-amp buffer... i just have to trace down which ones are for the front channels still..
Owen

Edit.. just been looking at the piccies again.. think i might rip the scart connector board and wireing out next time i have it open... (in about 15 mins time after the cd finishes)

[RetroAudio]

If you really want to get wild and crazy, why not eliminate the output caps altogether, providing you measure pretty much 0VDC at the output? I did it with my el-cheapo dvd player and am getting away with it nicely. Also, look at the p.s. caps since they make a diff to. Actually, just doing a cap change all over is probably your best bet IMO, but of course it's your call.....and time,.....and effort....

[DoomPixie]

i did think about leaving the output cap's out.. but i was getting a bit too much dc offset, wouldnt normally be a problem but the amp im testing with dosnt have dc blocking so thought i should leave them in for the moment at least.. But i am planning on going pretty wild on this, i was actually concidering stripping everything after the dac and putting a tube buffer in.. just experimenting really, want to test a few things out and get my sodering skills back up to scratch before i play with anything more expencive.. dont care if i kill this, i got it out the trash afterall..lol
Owen

[DoomPixie]

ok....
some more progress..
and have hit a bit of a snag.. :S

Progress first..
I have put some stuff in to help damp out vibrations.. (same stuff i used in my car, worked a treat there!)
there is also some under the transport..


Notice also the scart connector pcb is gone!

All back together again, seems to all fit ok:


Top cover:


Now the player works great.. its quieter than it used to be (no more anoying whirring sound when it spins up!) BUT if i put the top cover on.. i get a wierd noise in audio through speakers, can be heard when music is silent.. it is like a " tap tap tap tap tap" comeing through the speakers though.. it isnt there with the top cover off and there is a nice gap between the top cover and the gubbins inside so that cant be it :S
Any ideas?

Owen

edit: Put the lid back on and it has fixed itself..lol. no idea what it was now.. *shrugs*

[gmilitano]

Looks good.

You could also add some epoxy to the disc clamping bridge to stiffen it up.

Are you are going into a preamp or integrated amp with DC blocking? If so, is getting rid of the output caps alltogether reasonable?

Cheers,
Gio.

[DoomPixie]

Unfortunatley there arent any dc blocking cap's in the amp im running it through...
I'm testing the dvd player in my junkyard rig.. Basically everything in the set up has been salvaged from stuff..
The amp is a chipamp i built useing a TDA1544Q (THINK thats the number) that i pulled out of a borken card cd player, The Speakers are Old mission cabbinets (from the dump) that had blown tweeters, the bass drivers were swapped out for a pair of Car drivers i was givven (infinity kappa 2 way) Not the best system but sounds pretty nice for a system that all in all has cosnt me less than a crate of beer
I have tried to make some shielding for the power supply.. just need to finish it of and figure out how to mount it now!, The epoxy idea sounds like a good one aswell, i may well give it a try aswell later, Im still trying to work out which of the capacitors are in the audio path between the dac and output bupper.. I know they are there, just traceing the circuit back on such a small pcb isnt easy..lol..
If there was more space iside i'd put a tube output buffer in instead of the SS one.. but alas there isnt enough space really.. lol
Cheers
Owen