Modding the un-moddable

Looking at all the high end kit on here what I am about to say should raise a smile.

For one reason and another, the best solution to my needs is a cdp with an integral hard drive. There are are couple of well known ones out there so naturally I picked the cheapest, an Acoustic Solutions SP150

All was well with the world because I had never heard a 'good' cd player....that changed recently and I am now aware that my machine probably cost £7.50 in parts and another £1.25 to put together.

What I need to know is, apart from the companies who mod certain makes of cdp, is there anyone out there who could make a stab at improving the sound of the sp150? That's without dropping it off a tall building

Here's hoping

Bunty

 

Well the bottom line is that the audio output comes from a DAC followed by an analogue filter/buffer stage, and these are the two elements which respond to mods in CD players (which are basically all about cleaning-up the PSU, or occasionally, getting the fiter to do its job properly by parts substitutions). In other words - there's no functional difference, so have a look at Zanash's cd player mods document in the FAQ area here, open up the box and take some pics, and lets have at it

 

pm me ......!!!

 

Why not put a picture on the forum and let the modders do recommendations for it, Then you can choose what you wish to from the gamet of responces.
I looking forward to how Felix would go about this.

 

you can read my solutions in the articles section...but each player will have its own quirks .....Though I'd be reluctant to spend more than £50 [IMO] on parts on a unit with a low base value.....as you rightly point out the total parts bill is less than a a couple of fish suppers !

 

You could of course just stick a DAC on it if it has a digital output.

Post some detailed pictures of the insides.

 

Thanks to all for your replies.

In answer to one point, I'm afraid it doesn't have a digital connection, just a pair of phono/rca sockets. An offboard DAC is no go here I'm afraid.

I'm sorry to say I don't currently own a camera
might see if I can borrow one

I realize this is never going to be a Yamaha or Cambridge Audio beater but it would be interesting to see how close it could get.....and.....spookily, I have two work colleagues who own both of those fine CD/Hard drive machines, so a play off is definitely possible.

Bunty

 

Unbelievable

.......Finally plucked up the courage to mention my mega cheap piece of kit on this forum

.......Actually had a response from a number of well respected members of the forum

.......In the middle of negotiations to "enhance" it's performance

when


I carefully remove my cdp from the rack where it has sat untouched for months, stand up, trip over the hoover lead and am faced with the prospect of smashing my face on the mantle piece or throwing the cdp at the wall and using my, now unemployed hands, to break my fall........

The only glimmer of sunshine in this, is that it appears I will be sending off for modding a new unit

There is a moral in this somewhere about leaving well enough alone......but I am stubborn.

Bunty

 

Oh dear - how bad is the damage?

 

Apart from being stubborn I am also a coward. I shook the box and could tell there was a packet of marbles inside.....

telephone=Tesco's insurance=new box (hopefully)

face still as beautiful as ever

Bunty

 

Sounds like you did the modifications on ya own!

 

That would have been an excellent idea! infact any first time tweaker should do this

 

To cut a long story short my player has just arrived back with me.

It has been repaired rather than replaced with a new one, which is an issue in itself....

The weird thing is, it definitely sounds different than before. I am very familiar with a number of cd's and listening to them again I can clearly hear differences. I should add that these are improvements !

I will let you know if any additional mods improve it even further.

Bunty

 

the unit is now on my bench ......its a computer !

cd rom drive 80gig hd the computer board switched mode psu [uck] and a lm4549 doing the dirty work .....this has a dynamic range of 90 db ..........

so probabley explains the rather dull shut in presentation of the sound.

proposed mods

replace the caps in the signal path and power supply sectons on the dac/preamp chip

damp the case work

try and fit a digital out so a better dac can be used.

replace the nasty socketry with case mounted rca's and silver wire.

any other thoughts would be appreciated ......though changing the psu is out of the limited budget.

 

How do you plan on taking a digital output?

I know you said there is no budget for PSU mods but how about a very small transformer and 7805 reg dedicated to the lm4549 codec's analogue power line?

I would also check to make sure pins 33 and 34 on the lm4549 are not linked via a cap, or that turns on '3D Sound'.

 

tried the digi out ...my dac won't lock so I've not wasted any time on it ...must be a different format.

I've done all the mods ...sound has come on rather well, better than expected ..its not a world beater but at the price very acceptable.....dirrect from cd rom [buffered?] is quite poor but from HD is at least better than a budget cdp.

Changing the socket and wiring with AgAu made as big a difference as changing the caps and adding caps left out [?]

upped the main board supply caps from 1200uf to 2300uf pana fc and added an extra 1300uf pana fc for the dac chip all where 0.5uf wima bypassed.

change the output caps to 47uf stargets

I think Bunty will be we pleased !

 

Can the budget really not stretch to a dedicated supply rail for the codec?

It would only cost £15 in parts and would no doubt make a huge difference. You probably have some rectifiers and caps already?

Transformer: RS Stock no. 805-136
Rectifier: RS Stock no. 659-826
Smoothing Cap: RS Stock no. 227-1131
Regulator: RS Stock no. 298-8514

 

No........ total part cost of £25 used that up and a bit more truth be told.
10 wimas bypassing
8 panna fc big ones !
3 stargets
case damping
2 bulkhead rca sockets [teflon]
AgAu conductors

all adds up !

It will off back tomorrow

 

I've not heard from you ?

I do know that the unit has arrived back ...

If you can let me know your thought it would be appreciated !

 

Apologies for the delay in replying.

My thoughts: zanash received my cdp, worked his magic and had it back in the post to me within days!

Receiving the cdp (together with a quality pair of interconnects on a sale or return basis) I plugged it back into the Cambridge Audio pre amp, connected to the NAD multi channel AV power amp. My intention was to put it on repeat and let it run overnight. The interconnects were left to one side as I wanted to get used to the sound before introducing them into the system.

Well you can forget about a burn in period....I could instantly hear an improvement. As has been said the limiting factor is the 90db range of the dac, but even saying that, there are improvements in all areas. I am not going to try and use phrases that I don't really understand, I am just going to say that my cdp sounds better in every way.

No it's not a world beater but for the outlay it is much more than it was.

My only regret is that it was not possible to tap into the cdp and add an off-board DAC.

Peter, you are a star. Very many thanks

Bunty