Playstation as CD-player

Is it possible that whan i remove the caps C423 and C424 the load for the AVM is an other and therefore it sounds different ?

Maybe, you remove a muting stage too.

why you don't connect the caps direkt to the RCA ? The muting stage semms to be a bottleneck.

Even if you connect it directly to the RCA jacks, the muting stage is still there.

I don't want to use an external DC supply (brick/wallwart style) as I don't really have the space.

Well you might have to.

That's what
one new heavy box is needed anyway.
means I think.

A block PSU can allow you to run just one wire if you keep the regulators in the PSX.

What I was thinking about is exactly this.

I'm going to post a pic of the muting transistor removal within the end of the week. Maybe even in a few minutes.
 
AV adaptor going spare

I have a spare AV to RCA adaptor, which I will happily send to for free anyone that wants it.

basically this connects to the AV output and offers Left & Right Audio RCA output.

If you want to see if the AV circuit route (1 cap and no opamp) sounds better than the RCA circuit route ( 2 caps and an opamp)
AND you don't want to desolder the DC blockers then this is what you need. You can connect your favourite interconnects to it, though you are using a few cm of sony cable and extra interconnects , but it looks reasonably substantial

First come first serve, the image below, drop me a personal email via my profile if you are interested.

I don't need it as I removed the caps

Item is :

http://cgi.ebay.co.uk/ws/eBayISAPI....0240&ssPageName=STRK:MEWN:IT#ebayphotohosting
 
OK so here's the muting stage transistors disconnected.

Note that I didn't disconnect the AV MULTIOUT ones as I did not reconnect the caps.

And I just noticed that we can actually see the markings on the transistors. I wasn't able even with a magnifier.
 

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Re: Re: Re: SM PSU mods ?

jives11 said:


Thanks back. I assumed that a linear PSU capable of supplying the current equal to the Switched Mode would be physically too big to fit in the PSone case, in the cavity left by the old PSU (transformer size etc)

I don't want to use an external DC supply (brick/wallwart style) as I don't really have the space.

i was talking about making a new wooden box.
there is no space in the original box not even for
the regulators because the heatsinks are big.
a wooden box improves the sound to.
 
OK so for those of us who want to keep the factory PSX box we'll have to put an external block PSU.

It should not be too complicated. To filter the RFI that might pick up thru the regulator output wires, we would just have to put caps in the PSX right where the current PCB is.

I personally plan to make a custom PCB to be able to keep the two switches and the LED in the PlayStation working. I would put some filtering on it too.
 
DragonMaster said:
OK so for those of us who want to keep the factory PSX box we'll have to put an external block PSU.

It should not be too complicated. To filter the RFI that might pick up thru the regulator output wires, we would just have to put caps in the PSX right where the current PCB is.

I personally plan to make a custom PCB to be able to keep the two switches and the LED in the PlayStation working. I would put some filtering on it too.


yes if you want to keep but i don`t like it anyway.

and if you don`t want an external psu like jives11
then you can replace the caps and put a piece of metal
between the psu and and the board for shield.
 
Yes, I do want an external PSU and that's why I don't want to keep the current one in there.

I want to keep the AC away. With the opamp stage, we could hear humming(With high gain levels)

I also want to put the transformer and rectifier of my tape deck and turntable in an external box. Why? They put hum in the signal. When my TT is off but plugged, there's a lot of humming that can be heard(High gain also). When I unplug the wire, it depends of how far the power cord is from the RCA cables. So I want to keep the AC as far as possible from them. Even the other pieces of equipment that are next to them add humming.

I know that the case is ugly but it's size is coincidently the same as my EICO amps, EICO tuner and Superscope cassette deck. The only difference is that it is half as high as the others.
 
@ Dragonmaster
is it right, that you disconnected the transistors but you leave the resistors ?
Another question : on your picture you removed the caps left and right of the AVM. Aren't there for buffering the pwr. supply of the AVM ?

quote:Even if you connect it directly to the RCA jacks, the muting stage is still there.

No, you can remove the 2 100ohm resistors or sever the positiv line of the RCA's on the board.
 
Dragonmaster and others..

Yes I understand the desire to keep the case small and convenient. Earlier I suggested using a shield and better ventilation to the PS box.

A decent sized car audio amp box is pretty usable. usually quite well constructed, and a similar or smaller one can be used for the PSU.

Someday , maybe Santa will bring me a digital cam so I can take some pictures. Wooden cases are good too, but should be shielded to reduce RF pick up. A shielded "umbilical" cord" power wire can be fashioned to interconnect the PSU, regardless of type. The only issue is the fact that the resulting components may be either wider or deeper than the original.
Still listening to the cap removed, blue LED added naked PS:=)
In terms of the Golden Arches... "I'm lovin it"
 
is it right, that you disconnected the transistors but you leave the resistors ?

Yes. The other side of the resistors are connected to nothing now.

No, you can remove the 2 100ohm resistors or sever the positiv line of the RCA's on the board.

Yes, there's that too but it's harder to do.

Another question : on your picture you removed the caps left and right of the AVM. Aren't there for buffering the pwr. supply of the AVM ?
I just removed the 6 caps. Maybe they are not in the pic. Or maybe I have a different board revision (I have PU-8)
 
DragonMaster said:
OK so here's the muting stage transistors disconnected.

Note that I didn't disconnect the AV MULTIOUT ones as I did not reconnect the caps.

And I just noticed that we can actually see the markings on the transistors. I wasn't able even with a magnifier.

nice pictures Dragonmaster.

Q: The pops and crackles you get now. You stress they are low level, but are these because of a) no dc blocking caps or b) because no muting resistors.

I'm trying to decide if it's worth taking the plunge and following your transistor leg raising trick. Looks like it might be reversable ( bend back and resolder the leg )
 
Good morning,
dragonmaster, sorry but i have to contradict. If im not wrong you soldered the bypass connection on the pad before the 1K and 100 ohm restrictor. So the ristrictors are in the signal path.
2. You haven't a dc-blocker cap in the output stage, if your pramp haven't a dc-in cap blocker you might have problems.

@jives : Try to find the 100 ohm restrictors, solder them out like the transistors and connect your cap at this point. You will see that the bass-performance is better.
BR Dommi
 
Hy @all,
this morning i phoned to a friend because of the wrong caps i changed, and i thought to hear a difference. Now we are gonig to check it out with a blind test to debar suggestion. We will take one original PS1 and one with changed C424 and C423. I'm verry nosy if there is a difference or not. I will inform you.

BR Dommi
 
Dommi said:


@jives : Try to find the 100 ohm restrictors, solder them out like the transistors and connect your cap at this point. You will see that the bass-performance is better.
BR Dommi

Thanks Dommi,

so as I understand it, in your design there is a direct signal path with no caps, resistors, opamps or muting transistors.

I guess the 100Ohn resistors you speak of are beneath the board. Do you know which ones there are in Dragonmasters picture of removing the mute transistors ?
 
I'm trying to decide if it's worth taking the plunge and following your transistor leg raising trick. Looks like it might be reversable ( bend back and resolder the leg )

Yes, it is.

About the muting transistors, in every CDP I used, the transistors were only stopping the pop when the CDP was starting or stopping. They can only mute so they shouldn't work when playing music.
 
Unidentified Soldered Object (USO)

OK so I lifted the leg of the transistors as per Dragonmasters instructions which were very easy to follow. Not yet had time to check the sound

I was investigating the remaining resistors then I noticed this unidentified SMD in the signal path.

On my SCPH 1002 if I trace the Left & Right signals from the DAC, past the opamps then close to the RCA sockets. The traces seem to converge around a dark gray block with 6 solder pads and red ends. It appears to be in series with the signal and has resistance lower than I can measure , so I guess it's not a transformer. It's much bigger than the transistors.

Anyone know what this is ?
 
so i did it too.
i desoldered the muting transistors one leg but i thought i should desolder the 100 ohm resistors too.

unfortunately they were at the signal path and after that i heard silence.

guess what.

i managed to solder them back but it was really difficult.
they are very small.
i left the muting transistors leg unsoldered and now i am checking the sound.

it sounds more detailed and with that the modifications have finished for me.

i think i have done everything that could be done.

i will continue checking this thread for anybody needs my help.

now i need a good box to put it in.
thank you for your help.

p.s. when i started this the ps1 sounded desent.
now it sounds fantastic.