Playstation as CD-player

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jives11

jives11

Member
Joined 2004
Re: Re: Re: Re: Unidentified Soldered Object (USO)

Mick_F said:



Jives, I have also noticed this little thing and have no idea what it is. My current way to go is to use the AV path. (Remove the second set of caps, then a 4.7 uF and 1k in series to an external RCA and a 22k to ground after the cap.
The advantage of this mod is that is avoids all internal circuitry after the DAC (including the unknown thing), and the normal RCA output can still be used. No irreversible operations have to be performed on the normal RCA circuit.

Mick
Click to expand...

Thanks Mick,

Perhaps I should have gone that route, but I'd like to use the inbuilt RCA's.

I also think there are some more tiny ceramic caps between the signal and ground (top end roll off).

One thing that also puzzles me is that I can measure a short circuit between the left & right signals. If I insert the probes in the RCA connectors (not touching the grounds) I see a short circuit ? Also if I measure after the 100Ohm resistor from one channel to the other there appears to be no resistance.

What ever this device is I think it is responsible as this is where the two tracks come together.

If you measure the resistance between the AV left & right signals does it look like this ?

It's odd that the AV audio signal circuit is so different from the RCA one ?
 
M

Mick_F

Member
Joined 2005
DogBreath.de
Re: Re: Re: Re: Re: Unidentified Soldered Object (USO)

jives11 said:


Thanks Mick,

Perhaps I should have gone that route, but I'd like to use the inbuilt RCA's.

I also think there are some more tiny ceramic caps between the signal and ground (top end roll off).

One thing that also puzzles me is that I can measure a short circuit between the left & right signals. If I insert the probes in the RCA connectors (not touching the grounds) I see a short circuit ? Also if I measure after the 100Ohm resistor from one channel to the other there appears to be no resistance.

What ever this device is I think it is responsible as this is where the two tracks come together.

If you measure the resistance between the AV left & right signals does it look like this ?

It's odd that the AV audio signal circuit is so different from the RCA one ?
Click to expand...



I will measure these resistances this evening (if my children let me....). But as far as I remember, the resistance of the pos output between the channels is surprisingly low....

Mick
 
D

Dommi

Member
Joined 2003
highend-info.de
Re: Re: Re: Unidentified Soldered Object (USO)

jives11 said:


But Guys ? :confused:

This device appears to be in the RCA signal path. Am I being (more) stupid ? It's just that while we are moving toward minimalist signal paths we should understand what this is

Hy Mic, hy Jives
it`s only an idea. Someone tell me that whan you haven't a plug in the RCA the PS work at mono. Is it possible that the little part is for connecting both channels for mono operation ? I don`t checked it but i will do it if i had a little bit of time
:rolleyes:
Click to expand...
 
D

Dommi

Member
Joined 2003
highend-info.de
Oh, sorry, the file
 

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jives11

jives11

Member
Joined 2004
Re: Re: Re: Re: Unidentified Soldered Object (USO)

Dommi said:
jives11 said:


But Guys ? :confused:

This device appears to be in the RCA signal path. Am I being (more) stupid ? It's just that while we are moving toward minimalist signal paths we should understand what this is

Hy Mic, hy Jives
it`s only an idea. Someone tell me that whan you haven't a plug in the RCA the PS work at mono. Is it possible that the little part is for connecting both channels for mono operation ? I don`t checked it but i will do it if i had a little bit of time
:rolleyes:
Click to expand...


I think the stereo->Mono "down mix" is done inside the external modulator. this was a little black box with two RCA plugs and a mini jack in the middle. It took one audio signal and ..........

No , sorry, you could be right. the external plug took one channel audio and the Composite Video and has a mini jack to receive power via the middle hole. I guess when you connect this maybe this unit sums the two audio channels for a mono signal which is fed into the VHF modulator.
Click to expand...
 
B

back

Member
Joined 2005
back said:
hey dommi since you have done that can you measure the resistance between the channels and the ground?
before the caps of course at the output of the DAC.
i measure very small value 1k strange.
Click to expand...

i found out what was wrong.
there are 2 resistors 1k parallel to the output.
i desoldered them and i measured 100k per chanel
but the sound destroyed so i soldered them back.

after that i desoldered the two caps parallel to the output
and the sound became better.
they cause a treble roll off.

so after all the trouble the best sound comes
with 1 resistor parallel to the outout 1k per channel.
and if you don`t have caps to your pro 1 cap 10uf in series with each channel.
 
D

Dommi

Member
Joined 2003
highend-info.de
DragonMaster said:


That must be a clean signal! The only thing I'm worried about is that the pads where your coaxes . Sony PCBs normally are well made but we never know.
Click to expand...

Hy DragonMaster,
what you meen with "..are soldered to may lift" ? I don't understand it.

@back : Can you please read off the number of the caps you meen and the resistors ? Or better can you please make a picture ? Or please try to explain it again because i don't undersood the last 2 Part's.

I have to learn english :mad:

BR Dommi
 
D

Dommi

Member
Joined 2003
highend-info.de
Originally posted by back
<hey dommi since you have done that can you measure the <resistance between the channels and the ground?
<before the caps of course at the output of the DAC.
<i measure very small value 1k strange.

Hy back,
in my configuration there are only the new cap's and the 2 1MOhm resistors parallel to the RCA's. What should i measure ?

Regards Dommi
 
B

back

Member
Joined 2005
Dommi said:
Originally posted by back
<hey dommi since you have done that can you measure the <resistance between the channels and the ground?
<before the caps of course at the output of the DAC.
<i measure very small value 1k strange.

Hy back,
in my configuration there are only the new cap's and the 2 1MOhm resistors parallel to the RCA's. What should i measure ?

Regards Dommi
Click to expand...



forget it i measured it myself.

why you have 1mohm resistors parellel with the output?

aren`t they too big?

the originals are 1k
 
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