Adjusting Gain and Bias
Domenico,
as I wrote lately, this is all I know:
SCPH-1002 PAL
Serial-Nr. C6122782
Mainboard 1-658-467-22
DAC AKM AK4309VM
Laser unit KSM-440 ACM
PSU 1-473-383-12
The laser unit IS an ACM type and thus it is equipped w/ a metal transport. I checked this as a matter of course when I looked for the serial numbers of the mainboard and so on.
FWIW the entire writing of the laser unit is
(Blue Label)
KSM-440 ACM
21874
KJ485
Die cast´s imprinting is
Y1
AFAIK the ACM type laserunit has to get a metal transport with respect to Frank Stoelben`s register of versions. If there is no metal transport, it must be an AAM type laserunit IMHO.
Why did you ask me twice for the type of the laser unit? As I told you before this one was my first ps. It was mint before I checked the parts and serial numbers and did the measurements.
Kind regards,
Thomas
Domenico,
as I wrote lately, this is all I know:
SCPH-1002 PAL
Serial-Nr. C6122782
Mainboard 1-658-467-22
DAC AKM AK4309VM
Laser unit KSM-440 ACM
PSU 1-473-383-12
The laser unit IS an ACM type and thus it is equipped w/ a metal transport. I checked this as a matter of course when I looked for the serial numbers of the mainboard and so on.
FWIW the entire writing of the laser unit is
(Blue Label)
KSM-440 ACM
21874
KJ485
Die cast´s imprinting is
Y1
AFAIK the ACM type laserunit has to get a metal transport with respect to Frank Stoelben`s register of versions. If there is no metal transport, it must be an AAM type laserunit IMHO.
Why did you ask me twice for the type of the laser unit? As I told you before this one was my first ps. It was mint before I checked the parts and serial numbers and did the measurements.
Kind regards,
Thomas
Hi Thomas,
i ask you twice because you don't write it before that you've checked the metaltrasport. And i wonder because i had about 4 or 5 new ! ACM Units with Lasergain 24,3 mV. Therefore i wonder why you have a ACM Unit with only 9 mV. I had one Laserunit original PS 1 with AAM Laserunit and Bias 9,2 mV. But i had to adjust it to 11,4 mV to read all CD's. But i don't adjust the values to yours. So i have to look if i have a AAM Unit and Acm Unit to try your values.
BR Dommi
i ask you twice because you don't write it before that you've checked the metaltrasport. And i wonder because i had about 4 or 5 new ! ACM Units with Lasergain 24,3 mV. Therefore i wonder why you have a ACM Unit with only 9 mV. I had one Laserunit original PS 1 with AAM Laserunit and Bias 9,2 mV. But i had to adjust it to 11,4 mV to read all CD's. But i don't adjust the values to yours. So i have to look if i have a AAM Unit and Acm Unit to try your values.
BR Dommi
Adjusting Gain and Bias
Domenico,
I checked it first when I got the ps SCPH-1002, I checked it again when I discovered Frank Stoelben`s website in 2004, I checked it third when I did the measurements after reading your last posts concerning the adjustment of the laser unit.
AND I checked it lastly after your post #578 before last for your pleasure
I have never seen an ACM laser unit w/o metal transport. I agree to your assumption that the label of the unit w/ plastic transport was faked.
What I would like to say is that the so far supposed values for lasergain, gain and bias might be incomplete if not partly false.
There are 3 contradictions:
- concerning the lasergain of ACM: 24,4 mV vs. 9.2 mV
- concerning the bias: 1.56/1.70 V vs. 1.83 V
- concerning the gain: 1.76/1.82 V vs. 1.78 V
(see also posts #576, #577 and #579)
Now I am waiting for your confirmation or falsification of my measurements.
Kind regards,
Thomas
Domenico,
I checked it first when I got the ps SCPH-1002, I checked it again when I discovered Frank Stoelben`s website in 2004, I checked it third when I did the measurements after reading your last posts concerning the adjustment of the laser unit.
AND I checked it lastly after your post #578 before last for your pleasure
I have never seen an ACM laser unit w/o metal transport. I agree to your assumption that the label of the unit w/ plastic transport was faked.
What I would like to say is that the so far supposed values for lasergain, gain and bias might be incomplete if not partly false.
There are 3 contradictions:
- concerning the lasergain of ACM: 24,4 mV vs. 9.2 mV
- concerning the bias: 1.56/1.70 V vs. 1.83 V
- concerning the gain: 1.76/1.82 V vs. 1.78 V
(see also posts #576, #577 and #579)
Now I am waiting for your confirmation or falsification of my measurements.
Kind regards,
Thomas
Adjusting Gain and Bias
Hi Mick,
the laser intensity and as well the bias are adjusted w/o a CD in the drive. Only the gain is adjusted w/ a CD in rotation.
Do you think the gain I measured would be different w/ a different CD or a different value for lasergain or ...
Things are getting difficult now
Kind regards,
Thomas
P.S.:
Don`t forget that my recent measurents concern to a SCPH-1002 w/ ACM laser unit in mint and unmodded condition only. I never measured a ps w/ an AAM drive bcs. I´ve never seen one in good working condition. Thus I had to replace the worn out AAM laser units every time.
Mick_F said:
Hi Mick,
the laser intensity and as well the bias are adjusted w/o a CD in the drive. Only the gain is adjusted w/ a CD in rotation.
thokra2003 said:
Do you think the gain I measured would be different w/ a different CD or a different value for lasergain or ...
Things are getting difficult now
Kind regards,
Thomas
P.S.:
Don`t forget that my recent measurents concern to a SCPH-1002 w/ ACM laser unit in mint and unmodded condition only. I never measured a ps w/ an AAM drive bcs. I´ve never seen one in good working condition. Thus I had to replace the worn out AAM laser units every time.
OK,
now im totaly confused. I have a new AKM Unit and 3 PS here. The Lasergain is adjusted to 24,4 mV and i tryed it in two PS. In one PS with Bias 1,56 and gain 1,76 all CD' s were played. In the other PS i had to adjust the Lasergain to 11,4 mV by Bias 1,7 and Gain 1,83. With 1,56 V and 1,76 V the CD don't start.
I put it in the 3rd PS and i had to adjust the Lasergain to 24,4 mV and Bias 1,56 with a gain of 1,76 V
Now i think i know nothing !!!!!!
So it can't be the distance from the CD to the Laser. I don't had the time to check the 9mV, but i will do it.
My oppinion is that there have to exist different mother boards. I have to look if i can see any differences, because i have got at least 2 different
BR Dommi
now im totaly confused. I have a new AKM Unit and 3 PS here. The Lasergain is adjusted to 24,4 mV and i tryed it in two PS. In one PS with Bias 1,56 and gain 1,76 all CD' s were played. In the other PS i had to adjust the Lasergain to 11,4 mV by Bias 1,7 and Gain 1,83. With 1,56 V and 1,76 V the CD don't start.
I put it in the 3rd PS and i had to adjust the Lasergain to 24,4 mV and Bias 1,56 with a gain of 1,76 V
Now i think i know nothing !!!!!!
So it can't be the distance from the CD to the Laser. I don't had the time to check the 9mV, but i will do it.
My oppinion is that there have to exist different mother boards. I have to look if i can see any differences, because i have got at least 2 different
BR Dommi
Hey friendly forum folks I,m new to all this stuff i.e. diy hi fi electronics etc. However I have a passion for making useful things from the detritus of the modern world.I have perused this forum with great interest and now plan on building an ultra low cost hifi system .Anyhoo It looks like I have access to several first gen. playstations for virtualy $0. So my questions; could the power supply from a playstation( or the tranny and other stuff inside ) be used for a pair of 3875 gainclone mono blocks? Will it play Mp3's? TIA for your help and patience with a newbie. Cheers BOB
mudgeek said:Hey friendly forum folks I,m new to all this stuff i.e. diy hi fi electronics etc. However I have a passion for making useful things from the detritus of the modern world.I have perused this forum with great interest and now plan on building an ultra low cost hifi system .Anyhoo It looks like I have access to several first gen. playstations for virtualy $0. So my questions; could the power supply from a playstation( or the tranny and other stuff inside ) be used for a pair of 3875 gainclone mono blocks? Will it play Mp3's? TIA for your help and patience with a newbie. Cheers BOB
welcome Bob
The PSU inside the Playstation 1 is a switched mode supply, so has no transformer in the conventional sense. Wether it could be used to drive a pair of gainclones depends on the voltage you need. The PSU delivers 3.6 and 7.6 volts to the mainboard, at potentially high current. The pinouts from the PSU are described here :
http://www.diyaudio.com/forums/showthread.php?postid=775467#post775467
I'd guess that while useful, these power supplies are too noisey to supply gainclones.
You know I have not tried an mp3 disk BUT I'm 99% sure it will not play them, only CD, primarily because the Playstation preceeds mp3 by a good 6 years I'd say.
Which speakers do you intend using ?
Hey thanks for the quick responses.I picked up two 1001 playstations (both working) for $0 US but, unfortunately had to buy an AC power cord for $5 
. Anyway it looks like "Bob's ultra cheap hi fi project "is of to a good start. The basic plan is a PS CD player through gainclone monoblocks through full range speakers . To be compleated for < $100 US. Probably kind of ambitious but thats the plan for now. So tomorow I hope to do the mod's from Mick F's site with the simple output stage plug in version. So to the questions ; I plan on separating the power supply and transport (apart from any possible sonic/performance improvements I just enjoy building, and like the looks of lots of, little boxes ) sorry I do bloody ramble on ! any way do I just pull out the little connector between the power supply and transport? I don't want to break any thing. What is the best i.e. most 'Hi Fidelity" way to extend this connection ? how far appart should the PS and transport be? Do I ajust the trimmers with a screw driver or is a special tool required? Finally, is there some sort of DIY HiFi primer on the web somewhere which answers basic stuff so I don't have to waste folks time thanks alot Cheers BOB
but, unfortunately had to buy an AC power cord for $5 . Anyway it looks like "Bob's ultra cheap hi fi project "is of to a good start. The basic plan is a PS CD player through gainclone monoblocks through full range speakers . To be compleated for < $100 US. Probably kind of ambitious but thats the plan for now. So tomorow I hope to do the mod's from Mick F's site with the simple output stage plug in version. So to the questions ; I plan on separating the power supply and transport (apart from any possible sonic/performance improvements I just enjoy building, and like the looks of lots of, little boxes ) sorry I do bloody ramble on ! any way do I just pull out the little connector between the power supply and transport? I don't want to break any thing. What is the best i.e. most 'Hi Fidelity" way to extend this connection ? how far appart should the PS and transport be? Do I ajust the trimmers with a screw driver or is a special tool required? Finally, is there some sort of DIY HiFi primer on the web somewhere which answers basic stuff so I don't have to waste folks time thanks alot Cheers BOBAdjusting Gain and Bias
Domenico,
there are at least 4 versions of the SCPH-1002 as follows.
1-658-467-11 PU-8 / AKM AK4310VM
1-658-467-21 PU-8 / AKM AK4309VM
1-658-467-22 PU-8 / AKM AK4309VM
1-658-467-23 PU-8 / AKM AK4309AVM
At the moment I have version #1 with a replaced laser unit (new: BAM) and as well version #3 at my hands. The data recorded belongs to version #3:
I measured the other than the given values with my version #3 as you can see. There might be different basic adjustments for every version !?
Can You tell us, what versions you measured?
Kind regards,
Thomas
Domenico,
there are at least 4 versions of the SCPH-1002 as follows.
1-658-467-11 PU-8 / AKM AK4310VM
1-658-467-21 PU-8 / AKM AK4309VM
1-658-467-22 PU-8 / AKM AK4309VM
1-658-467-23 PU-8 / AKM AK4309AVM
At the moment I have version #1 with a replaced laser unit (new: BAM) and as well version #3 at my hands. The data recorded belongs to version #3:
thokra2003 said:
I measured the other than the given values with my version #3 as you can see. There might be different basic adjustments for every version !?
Dommi said:
Can You tell us, what versions you measured?
Kind regards,
Thomas
PS1
Well back into the loft goes the Playstation 1, thankfully.
As regards to it beating a high resolution cd player this I cannot understand this , so I will assume hearing acuity , system resolution and people not knowing what they are talking about all factors in the end result.
Even my partner shirked , so much, as to ask someone at HIFi world what the fuss was about. the reply given, was.
There is a lot of internet hype going around regarding the PS1, which should be disregarded, sadly this machine is getting a lot of unearned attention and is not as these forums say, capable of beating £1000 players, it is easily shown a clean pair of heels by all basic Marantz players and some budget DVD players.
I have to agree, and I also think it is amusing that some may have sold their £1000 players and kept the PS1. LOL .
I wonder how much of the hype is written by people who have not owned a decent Cd player ? or have a poor system.
I would compare it to a £20 or £30 supermarket DVD player, both the Toshiba dvd-220 and a Dual 5150 cd player stomped over it.
Well back into the loft goes the Playstation 1, thankfully.
As regards to it beating a high resolution cd player this I cannot understand this , so I will assume hearing acuity , system resolution and people not knowing what they are talking about all factors in the end result.
Even my partner shirked , so much, as to ask someone at HIFi world what the fuss was about. the reply given, was.
There is a lot of internet hype going around regarding the PS1, which should be disregarded, sadly this machine is getting a lot of unearned attention and is not as these forums say, capable of beating £1000 players, it is easily shown a clean pair of heels by all basic Marantz players and some budget DVD players.
I have to agree, and I also think it is amusing that some may have sold their £1000 players and kept the PS1. LOL .
I wonder how much of the hype is written by people who have not owned a decent Cd player ? or have a poor system.
I would compare it to a £20 or £30 supermarket DVD player, both the Toshiba dvd-220 and a Dual 5150 cd player stomped over it.
