For those interested, I have two (2) scph-1001 models I'd like to get rid of. One is unmodified and in excellent condition, the other has been modified with gold plated RCA's and modified output stage with WIMA's. Sony PSII remote to go as well to the first responder/payer.
questions, etc email to: kstylian "at" vt.edu
questions, etc email to: kstylian "at" vt.edu
For all those not convinced by the sound of the PS:
It does makes a big difference if one mods it with a linear PSU and a well done but simple output stage around a good opamp like opa2134 or LM4562, taken directly from the DAC etc... also it really needs a new case... with all those mods, my PS1 is playing in the same league like a modded (reclocked and everything) Marantz CD40 I have. To me that's a pretty good result for a PLAYSTATION! Btw, the Marantz is the best sounding player I have, sure that the're better sounding players out there which will beat the Marantz and the PS1, but they also cost quite a bit hehe... so, in my opinion, the PS1 is no "miracle" like people have been putting it sometimes lately... but it sure has got a lot of potencial, more than any other cheap cdp I've ever heard, and with the mods described, one gets a real good cdp for a low price. Better than any mid-class today's cdp out there... just don't expect it to blow your 5000 dollar cdp or so... 😉 my 2 cents...
It does makes a big difference if one mods it with a linear PSU and a well done but simple output stage around a good opamp like opa2134 or LM4562, taken directly from the DAC etc... also it really needs a new case... with all those mods, my PS1 is playing in the same league like a modded (reclocked and everything) Marantz CD40 I have. To me that's a pretty good result for a PLAYSTATION! Btw, the Marantz is the best sounding player I have, sure that the're better sounding players out there which will beat the Marantz and the PS1, but they also cost quite a bit hehe... so, in my opinion, the PS1 is no "miracle" like people have been putting it sometimes lately... but it sure has got a lot of potencial, more than any other cheap cdp I've ever heard, and with the mods described, one gets a real good cdp for a low price. Better than any mid-class today's cdp out there... just don't expect it to blow your 5000 dollar cdp or so... 😉 my 2 cents...
I wonder, for those who still have your original SMPS's, how prevalent a RF-suppressing ferrite bead is on the main Switching diode. I've an early (july 1995) 1001 and a late (1996) 1001, and the earlier one has a ferrite bead (and a larger PS cap) while the later one doesn't (didn't, just put one in).
martin.ca said:
Yes - I pondered this a while back
umbilical RF filtering
And figured out that you can carfefully remove the pins from the edge connector at one end, and hence put a longer, tighter fitting ferrite over each individual cable.
joydivision said:
Yes, that is what I imagined to do. A new output stage dircectly at the putput pins of the AK4309. Can you mail me the circuit you use. LM4562 is my favorite that I use in my modded KR Audio Electronics preamp.
Tolu, the schematic of the output stage is included in the "working thread" of my project: http://www.diyhifi.org/forums/viewtopic.php?f=2&t=1356
On the 2nd page, the last schematic of the output stage is the correct one...
On the 2nd page, the last schematic of the output stage is the correct one...
Re: 100% more output without soldering
I upped the output by 80% by just changing the op-amp input resistor from 18k to 10k.
I am now trying the same thing with better caps and keeping the original op-amp. Bypassing the muting circuit though...I don't know if it was tried at the beginning of this thread?
Tolu said:
I upped the output by 80% by just changing the op-amp input resistor from 18k to 10k.
I am now trying the same thing with better caps and keeping the original op-amp. Bypassing the muting circuit though...I don't know if it was tried at the beginning of this thread?
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I hate SMD! 
The built-in opamp sounds to weak to do further mods with it. The AV-multi-out sounds better but sound stage is too small. Everything plays at a small area between the speakers!
I think joydivision method could be the better one. I haven't opened the shield so far. What parts are between the AK4309 output and the AV-multi-out?
The built-in opamp sounds to weak to do further mods with it. The AV-multi-out sounds better but sound stage is too small. Everything plays at a small area between the speakers!
I think joydivision method could be the better one. I haven't opened the shield so far. What parts are between the AK4309 output and the AV-multi-out?
audio1st: yes, don't waste your time trying to improve the original circuit. I wouldn't say because of it being SMD... it's just that it is too complex (long signal path, many components in between or attached to it), and the opamps are crap... so unless you take out all the other components and substitute the opamps with good ones, it won't be worth fiddling around with SMD...
Tolu, I think between the ADC and the AVout is only one opamp... but it's the same crappy model as in the RCA out... just that it's only one stage and there are, as far as I saw it, no other components in the way, that must be why it sounds better...
Tolu, I think between the ADC and the AVout is only one opamp... but it's the same crappy model as in the RCA out... just that it's only one stage and there are, as far as I saw it, no other components in the way, that must be why it sounds better...
As far as I am aware, it is only the 100x models that have the op-amp and therefore can have more volume to the output.
It is not the extra length of circuit that will be the problem (20mm), just the quality of the op-amp? So no op-amp in the AV circuit, just muting transistors, resistors and caps.
Next I will bypass each of 4.7uF caps with SIX smaller value caps(silver mica included), and then it will sound really good..🙄 🙄 🙄 😉 Sorry for that, you never know???
It is not the extra length of circuit that will be the problem (20mm), just the quality of the op-amp? So no op-amp in the AV circuit, just muting transistors, resistors and caps.
Next I will bypass each of 4.7uF caps with SIX smaller value caps(silver mica included), and then it will sound really good..🙄 🙄 🙄 😉 Sorry for that, you never know???
Audio1st:
I don't know if I understood your post correctly...
but I'd say that probably all the playstation modelos do have at least one opamp in the signal path before the AVout. It's common practice... 😉 and it's definitely a good thing. And even better here, as you could simply increase the gain of that op and have the output level elevated to standard value. What is NOT good though, is the model of the opamp, and all the other (unnecessary) components like muting transistors, caps, etc... that's why I recommended not to "waste your time" with trying to mod all this... but hell, I didn't mean to say that it would be impossible to get the original circuit to sound really good... 🙄 you just have to do a LOT of mods to it... and as it is SMD parts, it will be much more difficult... that's why I tried to "convince" you of going for the external solution... but obviously, just do as you like... 🙂
I understand that you're joking with that 6 caps bypass thing... just wonder though, where you got such a crazy idea from lolol 😀
I don't know if I understood your post correctly...
but I'd say that probably all the playstation modelos do have at least one opamp in the signal path before the AVout. It's common practice... 😉 and it's definitely a good thing. And even better here, as you could simply increase the gain of that op and have the output level elevated to standard value. What is NOT good though, is the model of the opamp, and all the other (unnecessary) components like muting transistors, caps, etc... that's why I recommended not to "waste your time" with trying to mod all this... but hell, I didn't mean to say that it would be impossible to get the original circuit to sound really good... 🙄 you just have to do a LOT of mods to it... and as it is SMD parts, it will be much more difficult... that's why I tried to "convince" you of going for the external solution... but obviously, just do as you like... 🙂 I understand that you're joking with that 6 caps bypass thing... just wonder though, where you got such a crazy idea from lolol 😀
joydivision said:What TET is promising there, seems fishy to me. How are they suppose to be able to increase the output voltage without any soldering, if the DAC has a max output of 3.4Vpp (at least says so in the datasheet), which translates in about ~1.2V RMS compared to 2V RMS for most CD players.
The only way I could think of would be that they force the DAC to deliver a higher voltage by changing something in the digital domain (which, if even possible (I doubt that), could cause the ouput to be clipped, or at least the DAC chip's life to be shorted as it probably would get hot). So that all looks like BS to me...
Joydivision,
Like I said, I changed one resistor per channel and now have about 2V at the output. It won't be as pure as the common minimalist route, but it may have more grunt when using it with an amp with a passive-pre...
As for the 6 caps, the picture of the TET machine (IMO) seems to show four 10uF caps, each bypassed with 6 smaller caps. They do mention "28 caps" in their advert..😉
Just an observation..
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@joydivision:
I have read your thread at diyhifi.org. Would you seriously recommend this mod (with the opamp)? Is the result so much better than the original setup? How can you describe the sonic improvement of your mod (except that it is louder)?
I have read your thread at diyhifi.org. Would you seriously recommend this mod (with the opamp)? Is the result so much better than the original setup? How can you describe the sonic improvement of your mod (except that it is louder)?
audio1st: ok, understand now what you meant 🙂
Your solution is for sure a very neat "quick hack", getting the PS1 to play at normal output levels with minimal work. (Wonder why didn't Sony do this?? Why keep the signal at sub-standard levels, if it does pass through an opamp, which could easily be performing the necessary 1.5 or something gain? funny... 😕 )
That 6 caps bypassing thing only further proves that their work is "based on snake oil" lolol
Tolu:
actually it's not only me recommending that (or similar) mods lol... 😉
I went this way for two reasons: gives me the standard output level, and the opportunity to choose the output opamp, circuit and components I like.
Compared to the original PS (using the RCA out) I am convinced there's improvement in the sound, not related to the volume. That's pretty logical, because the signal goes through a crappy 2100 opamp and a few other components to reach the RCAs...
Comparing to the AV out, it can't bring any improvement on the sound, only in volume; as the AV is almost the same as taking the output directly from the DAC (except for two additional caps and the muting transistors). Yes, audio1st, afterall you were right, the 1002 only has the opamp in the RCA output circuit, not in the AV multiout. That's why everyone reports the sound is better from the AV out 🙂
Your solution is for sure a very neat "quick hack", getting the PS1 to play at normal output levels with minimal work. (Wonder why didn't Sony do this?? Why keep the signal at sub-standard levels, if it does pass through an opamp, which could easily be performing the necessary 1.5 or something gain? funny... 😕 )
That 6 caps bypassing thing only further proves that their work is "based on snake oil" lolol
Tolu:
actually it's not only me recommending that (or similar) mods lol... 😉
I went this way for two reasons: gives me the standard output level, and the opportunity to choose the output opamp, circuit and components I like.
Compared to the original PS (using the RCA out) I am convinced there's improvement in the sound, not related to the volume. That's pretty logical, because the signal goes through a crappy 2100 opamp and a few other components to reach the RCAs...
Comparing to the AV out, it can't bring any improvement on the sound, only in volume; as the AV is almost the same as taking the output directly from the DAC (except for two additional caps and the muting transistors). Yes, audio1st, afterall you were right, the 1002 only has the opamp in the RCA output circuit, not in the AV multiout. That's why everyone reports the sound is better from the AV out 🙂
Sure, you can definitely replace the original opamp with a opa2134 soic. Or any other good opamp which has the same pin configuration and doesn't suffer from unity gain instability or so... although you won't be using unity gain anymore... but still good to play safe lol... regarding supply voltage, as long as it is above +-2.5V it's ok for the opa2134 and many others. But in case they have the NJM2100 operating at single supply +5V (I don't think so, but it's possible), you can't just drop the opa2134 or other in and have it work... you'd have to improvise a virtual gnd and split supply of 5V/2 = 2.5... you know, with a 100k divider, two caps and all that stuff? just google for it, it's common practice. But then the problem would be, how and where to fit those components... see why I think it's not a good idea to fiddle around with the original circuit?
Also, there is another important thing here to consider... aiming for a 2V peak output with +-2.5V supplies isn't really a good idea... even if the opamp has high saturation capacities... I mean, look at the original circuit, for example... it only works with 1.34V peak signal or so, which is no problem at all with +-2.5V supplies. But rising it to 2V... I don't know... It'll probably work ok, but don't ask me about performance regarding THD and other details...🙄
Also, there is another important thing here to consider... aiming for a 2V peak output with +-2.5V supplies isn't really a good idea... even if the opamp has high saturation capacities... I mean, look at the original circuit, for example... it only works with 1.34V peak signal or so, which is no problem at all with +-2.5V supplies. But rising it to 2V... I don't know... It'll probably work ok, but don't ask me about performance regarding THD and other details...🙄
Thanks for the info "joydivision". I measured 2.5V at the pins and I guess the two 15k resistors and caps at the top of the picture are the voltage dividers. I may then try different feedback and input resistor combinations and see what happens. This is just cheap trial and error for me, if it all goes belly-up, I can always bypass the whole output stage as normal...😉
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I don't know how many different versions of the 100x there are?
Here are two different versions that I have, I am playing with the left hand model at the moment but the right hand model looks better. I don't know what op-amp is used with that one. I notice the DAC's are different (4309 & 4310) with extra caps round the 4310..
Here are two different versions that I have, I am playing with the left hand model at the moment but the right hand model looks better. I don't know what op-amp is used with that one. I notice the DAC's are different (4309 & 4310) with extra caps round the 4310..
