ccschua said:
Many believe op-amps and discrete buffer or amplification stages need low impedance more than low noise. I believe this is where your chip fails.
edit: I re-read and see you said "based" - that's a different story!! Anyway - op-amps don't respond to fancy regulation like the rest of a CD player, so leave it till last, that's my 2p.
Simon
My CD63ki was my real entry into the dark world of CD player modification, and it, this thread and Brent have taught me most of what I know! But the player never really gets musical and interesting, only more detailed and clear. 1541 players, OTOH, are hard to get detail from, but are inherently musical.
But let's not simplify things too much, the CD53/63 can reach staggering heights if you can do enough upgrades without breaking it. And I also believe that any player modded enough will sound quite similar to any other player modded enough - it should just sound like the music.
Simon
But let's not simplify things too much, the CD53/63 can reach staggering heights if you can do enough upgrades without breaking it. And I also believe that any player modded enough will sound quite similar to any other player modded enough - it should just sound like the music.
Simon
Ok shottkeys fitted and in time for football 
1st impressions were
Overly bright but increased "sweet spot" Thought this aint right had a look everything seems the right way round etc
Thought i'd better screw the board down and put a lid on it........
Phew harshness in the treble has gone and back to a more solid sound
1 downside..... I'm running outta parts.... well except those panas (if i can get those elnas out
) and a bit of seperation
1st impressions were
Overly bright but increased "sweet spot" Thought this aint right had a look everything seems the right way round etc
Thought i'd better screw the board down and put a lid on it........
Phew harshness in the treble has gone and back to a more solid sound
1 downside..... I'm running outta parts.... well except those panas (if i can get those elnas out
) and a bit of seperation
Schottkies probably do introduce a slightly brighter sound! I only ever heard the effect STRONGLY when changing them in an amp, however. I do think they clean things up a bit.
The lid adds weight so will subtly affect presentation. With the reduced weight (and therefore tighter bass) it will seem brighter and thinner. I once realised this when I added some paving slabs to my equipment rack and wasn't sure if it was better or worse... until they came off again and it was a "breath of fresh air", as the timing came back to speed and harshness and overbearing bass dropped back. This weight (storage) issue is also why metal and glass racks sound bad.
The lid adds weight so will subtly affect presentation. With the reduced weight (and therefore tighter bass) it will seem brighter and thinner. I once realised this when I added some paving slabs to my equipment rack and wasn't sure if it was better or worse... until they came off again and it was a "breath of fresh air", as the timing came back to speed and harshness and overbearing bass dropped back. This weight (storage) issue is also why metal and glass racks sound bad.
I decided to run a clock signal direct to the decoder on the works 63se with mild mods.
Ricardo you have a good ear so you need to try this and it only takes 5 mins to test.
RD14 / C521 near dac (same part) cut a leg.
Run short wire from dac clock output to decoder side of U193 near decoder (actually fitted with a resistor)
On the test one here the detail jumped out, the music became much smoother and fluid.
Going to do mine next week and then later on upgrade to a dedicated clock. I need to test if it will work on a different clock to the dac one first. I see no reason why to be honest.
Brent
Ricardo you have a good ear so you need to try this and it only takes 5 mins to test.
RD14 / C521 near dac (same part) cut a leg.
Run short wire from dac clock output to decoder side of U193 near decoder (actually fitted with a resistor)
On the test one here the detail jumped out, the music became much smoother and fluid.
Going to do mine next week and then later on upgrade to a dedicated clock. I need to test if it will work on a different clock to the dac one first. I see no reason why to be honest.
Brent
Hello Again,
It has been a while back since I've been here, but it started itching again.
I did lot's of mods to my cd67se, but now I would like to look into a discrete output stage. After some research on the web I found a few solutions.
Can you advise me what is the best?
OPA SUN
http://www.audio-gd.com/enweb/pro/diy/OPA.htm
Burson Opamp http://www.bursonaudio.com/burson_opamp.htm
Audioupgrade Output stage http://www.audioupgrades.co.uk/discrete.shtml
It has been a while back since I've been here, but it started itching again.
I did lot's of mods to my cd67se, but now I would like to look into a discrete output stage. After some research on the web I found a few solutions.
Can you advise me what is the best?
OPA SUN
http://www.audio-gd.com/enweb/pro/diy/OPA.htm
Burson Opamp http://www.bursonaudio.com/burson_opamp.htm
Audioupgrade Output stage http://www.audioupgrades.co.uk/discrete.shtml
rowemeister said:
I agree!
I've got both burson and a DOS running together in a different player.
The DOS is excellent in its std form. However, you can tweek it to increase its performance further.
If it were me, I'd go for the audioupgrades DOS. I'd also get Blackgates on it, Mundorf Supreme's on the output and drive it with SPowers.
You can always start with the std dos then add the hop ups later if you feel the need.
Ian
gy21 said:
This is true if you are talking about "pluging in" to 8dil sockets.
I've currently got this DOS running in my philips CD960 which is a TDA1541 player. The only change required to get it working was to ground the inverting input for each channel.
TBH if you're starting to make changes in this area, you can obvioulsy use a soldering iron so i don't see why this ability to easily plug in and out is an argument.
The DOS in std form is a much better sounding circuit than the Bursons. It will replace the entire output stage of the player. Unless you make all the mods to the filter and outputstage (on Rays list pg1) and even then, you will always be at a disadvantage running the Burson's.
I'd personally recommend the DOS over the Bursons.
Ian
I have been studying the various opamp solutions available and have some quite pertinent questions:
I changed from NJM2114D to LM4562 with enourmous gains in sonic quality. After that I tryed the LME49720 with even greater results (it takes a while to burn in though).
I did this mods just by swapping the parts, leaving the feedback circuits untouched.
In the CD53, I see the 120pF C601/602 caps are in parallel with the feedback resistors R603/604.
Are these caps needed to optimize the opamp sound ?
Ricardo
I changed from NJM2114D to LM4562 with enourmous gains in sonic quality. After that I tryed the LME49720 with even greater results (it takes a while to burn in though).
I did this mods just by swapping the parts, leaving the feedback circuits untouched.
In the CD53, I see the 120pF C601/602 caps are in parallel with the feedback resistors R603/604.
Are these caps needed to optimize the opamp sound ?
Ricardo