I have the discrete output as designed by Ray, using FETs, 2w "Kiwame" carbon resistors and polystyrene filter caps, powered by S Powers @15v+- and decoupled by Elna Cerafines, power taken from the original 20v+- "KI" toroid with schottky diodes and smoothed by 1000uF BG standards.
It sounds good. Compared recently to another good CD63KI with 4562 mine sounded richer with much better dynamics and a punchier bass. Surprisingly similar tonally, although it was a little better.
I also think with each in their current state of "tune", my CD63KI was a little better than Brent's "not-completely" modified CD17KI. The 17 has RIDICULOUS bass weight though
Simon
It sounds good. Compared recently to another good CD63KI with 4562 mine sounded richer with much better dynamics and a punchier bass. Surprisingly similar tonally, although it was a little better.
I also think with each in their current state of "tune", my CD63KI was a little better than Brent's "not-completely" modified CD17KI. The 17 has RIDICULOUS bass weight though
Simon
Re: Re: output stage again...
Ray, what do yo think about fitting a 6V2 Zener // 330nF cap to Q1 emitter, change R26 to 1.2K, take output between zener and R26.
R25 can be a trimpot to fine-tune the output to 0V.
André
6h5c said:This concludes the analog electronics lesson for today!
Ray
Ray, what do yo think about fitting a 6V2 Zener // 330nF cap to Q1 emitter, change R26 to 1.2K, take output between zener and R26.
R25 can be a trimpot to fine-tune the output to 0V.
André
Re: Re: Re: output stage again...
I don't think it's a good idea to fit a non-linear semiconductor in series with the signal path, if you know what I mean. Apart from that, the voltage drop of the zener and the offset of the output stage are changing when the circuit heats up, because there is no feedback. So the compensation will never be exact.
Ray
Andre Visser said:
I don't think it's a good idea to fit a non-linear semiconductor in series with the signal path, if you know what I mean. Apart from that, the voltage drop of the zener and the offset of the output stage are changing when the circuit heats up, because there is no feedback. So the compensation will never be exact.
Ray
Discrete output
Just love the way you do it.... always appearing when needed.
After all my mods (including 4 additional TX an two clocks), I really believe I reached the opamps limits so I am considering to build a discrete output.
My first doubt is about the FET´s you use... can I use any kind that I get on Farnell or do they need to be "paired" ?
Second question is related with the PSU.
Recently I got some +-15v Spowers and placed them on the opamps.
I nedded to do it because the +-12v rayregs where overheating due to the PSU (The TX I am using is a 30VA 2x18v followed by 2x10.000uF.)
I would like to use this +-15v PSU to feed the discrete.. is it feasible ?
Regards
Ricardo
Hi Ray6h5c said:You're welcome! I just kept on writing, I don't know what got into me...
Just love the way you do it.... always appearing when needed.
After all my mods (including 4 additional TX an two clocks), I really believe I reached the opamps limits so I am considering to build a discrete output.
My first doubt is about the FET´s you use... can I use any kind that I get on Farnell or do they need to be "paired" ?
Second question is related with the PSU.
Recently I got some +-15v Spowers and placed them on the opamps.
I nedded to do it because the +-12v rayregs where overheating due to the PSU (The TX I am using is a 30VA 2x18v followed by 2x10.000uF.)
I would like to use this +-15v PSU to feed the discrete.. is it feasible ?
Regards
Ricardo
Ricardo the 2SK170 FET is superb. I tested loads and this one had a perfectly flat responce curve. It really is good.
You can get the BR or GR version of this FET with the GR version being slightly better. I believe they are selected for their tolorence from the BR batch. I'm sure someone can correct me if i'm wrong.
The PSU you have will come into its own with the discrete. Expect good things.
Brent
You can get the BR or GR version of this FET with the GR version being slightly better. I believe they are selected for their tolorence from the BR batch. I'm sure someone can correct me if i'm wrong.
The PSU you have will come into its own with the discrete. Expect good things.
Brent
rowemeister said:Well in over 15 years of repairing cd players including hundreds of CD63s I have never seen one with a burnt out Decoder chip (a nice charcoal bleb on it) until now!!!!!
Congratulations to Simon
Brent
Aww, thanks mate, I do try
(I didn't even TOUCH the decoder area, so I'm guessing the DAC has had it too, how on earth do I do this?)
Note the slightly toasted bit top right of the chip
Brent
An externally hosted image should be here but it was not working when we last tested it.
Brent
SimontY said:
Aww, thanks mate, I do try
(I didn't even TOUCH the decoder area, so I'm guessing the DAC has had it too, how on earth do I do this?)
Apart from the new 5v reg you put in not being soldered correctly the +22V from you external (large) psu was flapping about inside instead of being connected to the 5v reg to the decoder. I suspect you gave your decoder +22V and lots of current
Simon you are indeed the "Special one"
Brent
