About LD1086 +5V Reg
Hi Ray
Following your work, I am using a LM340AT in place of 7805 (Q811 Digital +5v supply)
The improvement was very important..!
Now I have got some LD1086 +5v and would like your oppinion about possible improvements by replacing the LM340 with the latter.
If no improvement should be expected, could I use the LD1086 to feed the digital +5v on the dac in place of a superreg ?
Now I am following with interest the various experiments with discrete output stages.... I would like to try a valve output stage... can it be done ?
Best Regards
Ricardo
Hi Ray
Following your work, I am using a LM340AT in place of 7805 (Q811 Digital +5v supply)
The improvement was very important..!
Now I have got some LD1086 +5v and would like your oppinion about possible improvements by replacing the LM340 with the latter.
If no improvement should be expected, could I use the LD1086 to feed the digital +5v on the dac in place of a superreg ?
Now I am following with interest the various experiments with discrete output stages.... I would like to try a valve output stage... can it be done ?
Best Regards
Ricardo
Re: About LD1086 +5V Reg
Dunno, you must understand I did not try every existing regulator to see what happens. I'd say, try it and see what it does.
A valvestage is possible (I tried it) but I found the sound not too different compared to a discrete solution. So I chose discrete
Ray
RCruz said:
Dunno, you must understand I did not try every existing regulator to see what happens. I'd say, try it and see what it does.
A valvestage is possible (I tried it) but I found the sound not too different compared to a discrete solution. So I chose discrete
Ray
Re: Re: About LD1086 +5V Reg
Come on, Ray !!!!
You are the font of all wisdom.
I also tried a valve stage and also found it sounded not too different to the discrete solution. I stayed with the valve output !!
Andy
6h5c said:
Dunno, you must understand I did not try every existing regulator to see what happens. I'd say, try it and see what it does.
A valvestage is possible (I tried it) but I found the sound not too different compared to a discrete solution. So I chose discrete
Ray
Come on, Ray !!!!
You are the font of all wisdom.
I also tried a valve stage and also found it sounded not too different to the discrete solution. I stayed with the valve output !!
Andy
riccardo said:Fet have the same distorsion than Tubes...
About Valves, Vs. Lm4562, or Lm49710, Vs all world, why don't you try with THIS?
Not tried it yet.... what kind of improvements should I expect ?
It looks like just altering the noise floor filter but also loosing some high frequency volume...
I am interested but can not try before I fully undersand wht to expect.
Regards
Ricardo
Re: Re: Re: Re: About LD1086 +5V Reg
Hi,
I would love to post some pictures but I am not at home at the moment....................got to work sometimes!!
The PSU was very simple, 6v regulated for the heaters and 30v regulated for the 'HT'.
I used a variety of tubes fron ECC88 to subminature [pencil] tubes.
Pictures of both Ray's and my valve stages are on the thread.
Andy
RCruz said:
Hi,
I would love to post some pictures but I am not at home at the moment....................got to work sometimes!!
The PSU was very simple, 6v regulated for the heaters and 30v regulated for the 'HT'.
I used a variety of tubes fron ECC88 to subminature [pencil] tubes.
Pictures of both Ray's and my valve stages are on the thread.
Andy
Hi all,
hi Ricardo,
The question it's correct.
The sampling noise is not "white noise", but a consistent harmonics frequency residue of oversampling dac.
The PWM outputs of dac produce a broad spectrum of "coherent noise", is so common that differential.
Strangely CD63 is filtered only in the common mode RC cell, while no differential.
The filter opamps not have an adeguate high frequency differential rejection on PWM frequency working.
The result is that the opamps generate IMD. The IMD of opamps + noise results in a consistent IMD broad spectrum floor in the all audio band.
The noise foor of a original CD63 is about -90dBV, almost all formed by IMD or sampling residue, rather than players with philips CD471 is about -110dBV.
After modifing with 2 capacitors, the noise floor of CD63 becomes approximately -100 -105dBV because the opamp work in more linear conditions .
The result is a very precise and "natural sound" (because lack the IMD precisely....)
I believe that this is the most serious problem of CD63 MKII Kis, most serious that Jiitter and group delay ....
But this is "only my opinion".
All you can try to measure or to listen to the differences and decide whether this is or is not a problem to be solved ...
ciao
Mauro
riccardo said:Ciao Ricardo.
What is the results adding a 330 pF cap to the filter?
All noise, ALL, all, all noise, disappear.
Hi Riccardo
I believe the noise can substantially be reduced with this method but it will alter the overall response of the player right ?
I believe it will reduce noise and also reduce high frequency response.
Can you comment please ?
Regards
Ricardo
avr300 said:
Why not ? Trust your ears. Let yourself be surprised.
6h5c said:
I am sure this is ok for you guys but I only have one CD53 already very well modded.
All the mods I did where based on proven experiments did by other participants in this forum.
I must be 100% sure of the final results before I make any modifications.... As I only have one CD53 and must be very carefull with it and never modify just to "see what happens".
Did any of you experiment with this 330pF differential filter ?
Regards
Ricardo
OK, Ricardo
If you is 100% sure of other full Subjective and/or extremize tweek, my simple technical observation is not adequate of this 3D....
The pass band amplitude, phase, and group delay it's one problem, and my modify have on this one limited impact (some like bessel filter solution), but the problem it's the attenuation over 300khz, some Ineffective in the bessel or "group delay correction" and dozens dB in my propose.
This reflected in low side band harmonics (audio band).
In my opinion, work on Nyquist is most important and accurate work instead on the psu regolator of a digital circuit, but this is only the vision of a professional electronic, little just experienced of diys problems....
ciao
Mauro
Mauromauropenasa said:
My observation was not directed to criticyse your fine work.
I am not a professional so I must rely on others experiences before I try anything.
I was just testing the forum to see if anyone had already tryed your technique and maybe get some practical advise.
Folowing your previous comment i understand that with your modd I will get lower noise and not affect the audio response.
I will try this modd and report back to you.
Best Regards
Ricardo