Paradise Builders

[FdW]

Originally Posted by quan

Thank you Franz. How do you implement input resistor loading switches? Can you show me a close-up image?.
quan

No loading-resistors implemented there (in the picture ), it is a MM RIAA that I did build. As strange as it may be, I did not build the Paradise RIAA (sorry ) (but I always be here and help with the PSU).

P.s. The name is Frans

[Benedetto]

Originally Posted by FdW

P.s. The name is Frans

Not to be confused with the german style Franz !

[FdW]

Here a picture that tells a 1000 words (I hope). The scope is at 10nS and 500uV, the HF is sampling artifacts. If you remove the sampling artifacts from the signal, then around 600 to 800 uV signal is there. With this I am happy, the PSU is unloaded, there is no shielding, sitting on the living room table near to the SMPS. This all is at the limit for the scope.

Someone will be happy to see this/his positive supply fixed, I will now continue with the negative supply.

Any remarks, let me know, I will be happy to discuss this.

[FdW]

And here is the dark (negative) side

[PMA]

Originally Posted by FdW

Any remarks, let me know, I will be happy to discuss this.

Hi Frans,

can you try something like this? You may easily read the PSU noise and ripple from my measurement.

Regards,
Pavel

[FdW]

The funny thing is, I am still not sure why this one was oscillating (more than 2Volts pp), or in other words, why most others are not oscillating.

The things I did are:
1) Remove 2 MJE15031G from the positive supply and replaced by D45H11's. This lowered the oscillations somewhat but not much.
2) Paralleled the 330 ohm be resistors with 56 ohm resistors. Again, this lowered the oscillation somewhat (slightly more than in removing the MJE25031G's).
3) Added ce capacitors (as in the builders guide) but I had to use 4n7's and 2n2's to stop all oscillations.

There you have it, my report from the trenches.

[FdW]

Originally Posted by PMA

Hi Frans,

can you try something like this? You may easily read the PSU noise and ripple from my measurement.

Regards,
Pavel

No (I'm sorry to say ) I cannot (I tried). The 10nS and 500uV is near the limit of the scope, there is absolutely no resolution in the FFT (it’s near empty ).

[PMA]

Yes, the resolution of scope FFT is not enough, 8 - 12 bits. We need both fast scope and audio resolution FFT to get a complete view.

[FdW]

Originally Posted by PMA

Hi Frans,

can you try something like this? You may easily read the PSU noise and ripple from my measurement.

Regards,
Pavel

In your graph it is -105dB and with that I will be happy (unshielded and sitting near the SMPS).

[RCruz]

Originally Posted by FdW

And here is the dark (negative) side

Are you starting to build the paradise ?

If those are your boards, your first try did indeed oscilate ?