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Hi David,

You are more of a perfectionist than I am. I would just use DC-Link caps and a CCS.

I suspect that there are others who would find the diagrams interesting. I have learned so much from others who have taken the time to provide example diagrams and photos.

ray

Ray,

Thanks for the explanation. This is the first time I am doing DIY from scratch.

The parts used in modelling are chosen as I already have them. If I need to change, I will.

I have one issue with your last post. With the CLC filter, you are getting 20mV ripple which is too much IMO. Any ripple in the DC gets integrated with the signal. This ripple is at the input of the preamp. By the time signal comes out of power amp, it would be amplified 3-4 times. The result would be a compromised microdynamics and soundstaging. With the parts I modelled, the swing is less than a micro Volt. There might be other issues with the power supply which need fixing.

I will model with smaller caps and inductors and see when it takes me.

Gary Pimm wrote an article on the benefits of using a CCS years ago. I've used his boards numerous times and they are very convenient for setting your desired current.

https://www.pearl-hifi.com/06_Lit_Archive/14_Books_Tech_Papers/Pimm_Gary/Active%20loads%20and%20signal%20current%20control.pdf

Part of his article has the following.



ray

The Akido circuit also rejects noise on the power supply......

One more thing to learn, CCS. Geez guys, this reminds me of college days.....

It's like....HOMEWORK!

Got rid of the ringing. AC ripple is 0.7 micro Volts. Does this look good enough?

Why not do tube recifier? I ended up with a 5Y3 LCLC PS and had to add a separate 12v filament tranny when I went to a 1626 tube. My advice is to put this on a large chassis which will allow you 1) the space to keep things apart when needed and 2) the space to move and/or add things around when needed.

Ok, I understand how CCS impacts the linestage and its advantages. Since I am planning on a regulated B+ and extremely low ripple and noise power supply, CCS is not advantages in those categories.

As of now, I am not convinced CCS is the right topology for my application.
My requirements:

1. Low Distortion
2. Low Noise
3. Excellent Frequency Response
4. Micro details
5. Extremely low output impedance
6. Lots of headroom for transients

My DAC puts out 2.8V for PCM and 1.45V for DSD over RCA. That's 6dB difference. To bring DSD to the same level as PCM with headroom, 9-10dB would be plenty of gain for my system, I think.

Going down my list:
1. Low Distortion - CCS has lower distortion
2. Low Noise - CCS has higher SNR
3. Excellent Frequency Response - CCS has narrower bandwidth due to greater sensitivity to load capacitance
4. Micro details - CCS and Resistive load should be same
5. Extremely low output impedance - CCS impedance is about 1K (Rp). Not sure the impedance of resistive load topology. This is important to me because the preamp needs to feed 5 amps. Transformer coupling instead of CCS or tube buffer stage?
6. Lots of headroom for transients - CCS has limited headroom

May be it is my lack of understanding but CCS doesn't seem to provide the benefits I am looking for.

My understanding is, tube rectifiers sound softer than SS Shottky rectifiers. Once the transients are softened in the preamp, they are lost forever. No?
I will try tube rectifiers before finalizing. Stuart recommend damper diodes which I will try also.



Yes,