Revisiting some "old" ideas from 1970's - IPS, OPS

Add one more in the club.
For some hours now, I'm auditioning the NS modular amp with Vertical CFA IPS driving my 1.6 Magnepans.

The sound: exactly as Jeff and Vallery described it. It's holographic with very well balanced spectrum. It leans on the neutral side of things: as clean as Ncores I had for some time but much more engaging. Not as colored as my previous EAR 509 tube amp or as warm sounding as the Perreuax Radiance intergrated which had rounded highs, not the case with NS.
My Avondale monoblock probably has a bit better PRAT but it's not something you go missing. I would like a meatier sound in the upper mids and highs, cymbals are still compressed, but I think needs more hours to really break in, so I hope that will change

I want to thank members: filenet, for all the useful info he share with me, evanc for generously providing me with missing transistors, and of course Jeff and Vallery who were constantly confirming me in each stage of the build, their assistance is something you can count on.

Picture: load 8,2 Ohm, output: 10 Vrms
 

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Hello Valery,
I recently get an adi 2 dac as a source for my system(esl x and NS-CFA). It sounds spectacular. Still i cannot forget about USSA5 sound. So lets do it properly. I am asking you to design a tube pre amplifier with a fancy harmonic distortion level selection and do not forget a soft bypass system.
I am sure it will be something unique on diyaudio, and very acclaimed. What do you say?Are you in?
 
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Hello Valery,
I recently get an adi 2 dac as a source for my system(esl x and NS-CFA). It sounds spectacular. Still i cannot forget about USSA5 sound. So lets do it properly. I am asking you to design a tube pre amplifier with a fancy harmonic distortion level selection and do not forget a soft bypass system.
I am sure it will be something unique on diyaudio, and very acclaimed. What do you say?Are you in?

Yes, we will come back to this soon. I'm doing some tuning and tests on our new RIAA preamp (hybrid IC + tube). This development will allow doing the one you're looking for the right way.
 
Filenet, I'm little surprised by your request knowing that you also have the tube IPS on your amp. What preamp are you currently using ? Or do you use the ADI's volume control ?
I'm familiar with ADI 2 DAC and apart from it's DSP capabilities it didn't impress me at all. True It's full-body, typical of opa-stage,but is missing a lot elsewhere.
What exactly are you missing ? Could it be you want to play with harmonic profiles ?
 
Well i do not have an dedicated preamplifier. At medium and low volumes the sound is perfect, at high volumes it tends to be little harsh(maybe is my small room too) and i was thinking that playing with harmonics will soften the sound. I never tried tube IPS with this combination of dac-speakers yet.
 
Some time ago, I had a proposition from a friend of mine who has the ADI 2 DAC, to have a listening test with ADI as DAC/pre and NS amp. I wasn't that curious 'cause the other DACs I have (some lend for testing reasons) are simply better. Maybe I could give it a shot to give you some feedback

There are many factors to consider when the sound it is "little" away from your liking. Here are some

Cables
You might stubble upon an audiophile ones that has some upper rage sparkle that is somewhat annoying sometimes, like it happened to me. I've decided to go to monoblock scheme where cables don't matter

Input cap
Also, changing the input cap made huge difference (as is should). The original from Panasonic is the best value cap I've tried but I didn't had in hand this time so time and used Wima MKP. Now I've put a Rike PIO which gave the instruments more weight, less bright than Wimas.

Source
Finally I'm experimenting with the computer as a source with a Tinkerboard (Rasp-like SBC) and an Audio PC. There is a clear difference between them also when changing their power supply. Don't have to do A/B comparison at all to spot the differences.

To my particular setup, having difficult speakers (maggies) I had to double the whole capacitance of my psu,(now 60mF per channel) to bring a fuller sound to my system. That's the way it is, even the BOM indicated a bigger psu so it was kinda obvious.

My point: before bigger changes like another preamp, a possibility of changing other factors will be helpful to find out what's wrong.
I will report the listening test outcome with ADI 2 DAC
 
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VFA for bass, and CFA for mid/treble. I was afraid for noise, but there is none even with simple input regulator. Thanks Vallery and Jeff!
 

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