Hello everyone,
I'm recently playing with the design of my next phono amplifier I called Zenigata's phono. I put here the LTspice files and it would be nice if someone could revise it but also commenta are welcome.
Here you are the distorsion at 350mVrms output: just a -105dB 3rd armonic
The signal / noise ratio is about 85dB and the RIAA matching id +/- 15mdB
I'm recently playing with the design of my next phono amplifier I called Zenigata's phono. I put here the LTspice files and it would be nice if someone could revise it but also commenta are welcome.
Here you are the distorsion at 350mVrms output: just a -105dB 3rd armonic
The signal / noise ratio is about 85dB and the RIAA matching id +/- 15mdB
Only because you asked, 1. I am not so interested in "distortion" as I am in dynamic power. 2. I never buy anything with malevolent names or faces.
thanks for you comment even if i was looking for a more technical support.
I'm not wondered about your buying since I design and make for my pleasure only: Strange nowadays here, but true.
PS: If you don't know Zenigata go and look for "Lupin the 3rd" anime: it is the funniest one, and fur sure you'll change you mind 😉
I'm not wondered about your buying since I design and make for my pleasure only: Strange nowadays here, but true.
PS: If you don't know Zenigata go and look for "Lupin the 3rd" anime: it is the funniest one, and fur sure you'll change you mind 😉
If you select th flattop FFT window you'll be able to see all the spectrum, not just the top part - a window is needed unless the signal is precisely synchronized to the FFT aperture. Flattop window will allow accurate measurements of peaks if you need it - otherwise Hann is pretty reasonable and has a lower noise floor.
BTW its an interesting choice of topology, not seen very often, more like a standard microphone preamp (that's not a criticism!). Took me a while to find the RIAA network in fact (!)
thank you Mark for your reply,
As suggested here it is the FFT with Hann windowing used on a longer simulation time for a better frequency resolution. Now you can see the harmonics at 3KHz (-105dB), 5KHz (-150db) and 7kHz(-185Kz). I'm quite sure that real circuit is worst than simulation due the fact the components are not identical. The only nice information is that the armonics (in the simulation) linearly drops down and all of them are far below the -85dB noise level.
Regarding the topology, I would like to underline that the Sziklai configuration use a mu-follower instead a more common resistor: I don't know if someone has already used it but i (re)invented it for low noise, high gain, low distortion purpose.
The Sziklai is cascoded too: both configuration is used for "memory distortion philosophy" (http://peufeu.free.fr/audio/memory/) .
You're right about the RIAA, it is elegantly hidden 😉 . This configuration eliminates the RIAA serie resistors ,than in my experience, and not only, have a bad impact on the sound.
Finally, White follwer configration works as output buffer: on simulation it has barely no distortion and noise.
Thank you for your comments
As suggested here it is the FFT with Hann windowing used on a longer simulation time for a better frequency resolution. Now you can see the harmonics at 3KHz (-105dB), 5KHz (-150db) and 7kHz(-185Kz). I'm quite sure that real circuit is worst than simulation due the fact the components are not identical. The only nice information is that the armonics (in the simulation) linearly drops down and all of them are far below the -85dB noise level.
Regarding the topology, I would like to underline that the Sziklai configuration use a mu-follower instead a more common resistor: I don't know if someone has already used it but i (re)invented it for low noise, high gain, low distortion purpose.
The Sziklai is cascoded too: both configuration is used for "memory distortion philosophy" (http://peufeu.free.fr/audio/memory/) .
You're right about the RIAA, it is elegantly hidden 😉 . This configuration eliminates the RIAA serie resistors ,than in my experience, and not only, have a bad impact on the sound.
Finally, White follwer configration works as output buffer: on simulation it has barely no distortion and noise.
Thank you for your comments