The P3A doesnt have a superior PSRR, thus it is sensitive to the quality of the power supply. I replaced 0.1F RC supplies with R21 modules
(see https://www.diyaudio.com/community/...crc-power-supply-r21-ps-module.376003/page-10)
and was very pleased with the sound improvement.
(see https://www.diyaudio.com/community/...crc-power-supply-r21-ps-module.376003/page-10)
and was very pleased with the sound improvement.
Are you sure the suggestion wasn't for carbon film resistors rather than ceramic?
Please do not touch the amplifier. Instead, use variable loudness to add some richness in lower bass. There were many threads about loudness control, I suggest the one which has separate volume pot and separate variable loudness. You can dial in any amount of richness you like.
I still have very old JVC hifi from my teanage years, it has independent loudness pot. I used to have parrasound preamp with the same function.
Its completely passive circuit, which you just insert between the dac and amp. No need to touch the dac or amp.
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Other option is to insert small active eq. I use schiit loki mini+, its an amazing little eq, inexpensive, but exceptionaly well designed. They do have bigger more expensive eq, i have not tried yet.
We are quite good in finding solutions for non existing problems here but what about connecting old “warm” loudspeakers with woven tweeters to that P3A? If ChatGPT agrees with that of course, we don’t want trouble with the authorities.
Weird, second harmonic addition never sounds harsh. I have test cd for testing distortion detection, with series of second harmonic and addition of second harmonic makes all sound mellow. Tones with third sound sharp.
To me right combination of second (higher) and third (slightly lower in level) sounds best. Assuming absence of upper odd harmonics.
Situation with second harmonic can be more complex depending phase it is. Read what Nelson Pass reports about it.
I got preamps with barely measurable distortion (~0.0002%) which sounds like crap, and plenty of tube preamps with beatiful musical sound with ~0.02% distortion.
But second harmonic never sounds sharp and harsh.
This is simple jfet pre hamptone. Well known for sweet sound. Pure second harmonic.
Attachments
Please post fft spectra of 1kHz test tone before and after your dsp.
Otherwise adding octave above is enriching, hardly noticable at low level. Never sharp and harsh.
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Just joking. It is a typical German word spoken in the way of its meaning. Like rau with rolling r (raw).
The DSP in that test rig has been repurposed for another experiment, so it will take me a while to get it up and running again. I'll see if I have screenshots somewhere. If my memory serves me right, it wasn't noticeable at first, but when it was, it wasn't pleasant. At least not to my ears.