Hello Valerio,
just as you, I bought the SA30 second hand only a few months ago. I aso hesitated a bit. But since most of the time, you won’t read anything about happy users and most of the time you only read about the complaints, I gave it a go.
And I am happy for 99,9%. (I’ll talk about the 0,1% in a minute ;-). The detail, dynamics, the stereo image, … it is all great. I never had an amp for this price (second hand) that reached this level of sound quality.
Just like you, I was very interested in Dirac. My room is asymmetrical (L-shaped) and my right speaker leans to the open space.
(be sure when you buy the amp, that the mic is included. If not, you’ll have to buy a Mini dsp umik).
Using Dirac was almost flawlessly. Sometimes, when you want to go back in the process to the sound level settings from the beginning, there is no sound from the speakers. When you touch the left dB slider, the volume jumps a bit ‘high’, but nothing to worry about. I read this als from other amplifiers, so it must be a Dirac software issue.
Since I didn’t want Dirac to interfere with the stereo image information, I calibrated to a tightly focused image, with the 9 measurements in a space about 40x20x20cm around my ‘virtual’ head.
And what was also important was to lower the frequency curtain from the right to the left down to about 400Hz, so it does leave the higher mids and hi frequencies untouched.
The result is mind-blowing in my situation. I could not speak of any steady image and the Dirac corrected this almost completely.
I am using small Dynaudio monitors with a B&W subwoofer (connected high level on the speaker outputs of the Arcam). The low frequencies where not enjoyable before Dirac. Now playback is smooth down to 30Hz. Just incredible.
As you can read, I am very pleased.
I never encountered any dropouts, hiccups or clicks/pops. Only when my streamer was already playing when I was powering on the amp. This can by scary… So it is best to paus the playing before switching on the SA30. I am using a SONOS port also over coaxial.
What I tested the last few weeks is ROON. This works great. My SA30 is on the latest firmware and this is why i gave it 99,9%. It seems that the latest firmware broke Qobuz streaming in the MusicLife app on the Arcam. But when using ROON, I get the highest quality. Even MQA when the track is ‘recorded’ that way.
When you will be using a Wiim Ultra, you should not have problems with Qobuz streaming. I am considering an Eversolo DMP6mkII since I am mainly an Apple Music user.
I hope that the second-hand unit that you are buying is in good order so you can enjoy it as I do.
Kind regards,
Peter