I've been familiar with tape recorders since the late 1970s. Last fall, the desire to remember that very sound led me to a used equipment store. The result was the purchase of two cassette decks at once. It can't be helped if the digital files recorded even on the initial Type I cassettes sound...

If a good tube amplifier has enough power for headphones, it will sound better. For example, Cayin HA-3A on RCA sounds more lively with my headphones than Master 9P on ACSS with Audio GD R-7HE MK2. When playing from a cassette deck, the situation is exactly the opposite. Master 9P sounds...

Orang_sabar You can ask a question directly to the developer in a private message, but this requires registration on the forum. https://www.dastereo.ru/u/mr_hatred/summary

Rectifier Tubes may even last longer, last link. https://www.head-fi.org/threads/cayin-ha-6a-class-a-kt88-el34-tube-headphone-amplifier.918779/page-56#post-16555883

I understand, I had a loud clicking noise with the Unison Research SH. This is not the case with the Cayin.

You don't have to do that at all with the HA-3A, complete silence on and off.

Have you tried replacing the 12 AU7 preamp tube?

This is exactly what you are saying. It turns out that your combination of Nord Acoustics power amp and Magnepan 1.6QR speakers is no better in resolution than the $100 Edifier R1100. Those also show one layer of the choir without any problems.

It is amazing! Could you tell me with which headphones and equipment such metamorphoses occur?

I've already talked about it. https://www.head-fi.org/threads/kennerton-odin-magister-vali-magni-gjallarhorn-r%C3%B6gnir-thridi-wodan-thekk-and-thror-discussion.732814/page-569#post-17285106 On HA-3A, the bass sounds great, no worse than on Master 9P.

More than enough. From Heartland over RCA on the unbalanced STD output, it sounds great at 9 o'clock.

Or at least replace with modern Tung-Sol 12AU7W (6189) and 6V6GT. They are excellent lamps.

We have an announced HLD price about $300 lower.

Audio-GD products have no problem with the Mac OS. http://www.audio-gd.com/R2R/R1NOS/R1NOSEN.htm

The R7HE MK2 is always in NOS mode. The most lively, natural sound.