Audiophilepure

https://www.stereophile.com/content/treehaus-audiolab-preamplifier

My long-term reference Shindo Allegro preamplifier, one of Ken Shindo’s earliest creations, benefits from point-to-point wiring and separate chassis for left and right channels. It has the unmistakable Shindo sound and so provided an entirely different view into the music than the Treehaus did. The Shindo Allegro’s noisefloor was noticeably higher, and its presentation lacked the layering, separation, and transparent personality of the Treehaus. On the other side of the ledger, it manifested more physicality and more flesh-and-blood tonality and texture, both very well-known Shindo strengths. The Shindo plays records with stunning force and apparent realism. The Shindo’s soundstage is smaller than the Treehaus’s, but within that soundstage it rendered a sense of intimate closeness, searing viscosity, and bristling texture never equaled in my system

https://www.audiophilia.com/reviews/2025/8/19/ps-audio-pmg-signature-preamplifier

If this is the beginning of the new PS Audio PGM series, then I think they have already hit a home run with the PS Audio PMG Signature Preamplifier at USD 8999. I sense it will compete favorably and even beat many higher-priced preamplifiers. It is impeccably clean and quiet, but it retains its unique personality to my ears, which to me makes it special, just as the BHK Preamplifier did, but now at a new and higher level. And just like the BHK, which I kept for almost 10 years, I do think this is a keeper. I gambled, and I feel I won. No more to say. Very highly recommended.

https://www.hifinews.com/content/nagra-hd-phono-phono-preamp

The fascia is effectively divided in two with the Modulometer [see PM’s Lab Report] indicating the output level in dB and with an adjacent toggle to adjust its brightness in five steps, this next to a mono cartridge LED and rotary for setting the input loading. In the centre a ±6dB gain toggle acts on both MM and MC inputs, and to the right is an EQ rotary, mute switch and, lastly, the rotary that takes the unit from standby and selects the inputs of MC1, MC2, MM and the optional custom input (if fitted).

Inside are six valves – four EF806S-Gold pentodes in the EQ section and two E88CC/6922 triodes for the ±6dB gain block. The circuitry is dual-mono and pure Class A, naturally. For MC duties, the HD Phono employs a new generation of custom-made input transformer from a lineage that includes the original VPS transformer, in turn based on the Nagra IV-S tape recorder’s microphone input transformers. Talk about a pedigree! In Nagra lore, then, the HD Phono’s transformers are fourth-generation designs, offering 26dB of gain. The hand-wound transformer’s core is made with cobalt ‘and is cryogenically treated over the course of several weeks to improve performance’.