Audiophilepure

https://www.soundstageultra.com/index.php/equipment-menu/1298-townshend-audio-allegri-reference-preamplifier

With the Allegri Reference, there is no gain available as with a typical powered preamplifier, only attenuation, and this should be borne in mind when matching it to a power amplifier. If you enjoy listening at a high level, you’re going to need power amplifiers of appropriate input sensitivity and power to compensate for this. Rated at 170W, the Naim NAP 350 monoblocks I use have weapons-grade power—the NAP 350 has a claimed input sensitivity of 1V for full-rated power, and offers 26dB of gain. As a result, I could comfortably attain what I would term “session levels” with this pairing. A friend who uses an Allegri Reference partners it with a Krell KSA‑100S and big JBL monitors, and his system kicks serious ass, too.

On the title track of Duran Duran’s sole 1990 album, Liberty (LP, Parlophone PCSD112), the Allegri did a superb job of rendering Simon Le Bon’s vocals center-stage. Sterling Campbell’s energetic and bouncy drum style was projected with excellent power and drive, which I found surprising for what is essentially a passive device. Sure, the Allegri didn’t deliver bass rhythms with quite the same snap and articulation as my Naim NAC 82 preamp, but it certainly sounded less grainy. The Naim excels at speed, slam, and note definition, whereas the Allegri has other strengths, which are rare outside an extremely elite group of valve amplifiers of impeccable quality.

https://www.theaudiobeat.com/equipment/octave_hp_300_se.htm

One final thought is about warm-up time. The review sample of the HP 300 SE was delivered with, reportedly, many hours of use, but I was not totally comfortable with the sound until the unit had been on for at least an hour. The sound when first turned on wasn’t harsh or bass-shy, but rather unnaturally fast and insistent. I can’t say these made music unlistenable, but as soon as I discovered the sound of a fully warmed up HP 300 SE, I always turned it on an hour or two before listening, and I strongly recommend you do the same.

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’.