[ChrisAZ]

Day six update (long)
After 5 days and nights of breaking in (which consisted of leaving the amp on with no music playing), I sat down to seriously listen to familiar music through the amp. The music consisted of SACDs & CDs (since I’m installing a new cartridge on my turntable and upgrading my Ayre QB-9 DSD DAC):

* Angeline the Baker (and other cuts), Vermillion Road (Eric Wiggs)(CD) - a recording of acoustic guitar by my friend Eric Wiggs (Masontown), a brilliant player.
* Moonlight in Vermont, Ella & Louis (Fitzgerald & Armstrong)(SACD Mono)
* Joan of Arc, live, Famous Blue Raincoat (Jennifer Warnes) (20th Anniversary 24K Gold Edition CD).
* Un bel dì, vedremo, and other cuts, Puccini’s Madama Butterfly (Leinsdorf, RCA Opera Orchestra and Chorus, Leontyne Price & Richard Tucker) (SACD)
* Enter Sandman, Black Album (Metallica)(SACD). Because I needed some electric heavy metal rock to balance out my listening.

I have previously owned integrated amplifiers by Ayre, McIntosh and Prima Luna (my previous favorite, now up for sale), all within a few thousand dollars of the Pass. Any comparisons will be from memory, which is obviously sketchy - particularly since other components have varied over time.

So what did I think?:

Class A heat. Much has been made about how hot Class A amps get (often referred to as space heaters). Admittedly, I’m in Colorado and it’s cold (really cold) outside. But after 5 days and nights of running in a well ventilated stand, the case of the amp is nothing more than warm to very warm to the touch. For me at least, this is a complete non-issue.

Construction. This amp is lovely, built like a brick, volume control is smooth as butter, and the connectors and remote are top quality. I have no doubt that this amp will out-live me. Simple straightforward design (no bells and whistles) puts all the focus on the sound.

Power. Plenty of clean power with no hint of clipping, break up or harshness at sane listening levels (note the size of my room below) into Harbeth 30.1s.

Listening. This is obviously subjective, and I am no audio reviewer, so please bear with me if my listening notes are not very technical and if I gush (I love this amp).

* Angeline the Baker (and other cuts): Eric played on a recording I made of a song I wrote for my son, and his guitar parts were recorded in his home studio so I’m familiar with his recording set up. Per Marklund and Pre-War Guitar Co. acoustic guitars closely mic’d with ribbon microphones. The sound thru the Pass is tube-like but without the veiling I sometimes hear with tubes - clear, warm, rounded, never harsh. Did not sound like a transistor amp. In fact it didn’t sound like an amp at all. His flat picking of bluegrass and jazz tunes brings out the depth and timbre of these fine instruments. You can hear the wood resonate in the instruments as well as the occasional string buzz (steel string acoustic guitars exhibit some buzz at times when played hard). The soundstage here presents his playing fairly close up - as if you’re sitting about 6 feet in front of him as he plays. Just gorgeous sound, I could listen to this all day. If you love acoustic guitar, check out the master of this recording on Tidal.

* Moonlight in Vermont: It is hard to believe that this audiophile gem was recorded 64 years ago. As you might expect, voices and horn are up front with the combo slightly recessed. As a mono recording, I was surprised at the depth of the soundstage. Ella’s voice is silky smooth, Satchmo’s voice gravely and amused. His trumpet is muted and playful. The recording sounds completely transparent and alive against a black background. I’ve owned this recording for years, have heard it thru all of the integrated amps listed above, and it has never sounded more natural or musical. I felt like I was in the studio and I was in awe.

* Joan of Arc, Live: I played this cut 6 days ago (before break in) and was impressed. I revisited it now to see how the amp sounded fully broken in. I’m sitting about 10 rows back. Crystal clear and the ambiance of the crowd and the hall is evident. The chorus is breathtaking as it builds in intensity. As good as it was 6 days ago, it’s now on a whole other level. Warnes’ voice, dead center and up front, echoes and soars. The orchestra swells. Heartbreaking and smile/tear inducing at the same time. Epic. Chills. Wow ++++.

* Un bel dì, vedremo, and other cuts: I wanted to try something with a bigger orchestra and bigger voices - Madama Butterfly with Leontyne Price singing this famous aria (which I’ve seen performed by others at the Lyric Opera several times) seemed to fit the bill. For obvious reasons, I typically find symphony/opera less convincing in a small room through monitor speakers than listening to a live performance. But despite that prejudice, this recording was pretty glorious - particularly with the REL subwoofer giving an assist on the lower registers and given the fact that this was recorded in 1962. Great wide and deep soundstage. Precise location of the singers and instruments. Leontyne Price is amazing as always, the timpani booms. On other cuts Richard Tucker’s voice is sonorous. Handclaps sound natural. Very dynamic. Here I feel like I’m sitting midway back on the main floor. Not the same as being there, but a very good facsimile.

* Enter Sandman: OK, now for some head banging. Thunderous drums - very tight - again assisted by the REL subwoofer. Menacing guitars. Hetfield’s growl center stage, Kirk Hammett wailing on the right. I know this song isn’t particularly nuanced, and I’ve heard it reproduced better on a $100,000 plus monster system at a dealer in a much bigger treated room, but it shows that the Pass can rock convincingly. Maybe I need to listen to some Tool now.

Synopsis - This amp is musical, natural, transparent, and the music that passes through it is captivating. It is not tiring at all. It was at its best in my system reproducing acoustic guitar and jazz (no surprise), but was no slouch on opera or hard rock. Far more enjoyable than my prior amps because I end up listening to the music rather than critiquing or worrying about my components. A keeper.

System notes. The chain was a McIntosh MCD500, Wireworld Silver Eclipse 7 Interconnects, Pass INT25, Wireworld Silver Eclipse 7 Speaker Cables, Harbeth 30.1s on stands, REL S/5 SHO subwoofer. My music room is a closed 10’x10’ space with 10’ ceilings (i.e., a box with windows behind the seating area).

Cheers, Chris