Review: Primaluna Prologue 1 Tube amp

Category: Amplifiers

I ordered the Primaluna integrated amp to use as the basis of a secondary audio system as I'm presently building a room for my main system. The secondary system will live in a home office. The N803s are not the speakers I will ultimately use with the Prologue 1, but I was impatient to give this unit a whirl as soon as it arrived. I'm near DC and it took exactly five days to get the new amp from Upscale Audio on the West Coast.
As the commercial reviews suggest, the Prologue 1 came beautifully packaged, including a pair of white linen gloves for handling the tubes. I found it unusual that the tubes came already mounted in their sockets, but wrapped snugly in foam sleeves which must be removed prior to turning it on.
Taking it out of the box, the overwhelming impression is that this thing is built like a tank. There's no way, I thought, that this thing should cost only $1k. It's very heavy and very solid. The sheet metal is thick and superbly finished. The output terminals on the back of the amp are spaced a little too close together, but not impossibly so. For each channel, there is a terminal for 4 ohms, 8 ohms and a ground. The manual suggests trying both output impedances to see which sounds better. I started with 8 ohms, the nominal rating of my speakers.
My speakers are rated at 90db efficient, so I was not expecting wonderful things out of a 35 watt amp. After about a day of warm up, I started to do some critical listening. I'm quite aware that the amp won't reach break-in until it has upwards of 100 hours on it, but I have some strong early impressions. In a word, this amp sounds great! The tonal balance is definitely on the warmish side of neutral. There is no mistaking this for a solid state component. It is rich and sweet sounding absolutely effortless at low to moderate volumes. It wasn't until I really tried to goose it with loud passages that I heard even a hint of congestion into my suboptimal speaker system. Vocals and other acoustic instruments are reproduced with stunning harmonic complexity. There is very good bass extension albeit just a touch on the soft side into my 803s. These speakers require a lot more control than the Primaluna ought to have. It had enough, however. While not the final word in detail, the Prologue 1 was incredibly musical and involving. I'll eventually be paring it up with a pair of Infinity Primus 360s which stand to be a great match for it. If you've got a thousand bucks to spend on your electronics and have moderately efficient speakers, I can't see any reason to go past the Prologue 1. I will also point out that a big selling point for me was the automatic biasing circuitry which enables you to use even unmatched tubes in the output of this amp. There is never any user intervention needed to keep the tubes running at an optimal bias setting. By the way, the Prologue 1 uses a pair of EL34s in each channel as output tubes. Other tubes include 2AX7s and 2 12AU7s all mounted nicely and very accessibly on the top of the chasis under a removable cage. I plan to try subbing a pair of 5751s for the 12AX7s to see if I can further improve the already excellent focus of this amp. At $1095, the Prologue 1 is a super bargain!

Associated gear
Modwright/Sony 999 CD player, B&W N803 speakers