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
A few months ago, I purchased the Prima Luna Prologue 2 (the 40 wpc, integrated KT88 tube based amp). I was replacing a NAD C320BEE that I was using in a secondary system with the Prologue Two and quite frankly, I was very impressed with the resultant sound. I was so impressed that I wrote a review of the Prologue 2 here in Audiogon.

The sound of the Prima Luna has so impressed me that I have just replaced the amp in my main system (Musical Fidelity A300 CR) with a Prima Luna Prologue 5 (power amp version of the Prologue 2). I have only used solid state systems for the past 30 systems and now my household is all tube ... I am still amazed at just how exciting these tube amps make the music sound.

Best of luck with your Prologue 1.

Regards, Rich
Thanks for the comments. I considered the Prologue 2, but for a secondary system thought I'd be careful about spending the extra few bucks on an unknown improvement to an amp I hadn't heard to begin with. I think it would be worth checking out though. I've been rejecting the idea of getting a tube power amp for my main system as the more high powered stuff has a history of being unreliable. If I recall correctly, the Prologue 5 is a 40 watt amp also. I think if there were a 100 wpc version available, I'd have to give it serious consideration. I'm already planning to take a good hard look at their tube preamp for possible replacement of my ARC LS16 on the main system.
Actually, I replaced my 250 wpc solid state amp (Musical Fidelity A300 CR) with the Prologue Five. I live in an apartment house with more than its fair share of elderly residents, ... so I tend to play my music at low to medium levels. But if it helps any, the Prima Luna at 40 wpc plays noticeably louder than my old ADCOM 545, which was a 100 wpc power amp.

What I may be doing later in the next year or so (I am presently recovering from a spine operation that went horribly wrong) is replacing my current AR 302 speakers (85 db; 3 way; 10 inch woofer) with a single driver speaker system, like the Omega Grande 8.

I am using my Prologue 2 with the Omega Super 3 (93 db) and I barely nudge the volume control to get a decent volume level and very sweet sound out of my system.

Regards, Rich
Pscialli,experiment with after-market power cords.You will notice improved tautness over the stock Belden,though the "stock" cord does no dis-service to the mids and upper bass.
tpsonic, Actually, I did the whole thing with a mid-level Harmonic Tech cord. I never even unwrapped the stock cord. However, I've got some others to try. One of these is a Cardas Golden Reference which I have high hopes for. Thanks.
Sounds like you folks are having too much fun!

I spoke to Kevin last week at Upcale Audio after purchasing a AES PH-1 phono amp. I've been thinking of swapping my Musical Fidelity M250 Monoblocks with a tube amp. I'm kinda yearning for the sweet, warm sound of tubes. Anyway, Kevin recommended the Prologue 6 Monoblocks (@70 watts). He said that the Prologue 6 will do great in a dual purpose Music and HT set-up. I'm not familiar with tubes being used for HT, so I'm a little concerned about clipping etc. Have you folks had ay experience using your Prima Luna in a HT environment? Thanks.

About a year ago, in my main music system, I swapped out a Musical Fidelity A300 power amp for a Prima Luna Prologue 5 power amp. I have been very pleased with the move.

I am also running the Prologue 2 integrated in my 2 channel HT system (no subwoofer). See my review here . I live in an apartment and can only play anything just so loud, so the 36 wpc are more than sufficient. But if you go full out with movies ... then you will need the monoblocks. 70 watts X 5 or 6 channels should be plenty loud, unless your room is super large.

Prima Luna is a hell of a product. I do not see myself changing these amps anytime soon.

Regards, Rich