Review: Prima Luna Prologue Two Tube amp

Category: Amplifiers

Background ...

I have been in this hobby for almost 35 years and the only tube equipment that I have ever owned was my very first system ... a one piece victrola with a Philco tube stereo amplifier, a Voice of Music turntable, and two detachable speakers each containing a single 3 inch, full range, baffle mounted speaker. My dad, who owned a TV & Appliance Repair Shop in Brooklyn, was a big fan of tubes, as tubes were easier to service than the first solid state boards. After a few years, I "upgraded" to a solid state SONY HP-161 tuner/turntable compact system and I never considered tubes again.

Well, hit the fast forward button 35 years and here I am purchasing a Prima Luna Prologue Two integrated tube amp. The Prima Luna replaces a NAD C 320BEE integrated amp, that I have used happily in a secondary system almost every day for more than two years. Even though the NAD was not the most refined sounding of amps (when compared to a Musical Fidelity A3 integrated, for example), the NAD made music listening enjoyable for hours on end ... which is perhaps the best praise that I can give to a piece of stereo equipment.

If you are a reader of the hifi magazines (like I am), it has been hard to avoid the Prima Luna integrateds lately. Just about every magazine has featured a rave review about either the Prologue One or Prologue Two and they are attractively priced ... so much so, that the question became "which one should I buy?" as opposed to "should I buy?" The only issue was that I could not easily audition one (I live in NYC) and the Prima Lunas have only one distributor and he is 3000 miles away. Fortunately, the distributor is Kevin Deal of Upscale Audio. Kevin is someone that I trust and respect and have purchased equipment from several times. In all candor, knowing that Kevin was one of the key members of the Prima Luna team was comforting to me and so, not being able to audition the amp prior to purchasing, became less of a “must to do.”

I decided to go with the Prologue Two mostly due to a “technical talk” email exchange with Kevin that went ended with ... "the Prologue Two will have more pop in the bass." I was planning to use the Prologue Two with Acoustic Research 302 speakers (3 way; 10 inch woofer; acoustic suspension design) , which can go down to 35 hz, so for an extra $250, I figured ... why not take advantage of the extended bass response?

I have listened to tube amps in the past, but never with an eye towards buying one ... so I was very much in the role of the newbie when purchasing the Prologue Two. Knowing that the Prima Lunas were designed to make life easy for the first time tube amp purchaser was a comfort, as well.

The Audition ...

First a disclaimer ... when I listen to music, I tend to concentrate on the performance. I have never been one to get too hung up on audiophile concerns like soundstaging and things of that ilk. With that said ...

The first quality that I noticed about the Prologue Two was how quiet it is. The music seems to just emerge out of the darkness. The crisp, opening guitar chords of "Gimme Shelter" (Rolling Stones "Let It Bleed") seem to appear from nowhere. This is the same impression that I had when I first heard the album over 30 years ago. The Prologue Two also conveys a sense of solidness to the music ... a real sense of musical depth. When listening to Frank Sinatra's "Night and Day" (from "A Swingin' Affair"), the brass fanfare that drives the pace of the song and sets the tone for the rest of the album, sounds full and in command, not lightweight and screechy, as I have heard on other systems. On that same album, on "No One Ever Tells You," the band's instruments play counterpoint to Sinatra's vocals and the Prologue Two captures this interplay with just the right amount of delicacy and emphasis.

I have always listened to a lot of music with vocals. As a teenager, it was mostly pop music. Today, it can run the gamut from Bob Dylan to Placido Domingo. The Prologue Two captures the essence of the vocal performance with ease. I both heard and felt the full range of emotions expressed ... from desperation (Frank Sinatra “My Funny Valentine”) to longing (Bob Dylan “I’ll Keep It With Mine”) to swaggering pride (Frank Sinatra “Look At Me Now)” to pensive (Jesse Sykes “Oh, My Girl”) to operatic approaching doom (Mozart “Ah, son perduto!”).

Instruments sounded equally impressive with the Prologue Two. The violin on Bartok’s “Danses Populaires” (from "Le Violin Vagabond") had an almost three dimensional quality to it and the sound just seemed to hang in the air. The guitars on “Little Rivi Airhead” (Junior Brown “Down Home Chrome”) and “Oh, My Girl” (Jesse Sykes) sounded crisp, detailed, and musical all at the same time. There was a suppleness and pace to Oscar Peterson’s piano playing on “Caravan” (“Ocsar Peterson & Dizzy Gillespie”). Horns had just the right amount of bite and lightness to their sound (Maurice Andre “Trumpet Concertos).

From a construction and looks standpoint the Prologue Two shouts quality. If you appreciate solid, finely machined, neat looking equipment with a good amount of heft ... well, this is one amp for you. I went with the black faceplate version as it complemented the rest of my system. The stock tubes that come with the Prologue Two get the job done quite well, which is a good thing, as I am not into “NOS and tube rolling” ... well, not yet anyway. The amp gets pretty warm to the touch, but not hot, even after it has been on for a few hours.


To sum it up, I was very impressed and very happy with my Prologue Two purchase. Listening to music on this amp has been very enjoyable, as the music sounds inviting and I am finding myself playing more and more CDs and playing them all the way through. I am having a lot of fun with this amp. A special thanks to Kevin at Upscale Audio for first rate service both pre and post sale and his SoCal sense of humor.

The Baker’s Dozen of CDs Used:

Maurice Andre ... "Trumpet Concertos" (EMI Classics)
Joseph Canteloupe ... “Chants d’Auvergne” (NAXOS - SACD Hybrid)
Wolfgang Amadeus Mozart ... "Le Nozze di Figaro" ... Rene Jacobs (Harmonia Mundi)
Graf Mourja ... "Le Violin Vagabond" (Harmonia Mundi)

David Bowie ... "Ziggy Stardust" 30th Anniversary Edition (Virgin)
Junior Brown ... “Down Home Chrome” (Telarc - SACD Hybrid)
Bob Dylan ... "Biograph" (Columbia)
Buddy Holly ... "The Ultimate EP Collection" (See For Miles Records)
Oscar Peterson & Dizzy Gillespie ... (JVC XRCD2)
Rolling Stones ... "Let It Bleed" (ABCKO - SACD Hybrid)
Frank Sinatra ... "Frank Sinatra Concepts" (Capitol Box Set)
Joe Strummer & the Mescaleros ... “Streetcore” (Hellcat Records)
Jesse Sykes ... "Oh, My Girl" (Barsuk Records)

Associated gear
Acoustic Research 302 speakers (3 way; 10 inch woofer; 85 db sensitivity)
IXOS Silver GAMMA 1001 Interconnect (amp to SACD player)
Signal Cable Analog One Interconnect (amp to DVD player)
Signal Cable Classic Speaker Cable

Similar products
NAD C 320 BEE integrated (solid state)
Musical Fidelity A3 integrated (solid state)
Thanks for your fun review from a listening point of view. Now you are an initiated blood brother in tubeaholics not-so-anonymous.
Going along with the California sense of humor: No doubt, Kevin has you on his list to receive a frozen Christmas turkey, and your first taste of his special tubes available only to his loyal customers, just to raise your euphoria level a little more.
Nice to see your list of enjoyable recordings, especially those which are new to me.
California sense of humor? What's that?

Then again, I'm from Los Angeles, so an overweight, sloppy transvestite walking down Santa Monica boulevard is a daily occurence.
I, too, have considered purchasing one of these amps. Does anyone have any idea if the Prologue One and Two have different sounds? Does the One sound sweeter due to EL34 tubes? Or do they really sound pretty much the same? Thanks for any help.
Stunaramore, I purchased the Two for it's ability to utilize either KT88 or EL34 tubes. The One cannot handle KT88's safely.

While I can't comment on the sound of the One vs. the Two, the Two does sound different with EL34's vs. KT88's. Which is better is a matter of personal taste. I would highly recommend the Two!

Thanks for the review. I'm also giving serious consideration to this amp. One thought occured to me when I saw your pictures was that it seemed that your PII might need a little more breathing room. You might check with Kevin, but it seems like Prima Luna calls for about 6" of space above those KT88s.

Owning the Prologue Two has made me re-think my main system set-up ... it really is that enjoyable an amp. Thanks for noticing the rack height clearance. Since those pictures were snapped, I have move some components around and re-adjusted the rack height to where I have just about 5" top clearance ... not perfect, but better.

Regards, Rich
This is a fine amplifier indeed. However, after an actual listening session where I had both the Prologue and Cayin TA-30 on hand, I opted for the Cayin. I know these two are supposed to be alike, but the extended biasing, focus control, and sub-out flexibility were just so tempting. As for sound, I found the TA-30 to have an edge in transparency. The icing on the cake: The Cayin TA-30 can be used in single-ended configuration (4 watts) with only 2 tubes used and biased accordingly (easily done). It this configuration, it blows away the Prologue, and most of the competition may I add. Interestingly enough, the single-ended 4 watt configuration was almost as powerfull subjectively speaking. I of course ran out of power at very high levels, but for ''normal'' listening, it was all I needed !
Nice review - I considered buying one of these several months back, but after some research chose instead the Sound Quest SQ-88 integrated (actually custom manufactured for Quest For Sound by Consonance), primarily because I desired remote volume control. And I think the SQ-88 turns out to be even a better buy, since not only does it sport auto-bias, but one may swap the stock KT88 tubes with either EL34 or 6550 types and the bias will adjust itself to adapt these. Also, the SQ-88 can be had new for under a grand directly from Quest for Sound (list price is $1479). A recent review on this piece can be found here:
My small experience with tubes was when I bought a little HK integrated used. It was old, it was small, and sounded quite sweet. I do believe it is time to get some new stuff, and I believe it will be Prima Luna. The price is reasonable and what the heck, it sounds pretty good. Much better than trying to work vinyl through a Lexicon, which definately doesn't. Cheers.
Hi there. I recently bought a Prima Luna Prologue One. I read the manual and see a passage saying:

"While matched tubes are not a requirement, it is still recommended if you want to get the very best results. You can get the very best in replacement tubes as well as rare vintage NOS (New Old Stock) tubes from us and other parties if you wish to upgrade. In the USA, Upscale Audio's inventory of New Old Stock tubes is the largest you can find. Elsewhere,
independent suppliers can assist you to make your best choice."

My questions are:
How many types of tubes are there?
What are the pros and cons of using them?
How much do they cost?
What is New Old Stock tubes?
what types or models of tubes should I get to get the very best results out of Proloque One?

Thank you in advance.
Michael Tran
Hi Michael:

In hifi applications, you see primarily preamp (input) tubes and power
(output) tubes. This makes sense ... tubes for each half of the equation, so to
speak. There are tubes for other applications: rectifiers; ham radios; guitar
amps. Prior to 1970, tubes were used in most televisions. A tube, when you
get down to it, is an amplification device for a circuit. People like tubes for
the sound they produce in a component. In your Prologue One, the 12AX7
and 12AU7 are your preamp tubes and the EL34 are your power output tubes.

Tubes produce a very specific type of sound. Better tube components have
been described as having a warm, full, and analog type of sound. I have been
knowingly around tubes long enough (40+ years) to have heard both good
and lousy sounding tube equipment.

Solid state/transistors have been described as thin and harsh sounding ...
though the better solid state components sound just fine and can have a tube
like sound to them. It's like most things, the better equipment sounds
good ... the lousy stuff sounds lousy. The solid state vs tube debate can
sound like the CD versus Vinyl debate. In the end it is a matter of preference.

By the way if you ask my dad, who fixed radios and stereos in the 1940's -
70's for a living, which he preferred ... he would say tubes. To fix something,
you just had to replace the tube (which was cheap and easy) as opposed to
fixing or replacing a printed board (which was expensive and time

Most tubes produced today come from the Soviet; Eastern Europe; or China.
Your 12 series tubes cost about $10 each to replace. Your EL 34's cost about
$20 to replace. You should buy them in matched sets (tubes that have been
bench tested and have been measued to operate within a given range for a
number of functions). Then again, you can just replace the burned out
tube ... that's what my dad would have done.

NOS tubes cost a lot more. NOS stands for new old stock ... the original
tubes made in the 50's through 70's from such brands as RCA; GE; Mullard
(original British); Raytheon ... that some dealers maintain an inventory for. As
remaining supplies are used up, prices will go up, as well.

The tubes that come with the Prologue One are Chinese made tubes and are
pretty good ones. If you give Kevin Deal at Upscale Audio a call, he may recommend some Svetlana new production EL 34's and some Electro-Harmonix new production for your 12AU7's and 12AX7's. Kevin was in on the design of the Prima Lunas and he know his products as well as anyone else does.

This just scratches the tube surface, but should be enough to get you going.

Regards, Rich
Larinawong, After much experimentation I ended up using SED (the original and best Svetlana tubes with a 'flying C' logo) and the small tubes are the new EH tubes which I believe are the tubes now supplied by the manufacturer who uses their own logo (Primaluna). This produces a warm, full, and smooth tone. If you want more brightness or detail you might try JJ/Tesla EL34's and/or EI 12AX & AU 7's. All are new production and inexpensive.