Trueharmonix 6550 Tube Integrated Amplifier

List Price: $2,498

Review by

Michael Peshkin

Bewitched, bothered, and bewildered, am I....

Strings? Anyone who doesn't like strings has a problem. Guitar strings, violin strings, hammer dulcimer strings, mandolin strings, heck, even (hah!) piano strings. If a piece of gear doesn't melt me when I listen to string instrument of any ilk, then for me, that piece of equipment belongs on a high mountain peak, exposed to the elements until it turns to rust and minute pieces of plastic.

OK, so it's not environmentally correct, but...

How could something glows beautifully NOT sound good? Good is an understatement when pertaining to a lot of equipment made today. We're blessed with a plethora of great sounding equipment from new manufacturers, older manufacturers venturing into different realms of the audio wold, and great DIY (do it yourself) kits added to all of that.

A company spokesman siad of the amp, "Our design goals is where price meet performance without losing any sonic sounding. Our main advantage is power transformer. which is our design and been sold to many company through out the world. We have supplied the OEM Transformer to many companies for over 20 years; some still well known".

TruHarmonix has, with this integrated amp, made a statement in sound and in great looks. Simply put, there is no reason anymore to look the other way when deciding whether to buy 2 pieces of gear or one. No compromises are made by having the power supply, pre- and amplification in one chassis. Fewer wires! If you want to get great IC's and power cords you need only buy for the one component!

Instead, that allows one to purchase a lot of CDs or LPs or downloads, for that matter. Heck, for the cost of good cords you can buy a nice rack to put your equipment upon! That is very important to keep in mind when owning tube gear, they don't like rickety furniture and will sound far better with a good foundation. I'm a believer in big, beefy stands. In fact, I love everything beefy, including power supplies in equipment. I love ”big iron.” The big iron in this case, of course, referring to the massive transformers on this integrated amp. Massive power supplies are always going to give the chance to any amplifier, to strut its stuff. If current cannot be supplied properly, we hear weak bass, strained vocals, smeared imaging, and a host of other ills.




The Trueharmonix 6550 offers two types of tube outputs, ultralinear at 60 wpc and triode at 30 wpc. Why two modes? Because they sound very different, so it's like having two different amps in your system. Tube Complement is 4 x 6550EH; 6N9PX2; 6N8PX2, 5Z3PX2 and there are three inputs (non-balanced) and two outputs for either 4 or 8 Ohms. Dimensions are17.1 in ( wide ) x 13.8 in ( deep ) x 6.5 in ( high ) with a hefty weight of 55lbs. Important to note is that there is no remote control, you'll have to get off your butt to change inputs and volume. This is a purist product that features ALPS Potentiometer, Valve Rectifiers with Choke, SCR Coupling Capacitors, Carbon film Resistors (improve sound quality) and Russian ElectroHarmonix 6550 output tubes.




This is a string-lover's amp. I can't recall being as enthusiastic about guitar music. I was swaying and literally moaning as I heard how purely Neil Young's guitar was reproduced from both the CD and the LP of Live at Massey Hall. His voice so very real that I could easily believe I had been transported to Massey and January 19th, 1971.

My tube preamp and solid state amps are smooth and this recording sounds fabulous when played through my Infinity Preludes. The amps are 100 watts each. The Bewitch is 12 amps each side. Both deliver that pressure wave from Young's guitar, but the tube amp does it in a slightly more believable way. I can almost see Young's fingers moving on the frets of the guitar...decays of strings were very, very real sounding. I have a lot of friends who are professional musicians and get to hear live guitar very often. I get to hear it in the room where I played the Neil Young recordings. I know what's real (but I'm still trying to find out, “What is reality, man?”) and what slips short of real.

I hooked up the Dynavector P75II phono stage to the Truharmonix along with my Audio Alchemy CD player. I found myself playing recordings that were both well done digitally and on LP. I found myself enjoying CDs, as much as I already do, much more so than with my amplification. I heard nothing that made me WANT to play LPs instead of CDs. Both were eminently enjoyable.

From Joshua Redman to AllanToussaint, Joni Mitchell to Linda Ronstadt, Cream to Vivaldi, I played CD and LP and loved listening to both. If I had any quibble at all it was in the very bottom of the musical spectrum. Even though the Preludes have their own powered (100 watt) subwoofer, the sub's amp cannot pass on what it isn't given. Thus, the extreme bottom end seemed a bit rolled off. 400 watts as opposed to 224? No matter, after a short while I didn't miss it; drum attacks were visceral, hard-plucked bass on a Jazz recording still thrilling.

Toward the end of the time I took listening notes I did some tweaking to the Infinity speakers. I had put captured cord IEC adapters onto the sub's amps. I've done this now to almost all of the equipment that has captured cords (read “lamp cords). I find the difference to be startling. Lots of folks do not believe wires make a difference. I can't think that the heavy gauge wire that brings electricity to your equipment can do so efficiently when the wire going into that equipment is a few strands of hair-thin copper wire. There are other reasons of course, but that one is my biggest concern, including shielding on decent power cords too, of course.

TruHarmonix believes that it is so, their warranty states to use their heavy-duty power cord or void your warranty. I asked to use my TG audio power cords and they had no problem with that, they only wish to make sure the amp gets enough current through the wire and into the amp. I heard almost no difference...none that I could equate as good or bad, which means the supplied cable is pretty darn good.

I discovered, as I was switching cords, that one of my cords looked different from the other TG audio cords. I instantly knew how I'd gotten that wire, so I e-mailed Grant Fidelity and asked if I had returned the cord supplied when I reviewed their amp this past summer. I had not! I needed the cord, so I bought it from them rather than pay almost as much to ship it back. I tried it, too, with the 6550 amp. I didn't hear anything with it, either. That's I understand with my miniscule amount of any type of knowledge, it denotes their power supply is very robust as when a power supply is not, or with line stage gear having smaller power supplies anyway, I can hear the difference quite easily.

I really enjoy doing “things” to my systems and the individual components. Some do not reveal much difference when using tweaks, some react to a new set-up dramatically. Gear that is “highly reactive” is usually, not always mind you, less expensive. There are some beautifully made, affordable components out in this audio world, the Truharmonix amp is definitely one of them, but it is one of those components that is NOT highly reactive to tweaks.

The power cord made that little bit of difference, as did the cones that Truharmonix had sent, but not hugely so. I put an IEC adapter onto an older CDP...the difference that a larger gauge, shielded cord made with it was dramatic! The same thing with an older Kenwood KD500 turntable. Unbelievable!

But the Truharmonix is a buffalo.

I was caught, with the two guys I worked with an 1973, in amongst what was then the largest buffalo herd in the US. To the buffalo, the pick-up truck we were in was merely another buffalo. I reached out of the window and felt the fur (?) of the monster that rubbed his sides against the truck and there was no reaction at all...the buffalo (our truck) was merely rubbing against him or her. Infallible, unflappable.

I wish I had a “tubes are finicky” guy in my room to hear the Truharmonix along with any music I played. LP or CD, it didn't matter. Attack, decay, tonal structure, and then the REAL IMPORTANT STUFF, imaging and sound stage (I am kidding about that, really I am) impressed me with whatever the music and/or recording threw at that amp.

You can listen with two settings with your Truharmonix amp, Ultralinear or Triode mode. Remember, you must turn off the amp to switch between UL and Triode.

I listened to most of the recordings in Ultralinear. My biggest quibble was what only seemed to be a slight loss in the upper and lower extremes. That loss was such that no one, including me, would never take notice if they didn't have that extra 75 watts (or so) per channel that my Monarchy Single Ended solid state amps possess for comparison. Infinitesimal!

But interestingly, I felt my speakers responded better in that regard, when in Triode mode. Everything was smoother, warmer, more rounded. The type of listener who enjoys hearing the warts of a recording
may enjoy the Ultralinear setting with more available watts than the Triode setting, but I really fell in love with that Triode warmth. I'd gone a bit looney how violins and other bowed instruments had sounded in Ultralinear, but in Triode...I melted into my couch...the sound was so rich and textured it made my heart go pitty-pat.

Listening to Breaking Silence Analogue Productions' CD (CAPP 027)of Janis Ian's soul-searching, I reacted just as strongly to tattoo as I did the very first time I heard it. The title cut, Breaking Silence still reveals Ian's anger and desire, and the Truharmonix does absolutely nothing to hide those facts.

This is an amp for people who like to feel their music, emotionally and physically. I write often about air pressure, the movement of air an instrument must make to produce sound. Many speakers cannot do it, many pieces of equipment can't deliver it. Shockingly, I can sense and feel that presence even when I'm listening to music from the desk where I write this review. I felt it the other day when listening to Bill Frisell's Ghost Town (Nonesuch 79583-2) and felt the banjo. Surprised the hair off my head! I had a full head of hair before I listened to that CD, now I'm bald.

I highly recommend you have a listen to this amp with some reasonably efficient speakers, but that power supply is not going to crap out if you aren't trying to allow your neighbors on the next block to listen to your music along with you. I listened to some Led Zeppelin at the volume my hippie-artist wife needs to listen when hearing that band. She was jumping around the room like the wild woman I married 36 years ago.

THAT is my number one indicator as to whether a piece of equipment I'm reviewing is worthy of someone owning. If she drops XX years and acts like she did when she graduated art school in 1971, then something's got to be right!

I saved the best for last, though. Strings! Jordii Savall's Cello is a sound I can't live without for long. I have to buy more of his CDs because Mr. de Sainte Colombe le Fils (AliaVox), if it was an LP, would have been worn out by now. The growl of his bow on the strings of his instrument is easily heard...the bow (!!) not simply the strings. The power of this CD is lost on my smaller system (before I made some changes specifically because of what I heard from this recording) as I'm sure it would be on lesser equipment anywhere. The Truharmonix amp loves strings! Did I tell you that yet?

I played some Vivaldi LPs before I sent the bearing of my VPI table off to be re-manufactured. I was awake yet dreaming; I could not keep my eyes open. The music from the Infinity speakers was truly mesmerizing. That, “You can see the rosin falling off the bow” thing some speak of was not what I heard...I think I may have heard the rosin falling.

I asked a few questions about the amp, one of which was the choice between Triode and Ultralinear:

The Triode mode will give you a little softer sounding feel to the music. I found I liked the Triode for most of the music I listened to, but with electric guitar, for instance Bill Frisell's CD, East/West, sounded a bit hard and slightly distorted in the treble region when I had the amp set in Triode mode, but smooth as papaya skin when set to Ultralinear. I liked that feature, electric (Rock, etc,) in Ultralinear, acoustic in Triode. I enjoyed the sound of orchestral music in either mode, Ultralinear giving a bit more detail for soundstage cultists.

I enjoyed my time with the Trueharmonix 6550 immensely. Elegant looking, elegant sounding, it is a tube lover's dream. While not able to produce the rather huge dynamic swings of my solid state Monarchy amps are capable of producing, the musical qualities of this amp are truly wonderful. If you like Chamber music or small combo Jazz, the 6550 would be a superb choice. In my rather large room, 15X26, I need the power the Monarchy amps deliver. In a smaller room, this amp might make you happy for the rest of your life.

I have heard tube amps with the power output of the 6550 that delivered the dynamics and speed of solid state; the Grant Fidelity amps come to mind. But the finesse of the 6550 is unsurpassed.

Along with its impressive sound are rather impressive specs, beginning with some of the parts used; precision carbon resistors, French polypropylene SRC capacitors and a Japanese Alps attenuator and some very solid looking and feeling tube sockets. The tubes slipped in rather easily and yet were firmly held (I've fought to get 'em in and out in some amps).





There are some fabulous tubed integrated amps out there for the savvy buyer/listener. If I was to choose between, say the Grant Fidelity amps and the Truharmonix, I might end up sitting in a corner drooling and babbling incoherently to myself.

It took a long time in the place I call my oubliette, to get “the take” on the 6550.  I wasn’t sure I liked it, then I liked it best in Triode, then switching back to Ultra-Linear, I decided I liked that best…REALLY LIKED IT!  Then I played some medieval music…very light, very airy…Harmonia Mundi LPs are wonderfully recorded.  Triode!

I don’t think I ever did decide which I liked better, I only know I liked listening to music with this amp more than I would have imagined; a very good reason to remain in my oubliette.  If you’re looking for an amp that will impress your friends  and yourself with its good looks and good sound, AND don’t want the muss and fuss of separates, this beauty fulfills the requirements, highly recommended.


*an oubliette was “a little place of forgetting” where someone was placed to live until their demise…which was often quite soon as they received, in most instances, no food, no blankets, no water…  For me, my oubliette is a place for ME to forget the rest of the world exists, at least until dinner time.



Technical Specifications
Tape, CD, Aux
Frequency Response
13 Hz to 60 kHz (-1db)
Power Output
Triode 30W x2, Ultralinear 60W x2

Input Sensitivity
Input Impedance
100K ohms
Tube Complement
6550EHx4; 6N8Px2; 6N8Px2; 5Z4Px2
Output Impedance
4 ohms & 8ohms
Power Requirements
110 V 60 Hz
14 in. D X 7.5 in. H X W 17.75 in.
approx. 70lbs. (63 lbs. Unpacked )

Our speaker reviews

Back to other audio reviews