BASE PRICE: $1,995





From day one, one of Stereomojo’s prime directives has been to seek out, find and publish reviews of two-channel, affordable high-end audio gear ignored by everyone else. So far, we’ve been pretty successful, as a large percentage of our reviews are world’s firsts. Here is yet another one, and this time we’ve found a real gem.





The Audio Horizons 2.1nB/8.0iMCpn (yes, that model number is way too long and complicated, but we will explain in a moment) is a very high-end stereo tube preamp at a remarkable price. Or prices. You see, that long model number identifies the base preamp plus the upgrades the purchaser has chosen to be custom built into it. Every unit is hand made to the buyer’s specifications and the long model name reflects a long list of options from which to choose. Amazingly, all the options are available to be added at a later date, which goes a long way in keeping you off the frustrating and expensive audio merry-go-round that is de rigueur in this hobby. If the TP 2.1 – we’ll shorten the name for now – only had that to offer, it would be pretty cool already, but there is much more to this made in Sacramento, CA preamp. According to the company, It boasts specifications found only in preamplifiers costing two to five times as much, such as razor straight linear frequency from 10Hz to 50kHz +1/-2 dB, THD guaranteed not to exceed 0.05% from 20Hz to 20kHz, dynamic range of 90 dB, signal to noise guaranteed to be in excess of 110 dBv, A weighted, and channel separation (crosstalk) better than  90 dB at 1kHz. Individual TP 2.1 specifications come with each unit, and we are told that units typically exceed these specifications. One usually does not see the word “guaranteed” in a specs lists, but there it is.

Those specs are generated by an equally impressive parts and design features checklist, and bear in mind these all apply to just the base unit sans options:



If you skipped the list, you missed the fact that this unit is fully balanced via XLR’s in and out. I don’t know of too many fully balanced tube preamps at this price. There is the BAT VK-30SE, but it is about $5,000. The Cary SLP-03 is $2,500, but offers only balanced output and not input. To get both, you have to step WAY up to the SLP-5 at $7,000.


As mentioned earlier, one of the most inviting aspects of the TP 2.1 is its lists of options. This is from where the long model numbers are generated. Each option adds its own letter designation. Let’s take at look at them.

TP 2.1n

Add noise suppression/Propriety tube caps  $250

TP 2.1B

 Add Premium output/input transformers         $795/up

TP 2.1R

                    Add Remote Volume Control       $350

TP 2.1RP

                     add Remote Volume and power   $450

TP 2.1

Add four new low noise Siemens tubes E 88CC gold pin   $300


Buyers can also order different phono sections denoted by “8.0” for use with a turntable, either built in the 2.1 chassis or in a stand alone version

TP 8.0iMM Moving magnet phono amp in TP 2.1 $550/up

TP 8.0sMM Moving magnet phono amp in stand alone chassis $695/up

TP 8.0iMC Moving coil phono amp in TP 2.1 $ 895/up

TP 8.0sMC Moving coil phono amp in stand alone chassis $1,040/up



Whew. That's a lot of different options! I have seen less options on a new car sticker, but the personalization does not end there - it extends to the casing and knobs as well. They offer the 2.1 in silver or black metal finish and with machined metal or wood knobs!  The one I received is what they call silver, but it is not the typical hard silver you see so much. The front bezel is more of a soft, silky silver that evokes a sense of quality and yes, even luxury. It is not just a flat piece of metal either. It is beautifully beveled and machined. I have seen less craftsmanship of the faceplate in many more expensive competitors.

The list of options may be perhaps a little daunting, but well worth some study. Victor Comenchero, Director of Marketing or designer/owner Joseph Chow will be happy to work with you to assemble the model that both fits your needs, wants and budget. By the way, the prices set for the options when the unit is originally built are the same for the upgrades you may choose to add later. No gouging here.

Mr. Chow has chosen not to include a power cable, deciding that no serious audiophile purchasing this level of equipment would be content with a $4 cheapie power cord. If you are content, like most people you surely have a computer/component cord laying around anyway. Of course, Audio Horizons also makes cables, including power cords, so I'm sure Joseph will be happy to let you audition one of his when you do an in-home trial of the preamp. See how nice that works?

We should also note that there is no facility for headphones, nor is there an such an option.





If you have read some of my reviews, you know that I have a pet peeve – excessively bright lights on the front. It always amazes and frustrates me how a single, small LED can light up a whole room. Linda and I like to listen in a completely darkened room, so when a component has even one zillion watt LED, it means I break out the black electrician’s tape and cover the offender up. I also keep some dark blue theater lighting gels to place over displays on things like CD players that need to be seen, but are way too bright and not dimmable. Well friends, the TP 2.1 has a front panel readout that illuminates an “Audio Horizons” logo as well as very small orange icons that indicate which input is chosen. I’m thrilled to report that the blue-lit logo is a perfect level of brightness. No tape or gels needed. And it is very attractive, again lending a aire of “Hey, I’m expensive!” to the 2.1’s persona. Very cool.



My 2.1 came with the optional remote volume control. As you can see, the remote unit is medium in size and is made of black plastic. It also includes buttons for many functions. So, when I used it the first time and only the volume buttons worked (and not even the on/off function), I thought something was wrong. As it turns out, there is a reason they call it the remote VOLUME control because that’s all it does. When I asked Victor about it, I got this reply: “The 2.1/8.0 combination does not have enough room in it for the power/volume remote so we included only the volume remote.  We will not have a full function remote until the summer of 2008, and at that time we will make the chassis just a shade larger to accommodate the remote features.” Okay, so they are planning ahead. Smart. The ability to control volume is by far the most important and most used feature, so I was happy with that and impressed at their forward planning extended to something as, well, remote as the remote.










Looking at the topless TP, it is easy to see the quality craftsmanship does not stop with the casework. The layout and neatness of the circuit design demonstrates Joseph Chow’s care and expertise. If you are saying to yourself, “Wait – that doesn’t look like a straight line with gain”, you are right. That, however, is by design. Mr. Chow correctly observes that there are two basic preamp design philosophies, one being the “straight line with gain” which, though simple in name, is quite difficult to execute. The other is the opposite approach where the designer tries to overcome the “straight line” difficulties with exotic, complex circuitry. Mr. Chow claims there is a third way – namely his way, which is explained on the company’s very informative website. Mr. Chow’s way “… seeks instead to look deeply into the circuit function, the materials used in it, and the sonic goals to be achieved.  By analyzing these, especially the inherent sonic characteristics of the materials and components at every stage, Joseph Chow seeks neither to eliminate components, as those in the simple design school do, nor to compensate for them, as those in the exotic design school do.  Instead, he seeks to harmonize the inherent characteristics of materials with the circuit design itself.  This search for harmony between the materials used and their function within the overall architecture is what defines and distinguishes Audio Horizon design.  The focus is always on the sound characteristics inherent in the materials themselves and, given their characteristics, to achieve at an affordable price the highest quality sound possible.”

There was quite a bit of discussion with Victor about tubes. When I asked about the tubes used in the base model he said, "The base tube we use is a Tesla 7DJ8 or an Electro Harmonix 6922. We think the Tesla is superior and if the customer does not ask, we install the Tesla." He had also talked about the tubes in the upgrade package which are Siemens new-old-stock. If you are not familiar with that term, abbreviated to "NOS", it means the tubes are antiques that were made many years ago before transistors took over. However, these "antiques" are unused or lightly used tubes that test as if they were brand new. Almost all tube veterans agree that those older tubes sound much better than contemporaries.  The problem is, since they are no longer being made, the supply is very limited and often fetch very high prices, sometimes in the hundreds of dollars. But they can make hundreds and even thousands of dollars difference in sound quality, too. Joseph and Victor listened to many NOS tubes such as Mullards before deciding on the Siemens, determining that they had the best overall sound.



After all of that background, the bottom line is how it sounds. In a word, excellent! I ran the 2.1 in front of my reference Halcro MC20, 400wpc power amp and the Luminous KT-150, both reviewed here previously. The Halcro was run in balanced mode and the Luminous, lacking balanced circuitry, in standard. In addition, the 2.1 provided the input for the $20,000/pr ATC SCM50 self-powered speakers that came in for review. Victor sent two pair of Audio Horizon cables to use for the review, so those were the choice.

Preamps for comparison were the matching Halcro pre and the pre by Gary Dodd.

There is actually not much “sound” to describe with the TP, which is exactly what a preamp should do. Via CD from the Stereomojo evaluation CD’s first cut which tests soundstage reproduction, the image projected sounded unlimited.

We interrupt this review to introduce yet another Stereomojo innovation. From time to time as we refer to certain reference cuts, to help our readers further enjoy, relate to and understand our comments, we will make those sound files available for download. You can hear the exact example of what we are describing as you read! For download speed and copyright reasons, we will only provide lower quality mp3 files, so they will not be reference quality or full length like we use, but they will still give you a sense of what music we are referring to. Right away! Talk about immediate gratification. To download, just right click and choose "save as" or save link as. Tell it where you want it to land on your computer. Double click the file and it should open your chosen sound file player. Voilà! Try it. Write us and let us know what you think.

Stereomojo Soundstage Test Cut

We now resume the review in progress....


The 12’ ceiling and my 24’ room width seemed to be the only factors that bounded its size and scope. It easily matched that of the Halcro pre and surpassing it the definition and separation of layers which was later revealed in “The Mission Soundtrack” and Rimsky-Korsakov’s “Dance of the Tumblers” from Reference Recording’s “Tutti” HDCD. Both cuts are rich in orchestral texture and vivid, deep layers, with the Mission track adding choir and African percussion. To me, what defines how “high-end” a product is, is how hard the listener has to work to hear all the different audio qualities contained in the music. There was no effort required, no straining or leaning forward to hear how the 2.1 handled these tracks.

There also seemed to be no limit on the dynamic range. At the Vegas “THE SHOW”, Peter Noerbae of Montana Speakers turned me on to a great 1996 recording of Johnny Adams entitled “One Foot in the Blues”. The sonics and the music were both incredible, with one of the best renderings of my beloved Hammond B3 organ ever on CD. It sounds as if the engineer used very little or no compression or limiting, so the dynamics are explosive, which is exactly why he played it on his massive KAS, 6’ tall, $38,000/pair speakers (pictured in our Las Vegas report).  He said the “KAS” designation stood for “Kick Ass Speaker”. It was, and so is this recording. I bought it as soon as I got home. The 2.1 completely got out of the way of Johnny’s vocals and Dr. Lonnie Smith’s masterful B3 work.

The Dodd preamp has a bit more in dynamics because it starts from a bit quieter sound floor – but only because it runs on rechargeable batteries which takes all the nasty AC current out of the equation. When I say “a bit”, I mean “a bit”. The difference was subtle. The TP’s dynamic range and overall quietness is outstanding at any price and astonishing here.


The Halcros tend a bit on the dry side, but the 2.1 juiced things up. Individual voices and instruments were a little more rounded and meaty through the TP.

The Ronstadt cut on the SM evaluation CD features very long, floating and shimmering reverb trails - something that is very difficult to reproduce digitally. It also requires a very high degree of resolving power in the analog domain. The TP really strutted its stuff here with perhaps one of the best performances ever. Better than the Halcro and at least the equal of the Dodd. By the way, the Dodd goes for $3,300 and is not balanced and has no phono section.

If there was one criticism to be voiced, it would be that the top end of the 2.1 from the high upper mids on up were a little on the soft, cool side. Not vague, slow, fuzzy or dull, just not as sharp as some others. The only thing fuzzy about the 2.1's sound was the timpani mallets used in the Mission cut. When played back correctly, the mallet head material is obvious. Fuzzy! For the TP's top end, think of "silky" but just a tad less smooth. For many, this will be a welcome interpretation. For others who prefer bleeding edge, etched in glass type sound, not so much. I'd say for 99% of new owners who upgrade from anything less than a super-pre, you will be so bowled over by the new sound that quibbling over an octave or two will be silly.

The top end quibble does not extend to the most important midrange where things were deliciously detailed, dense and delightful. Vocals were warmish but not over cooked - something difficult to voice with tubes. There was no harshness or glare and very long-term listening was a joy.

Bass? One of the hardest things to reproduce in tubeworld. There was no lack of bass at all. When I hooked up the 2.1 to the ATC self-powered speakers which can only be driven via balanced XLR, the Dean Peer's bass solo cut was almost scary. I might point out that these ATC's are used by many of the world's top recording studios, producers, mixers, mastering engineers and recording engineers. For example, they are six-time Grammy Award winning Michael Bishop's choice for his home system. They are relentlessly clean, clear, revealing and powerful. The frequency response is virtually ruler flat. If there were any maladies in the 2.1, they would have been exposed like an elephant in a spotlight. No such pachyderms were detected. The low end did not call attention to itself in braggadocios sort of way, it was just there when needed. The Peer bass solo cut was snappy, deep and well controlled. Male vocals were timbrelly centered and not throaty, chesty or nasally.

This is where I need to disclose that the first sample Victor sent had a problem with sibilants. That and the top end being over the top hot. I tried several common remedies such as cable swaps and AC isolation, but the the problem was with the 2.1. I think it was a a tube or tubes issue, but Victor ask that I send it back to make a small internal adjustment. When it came back, the brightness and sibilance was gone, but a tiny measure of the high end went with it. If there was a solution somewhere right in the middle between the two, that would be perfect. It must be emphasized that the "softness" described here is very minimal. The sound is not dull or lifeless, quite to the contrary. You might say we are even being a touch picky and you would be right. If this were a lesser preamp, it would not even be worth mentioning, but when a component is contending for state-of-the art, top echelon status,it definitely must be pointed out. And make no mistake, the Audio Horizons TP 2.1 is very much a candidate for best of the best status. It could be that since the tubes were NOS, they might have been just a bit off or didn't appreciate our Florida humidity.




The "8.0iMCpn " designation in the model number of our test sample indicates that it was equipped with the Moving Coil option with "additional noise suppression, a power supply upgrade, and upgraded Hovland caps for a sweeter, smoother, more finely textured and coherent midrange", according to their website. This option, built into the TP2.1 chassis, costs $1,495. The reference analog front end was my TW Acustic Raven One with Graham Phantom arm and Dynavector DV-XX2MK2 cartridge. Cable was the excellent Cardas Neutral Reference.

RIAA Frequency Response (FR): 20-20kHz +/- 1dB
Noise level: -82 dBv to -90 dBv in the integrated version depending on the
load and whether it is an "n" version; -84 dBv to -92 dBV in the separate
version depending on the load and whether it is an "n" version.
Channel Separation (CS): 70 dB
Total Harmonic Distortion (THD): 0.06 % @ 1 volt output


The phono section uses two 6922 (E88CC) tubes. The one tested had the upgraded Siemens E88CC tubes in it and the "N" option mentioned in the specs list above.


"Quiet". If there was a one word description of the phono section, it would start with "quiet". No hiss, no hum, no noise. The Dyna XX is a no-holds-barred, dynamic big-boned pickup, full of emotions and drive. Again, the job of a phono pre is to just get out of the way and the let the analog system do its thing without adding or subtracting anything. Like the TP2.1 itself, soundstage and imaging were superb, placing the musicians firmly where they should be in front, behind, above and beyond the speakers. Playing the LP versions of cuts from the Mojo Test CD, the TP2.1 left no doubt as to the superior playback of quality vinyl.

Ms. Ronstadt was even more dimensional and fleshed out as she sang about how "Shattered" she was after being dumped. Her performance was even more gripping and inconsolable. The tender, wafting solo piano intro sets the stage perfectly for what is to come with its barely played, sparse phrases that are so difficult to replicate, each note being masterfully nuance with very small dynamic differences, but vital to the overall morose mood.

"The Mission" LP, with its multi-layered orchestra, oboe solo, mixed choirs and African percussion complexity was child's play for the 2.1. Gorgeous.

I played dozens of LP's through the 2.1 with no complaints to register. I think even the slightly soft top end of the TP's character was somewhat ameliorated by the crystalline top end in the phono circuit, bolstered by the Raven/Graham combo. A true torture test for any analog system is Classic Record's reworking of Reiner's "Zarathustra", reissued on four 45rpm disks. They have taken an already explosive recording at 331/3 and upped the ante considerably. The 8.0iMCpn navigated the hellacious Chicagoans deftly. From the opening "at the bottom of an abyss" pipe organ pedal, to the powerful swells of the well known 2001 Space Odyssey theme, to the delicate, pianissimo passages, Richard Strauss' answer to Nietzsche's book by the same name which espouses an end to morality, is teeming with diverse emotions and musical messages. This Classic reissue and the 2.1 coalesce to proffer exactly what the master tone-poem composer/orchestrator invisioned. Take that, Nietzsche!


The phono option, even at $1,495, is judged to be worth the investment. But remember that you need not purchase it right away, and there are twelve other less expensive MM and MC options starting at $550. Incredible..

There is one significant caveat regarding the phono section's cartridge loading and adjustments. Usually you will find a series of dip switches with which to change from one moving coil cartridge's specs to another. Not the case here. When I enquired about this function, Victor said, "In the 8.0i versions as opposed to the 8.0s versions, the MC matching network is inside the unit and when a new cartridge is used, a new network is sent along with photo close ups to show where it is located. The new network then must be soldered in place of the old one, or the customer can send the unit back to Audio Horizons and we will do it at no charge." Obviously, if you only own one cartridge and don't upgrade or change often, this is not a problem. However, if you have several different carts with different load characteristics, this could be an annoyance. Especially if you are not handy with a soldering gun and need to send the unit back and forth.

So. We have described the TP2.1 as clean, revealing, soft and beautiful. Sounds like the ideal woman, eh?




The Audio Horizons 2.1nB/8.0iMCpn stereo tube preamplifier is a hidden gem that needs to be exhumed from the grave of anonymity. Its level of sophistication, craftsmanship, parts quality and audio performance, even in its base model at only $1995, represents outstanding value. This is even more noteworthy because it is made in the USA. Much of this is value is there because it is not sold in stores and does not have a distributor. It is sold direct and not with the typical profit margin of other direct sellers. These factors alone make it extremely worthy of top consideration for those seeking a top quality tube preamp - or any top quality preamp, tube or not. Augmented by the included balanced circuitry for both input and output, competitors start to thin out significantly. The coup de grâce has to be its phenomenal smorgasbord of available options for the preamp itself as well as the over-a-dozen choices for the phono section alone. But the TP 2.1 resurrects from the coup de grâce killer status to transcendent because of Joseph Chow's upgrade policy which permits owners to upgrade to any of the options at the original upgrade price with no premium or penalty for waiting 'till later. He also offers a 30-day, in-home trial.

The price as tested with options of $5,195 is not cheap, but we believe it more than competes with other brands at much higher prices. What we do not know is know is how the base model at $1,995 performs, but we think it is safe to extrapolate that it also functions at a very high price/performance ratio. But that you can decide for yourself via the provided in-home trial.

Remember that the remote control option only operates the volume up and down, though there is a second more costly option that adds and on/off function. About the only option and feature it lacks is a headphone jack. We suggest that Mr. Chow find a better and less complicated way to denote model names and numbers, even if it means putting together a few select base-plus-options packages. Also, having to engage in soldering or sending the unit back when a new cartridge with a different setting is acquired is awkward.



The Audio Horizons TP2.1 with the 8.0 phono section, because of the excellent qualities and value chronicled in this review,

is conferred our Maximum Mojo Award.

Audio Horizons webpage