Review: H2o Audio Signature Monoblocks

Category: Amplifiers


H2o Audio Signature Monoblock

Retail Price: $5,500.00 per pair

It was late July or early August and I was stuck in a hotel, on business travel while I was surfing A’gon and the other “audiophile” websites when I happened upon the Apogee user forums. There was quite a bit of buzz going on about a new startup company, H2o Audio. Henry Ho of H2o Audio had been building large class A amplifiers for many years at this point, trying to create the perfect mate to drive his Apogee Scintilla’s. Well from what I was able to garner from the Apogee website, Henry had been tweaking an amplifier using the B&O ICE module. Henry had come to a point where he felt he had created an initial stereo amp that achieves much of what he wanted. This amp went out to a few members of the Apogee users group on a trial basis. There was enough positive response to pique my interest. At this point I emailed perhaps five or six members that have had experiences with the H2o. After much email exchange and a few phone calls I had learned the modestly priced H2o stereo amp had replaced VTL 450 monoblocks, Pass Labs X600 monoblocks, and gave Reference Line Silver Signature monoblocks a run for their money. Now this was a $2,000 retail stereo amp at startup pricing. I did take this information with a grain of salt, as I am inherently a bit skeptical on new products. What intrigued me most is more than a few people replaced their tube amps with this amplifier. I have always preferred the sound of a good tube amp. In what respect you ask? In my experience tube amps almost always seemed to portray the “organic” feel and texture to instruments better. After many emails and phone calls with owners of the H2o I was intrigued enough to give Henry a call and chat a bit. I will also say I am very happy with owning Quicksilver V4 monoblocks at this time. The *only* issues where the heat produced, and perhaps not the last bit of control in the bass. With that being said, even though the H2o amps had a trial period after purchase I was not about to sell my V4’s to “experiment” with another “flavor.” Henry and I arranged a weekend in which I drove up to Richmond, VA with my First Sound Presence Deluxe Mk. II preamp and about 46 CD’s with me. (Just the necessary CD’s for demo!) I got into town quite late in the evening, expecting to go over to Henry’s house early in the morning. Now for those of you who have spoken to or met Henry, you already know he is a gentleman in every sense of the word. Henry insisted I come over that evening to get an initial impression of the system. I had listened to his system with an Adcom GFP-750 preamp (I think it was that model) as well as Henry’s Fire preamp he is building. We ended up inserting my preamp into the system in which Henry had set up with the standard H2o monoblocks. I was truly astounded. I may have made it through 8 or 10 of my necessary 46 or so “test” CD’s and I was talking to Henry about build time. I was also intent on making sure there was still the “trial period” as all the feedback I have heard, as well as his system was with Apogee speakers. I had Meadowlark Nighthawks at home… 4 Ohm load, 91 db, etc… not the same monster of a speaker to drive. The H2o also has an extremely high damping factor (1600 if I recall correctly) in which was a concern of mine. After speaking with Pat McGinty of Meadowlark Audio, he put to rest any worries about damping factor, as he said with a correctly designed speaker, the higher the damping factor, the better in general for bass control. I had been told by a couple of the H2o owners that Henry also had a “signature” model of his monoblocks that aren’t advertised… Of course I had to ask how much better they were than the standard monoblocks I was currently listening to and enraptured by. Well the reply wasn’t 5% or 10% better, but “a substantial and significant improvement” from Henry. I placed my order that evening, actually morning, as we listened well past midnight and into the morning. Thanks again for the great hospitality if you read this Henry!

About six weeks later I was placing my brand new H2o Audio Signature Monoblocks into my listening rig.

After verifying all of the cabling was correct I put Patricia Barber’s Modern Cool album in and let it play. I gave Henry a call to let him know, I am not certain these amps will work for me, they are just a bit bass heavy. Henry assured me I have the trial period to get used to it, and not to make any critical decisions until the unit has broken in. Well, it wasn’t but 30 minutes later I was calling Henry back to inform him his amps were not bass heavy. After swapping albums to Gerry Mulligan Quartet – Dragonfly and my next thought was, “where did the bass go?” and then I noticed the piano notes drifting off with subtle decay… This was the first 30 minutes or so with the new, unbroken in, H2o Signature Mono’s in home. After the second call to Henry, feeling a bit embarrassed, I promised to let the amps break in and then make a judgment. What was becoming crystal clear, even with unbroken in new amps were these amps were true to the material that was being fed through the system. Hours and days, days and weeks had passed… the treble and high frequency extension was the first to settle down during the break in process. Next after about 500 or 600 hours (in my rig) the bass seemed to stabilize, more muscular and with supreme finesse. This is not easy to put into words, however at 600 hours the midrange sounded good, perhaps even very good. However, the midrange was still ever so slightly recessed. I was considering swapping cables, and actually making some calls. I left town on a business trip and came back a few days later and the midrange had fleshed out beautifully. It was hard to comprehend that much of a change occurred this late in the game… there was about 780 hours logged at that point.

Overall, I have had the H2o Signature Monoblocks in my system for about 10 weeks now. I truly wanted to give them enough time to go through the break in process. I feel the last bit of break-in, in my system, was right around the 800 hour mark. That landmark was reached about 5 to 6 weeks ago.

I have had the intention to write a review on these amps since I brought them home. I have tried to bring myself to write a “review” of these amps at least a few times in the past couple of weeks. For those of you who know me, and others who have read a bit of my ramblings, I am usually not at a loss for words…

However, painting a sonic landscape that these amps provide has seemed evasive to me. One word keeps coming to mind… actually from the first track played when the amps were brand new, to the next track, to right now listening to background music. The word to me that best describes these monoblocks is “chameleon.” I have heard phrases in the past that “the amp just gets out of the way and lets the music through” as well as “the amp doesn’t impart its own sonic signature on the music, you only hear the music” – well both of those phrases hold true with the H2o Signature Monoblocks. However, I also feel the H2o Signature Monoblocks take it a step further… by stating I feel the amps are “chameleon” like or in character evoke a different aura in itself. Well let me state I have had amps that have “just let the music through” or have “gotten out of the way” with no signature. Those amps all DID have a signature looking back on them. One that just let the music through was very musical indeed. Anything you played upon it was musical, a poor recording, a good recording, it was all musical. I have owned amps that “got out of the way” and were transparent into the recording and the details… that again was the amplifiers perspective on the material being played.

Why I am having difficulty here describing the H2o Signature Mono’s is the fact of their “chameleon” nature. What I have determined with these amps, it IS the music, the material that you feed the system. In my opinion these amps DO allow the music to show through. You have the emotional context of the artist recorded with these amps. There are recordings that offer all of the above… those recordings we all have that you can hear a pin drop, are pristine in sonics, but almost seem rehearsed and unemotional. If that is how the material was recorded, I seem to think these amps portray that. Just the opposite is true, the dynamic shifts and subtleties, both micro and macro, occur in spades with these amps, many times within a given song. The opposite end of the spectrum is also present, if you put in say Keb Mo, where there is rhythmic drive, naturalness, musicality and also the presence. These amps will have the pace and timing and drive with the ebb and flow of the music if that is how it was recorded.

The more I write – the more I am beginning to feel this isn’t a “review” as I don’t feel worthy of putting all of the audiophile adjectives into perspective here. I will try my best to convey a bit more of my experience with this product and can leave it at that.

I can honestly say for the first time in my audiophile life I have sold a tube amp from my system. I had the remorse. In the past I would sell the solid state amp and go back to tubes… That remorse went away for the first time not having a tube amp in my system. That in itself speaks volumes to me, if not others, for I have always preferred “tube” sound over solid state. Now, there may be more “air” with some tube amps than with the H2o Signature Mono’s but other than that, in my opinion there is no drawback.

Audiophile attributes top to bottom: The treble is as accurate as I have heard on a solid state or tube amp in a home based system. I say this taking into account when the volume is played at moderate to higher levels, the best performing amps in my comparison tended to have a slight “grain” or almost “veil” in the treble crispness and clarity. With some amps, I would never have said that, until I have had these in my system.
The midrange is true to the recording. I would say it is similar to a tube amp in the regard of the overall speed and liquidity of this amp. The H2o Sig. Mono’s in my system equal or bests some great tube amp electrostatic systems I have had in the past with all of the benefits.
The bass is what is recorded. It is not only accurate but extremely well controlled and defined. Depending on what you are listening to and how it was recorded will be easily detected with these amps. No matter the volume, whether playing very low, or at quite high volumes, these monoblocks have power and control over the music to the extent it seems effortless and natural unforced as the music emanates from the speakers. Dynamics and organic texture is also apparent at low listening levels. You will not have to “goose” the volume up to a certain point to make the music come alive.

Overall I would state the H2o Signature Monoblocks are not only “chameleon” in nature to the program material being fed, they also posses the following qualities… The absolute speed and liquidity coupled with the finesse and stygian control of the woofers, all taken into account with the organic, natural portrayal of the instruments all add up to some of the best sonics I have heard in both the tube and solid state camps. There is such an effortless and natural, organic feel to the music… yet as I write this I can put in another cd and state how dynamic and well paced these amps are…

The H2o Signature Mono’s run cool to the touch, even after 33 days of constant playing during break in. They are rated at 250 wpc into 8 ohms and 500 wpc into 4 ohms. I have some photos of the H2o Signature Monoblocks under my virtual system “Sonic Oasis” here on Audiogon. The amps are approx 13” wide x 13” deep x 7” tall. The case is full aluminum (8 gauge I think – very thick) and black powder coated. The faceplate is anodized aluminum which can be ordered in silver or black. There is one solo Blue LED on the front of each amp when power is on. There is a removable IEC for the power cord. The Sig. Mono’s have dual sets of binding posts on the rear of the amp, as well as both single ended and balanced inputs which can be switched externally with a toggle switch. Each monoblock is approx 50 lbs. or so.

Again, this review mirrors my experiences, in my system, and is based upon my opinions. I hope this helps shed some light onto this new startup company’s product. The website is:

The website is under construction so don’t expect much. I am not sure if Henry has a dedicated phone line as of yet, if you wish to contact him there is email contact on the website, or shoot me an email and I can give you his number. I am in no way affiliated with H2o Audio. I am an extremely satisfied customer – both with the product and how Henry runs his company. At the time I ordered, there was a two week trial/satisfaction period after purchase. Anyone in the market for an amp in this price range would be doing themselves an injustice not to look into this amp, in my humble opinion. Soon there should be reviews coming out in 6moons as well as another I am not certain of.

Amplifiers I have owned in the past include (but not limited to… in case I leave one or two out): Bryston 4B, McCormack DNA-1 Deluxe, Music Reference RM-9, Sonic Frontiers SFS-80, Cary SLM-100 monoblocks, McCormack DNA-2 Deluxe, Quicksilver V4 monoblocks. I know there are others I am leaving out, however these are the amps that have had extended stays in my systems.

Associated Equipment:

Meadowlark Audio Nighthawk speakers
Synergistic Research X2 Resolution Reference FX biwire speaker cable
Electraglide Mini Khan Plus power cords on H2o Sig. Monoblocks
Synergistic Research X2 Resolution Reference interconnects (single ended)
First Sound Presence Deluxe Mk. II preamp ( NOS Siemens 7308 gold pin tubes )
Electraglide Ultra Khan II Statement power cord on First Sound Preamp
Electrocompaniet EMC-1UP CD player with spider clamp
Electraglide Mini Khan Plus power cord on Electrocompaniet CD player
Everything *except* First Sound preamp is run through BPT
BPT 3.5 Signature balanced power conditioner
Electraglide Ultra Khan II Statement power cord from BPT to wall
FIM 880 wall outlet upgrade
All components *except* H2o’s and speaker sit upon Zoethecus
Zoethecus z.5/r shelf with z.slabs under all components
Ridge Street Audio Designs cable lifts
Eighth Nerve Room Pack – wall treatment
Thanks for the review, I have been interested in these amps for a while now. A member of the planer speaker forum at Audio Asylum has just tried the stereo version with his Maggies...he was as impressed as you.

After reading what I wrote above it seems apparent to me that I did not convey just how pleased I am with these amps. I still am a bit frustrated by not knowing exactly how to put the performance into words that do it justice. I think that fact in itself left my "review" a bit cold sounding. I want to express that I am very pleased with the performance of the H2o Signature Monoblocks. They continue to astound me and gain my admiration. I would also add if you are considering a new amp I would highly recommend considering these. All of the glowing press that drew my attention to this company was mainly based upon their $2,500 stereo unit. I feel the H2o Signature Monoblocks will be a "staple" of my system for many years to come!
Others who has posted on other audio websites have said the midrange is thin & astringent.
Interesting comment Kevziek, I would agree with you partially: when the unit was new and was breaking in the midrange was a bit recessed. It was not thin, nor astringent. I do think I have read one, yes one, no idea of plural in this case that got Henry's first prototype that was unbroken in... I am certain that would sound less than superb in both instances, not broken in, nor a final tweaked production model.

I truly wish you have had personal experience in which case you would shake your head to those who repeat negative comments with no valid personal experience of their own - especially against a product that will be given its praises in due time. Soon review samples should be arriving at some of the online 'audiophile' publications... time and ears will tell...
I haunt all audio sites, and have never run across, "Thin, and astringent," in reference to the H2O. There was one ill fated trial period (minutes) at a particular audio party, reported in Audio Circles, where it really never got a fair hearing. The system was exhibiting a whine. Otherwise, all reviews have been very like audiofankj's. I have had a train of listeners at my place. They all agree with the review.

I can see where people may put the amp in their system, perhaps containing a clinical, piercing CD player, the resulting sound being not to anyone's liking. Like audiofankj says, the H2O is a chameleon.

Look at the reviews at the H2O site, and the new one by Scott at the Asylum.
Any information on the reliability of these amps or has anyone encountered any problems in performance?