H20 Revisited

I've come across several glowing reviews of the H20 M250s and S250 from a few years ago, but haven't found much additional feedback over the past 12-18 months.

Are there still satisfied owners out there? Has anyone auditioned the amps recently? Do they still stand out against the alternatives in the price/class range?

I'm narrowing down a list of SS amplifiers to audition and would love to hear if the H20s are still at the head of the class.
I am still using my H20 and am very happy with it. There are lots of Icepower amps around. Most use Icepower modules with a built in switching power supply and have a very small chassis. The H20 uses a large linear power supply and large chassis. This allows changing the power supply bypass caps to tune the sound as I and a few others have done. This is not an option with small chassis, SWPS amps.

There is now a lower power H20 model available using that I auditioned briefly. It sounds similar to the the Signature stereo version at lower cost.

Bob is right on. I would look into the lower powered H2O as well for most speakers. The High powered amps are suitable for tough loads. I tuned my M250 monos with Sonicap Platinum bypass caps to my great satisfaction. I think these are being applied stock now.
I have had my S250S four years now without any problems. It is very sensitive to power cord and IC changes, actually I can hear any change I make quite easily.

I recently aquired a tube preamp and like the sound much better than the SS pre I have. IMO this is a very neutral amp with enough power for most speakers.


Glad to hear there are satisfied H20 owners out there. I'm also looking to audition the Bel Canto REF 1000s (Lunar Eclipse award from 6 Moons) and CI Audio D200s.

My Dynaudio 52SEs (4ohm, 86db) are moderately hard to drive, and I've read they respond well to high power... so I'd like to see what happens with a little more juice than my 40W Rotel can provide... maybe more life at lower volumes?
Beware the Ref 1000's on higher efficiency speakers- the flaws were easily revealed (lack of body; slightly grainy highs) when compared to the much superior Symphonic Line RG4 MKIII amps that replaced them. If you have less revealing; more power hungry speakers however, it may be a good match...
06-19-08: Sutts
Beware the Ref 1000's on higher efficiency speakers- the flaws were easily revealed (lack of body; slightly grainy highs)

Ditto that. My speakers are 92dB...not that high relative to many others.
I've been listening to H2O M250 SA on a pair of Gallo Ref 3.1> Amazing
clarity and focus. Top to bottom almost perfect. I have tried using
many power cables, found Fusion Audio Enchanters took them
to the next level.
My H20 S250 replaced my tubed ARC VT100MKII in May 2005 and I am still most happy with it. When I first auditioned it I found that it was the first non-tubed amplifier that I could listen to without bleaching out the harmonics. Since I bought it I've had Henry upgrade it with the newest ICE modules and V-Cap bypass caps. As Rpw states, it is most sensitive to power cords and ICs. Its definitely worth an audition in your system. Henry Ho will send you one for a test drive.
Hi Crubio,

I agree with you.

May I ask you what your source is? I am using a non-oversamping DAC. I have found nearly all oversamplers an annoyance. I have not tried analog.

Yo Rlf, if you care to get even the rudest solder iron, you can easily change those bypass caps. I have found Sonicap Platinum .1 ยต caps better to my liking.
Thanks Muralman1 for the suggestion. However I'll first have to take a course on soldering 101. Seriously, I did find the V-caps an improvement stock bypass caps. If I remember correctly you did try the V-Caps. If so, how did you find the Sonicap an improvement over the V-Caps sonically?
I may have been too hasty with the V-caps. I tried them through 2 months. When I switched to the Sonicaps, they sounded great to my ears from the start.

There is no soldering class needed. Some Wonder Solder and a cheap gun is all you need. You just soften the hold of the V-Caps, and replace with the others the same way by heating the plate and wire then applying the solder.

You have to be sure the caps, and wires are slung low, so they don't short on the amp lid.

It's a snap. I am no electrician, but I built myself a DAC. starting yesterday. The right speaker sounds marvelous, but the left is doing it's best imitation of the Amttyville Horror House. Like I said, I am no electrician.
I have owned a pair of the H2o Signature Mono's in the past, and now currently have the H2o Singature Mono Special Edition's.

These are Henry's all out assault on what he can do in a pair of mono's. Henry is using the V-Caps in these monos as well as a few other design tweaks.

As for the Sonicap Platinum vs. V-Cap my older pair had the Sonicap Platinums and while very good, the V-Caps are clearly superior to my ears, cleaner, more lifelike dynamics, pristine extension with no source of grain...

Vince - the V-Caps do take a long time to break in, and do not sound great until that happens... :/

I have had three sets of tube monoblocks in between my first pair of H2o mono's and this current pair. While my personal preferences lean toward the sense of spacial cues a good tube amp has, the H2o paired with a great tube preamp will give you 95% of a great tube amp sense of spaciousness. On top of that you gain better transparency, startling dynamic prowess, liquid midrange, etc., etc.
One important point with the bypass caps. Unplug the unit and discharge the big electrolytic caps before working on the unit. There is significant voltage waiting to zap you.

Also the stock binding posts are nickle-plated. Just about any other Cardas model will fit the chassis holes and sound better. You must disconnect the module leads because high temperature is required to solder the binding posts and is enough to damage the amp.

Which V-caps? The OIMPs or the TFTFs?
Audiofrankj: I'm curious if Henry has the Special Edition available for the Stereo 250 Signature too. I couldn't find anything on his website about it. I am also using a tubed preamp with my H20--an Audio Research Reference 2 modified by Great Northern Sound with great effect including the attributes that you mention including that fabulous liquid midrange and spaciousness.

Vince: When Henry installed my V-Caps he broke them in for about 2 weeks. Before he sent the amp back to me, he e-mail me that he was a little worried about the sound until they started to break in but once they did he was elated and stated that "my H20 set new standards" at least at that time. I've recently upgraded both speaker cables and Interconnects from my preamp to the H20 with more improvement in sound. I borrowed a whole bunch of cables from The Cable Company's lending library to tune in even better sound. It is amazing how changing cables can affect one's impression of this amp. It is so sensitive to changes and I can see that with the wrong cables one might not be impressed with the H20.

Dotsystem: He did replaced the nickel binding posts with Cardas as you had recommended to me in the past. Thanks for that suggestion.
Rlf, those were astute observations. When confronted with one of the web's most vociferous H2O critic, I asked about the attending wires and components on his listening. His answer told all.

These H2O amp systems are the most difficult to get all right. When you do, though, you really know how special these amps are.

I have given up on production speaker cables. I am making my own using very short ribbons to go with my H2O monos. I never will be tempted to buy commercial SCs again. The change was hugely positive.

My Audio Note DAC is also crucial to my system favorability. Crubio heard that.
Rlf: My apologies for not noticing your question earlier. I am not certain if Henry is offering a Special Edition on the stereo model. You may want to inquire with a phone call.

Don_s: The V-Caps are the TFTF's.
Audiofankj, Thank you for the response.
Standing at $2000 new, the Signature 100 stands as my personal reference for what is possible at and under the $3000 mark. It has the cajones to drive any speaker on planet earth, and is what I consider to be a solid 8 out of 10 in every regard to sound reproduction. In the year I have ran the Signature 100, I have yet to find anything it cannot do very well. Linearity? Check. Ridiculous dynamic power reserve? Check. Great low level resolution? Check. 'Musicality'? Check. Extended, non brittle highs? Check. Clean and open midrange? Check. Well extended, detailed, and controlled bass response? Check. Super quiet back-round? Check. The list goes on and on..

That said, I should make it clear that I do not feel that the Signature 100 is the perfect amp. I seriously doubt that such a beast exists. However, when you consider all that you get with the amp for its price point, it bewilders me as to why more people haven't taken it for a spin. Unless you run speakers that were specifically voiced to work with tubes, this affordable super amp should be on a lot of peoples 'short list'.

That said, I feel the amp struts its stuff when paired with a good linear, if not an ever so slightly *warm* sounding tube pre. I've had much success running it in conjunction with the Lamm LL2 Deluxe. Those looking to dip into a more affordable pre amp to match their H2O should look at the Transcendant Ground Grid.

Good as the Signature 100 is; the real star of the Henry's product line is the "FIRE" pre-amp, but that's a whole other ballgame right there.
Rumadian, what are you doing for a source, and what PCs, ICs, and SCs are you using? The choices are crucial to good sound.

Like any other good component, the better situation you can give the Signature 100, the better it will sound.

That said, I honestly feel that this particular amplifier requires super high end sources, interconnects, speaker cable, what have you - to sound pretty darned good.
Agree with Rumadian on the Sig 100- the extended listen in my system was amazing. Only gripe would be a slight midrange coolness that can be easily tailored with a tube pre. The low level detail and dynamics are still unmatched in my system. The most musical enjoyment I have had for late night listening including my tubes. Im going to pick one up
True, but with reservations. Class D requires different answers as to how to
bring out their best. Cost is less important than type. In fact, some very costly
components can do a lot of harm to the music. I have had my H2O amps for
years, and have learned a lot. If you please, here are some of my findings.

1) fully shielded power cords. Money does talk here.

2) simple interconnects. I use Speltz ICs. That way I can keep them long, and
my SCs short. I have mono amps. There may be better, but they will follow
the same principle of simpleness.

3) Naked SCs. I have found DIY ribbon SCs to be the best, and they cost so
little. Insulated SCs emit a very audible haze to the music. I interpret this to
random capacitance injection. The thicker the insulation, the more distortion,
regardless of price. Don't even think of hose through a box SCs.

4) If you are using a digital source, no over-sampler player (the vast majority)
will come close to the performance of a fine non over-sampler. The
superiority of even the cheapest NOS player over the most vaunted SACD
player will amaze. Digital filters do horrible things to music.

These same class D winners will make little to no difference to any
conventional amp usage.