The H-K 630 should not be confused with the later AVR series 630. It dates back to the early '70s.

I have had mine for about 20 years, bought principally to mate with my Klipsch Heresy IIs. The Klipsch gurus and fanatics seem to have a universal positive opinion about the x30 receivers for Klipsch. I can agree with their assessment.

Because the power amp can be separated from the preamp there are 3 configurations ot is capable of: 1) receiver, 2) preamp/tuner and, 3) power amp. This option should be a standard feature. Most smaller powered receiver like the 630 do not have it. With the 630, because of the fantastic quality of the power amp, it is worth getting just to use as one along with a separate preamp. I keep mine just for this purpose and run a Soundcraftsman preamp into it and the 630s tuner to the Soundcraftsman from the tape output of the 630. The preamp is decent but limits the power amp's potential. There is nothing the is a major problem with the preamp, it is better than many but, the power amp is just that good. The tuner is typical of most receivers in its price and power range. Very adequate with smooth sound, slightly rolled off in the highest frequency range. It is not a dx'er but, locks on stations well and not as susceptible to multilateral problems that seem to plague those high end tuners. It works well with a simple ribbon dipole.

Build quality is better than many other Japanese sourced receivers of the period and later. The feel of the knobs, controls, layout and faceplate are first rate. I can think only of the Sherwood imported receivers of that period that seemed to put as much thought into the impact or the visual and tactile on a buyer and user. The blackout dial is a plus and negative with receivers this old. For heavy FM users burnt out bulbs all but requires replacement. For those using other sources, the dial and meter lamps go out saving them from burnout as fast as most receivers that do not have the feature. The receiver lacks any toggle switches and slide controls so less of an entry point for dirt and floppy switches. The push buttons have a nice feel, nothing flimsy about them

The tone controls can be adjusted for each channel something many high end amps and receivers had stopped doing making their use even more limited. All in all, this is a first rate unit with attention to almost every part.

The overall presentation and sonic delivery is neutral. Not like the Yamaha Natural Sound that is also neutral but lacks the life in its presentation. The H-K does not strip out the life and dynamics. Coloration is very low and if you are sensitive to detail and nuances, it can deliver. Strings do not sound steely and plucked strings have fast rise and decay. With flute, you can hear the breathing across the mouthpiece on good recordings. Listening to organ is where many Amos and speakers die. They go low and sound is not continous with pipes. Many amps just have too much ceiling and not enough power supply to maintain these long. The dual supply really shines here.

I have a decent inventory or receivers, amps and speakers I have been going through. While the H-K has not been up there with the best with. Number of speakers that as good as they are had to go as I downsize such as Bozak Symphony and 302s, it seemed to always just make the cut and went on to the next round. Receiver competitors included totl such as the Sony STR6120 and STR6060, Philips 797, Sherwood SEL200 and JVC J-RS301. All but the JVC are some of the best of the best and the JVC packs a punch much beyond its 60 watts.

Round after round removed speakers and electronics until there remains the H-K, Sherwood SEL200 receiver and the Sherwood S9500c 1st gen ss amp and S3300 1st gen ss tuner. Speakers are the Wharfedales W70s that have been recapped without caps, KLH Fives that have been recapped, woofers and midrange surrounds sealed and new woofer room baffle sealing and, the Klipsch HIIs. The HIIs are original and only making the cut in last place and on the edge. If it were not for the H-K,they probably would not have made the cut this last time. Most amazing is the H-K has knocked out both the Philips 797 and Sonys. With the Fives it really shows its strengths and weaknesses. With the Wharfedales it does well at low levels that is very important to me because of future plans. At moderate levels it seems to start breaking up at lower levels than with either of the others but all but the Sherwoods could not compete at the low levels.

The Fives deliver with it. The Sonys in comparison show a ceiling not noticeable except when comparing them. The Philips have more air and detail but, it its weakness, it starts to sound a might dry and analytical in comparison. The H-K manages to deliver just the right balance.

With the Klipsch both Sherwoods do well with the SEL getting more bass subjectively out than the S9500c or the H-K but the H-K seems to make the bass as far as it goes more believable but not a thumper. The pairing has great dynamics even at low volume, they just open up at so much lower volume than with other amps.

I still have not found a winning combination and suspect I may be looking at a tie and each combination just the better under particular conditions.

Propulsive bass, good timing, crisp treble. More power than its 40 watts suggest.

For some, the bass might seem overwhelming and treble might sound a bit harsh. Midrange constricted by the rest of the audio spectrum.

Partnered with: Marantz CD6000 KI Dynaudio Audience 42 For a 40 watt integrated, it has enough power and punch to drive my Dynaudio's to a pretty loud level in my bedroom system (much better than a mini-system)! In fact, I tried out a HK 670 recently and while that amp might have more headroom than the HK630, it lacks the little Harman's clarity and timing. The HK 630 offers a fantastic sense of rhythm and bounce, giving dance and rock added propulsion. In fact, compared with the HK670, the HK630 has greater clarity, bounce and timing. The HK670 sounds muffled and lacking in detail. Only problem I've encountered with the HK630 is the slightly constricted midrange, which seems to be overwhelmed by the sometimes over bright treble and powerful bass. Still, all in all, this is a great little amp and deserves a strong recommendation if only because of it's ability to bring music to life through its sense of vitality and rythmic bounce!

Similar Products Used:

HK 670 (same price, more power, worse sound), NAD 3020.

High musicality and energy, solid and dynamic bass, overall good sound.

For it's price - nothing.

I am using this amplifier already 2 years. I like it's design and it's sound. The power is enough for one big room (30m). It's bass is solid and dynamic, the highs are good too. I was using before Technics equipment and now can understand the difference, when have this amplifier. It has musicality and energy for any style of music. It's sound is natural and spatious. The incredible energy, with which it presents the music is so good that you can feel yourself like at the concert hall. For it's price this amplifier is really perfect. Now i am planning to buy HK670, which must be better.

Similar Products Used:

Technics SU-V500, Marantz PM-48

Surprising musicality with openness, transparency, warmness, deep and solid bass.

Power stage lacks a bit of accuracy and precision.

Remarkable little amp. Can´t do everything but performs even complex material with stunnishing coolness. Especially recommended for usage as good quality preamplifier (splitable!).

Sound staging, tonality, musical involvement, low volume performance, value .

Cheapy remote, Needs to be warmed up before it reaches it's peak performance

I saw this amp as an end of line bargain in a local Hi fi shop. After an auditon I paid £149 for it. Which is around half the original price.
I do like this amp a lot I am in the process of rediscovering my CD collection. Such is the presence and depth that this amp lends to the music. Instruments are well defined and imaged strongly within the stereo mix. It is a pacey amp I have yet to find it caught with it's trousers (pants) down when it comes to compex pieces of music. It seems to succeed in picking up details that I had never even heard before on some tracks.
It does, however, require a little warming up and it does get warm before it starts to deliver the good stuff. On the first listening of the day you can hear each subsequent track becoming richer and broader.
Build quality is good and I really like the styling especially the source selector switches and large motorised volume knob.
It's loud, louder than it claims and the sound seems to fill the room even at low volumes.
Turn it up (if you dare)and it's like a loud rock concert you feel the music more than you hear it and I mean that it a good way.
This amp is fun in a way that cheaper amps can't acheive and more expensive amps shun.

Similar Products Used:

Rotel 931

Everithing that Ludvig said is correct. I am using this amp as preamp for HK signature 2.1. Because of that I got no problems with"noises" so :

I bought this little amplifier a month ago and I’m still impressed everytime I turn on the music. The sound is very clear and rather detailed. It leans a bit on the bright side but in a way that you’ll never get tired of it. The most impressive characteristic though is the dynamics, especially in the bass range. The bass is deep, tight and chestpounding in a way that a 40 W amp should not be able to produce! Your speakers grows in size and sometimes you wonder if that expensive sub you bought really adds anything to the music that this HK amp can’t give you with your main speakers.
So long so good. There are some drawbacks also. The word is noises. The input source selection is made by a cheap integrated IC switch that lets the disconnected sources play in the background of the selected source. Not loud at all but still audible. So when I really want to listen to music I have to turn off my tuner to lower the noise floor. The other noises are the button noises. When you switch on your amp BOMP! When you change source CLICK! When you push the ”source direct” button BBBAAAMMM!! The last action readily applies DC on the amp outputs for a second, making tha woofer hanging on it’t maximum excursion for a second! How could this behaviour be accepted by HK???

Conclusion: Musically this amp I really terrific! Operationally a horror. Don’t play with the buttons, turn off all sources without the active and you’ll have a great musical experience.