I have this unit for 17+ years.

about 3 years ago it "shorted" and I had it rebuilt upgrading the capacitors and replacing any resistors which looked worn out.

Over the years I've tried several different power tubes including the EL34 Svetlana, EL34 Mullard & KT-77 Electro Harmonic. These did make a difference in sound, but interestingly changing the original Sovtek input tubes to E.Harmonica ECC82 (gold pin) made as a significant difference as chaning the Sovtek Output tubes - possibly bec the originals were some 10+ years old at that time.?

Regardless of the tubes selected the Simply 2 and always sounded very "musical" : ie warm, but lotsa presene and air. Bass is taught and is there but definitely softer and not as impactfull as a good solid state. I found changing the tubes very useful for tweaking the sound.. eg the Svetlana EL34 were more midrangey and gave an edge to the vocals.. the Mullards EL34 were warm and yielded a lotta prescence. If I had to pick I would say the KT77 E.Harmonica gave the best overall performance in terms of being clear, more detailed and having a slightly taughter base. A big advantage of the S2 is with just 2 input tubes it "cheap and easy" to try tubes.. As such I have a pair of 6CA7 E.Harmonicas on order!!

irregradless of the tubes selected, this amp has surprisingly drive.. granted my upgradeds to larger , higher Quality Capaictors would help, but this amp - if matched with the right speakers can real sing!!

todate I've run the Simply two on anything ranging form small bookshelves with 4" woofer to my PSB Image T6, a 3 ways, 3+ft floorstander with 2x 6.5" woofer, 1x 5.1/4" midrangea and of a course a tweeter..

Other speakers used were the Synthesis Melody, System Audio SE, Wharfedale Jade 3, Wharfedale Diamond 220s, Mourdant Shorts etc. I also used them with Wharfedale Diamond 10.3, AAD 3 ways and the forementioned PSB Image T6

With the exception of the Jade 3s, the S2 had absolutely no problem driving them.. Most impressive being the PSB floorstanders as they are situated in a large 20x30ft x 11.5ft high living room and yet I could get ~85db from them (ie sound level just short of acquiring hearing damage with prolonged exposure!). The only speaker they didnt drive well were the wharedale Jade 3s bookshelf 3 ways which are in my 20x18 study room. This I suspect is because @ 84-85db, they are v low sensitivity and a sealed box design while all the others were ported and typically 88+ db and up

All in all a great and stylish Lil Amp!!.. "not cheap", but after nearly 20 years of ownership great value as I still get kick from looking at it. and it still receives compliments - not just from Audio people, who recognize it, but also from non-audio types who intuitive know this lil amp was crafted with "brio"

I guessed the biggest compliment I can give is that afte many years and many other more powerfull amps, I still enjoy listening to it (esp small group Jazz and vocals, but it does other music pretty well too) and am planning of buying a set of matching speakers from Unison's Sister Co - Opera for reputedly these are specifically matched to Unison equipment and thus really "sing" well together

Througly recommended: Pricy but a good long term Investment

It's a great maschine.
Sounds amazing and it is an ultralinear amplifier.
I use it since year 2000 with a pair of Aliante Iperspazio loudspeakers and a CP67 cd player : it is true happiness ! :-)))
I can't describe with other words.

- incredible sound for a single ended of 12 Weff - possibility to choose a low feedback

- none for the price ...

This ampli is really quite amazing...! It is a "single ended" amp with EL34 and ECC82 as driver. It is rated for "only" 12 Weff but sounds like 20 ! The music is very detailled, not agressive, certainly due to the possibility to choose a low feedback (about 1,5dB)... It gives life to music ! And in addition, it was offered with a volume control remote ...

This is a lovely amplifier. When I first listened to it, I was surprised by the dynamics, and it's here that you gain on the quad II/leak stereo 20 sound (I also have these). If you're thinking of getting a valve amplifier, then do think of an S2 (ie aria = new unison research): the sound is dynamic, smooth, detailed, and the thing is pretty! By the way, it works wonderfully with LS3/5a s, even if it shouldn't!

Similar Products Used:

Quad IIs Leak stereo 20

excellence mid and high, unbelievable images,
best on jazz, Like Danny Summer from Hong Kong, the new CD
with the HDCD.

Just a bit weak on the bassi ! needs tower type speaker.
Sensitivity 90db, will be good.

Well, there is no comparison between the Antique Sound
AQ1001 DT 50W to a 12W S2 by Unison Research.
the sound is the fact, not power.
needs a good pair of tower speaker, and have 90db Sensitivity.



p.s. Is good to try a difference manufacture tube !!

Similar Products Used:

(ANTIQUE SOUNDLAB AQ1001 DT INTEGRATED AMPLIFIER) but 50W

Clarity, speed, image and, might I add, good bass.

Cannot match with just "any" speaker.

I've used this little intergrated with a few speakers and it never let me down. Matched with Triangle, Merlin, Angstrom and some electrostats it made these speakers shine. We have to remember that we are not working with huge amount of power but married to speakers that don't have a "roller coster ride" impedence and are relatively sensitive , you can really make your transducers "show off" their stuff.

As for bass. This topic goes hand in hand with the above statements. I have had speakers that "barely" had bass with six times more watts get some gusto when paired with this amp. I was surprised that my Triangle Titus speakers could perform so well (down to 60Hz). It wasn't deep bass but that's what 60hz sounded like "present" not just the "backgroud", barely audible, no impact bass. Don't get me wrong, you're not going to shake any foundations but the sound is all there.

The sound is as clear as a bell (beware bad recordings), transients are snappy and imaging can be scarry real. The most important thing is that it makes me feel the music.

Five stars all the way especialy for this price point!

The Simply Two is my first excursion into tube amplification. I had been using the Adcom 545II in a system with Rotel/Adcom-600 digital, and a Rega Planar 3 turntable. I'm continuing to use the Adcom 565 preamp as my phono stage. Speakers are ACI Sapphire IIe (this is a wonderful product) with a pair of ACI Sub1 subwoofers.
The Simply Two delivers pretty much what I expected from the switch to tubes: smooth, warm high end and a somewhat dull and fuzzy bottom. Very few mid-fi manufacturers do bass better than Adcom, so a little disappointment was to be expected. The Simply Two only provides 8 watts, so it's a little much to ask it to drive a pair of 12" subs clearly and cleanly.

Overall, though, I like this amp. It has a very sweet sound on brass, and I found it to be extremely well-suited for acoustic jazz. Soundstaging is very good, and the amp really puts out a lot of sound for its power rating. I would not reccomend it for rock listening, and it's probably not well suited for a large listening room. An excellent value, however, given the right listener profile.

It seems that the Simply Two doesn't really reach peak perfomance until it's been playing for about an hour. I should note, also, that I replaced the (2) stock Sovtek EL-34s with Svetlanas after about 8-9 months. I felt it made a considerable improvement, but one caveat: the Svetlanas don't fit particularly well in the Simply Two, and can easily break at the base when you remove them.

Music

Besides Music,what else you want this amp to play?

This amp play "Music". unlike other push pull amp,this amp
(single-ended class A)will not coloured the sound so that
you will heard what the records actually sound like.
Sonically,you will not heard all the records in a "warm"
,"smooth" artificial sonic features,you will only heard
the transparency of the music. although the bass is
"weak",i strongly recommended all you to try this amp
(HK$8,500 only)

Several points i'wd like to suggested here in order to
dig out all the essences of this small amp:-

1.replace all the original tubes(they are solvek etc,sound
harsh) with some reasonable tube such as "amperex EL-34"
& Mullard "old"(big logo,BVA signed) 12au7(ecc82)
the different is terrible!

2.find some pyramid shape lapis luzulli semi-gems stone,
yes,its stone,not metal cone,not woody cone!(i tried almost
all the cone for the last 18years)i'don't know whether your
country can buy this "lapis lazulli" or not,however,thats
the perfect material cone i ever used.For the same reason,
all the semi-gems(good stones) will sound like the
composite of wood & metal,try to find some(such as pink
crystal,red jasper,agate etc...)in cone pyramid shape,
its can be found in Hong Kong Chinese emporium.

3.linked the simply 2 with a pure silver cable like KCAG
,silverstreak,audio note cables etc.

4.another end linked with a 4tc speaker cable(or double
the 4 tc,do not try 8tc,its too warm!)

Afetrall,enjoy the music!

Similar Products Used:

Audio Innovation "alto"