Integrated Amplifiers: Audio Research, Unison Research, or Other?

To S. Andrea Sundaram,

I just read your review of the Audio Research VSi60 integrated amplifier. I found your article very interesting. I plan to buy an new amplifier and your help will be greatly appreciated. In my message, if you find some English grammatical errors, please forgive me because I speak French (I live in Gatineau, Quebec, Canada).

My last amplifier was an Antique Sound Lab Leyla 845 tube amplifier. I loved its sound, but in 12 years it needed to be repaired six times. It needs to be repaired again but this time around, I decided to change it. The other components of my sound system are the following: Lynn Ikemi CD player and Reference 3A MM de Capo speakers

To replace my amplifier, I have opted for one of these four integrated amplifiers: Simaudio Neo 340i, Unison Research S6, Unison Research Sinfonia, or Audio Research VSi60.

So far, a store in Montreal lent me their demo Simaudio 340i integrated amplifier for a week so I could listen to it at home with my CD player, my speakers, and in my listening room. I eliminated this product because it lacks all the qualities of a tube amplifier (presence, warmth, soundstage). Next week, a store in Ottawa will lend me its demo Unison Research S6 for a week.

The problem with the Audio Research VSi60 is that the dealer in Ottawa does not have it in stock and the other closest dealer (in Montreal) does not have it in stock presently. When they get it, they will not lend me their demo for a week, even though I will pay the full price for it and get a credit when I return it, as I did with the two other stores.

Have you ever listened to the Unison Research S6 or the Sinfonia? If so, if you compare them to Audio Research VSi60, what would be your choice and for what reasons? Do you have any other suggestions for other amplifiers?

Denise Franche

I recall hearing a Unison Research amplifier at a dealer, but it's been too many years for me to draw meaningful conclusions from that experience. I looked at the specifics of the two amplifiers you mentioned, and also a review we published of Unison's S6 back in 2004. Since both of the Unison amplifiers are single-ended designs, I would expect their overall characters to be similar to that of your ASL amp. While I don't think many people would mistake the Audio Research for a solid-state amp, its bass is leaner and tighter, top-end less forgiving, and overall character less liquid than I've come to expect from most single-ended designs -- the  VSi60 has a push-pull output stage with a solid-state input. If you enjoyed some aspects of your experience with the Simaudio, but wanted a touch more timbral color and openness, then the Audio Research may work for you. Does the dealer in Montreal at least have some speakers similar to yours through which you could hear the amp at the shop? Otherwise, I think it more prudent to go with an amplifier that, by all accounts, has the distinctive charms of tubes, and that you can audition in your own system. Bonne chance. . . . S. Andrea Sundaram