Two SI 5066 digital amplifier reviews

[Colin]

http://www.stereotimes.com/amp041805a.shtm

http://www.enjoythemusic.com/magazine/viewpoint/0705/nearfield7.htm

If you own an earlier pair of lower voltage Stax headphones I encourage you to try mating them with a Sonic Impact T-amp. While the end result isn't as compact as the latest generation Stax ear-bud, it still delivers a fully portable monitoring solution for a ridiculously low price.

So there you have it the Sonic Impact T-amp ranks as a fine electrostatic headphone amplifier, but is extremely limited as a loudspeaker amplifier. And it's cute in a cheesy plastic Jetson's way. Fortunately, the T-amp is also dirt-cheap.

[raypenn]

Thanks Colin - interesting reading.

[Colin]

Got Sonic Impact 5066 digital call T portable amplifier with 12-volt adapter. It is as small as my hand and lighter than my cell phone. With no batteries, the spaceship-shaped thing is basically empty. Had to put pin connectors on my speaker cables. I compared the $35 device to a $5 harmon kardon 330B straight (not twin powered, but I rarely head bang anyway) and the Harmon kardon as pre-amplifier to the SI, $2K Roksan Caspian solid-state receiver, a massive $5K Delta Studio 6s33s with KT88s and the SI itself on LaScalas.

In one brief listening session, I thought the little amplifier was indeed amazing. I liked it better than the harmon kardon alone. By comparison, the harmon kardon is almost too full. It is easy for it to sound too loud. With the harmon kardon as the front-end, the SI was better, almost as good as the Roksan Caspian. After an evening of swapping though, I really came to appreciate the incredible vocal texture of the 6s33s. My initial impression was that a lot was missing with the 6s33s; the low bass was as full as the harmon kardon, the top end not as refined as the Roksan Caspian. But my, oh my, the mid-range was gloriously detailed, rich and full. A lot like a very good single driver speaker without any crossover interference. I can easily see digital amplifiers replacing most solid-state and many tube amplifiers, especially when coupled with tube pre-amplifiers.

I also listened to the SI straight from a cheap universal player to my Stax SR-30 headphones, for which the SI are intended. This was indeed a winning

The long-discontinued Stax SR-30s with the SRD-4 adapter are known as the Electret-34 system. They were $200 in 1995. The Stax SR-30s are not electrostatic headphones, but sound quite similar. On tubes, they give a bright shining sparkle to the sound. With the SI, they were not bright or sparkling. They seemed much better balanced. Not so much neutral or transparent, because that implies airiness and clarity as merely competent, more natural. Definitely going to try this SI amplifier up against my 2A3 Paramours on the Khorns.

[Colin]

moved to new thread

[meuge]

I was interested to hear what the digital amplifier craze was all about, so I got myself a Teac... which is supposed to be better than the SI in many ways.

Now, before I go on, let's get one thing straight - for $100, what the Teac does is unreal, and likewise, what a $30 T-amp can do with those $30 is probably amazing.

But when you really get down to the absolute quality, and not just price/performance ratio, I felt that the Teac was lacking. After about 1 month of direct comparisons to my B&K Reference EX4420, I am prepared to say that while I detect a certain change in the air, it is as of yet, far from being a hurricane.

Certainly, the clarity of the sound, as well as the noise level were superb with the Teac... and superceded every amplifier I have heard to date. The amp also has a very sweet midrange, that seems to be emphasized a little. At low volumes, digital amplification cannot be beat, due to the miniscule distortion and nonexistent noise. But during complex passages, at medium volumes or higher, the amp would choke and the music would lose its realism. Also, the bass control of the little amp is certainly far from excellent. Even with my 15" Titanic crossed over at 80Hz, there was a huge difference in bass response, as well as bass control.

This being said, I was happy with the amp for the price, and I was going to build my parents a system that used it, but I don't see it replacing my 70lb monster just yet.