Recommended Preamp for pairing an Adcom 555II Amp and Theil CS 3.5 speakers

iowanna33
Recommended Preamp for pairing an Adcom 555II Amp and Theil CS 3.5 speakers

Your Audio Engine B1 has
Analog Output: 2V Max.
Analog Output Impedance: 57 Ohms.

And your Adcom 555II as was pointed out has:
100kohm input impdance
only needs 1.75v in for full 200w output

As you can see the 2v from your B1 is more than enough to run the 555 to full output, so you don’t need an active preamp with gain that you don't need.
Also the output impedance of the B1 is 57ohms and this is a great match for a passive preamp, which will aslo match prefectly with the 555’s 100kohm input impedance.

Get one of these and save a fortune, you’ll have the most transparent/dynamic sound and save a fortune on not needing a fancy/expensive preamp that will colour the sound in comparison.

$49 http://www.schiit.com/products/sys passive only

$349 http://www.schiit.com/products/saga if you want to switch from passive to tube output as well .

$699 http://www.schiit.com/products/freya if to want to switch from passive to solid state or tube output.

In all three I think with your setup the passive will win out, so for $49 go the first one.

Cheers George

@kalali  You beat me to it!  I was going to respond to George much as you did above that my anecdotal understanding of passive units is that the PRAT as the Brits like to call it, is diminished.  I'm not making a categorical statement here, just that anecdotally over many years reading lots of audiophiles' experiences, that the drive is diminished by passive gear.

I have tried the $49 Schiit Sys between my CD player and 555 and the sound quality was completely lifeless and flat as compared with my Adcom preamp and nowhere near the sound quality when I experimented with the tube preamp in there. The volume control on the Sys is also marginal at best. But it's definitely worth the $49 price when used as an input selector.

iowanna33  This all depends if you want the source to be transparent or you want to colour the sound, which a tube pre will do.

If you want to have it all, get the Freya and you have passive, solid state, and tube that you can change on the fly while listening, all with little or no gain, which in your case you don't need. Many here and on other forums that have bought it prefer the passive mode after they've lived with it for a while.
  
And in it you have the best volume control with the Freya which is 128 position switched relay volume control, better than any rotary volume pot, and it's all remote controlled, 3 x inputs, 2 x outputs all RCA or XLR. 
http://www.schiit.com/products/freya only $699 and you can send it back if not happy, win, win. 

Cheers George