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


My Bryston 0.5B preamp was inadvertently put down over the holidays by an incident now known as 'The Sippy Cup Mystery'.  Regardless of the cause, I need a new preamp for my system.  I am driving a pair of Thiel CS 3.5  (with the electronic bass equalizer) speakers with an Adcom GFA-555II amp.  The majority of the eclectic music (classical, 80s, folk, funk) being played on the system is streamed from iTunes through my Audioengine B1 DAC.  I have read a number of posts with various recommendations for the GFA-555II or the Thiel CS 3.5s but not for their paring.  Short of winning the lottery this week, cost is a factor. Any suggestions or directions would be very much appreciated.
iowanna33
Thanks John, and I am sure the OP appreciates your research.  I always said you almost know as much as me...  :-0

I used Stereophile's specs:

https://www.stereophile.com/content/adcom-gfa-555-power-amplifier-specifications

but, I suspect John's might be more correct.

If the 3.5's eq is used between pre and amp, it would probably also offer some "buffering" in this regard as well.

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


Your lucky you don't have the 3.6 as they are a pig to drive to get the best out of, these 3.5's are a different beast and quite easy for your Adcom 555 mkII

https://www.stereophile.com/images/archivesart/189CS35FIG1.jpg

Stereophile's John Atkinson:.
" Jim Thiel has used some form of conjugate load system in his crossover designs to give such flat curves with frequency. (This is where elements are added to the crossover to compensate for phase and impedance changes to result in a simple resistive load.) I would suggest, therefore, the Thiel CS3.5 should be easy to drive, even given its 4-ohm rating."


Cheers George
I have had the older 555 paired with the 750 preamp for many years in my vinyl only system. I recently bought a full-tube preamp for another system and used it with the 555 for a few days and it really rounded out the rough edges, especially when played at higher volumes. There's another thread where someone is asking for tube preamp recommendations and should give you some good ideas. Lots of options out there, new or used.
I would search out a tube pre. As mentioned above, being mindful of gain and output impedance.