2. amps-preamps
  3. 1133327014

Conrad Johnson ACT2 against Audio Research Ref 3

I am in the market for a nice line stage preamp. My list has been narrowed down to 2 preamps based on reviews and many listening sessions availabe to me. I do have a local Audio research dealer and have heard and loved the Ref 3 but not Conrad/Johnson. Any thoughts regarding the ACT 2 is greatly appreciated. Thanks.....
ginas
oneobgyn
410 posts
 
Simply put......The deficiency that Guido heard was a human error based on his activating SE and not balanced outputs on the Ref 3. It has nothing to do with a fully balanced system. Having said this however I rest assured that Guido is going to love his Ref 3 as I do.
guidocorona
4,298 posts
 
Just spoke to leonard at ARC:

Ref 3 is a truly differential design. No splitters/inverters are used to simulate balanced operations. Two 6H30 tubes are used for the positive signal, and two for the return signal. If the Ref 3 is switched to SE operation through the remote control, a relay switch is activate which turns off the return signal on the XLR connectors and takes the 6H30 tubes responsible for the return signal out of the active circuit. Leonard suggests that if single ended operations are desired, the user should employ RCA ICs instead of balanced ones. However, he confirms that turning off the balanced signal on XLR, or using RCA connectors will still result in a 'good' sound with a predictable loss of 6DB of gain. This 'good' sound will however be noisier, slightly flat, and pinched, if compared to the sound of Ref 3 in a fully balanced configuration.

One further note, according to Leonard, the 6550C tube employed on Ref 3 is in fact an original SED Wing 6550 manufactured in the St. Petersburg plant, rather than the lesser pseudo-Svetlana equivalent.
guidocorona
4,298 posts
 
Please note that in the previous post I should have been more specific: instead of 'sound' I should have specified 'Ref 3 sound signature'. The reason of course is that the actual sound is a function of all components. As such, we can't make a categorical statement about how best to run the Ref 3--single ended or balanced. It will all depend on the rest of the system.
jafox
1,470 posts
 
Guido: Thanks for the update. Sounds very much like my scenario 2 on the input except the "-" phase is deactivated rather than simply grounding the input which results in the same .... and scenario 1 on the output. Good to know as both of these are the "purist" approach. Any word on work done here to trickle down to a new LS model?
oneobgyn
410 posts
 
Guido

Perhaps I am too simple a person here or are you just missing the point?

To me it is very simple. If your system uses balanced interconnects that is the option you select on the remote control and if you are using SE interconnects, this is what you select on the remote. Of course there will be a 6 Db dropoff from XLR to SE.

You seem to be complicating what in my mind is something very simple.
More to discover