Jeff Rowland Pre with Pass Labs X350.5 or X600.5

Hi all, my apologies. . . I am not at all familiar with older pres from JRDG. . . but -- for what it matters -- I have reasonably good experience with the current JRDG Capri, which has been in my system for the last couple of months. I still contend that it is a magnificent device, although after several hundred hrs of breakin of Capri connected to the PC1 PFC unit, I am coming to the conclusion that I prefer it even better without PC1. . . greater extension, authority, staging, imaging, micro detail, macro/micro dynamics. My early Capri+PC1 findings were based on both devices rrelatively fresh from the factory, and my findings after break in appear to differ with my original ones. It is fair to remind that PC1 was designed for high current devices such as 102, 201, and 501 amps, not for low power devices like Capri. JRDG does not necessarily support use of PC1 on Capri. As for Capri matching Pass amps. . . Pass amps have an input impedance of 22K Ohms, while Capri has an output impedance of about 40Ohms in balanced mode. . . compatibility should be without problems. Pass and JRDG being balanced designs, I suggest connection of JRDG pres to Pass amps using XLR ICs.

I confirm that I originally preferred Capri over Ref 3. I will resume comparisons of Capri with my ARC Ref 3 in a couple of weeks, after I receive a set of 6H30DR NOS tubes.

And yes, Capri being this good, I am already fantasizing about the upcoming JRDG Criterion 2-box pre, which is expected to start shipping early in Q3.

Guido

Coherence II appears to have an output impedance of 50Ohms. See:
http://jeffrowland.com/ClassicSpecs.htm#Coherence
On the same page above, you will find Synergy II appears to have an output impedance 40Ohms unbalanced and 80Ohm balanced.
If input impedance of Pass amps ranges from 20KOhms to 30Kohms, compatibility with Coherence II and Synergy II is all but assured. G.

Thanks for all your posts.

Can someone tell me whether the Synergy 2i or the Coherence 2 with separate Rec outputs can be used as a tape loop for using a signal processor.

The spec sheet for the Criterion shows 40 ohm input impedance, Balanced and Unbalanced and Output is 60 ohms Balanced and Unbalanced. The Capri Input is 48 ohms Balanced and Unbalanced while output is 80 ohms Balanced and 40 ohms Unbalanced.

Those impedances are reasonably close to the Pass. I can understand why a recording engineer would be concerned with Unity Gain and exact impendance matching, but for audiophile products I believe that we just need to be in the same range. Correct me if I'm wrong. These levels are so close that it's a matter of turning volume to 75.7 vs. 73, or some similar small difference.

Dave