Thiel Owners

velocityofhue,

I realize the BAT VK600 amp is much older than the Pass 150.8 and understand the power difference. From your assessment what are the sonic differences between the two as I've found BAT to be a viable amp to mate with Thiel's.

I'm considering their REX 500 in mono or even their newly released REX 300 in mono. From my experience with Thiel, amp selection is as important as Thiel model selection. 

ig316b,

Maybe Tom can jump in as to the evolution of the coax from CS2.3, CS6, CS7.2, and finally CS2.4. 

To clarify to members engaged in this thread ig316b already has the Thiel SS2 subs. Since he already made this investment the discussion went in the direction of easiest upgrade path for him. He noticed the improvement with the CS 7.2 coax over his CS6. That being the case then getting a pair of 2.4 with the SS2 would be his best choice. 

Yes subs will not integrate as smoothly but will have better bottom end. The coax is better also. 

The other variable we discussed was the upgrade path. The CS 2.4 crossover is simpler than the CS6 so cost would be less and with less parts dynamics improve as well. 

Throw in Tom's bag of full upgrades and you've scratched that itch you've had for some time. 

As jafant mentioned the " CS 2.4 is a Honey of a loudspeaker". 

The room I have the CS 7.2's in is a joy to go in. Not a typical room to say the least. I'll see if I can upload some images to share. 

I have in my possession the upper midrange notch filter upgrade Tom designed. I will get it installed soon and report back. This targeted upgrade is for the 100uf electrolytic back in CS7.2 upper midrange. This notch filter, to a lesser degree, is implemented in other models as well.

 @duramax747

I too am thinking about the BAT amps you mentioned.  I would prefer the 300 in mono as they are less expensive for sure and also much lighter in weight versus the 500.  However at this point,  i do not think the 300's are available.  I currently use a really good amp,  the Coda 16, and until i can audition the 300's,  i will just wait.  Please keep us updated on your amp trajectory.  

I do not have intimate knowledge of the upgrade progression of the coaxes; they came after my time at Thiel. I do know how the path worked. Jim constantly isolated the weakest link of the products at large and worked on a solution to implement in the candidate model which surfaced via that process. So every newer product had advancements over its older forebear. And every new model had multiple driver advancements in its recipe.

The model progression (excluding the SCS series) of the coax is:

1995 CS7 - 1996 CS6 - 1998 CS2.3 - 1999 CS7.2 - 2003 CS2.4 - 2007 CS3.7

 The SCS and its permutations also added knowledge and solutions in a parallel timeline. So, the CS6 is near the beginning and the 2.4 near the end with 7 intervening years. The advancements affect all areas: materials, geometry, motor performance, etc. which all serve to simplify distortion modes, which allow simpler crossover circuits to correct those misbehaviors. Jim consolidated driver and crossover behavior, working toward a goal of more ideal system behavior. I directly experienced such improvements through the first 20 years of innovation. They are significant in every model development.

Part of the elegance of the 2.4 is the mechanical crossover between the midrange and tweeter. That idea percolated since the 1990 SCS, our first unitized driver. The pipe dream of a non-electronic crossover gradually took form as we developed the chops to jump from imagination to reality. The 2.3 - 2.4 small coax still had to be controlled. That took 15 XO parts. The CS6 coax took 40.

Regarding the notch filter upgrade which Duramax mentions. Thiel's need to control drivers through 7 octaves vs most speakers' 3-4, necessitates some big caps. We used PP film caps where feasible. And we developed that yellow1uF styrene/tin bypass cap for the 1989 CS5 which spread to all models, to good effect. We also limited our largest cap value to 100uF and ganged them for values up to 400+uF. The CS7.2 has such a 400uF bank in an upper midrange notch filter. Experience shows it to affect performance in its operating range. I have replaced that bank of 4x100uF electrolytixs+1x1uFs/t with two versions now under test and trials. A is 8x50uF el+1x1uF cascading multi-section PP (details proprietary.) That is what Duramax is trying. Next version is the same new 1uF core bypass plus 6x40uF els + 6x10uF PP film caps. He and I will test those next. Note that these solutions would be too expensive for classic Thiel's cost/performance plateau. But they do serve in learning new directions. Today I am working with such an upgrade in the 300uF SCS4 woofer series feed cap. I'll post outcomes when I have something to share.

ronkent

I sure will. Dynamic headroom is a must for me so if the first watt sounds great and I can get plenty additional watts then why not. I have Pass XA200.5 in room now. I was using Bricasti M28 before that. 

If you look at the lid off the Rex 500 and Rex 300 it appears the Rex 500 has a very different layout. The paper in oil caps in 500 are not seen in 300 for instance. 

Tom

Thanks for chiming in and providing reliable intel.

Duramax, Well if i had the dollars and even more, the space for it, i would get a 500 now and then go mono in about a year as i think it is pretty easy to convert them  (not sure if it can be done at home or sent back to the factory).  

guessing you like the Pass.  had their XP22 preamp a few years back and much prefer my current preamp (especially with Thiels) the BAT VK 80.   if you are ever in the Greensboro area, please let me know.,