Thiel Owners

prof & thieliste,

Thank you both for sharing your journey as it mirrors mine to a degree. I too have found it diificult to find a replacement speaker from the Thiels. Once you have them dialed in and with the right amp they are tough to beat.

I’ve opoted on a different path. I have quite a few pairs of Thiels and decided to upgrade the models I like best.

Curreently I have the CS 7.2 in listening room after many months of the CS5i in the room. I’ll cut to the chase and suspense and identify the upper midrange suck out is the weak link in the frequency bandwidth. The reason is the cost/performance formula Thiel followed allowed Jim to choose 4-100uf electrolytic caps to achieve 400uf.

Fighting price points I understand this decision. 

Although it does not use the signal 400uf electrolytic like the 2.7 uses,  it still degrades the upper mids so they sound thin and recessed. 

Yesterday,  I had a gentleman come over for lisening session. He has the Thiel CS 3.7. We listened to about 15-16 selected tracks and discussed the attributes of the CS 7.2. He mentioned his 3.7 had more weight in the middle than the CS 7.2, but the bottom end of the CS 7.2 was better and highs we about equal. 

We had the discussion that the CS 7.2 upper mid range can be remedied, but the bottom end on the CS 3.7 was set in stone. Hence why I have kept them as I knew they could be improved.

Tom alluded in this thread to the fix he designed for the 4-100uf electrolytic caps.

Please understand this is not the full upper mids network crossover but a portion which is a part of the problem creating this suck out.. The thought is, to single out the 100uf caps and hear what Tom designed as an alternative. Tom sent me his schematic and the idea of using a CU cap that he designed I must say is brilliant.

Knowing copper foil caps very well I know they have plenty of weight to them and are ultr smooth. Just what is needed. This isn’t replacing crossover parts with better parts. This is implimenting a better design and using higher quality parts.

I’m happy to report that Tom is making this upgrade as I type this post. I will hopefully receive it this week and install it in the CS 7.2.

The gentleman with the 3.7 will be returning so he can listen again after the upgrade.

In addition I have a member in this thread stopping by, actually he is staying over night, who wants to hear the big Thiels with his McCormack hot-rodded amps.

I will report how this session goes and I know at least one will chime in here to report their experience.

It will be interesting to hear feedback as this is only a portion of what Tom proposes for the CS 7.2. Implementing his Bi-Flow technology, his wiring ( not a wire upgrade and I’ll leave that to Tom to explain the benefits), the remainder of his crossover upgrades, and the film technologiy that I have heard and know it will be revolutionary for the audio industry.

This is why I haven’t moved on from my big Thiels, as I have the back story as to where they will be going as far as their performance.  

I will be receiving a pair of 3.7 very soon. When they arrive and they are beaming with confidence at their ability to be a conduit to the music that is played through them, I’ll open the door to the listening room where the uppgraded CS 7.2 are only to say "Say hello to my little friend"! Your older brother. 

hi Gentlemen,  Thank you for the input and comments.  A special shout out to Jafant for maintaining this thread,  and to Tom Thiel for all his wonderful advice and input.  

@duramax747 

very interesting stuff.  Please do keep us informed

Installing 4 100uf caps replacing the 1 400uf cap is well worth the improvement . But there are 2 problems to address one is the space on the board and the other is the small size of the eyelet where the leads are soldered. This became an even larger problem when I installed  15uf and 1uf Purity Clarity Caps which use 16awg stranded lead wires .  I had to install larger eyelets to fit all the wires . 

Reading duramax747 question about replacing 4 100uf electrolytic caps with 1 Cu foil cap on his 7.2 work on the 2.7 replacing the 400uf on the mid , if so do you think it would sound better than replacing the 1 400uf electrolytic cap with 4 100uf electrolytic caps ?

Question for Tom , would changing the 416uf to a 226uf work on the 2.7 mid range ? would/should the negative 565uf be lowered by 1/2 at the same time  ? 

Tom

please disregard my questions , my fingers were moving faster than my brain .  A 400uf film cap would be way to large to fit on and in a 2.7 and changing the values on the mid range would require changing the woofer's values,  I don't want to try to reinvent the wheel .