Thiel Owners

The CS3.7 XO pic I’ve seen shows good coils but sandcast resistors and CYC MKT caps. The drivers are probably the best ever from Jim Thiel (ie, some of the best ever from any manufacturer) but the passive parts quality is wanting, IMO. If I had 3.7s I would certainly replace the resistors with Mills MRAs which are cost effective, high reward/low risk. Replacing the caps *might* be more risky but I would probably do that, too. There is a LOT of capacitance on that board, so might have to go outboard if replacing everything including the big electrolytics. I would start with the tweeter and midrange caps.

That said, waiting for Tom Thiel’s solution is probably advisable for the less adventuresome.

thanks Beetle,   and i am definitely less adventurous.   I think that ultimately if there is an outboard crossover where we just hook the speaker cables to it and then wire right to the drivers,  that would be something i could do.  but they do sound great and part of me is afraid to tinker with them.  you do not live in NC by any chance :)

beetlemania
Thank You for the CS 3.7 XO network analysis. We have several owners of that model here that may want an upgrade once a working prototype is established.  Hope your Spring in Utah is going well.
Happy Listening!

Guys - we have learned enough to repeat the successful upgrade that Beetle performed. But we have not yet approached the comparative analysis to find cost-effective performance points. Beetle-level parts cost would exceed $1K, and parts cost is not the whole job. So I believe more work is in order.

tomthiel
Absolutely! I will leave this wonderful opportunity to you and the other DIY guys here. Thank You for citing the first price of beetlemania 's work.I am excited and looking forward to the next offered XO upgrade with corresponding price.  Feel free to list the cost between different critical parts as progression evolves.

Happy Listening!