Guys:
Most of we longer term owners of the ModWright Transporter performed a bunch of tube rolling and the majority settled on the EML 5U4G Mesh Rectifier and 6SN7 Tung-Sol Round Plate Signal Tubes. One in our midst, Philistine, has continued to search for a modern production tube to better or at worst be the equal of the round plates. He ordered a pair of these:
http://grantfidelity.com/site/Shuguang+Treasure+CV181-Z and had them shipped directly to Dan for approval to use in the Transporter. Phil told me Dan approved them and then sent them along to him for evaluation in his system. I will not provide his comments about the tubes as hopefully he will post comments soon but he told me they made more impact in his system than does the EML 5U4G Rectifier. Whoa!!! Being a tube rolling junkie I could not resist temptation and ordered a pair. They were waiting for me when I arrived home today and after listening to the system for approximately an hour I replaced the Round Plates with the Black Treasures.
The Grant Fidelity Website claims it takes up to 300 hours for these tubes to reach their peak. No joke, my immediate reaction to these tubes, brand new, is that they are better in my system than the Tung-Sol Round Plates. Tighter bass, cleaner-more detailed highs and more dynamics to the sound. Midrange is not as full sounding but not lean by any stretch. If these continue to get even better it will be unbelievable.
If you are purchasing a new ModWright Transporter or have recently purchased one just save yourself some time. Purchase an EML 5U4G Mesh Rectifier and a pair of the Black Treasures. The best part is that both are new production tubes and come with a year warranty.
This is a professional review of the Black Treasures:
http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.htmlKen