Wavelength Brick USB DAC tube rolling?

Restock,
Thanks for your reply. My used Brick came with a Teonex 6067, Google has little or no info on it. I just put in an Amperex 7316, I'm still evaluating that one. I wanted to try the Mullard CV491 as well, the premium tubes get really pricey. I do have the Opticis cable, I like it very much. Someone had posted about using an alternative battery power supply, I'll have to look into that as well.
I did see a few negative posts about the Brick here, but I like mine. I'm using it with an iMac desktop, far better than the Dell desktop I was using it with. Sounds like you're enjoying your Brick, too!

Herman, just to clarify, I was referring to an external battery supply for the Opticis cable to replace the inexpensive stock power supply, not for the Brick itself.

I need the Opticis cable because my iMac and stereo rig are about 45 feet apart. This is what the Opticis is really for, long USB runs. Didn't want to go wireless, with the potential problems of that. I must say, mine sounds pretty good! I'd love to hear the Cosecant, you don't really see any on the used market.