Wavelength Brick USB DAC tube rolling?

Although Gordon mentioned that the Brick should not be too sensitive to tube rolling, I did notice a discernable difference between tubes over the past few months I had the Brick.

My Brick came standard with a Ei 12Au7 goldpin, which resulted in a detailed and quick sound that is a little on the lean side. The RCA cleartops I tried are fuller sounding, with a liquid midrange, smooth highs and full bass; detail as well as spatial clues are not quite as well developed (the RCA cleartops were OS and I am not sure how well they measured on a tube tester). The one I ike the most so far is an RFT La Radiotechnique that was tonally somewhere between the Ei and the RCA without sacrificing any detail - well balanced, good timing and dynamics, good spatial detail.

Finally I got some recommendations from other users that I will be trying over the next few months: Mazda trible mica, Amperex, Telefunken, etc.

Also, I have an Opticis USB extension cable on the way to isolate the Brick electrically from the Macbook.

Enjoy the Brick!

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!

Check with Gordon, he recommends NOT using a battery supply.

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.