Pre-amp suggestions for Thiel 2.4/Pass Labs XA30.5

Not to suggest that good bass it the number one priority, but IME without good solid bass response the Thiels can sound a bit tipped up. I think the part of the appeal of the Thiels, is due to the outstanding balance of all paramaters, rather than any specific one. FWIW, I wouldn't completely ignore the bass, it can overlap into other areas of appreciation.

"without good solid bass response the Thiels can sound a bit tipped up." Explains a lot of the stereotype, but also what some swear by Theil as among the best speakers ever made - got to have the right amp:)

Not to suggest that good bass is the number one priority, but IME without good solid bass response the Thiels can sound a bit tipped up. I think the part of the appeal of the Thiels, is due to the outstanding balance of all paramaters, rather than any specific one.

Explains a lot of the stereotype, but also what some swear by Theil as among the best speakers ever made - got to have the right amp:)

Agree with both those statements. It's funny that with my 250wpc MF SS integrated amp, I found the top end harsh and the overall sound a bit thin, whereas with my 110wpc ARC tube amp, I have a much more natural and neutral tonal balance without any portion of the frequency spectrum thrust forward or recessed. I think the power supply in the ARC amp was clearly superior to that of MF.

Cal3713...if there is a way to audition the X250.5 before purchasing it (or maybe negotiating a time frame in which you can return the amp if it's not a good fit and just be out the shipping costs)?

I ran an X250 w/2.4's for a year or so & while they sounded & imaged fantastic on really well recorded/produced material they were really fatiguing on less than perfect material. I had a decent front end & all the recommended ancillaries so it wasn't that. Never got around to trying them w/a tube amp before I sold them & moved on. My guess is tubes are the synergistic combo

The impedance and phase angle would be challenging for most tube amps. Getting a tube amp with enough power to handle the load can get expensive. A tube pre that matches the input of the amp could work nicely.