Tube preamp suggestions.

interesting thread. I had an LS25MKII, currently have an LS15 on tap, but have been using a Promitheus TVC. TOmorrow however I get to hook up a BAT VK5i (6922 for current sources and signal gain). I have been a bit mental lately zeroing in on a long term preamp. I suspect the vk5i will be a good match and offer the traits I desire. I like a bit of romance, yet fast, detailed, and powerful with a dense soundstage. The TVC is surprisingly good at most of these things but lacks that last bit of palpable realism (to my ears) capable of the rest of my gear. I really mean the TVC is outstanding though, and especially for the asking prive... I have been listening to it for weeks now and swapping back and forth between that and the LS15 there is no obvious "winner".
However, I suspect that Vk5i will be in another league and I look forward to getting to know it. It has been my experience with the LS25MKII, that, basically it is ruthlessly revealing. Very detailed, yet sometimes painfully illuminating subtle flaws in either the source material or elsewhere... Probably a great tool for a mastering engineer's studio but a bit too much for my tastes (I did not have a go with it in my current system, rather previous incarnations with similiar equipment, it is quite possible that it would be a stunning match with the Pass!). It all depends on your own desires (obviously) and some find great peace with the 6h30 designs (it is probably wrong to stereotype a gain device). I would like to try other manufacturer's implementations on this tube, esp say the BAT Vk51 someday.

Have fun

I would second the recommendation for the Joule Electra LA-150 MkII. I previously owned the Blue Circle BC 3000 MkII, and the Joule provided a dramatic increase in bass impact and harmonic fullness. Here's HP's description in awarding it a 2007 Golden Ear:

"With the LA-150 [MkII], your'e going to think your speakers have bottom-end response like they never did before. And it won't sound 'wrong' either. That's because Barber has elicited from the electronics a correspondingly alive and dynamic upper midrange, though not enough of one to make you think it is a euphonic coloration, so skillful is the design. All all this is bathed in glorius 'tube' sound, like a darker version of the classic gear when Audio Research ruled the waves, and with even less distortion."

I don't listen much to reviewers, but everything he said is true in my system (solid state amps driving monitor speakers). But you must get the MkII version -- the original used the 6h30 and reportedely sounds very different.

I haven't heard and didn't consider the Lamm after living with no remote during my (otherwise favorable) Blue Circle experience. My only hesitation would be if your speakers are already bass-heavy, in which case the Joule could be too much of a good thing.

i would suggest a vintage preamp to match your vintage mac amp. perhaps a mac c22 or a conrad johnson premier 3.

don't consider any preamps past the 80's. there are a number of older preamps which will suffice.

Heard that the Promitheus TVC needs a long patiently breaking in period of at least 400 hours to perform its best.