VAC preamps - too expensive?

@kmmd Unless the design has changed, the Master's fuse holder is a bottom feeder. So unless the unit is on an upper shelf, it needs to be pulled out and flipped over to change fuses. I installed a QSA red/black. While I had liked the AM Ultimate, the Ultimate Premier seemed a design change toward neutral with an emphasis on presence. At least the latter entails an upper end bump, the opposite of what creates a sense of warmth. Alfred at Highend said that if I didn't like the UP, the Master wouldn't please either. 

@highstream

That’s interesting regarding the VAC power supply fuse holder. I’m 100% sure I loaded from the top, since my preamp sits inside my entertainment center and can only be accessed from the top.

I found the M1 fuse in my N20 to provide a neutral sound and more definition and presence. I’m not sure of a “bump.” I don’t think that I’ll move to the M1 for the VAC due to the long burn in time. Have you tried the SR fuses? I haven’t tried the purples but have an orange in my Theta. They don’t seem to take as long to burn in, but they blow pretty easily.

Yes, I’ve just replaced the Purples in my Lampi dac and VAC preamp with the QSA. Extraordinary difference.

The "bump" I referred to is how sound is engineered, from what I read. True neutral is a perfectly flat response curve. Apparently, most people would not like the sound of that. So for a more palatable, "balanced" sound, a little bump is added on each side of the middle. If more gain is given to the bass, that means warmth. If more on the upper side, that means greater sense of presence and detail, as I understand it. For example, when the SR Orange came out, the initial review on Agon noted that instead of the Red’s "neutral" sound, which I didn’t like, the Orange seemed to include a mid bass bump, because it had gained a bit of warmth. That was continued with the Purple. One upshot of this is, as I understand it, that when audiophiles speak of neutral, what they’re unknowingly talking about is a frequency response that has been modified from flat, and not necessarily in a balanced way.

Thanks for the info, and it makes sense.  I wonder if anyone has run REW frequency response for a component with fuse swaps.

Going back to the many skeptics and sour grape guys in 2021.  Tell me.....how many companies are there where the CEO (Kevin Hayes) is highly likely to answer the phone when you contact the company??....and then he will speak with you for as long as necessary to thoroughly answer your question!! My Sig Mkii se with phono stage is an amazing piece of precision equipment that compliments my entire system. I can only dream as to "how much" the Master series could improve upon the sonic results I am so fortunate to experience.