Let's see what I have done in the last 1.5 years.
The first M7 I made produce pretty "sweet" sound. However, the extreme ends are hard to reach. Originally, the M7 comes with WIMA caps. I later on changed them all to Auricaps. The base and clarity seems to be much better. I then sold the item to my colleague.
The second one I worked on is the Matisse, which was built many years ago by "Uncle Bun". It is very Hi Fi ... I changed all the WIMA to Jensens and the thing becomes much better. I lend it to my sister afterwards. The problem with this pre-amp is, the female aren't "feminine" enough.
Next comes the McIntosh C22. This one I kept for the shortess period of time. Not very satisfying. No outstanding performance, just an average toy. Probably some kind of design fault or so .... don't know.
Then, my current M7. Spent quite a fortune on it with separate PSupply. Unfortunately, no money to get a real hi class transformer. This one uses the Matisse rectifying board and RMG resistors together with Jensen caps. So far, this is the best Tube Pre-amp I have ever built. Sweet sound, moderate clarity, sound stage okay but not outstanding. Female vocal sounds nice and bass is not too deep.
Finally the Pass Labs. As some of you pointed out already, transistors built pre-amp gives more clarity and details. It is true. Sound stage noticably wider than the M7. More punchy bass and match with my CEC CD player well. Some Singers seem to have "improved" their singing skills when I use this Pass Labs to play their songs (tho' not true for ALL singers).
The Pass Labs still needs around 1 month to run in. See how it goes then.
CAT |