Hi Nocca,
I built the HJFP2 (jfet) recently and have been very happy with it. I can't compare it to the DRS or Hardy preamps because I've never heard them. However, I can confirm that the sound is clean and powerful. The transformers are made by Altran.
I was so pleased with the HJFP2 that I became curious about the HVTP2 (tube) model as well. I found a person who had built both and asked about the differences in sound. He told me that the tube-version sounded like the jfet except that it produces more power and punch on large transients. The Hamtone FAQ
http://www.hamptone.com/general_faqs.htm addresses the sonic differences between the two preamps, and mentions that the tube version is preferable for larger transients while the jfet is better for faster transients.
The person who told me about the "punch" of the tube model said that the punchy effect didn't occur unless the preamp had warmed for at least an hour, but after that it was quite apparent. The punchiness would be great for drums (i.e., large transients), but might not be noticeable on other instruments that have a lot of even, fast transients.
If I had to do it again, I would still build the HJFP2. It's cheaper, no tubes to worry about, and I don't have to wait an hour to get the special sonic qualities of the jfet.
BTW, the jfet really does have some cool effects when driven hard. It gets quite colorful at higher gain. At low gain, Scott Hamptone refers to the sound as "tingly". That's about right. It sounds great on stringed instruments.
The DI is really stellar on this unit -- I'm sure the tube model is great as well. Full, fat, bottom end with a razor sharp top -- CRACK! stike
For $575 and about 15 hours of interesting work, it's a bargain. It's still a great deal at $875 preassembled.
I don't think you can go wrong with either model, the circuits are basically the same with minor differences for the gain sections.
- Jim